Reconciling ice core CO_2 and land-use change following New World-Old World contact

Domain: earth_science
Published: 2024-03-05
Editorial outcome: minor_revision

Abstract
Ice core records of carbon dioxide (CO2) throughout the last 2000 years provide context for the unprecedented anthropogenic rise in atmospheric CO2 and insights into global carbon cycle dynamics. Yet the atmospheric history of CO2 remains uncertain in some time intervals. Here we present measurements of CO2 and methane (CH4) in the Skytrain ice core from 1450 to 1700 CE. Results suggest a sudden decrease in CO2 around 1610 CE in one widely used record may be an artefact of a small number of anomalously low values. Our analysis supports a more gradual decrease in CO2 of 0.5 ppm per decade from 1516 to 1670 CE, with an inferred land carbon sink of 2.6 PgC per decade. This corroborates modelled scenarios of large-scale reorganisation of land use in the Americas following New World-Old World contact, whereas a rapid decrease in CO2 at 1610 CE is incompatible with even the most extreme land-use change scenarios.

Introduction
Ice cores present a unique opportunity to perform direct measurements on ancient atmosphere encapsulated within the ice. Records of the last 2000 years, the Common Era, offer the highest resolution archives of greenhouse gases, allowing us to observe multidecadal to centennial scale atmospheric changes, and providing a baseline for preindustrial atmospheric values. Ice core records of CO2 are therefore a powerful tool in understanding the global carbon cycle.

Highest-quality CO2 records for the last 2000 years are limited to just two archives: the Law Dome and West Antarctic Ice Sheet (WAIS) Divide ice cores1–4 (Fig. 1). Much lower resolution records are also available and have been used to confirm broader past-millennium CO2 trends, but application to studies of high-resolution changes, as in this study, is limited due to their significant signal attenuation5,6. Each ice core has limitations in terms of accurately recording atmospheric variability. The Law Dome ice core offers the highest accumulation-rate (60 cm water eq. yr−1) and therefore potential for the highest temporal resolution gas record preserved in the ice (gas age distribution width of 8 years at Full Width Half Maximum (FWHM)) due to minimal smoothing by gas diffusion and mixing in the firn column prior to bubble close-off. The Law Dome data were measured with pioneering techniques in the 1990s, greatly advancing our understanding of CO2 in the last millennium7. However, the sampling resolution is relatively low in some periods. The dataset has subsequently undergone multiple revisions, filling data gaps, extending the record, investigating differences between early and later measurements, and adjusting error values2,8. The WAIS Divide record provides higher sample resolution and precision, but the core has a lower accumulation rate (19.8 cm water eq. yr−1), which results in greater smoothing of the gas record by firn-based processes (gas age distribution width of 19 years FWHM). There are multidecadal features present in the Law Dome record that are not observed in WAIS Divide. This may be partly due to the greater extent of firn-based smoothing at WAIS Divide but, even so, the most rapid CO2 changes present in the Law Dome record have been difficult to explain within our current understanding of the carbon cycle and in even the most complex Earth System Models9–11. In addition to this uncertainty regarding atmospheric CO2 history, the absolute mixing ratios of WAIS Divide range from 0 to 6 ppm higher than those of Law Dome between 750 and 1800 CE3,4, though the exact cause of this artefact remains elusive2,3.

The Law Dome and WAIS Divide ice core records of CO2 are fundamental to modelling studies of climate and carbon cycling throughout the Common Era4,5,12. The Law Dome CO2 record is used exclusively in the Paleoclimate Modelling Intercomparison Project13,14 which contributes to climate model evaluation at the IPCC level15. Several rapid CO2 changes in the Law Dome record have been highlighted as potentially coinciding with major events in history, such as plagues, migrations, and wars16–18, as well as inferred climate-CO2 feedback5. The most high-profile example is that of the distinctive Law Dome 1610 CE CO2 minimum, a rapid decrease in CO2 of ~10 ppm over 90 years, with a distinct minimum at 1610 CE (Fig. 1). One hypothesis is that the distinctive low value (termed the Orbis Spike18) is caused by the contact between New World and Old World populations. Subsequent pandemic-driven population decrease, followed by large-scale land abandonment in the Americas, could have driven land biosphere regrowth and CO2 uptake18–20. This interpretation has led to the Law Dome 1610 CE CO2 minimum being suggested as a marker for the start of the Anthropocene18. However, the WAIS Divide CO2 record does not exhibit a 1610 CO2 minimum and instead shows a smaller and more gradual reduction in CO2 into the 17th century (Fig. 1).

The observed differences in current records create significant questions in our carbon cycle interpretation for the time. Here we directly address this challenge by presenting a high-resolution CO2 record through the period of interest from the Skytrain Ice Rise (Skytrain) ice core21,22.

Results
Skytrain ice core CO2 record
In this study we conducted measurements of CO2 at 31 depth intervals spanning the period 1454 to 1688 CE in the Skytrain ice core. Samples were measured using the Oregon State University (OSU) crusher system3 with 2–3 replicates per sample giving a pooled standard deviation of 1.0 ppm. Smoothing splines were generated for each archive record using a bootstrapped Monte Carlo simulated cubic smoothing spline procedure (n=10,000 histories with a 50-year cut-off). The splines allow clearer comparison of the trends of the records.

The Skytrain record shows a gradual decrease in CO2 into the 17th century (Fig. 1), with a reduction in CO2 of 8.0 ppm over 157 years (Table 1) based on the spline fit to the data. This does not agree with the greater, more rapid decrease in the Law Dome records, which indicate a total reduction in CO2 of 9.9 ppm over 84 years. The Skytrain record instead aligns with the previous WAIS Divide record which shows a total decrease in CO2 of 6.7 ppm over 117 years. Average decadal rates of change in atmospheric CO2 across the period of declining values emphasised differences between records, from 1.2 ppm per decade for Law Dome to 0.6 ppm per decade at Skytrain and 0.5 ppm at WAIS Divide. Interestingly, the absolute CO2 values of Skytrain lie between those of the Law Dome and WAIS Divide records, but with some periods of large intra-core differences that cannot be atmospheric in origin, for example between 1525 CE and 1575 CE.

Firn-based smoothing of the ice core gas records
A caveat to consider when comparing ice core gas records is that each record has undergone different levels of smoothing (i.e., low pass filtering) in the firn and during bubble close off. The signal attenuation for Law Dome is smaller (accumulation 60 cm water eq. yr−1; gas age distribution 8 yr FWHM) than the WAIS Divide record (accumulation 19.8 cm water eq. yr−1; gas age distribution 19 yr FWHM) and Skytrain record (accumulation 13.5 cm water eq. yr−1; gas age distribution ~27 yr FWHM). It is thus expected that Law Dome captures faster rates of change and higher frequency variability. But is it possible that the broad minimum around 1610 CE (about 40 years) was an atmospheric CO2 change that was recorded at Law Dome but completely smoothed away at both WAIS Divide and Skytrain? To answer this, we take a multi-stage approach.

Firstly, we assume the Law Dome record, although undergoing some smoothing, is a close representation of the true atmospheric history, given the high accumulation rate of the site. We then convolve the Law Dome record with the firn filters of WAIS Divide and Skytrain. These firn filters, or age distributions, were generated using the Oregon State University (OSU) firn model (see methods) and model the firn smoothing specific to each ice core site23–25. The resultant convolved histories should closely reproduce the WAIS Divide and Skytrain records. This is not the case (Fig. 2). Instead, the convolutions preserve a distinctive 1610 CE CO2 minimum whereas this is not present in the WAIS Divide and Skytrain records.

We note here that the Law Dome CO2 record has itself experienced some smoothing in the firn, so while close to the atmospheric record, it is not a true representation. It could be possible to deconvolve Law Dome with a modelled reverse filter to the original signal5. However, the 1610 CE CO2 minimum in the Law Dome record would only be sharper still, and thus the convolutions would also then show a stronger 1610 CE CO2 minimum, something which only disagrees more strongly with the data. Using the original record alone avoids any potential errors from the accuracy of the modelled reverse filter being introduced.

The convolution predicts that the 1610 CE CO2 minimum should be preserved in the WAIS Divide and Skytrain cores if it is a true paleo-atmospheric signal, assuming no unexpected changes have occurred, but could our firn filters be underestimating the degree of smoothing in the cores?44 For example, our firn model does not account for small-scale (cm-scale) density variations from layering and associated effects on bubble closure which can drive some pores to close-off above the traditional lock-in zone and thus lead to age-reversals and slightly broader firn age distributions.

Lacking an adequate physical model to simulate the potential for greater degrees of firn smoothing we rely on an empirical, independent check of firn smoothing using methane (CH4) records. First, we determine whether the 1610 CE CO2 minimum seen in the WAIS Divide and Skytrain convolutions can be eliminated by varying the firn filters within a reasonable range. We increase the width of the smoothing until the convolution output best matches the measured CO2 records of WAIS Divide and Skytrain using a test which calculates the offset between the convolutions and datasets (See Supplementary Information and Fig. S1). To then test if these are realistic firn filters, we then apply the same firn filters to the CH4 records from the three cores, as CH4 shows significant multidecadal variability over this time interval that are at least as rapid, if not more rapid, than the CO2 variations26,27. Convolution of these wider filters with the Law Dome CH4 record should recreate the Skytrain and WAIS Divide CH4. Instead, the output is significantly more smoothed than the record (Fig. 3) with the rates of change reduced to about 50% (see Supplementary Information). We therefore conclude that no plausible smoothing scenarios exist to account for the absence of the 1610 CE CO2 minimum in the WAIS Divide and Skytrain CO2 records, and a plausible explanation is that the Law Dome 1610 CE CO2 minimum is formed of a small number of artefact data points. The cause of such an artefact is currently unknown but may be related to imperfect post-coring storage conditions2.

In an alternative approach, one could use the CH4 records from all three cores to determine age distributions of WAIS Divide and Skytrain independently of the CO2 record and provide not only estimates of the upper limits of the firn age widths (as done here), but also the lower limits. However, this would require high-resolution, continuous CH4 data from Law Dome. Tentatively, we can place some constraints on the lower limit of the firn age distributions by examining a CH4 minimum that immediately precedes the CO2 drop (~1590 CE). This minimum is fortuitously nearly coincident with the CO2 drop of interest (Fig. S4), about half the width of the CO2 drop (~20 years versus ~40 years), and about same width as the gas age distribution of Skytrain and WAIS Divide. If our original estimates of smoothing based on firn models were accurate, we would predict that the CH4 minimum would be absent in WAIS Divide and Skytrain. This is clearly the case in WAIS Divide record and most likely the case in Skytrain record (although our measurement unfortunately did not extend to the predicted levelling off in CH4 post 1600 CE (Fig. 3)). However, other features present in the low-resolution Law Dome data are not obviously comparable to the WAIS Divide and Skytrain features such as divergence in the preceding CH4 bump of the 1500’s CE. Measurements of CH4 and other gases at the Law Dome site via continuous flow analysis (CFA) are thus a crucial prerequisite for future work on understanding the smoothing imparted on ice core gas records by firn processes.

Implications for land carbon fluxes
We now explore the biogeochemical implications of the gradual CO2 decrease around 1600 CE that our revised CO2 history suggests, relative to the rapid 1610 CE CO2 minimum seen only in Law Dome.

We performed single deconvolution experiments to reconstruct the net carbon flux to the atmosphere from an external reservoir—in this case the land biosphere. In brief, the atmospheric history of CO2 is reproduced in a carbon cycle model by making small adjustments to the land-atmosphere carbon flux at each timestep28. The ocean-atmosphere carbon flux (Fig. S5) is allowed to evolve freely and thus acts as either a passive sink or source depending on whether atmospheric CO2 is increasing or decreasing, respectively. This technique requires a continuous record of atmospheric CO2, interpolated to the model timestep, which we take from the suite of bootstrapped spline fits. We perform the simulation with the OSU Carbon Cycle Box Model29 with a 5000 year spin up under pre-industrial conditions and timestep of 0.25 years.

The Law Dome-based reconstructions show a sharp net sink from 1570 to 1620 CE (mean ± 1-sigma s.d. = 0.47 ± 0.19 PgC per year) that strengthens to a maximum up to 1 PgC per year from 1590 to 1600 CE (Fig. 4a). This is followed by a net source of about +0.25 PgC per year from 1620 to 1650 CE. Conversely, the WAIS Divide and Skytrain-based reconstructions (Fig. 4b), which are both in good agreement on timescales longer than a decade, show a much shallower sink from 1570 to 1620 CE (WAIS Divide: 0.24 ± 0.10 PgC per year; Skytrain: 0.28 ± 0.13 PgC per year). A compilation that combines all the data with a more conservative, 100-year spline cut-off period (See Supplementary Information) yields a similarly shallow sink with a slightly tighter constraint (all data: 0.26 ± 0.05 PgC per year) (Fig. 4c). This is in broad agreement with a previous study which utilised a double deconvolution technique that simultaneously constrained the land and ocean fluxes using both the concentration and isotopic composition of CO2 from WAIS Divide4. Over a slightly broader minimum from 1550 to 1650 CE, the double deconvolution yielded a mean land carbon sink of 0.34 ± 0.06 PgC per year. The full model output for each ice core record is available in Supplementary Data File 2.

We now compare our top-down estimates from the three ice cores with bottom-up scenarios for anthropogenic land-use change (Fig. 4). The bottom-up scenarios can broadly be divided into two groups: low-end scenarios that are driven by HYDE 3.1 and 3.2 land use datasets30 and high-end scenarios driven by the KK10 land use20. Both scenarios are driven by similar changes in population but differ significantly in their assumed per-capita land use with the high-end scenarios averaging 7 hectares per capita (but varying with population density) and the low-end scenarios set at a constant 0.5 hectares per capita20,31. This results in much greater areas of land abandonment and subsequent regrowth of natural terrestrial biomass in the New World in the high-end scenarios. The details of the scenarios, which utilised the LPX Dynamic Global Vegetation Model, are described in Stocker et al., 2017. Note that net uptake by peatlands is relatively minor on the shorter timescale of interest here (0.03–0.05 PgC per year)4,31.

The low-end land use scenarios, which show negligible variability in land carbon uptake during the period considered, are inconsistent with all top-down reconstructions. In contrast, the high-end scenarios are in good agreement with the WAIS Divide, Skytrain and combined reconstruction, but are inconsistent with the Law Dome reconstruction. This supports our analysis that the 1610 CE CO2 minimum is implausibly large and reinforces previous modelling work that showed the timescale for major regrowth is too long to induce a dramatic dip in atmospheric CO2 9. The more gradual uptake we estimate (~0.26 PgC per year) suggests the high-end scenarios are sufficient to explain the drop in CO2. This challenges previous work which, based on the longer-term carbon balance over the last millennium4, suggested the high-end scenarios were implausible, as well as recent work which revised downward the per-capita land use in the Americas11.

It is important to note that underlying the state-of-the art land use and carbon cycle models are population estimates that are very coarse resolution (100 years until 1700 CE). Now that our data precisely define the timing and magnitude of carbon uptake, further work modelling population dynamics, land-use change and carbon cycle changes during the New World Pandemics is warranted.

Alternatively, the CO2 decrease could be due in some part to natural carbon cycle feedbacks that were triggered by a cooling in the Northern Hemisphere5. In the case of the 1610 CE CO2 minimum this would require a sudden cooling and similarly rapid warming. Intriguingly, many tree-ring based reconstructions of Northern Hemisphere temperature record a strong cooling around 1600 CE, but this oscillation is not particularly exceptional in the wider context of decadal-scale cold periods of the last millennium. For context, the two coldest decades of the last millennium are in the 1800s followed by 1462–1471, 1695–1704 and 1452–1461 as the 3rd, 4th and 5th coldest, respectively32. Thus, if the terrestrial carbon cycle was particularly sensitive to rapid coolings, most crucially, with a response time capable of driving a decadal scale drop in CO2 as observed in the Law Dome ice core, we would expect similarly large CO2 decreases following 1450/60s and the early 1700s. Instead, CO2 is either stable or even increasing during these intervals. More likely, a series of coolings starting as early as the 1300’s in the Northern Hemisphere (in particular the Arctic) contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE.

Remaining questions
Is the 1610 CE minimum in CO2 a natural expression of carbon cycle feedbacks, a global marker of land abandonment, or an artefact of ice core data? Based on data from the Skytrain ice core our analysis provides evidence that the large 1610 CE CO2 minimum is not a true atmospheric signal, and that other, lower accumulation ice core records are faithfully recording a gradual atmospheric CO2 decrease. The gradual decrease observed in the WAIS Divide and now Skytrain ice cores agrees with our current understanding of climate-carbon feedbacks and high-end scenarios of carbon uptake following land abandonment while a large, sudden dip in atmospheric CO2 as in the Law Dome record is inconsistent with all current land-use change scenarios. Whether the CO2 decrease resulted from natural or anthropogenic processes, or a combination of the two, remains an open question. It is possible that large-scale land abandonment, in tandem with a hitherto unidentified climate-carbon feedback, could explain the minimum in the Law Dome record.

Furthermore, our evidence against the 1610 CE minimum is indirect and the origin of the low values that make up the minimum in the Law Dome data remains unclear. Remeasurement of existing Law Dome samples or, better yet, collection of new very-high resolution cores in other regions of Antarctica, may improve our understanding of the origin of the feature. With the advancement of measurement techniques of CO2 and its isotopes since the first pioneering Law Dome measurements, new records could greatly enhance our understanding of rapid anthropogenic and natural carbon cycle changes.

Methods
The Skytrain ice core was drilled on Skytrain Ice Rise in West Antarctica in 2018/201921, to a depth of 651 m, reaching ice ages from the last interglacial at its base. The samples in this study are taken between 83.2 m and 104.0 m, with respective ice ages between 1182 CE and 1443 CE22, and respective gas ages between 1454 CE and 1688 CE33. Accumulation rate in this section is 13.5 cm w.e. yr−1 on average with a present day 10 m temperature of −25.9 °C. For further detailed information on drilling, site characteristics and age scale generation please see references21,22,33.

Sample dating
Discrete samples throughout the period 950-1750 CE had been previously measured for CH4 at approximately 20 yr resolution. Samples were measured using the Oregon State University (OSU) melt-refreeze wet extraction system with associated gas chromatography (GC)26,34,35, referenced to the WMO X2004A reference scale36 and calibrated using a NOAA primary air standard. An average blank correction of 8.3 ± 2.7 SD ppb, and solubility correction of 1 ppb, have been applied. Uncertainty of the measurements is 2–3 ppb22. These measurements were incorporated into the ST22 chronology22,33 for the Skytrain ice core, which is used for all ice and gas depth-age dating in this study. Specifically, we use the ST22-WD ages, as opposed to the ST22-AICC ages.

CO2 analysis
CO2 analysis was carried out on the OSU needle crusher extraction device with associated GC analysis3. The extraction system composes a vacuum chamber inside which a ~2×2×2 cm ice sample is placed. A pneumatically driven bellows, with head attachment of multiple metal needles, impacts the ice ten times to mechanically crush the sample, releasing the gas trapped inside the ice. This gas is dried inside the vacuum system by flowing it through a U-shaped metal trap cooled to −90°C using an ethanol-liquid nitrogen slush bath. The remaining gas sample is frozen inside a manifold of sample tubes, kept at −260°C using a helium compressor. Sample tubes are sealed, transferred to a GC, and warmed to room temperature before injection and analysis.

Measured CO2 values are calibrated using a NOAA primary air standard (WMO scale X2019) and adjusted for an average full system blank value of 0.8 ppm. A gravitational correction was applied per-sample based on a measured δ15N value of 0.16 per mil33, equating to an average correction of 0.7 ppm.

Dependent on the size of the original sample, which was based on availability of ice at the required depth, 2 or 3 replicates were run of either true depth (exact depth replicates located next to each other across the width of the core) or proximal depth (located directly above/below each other in the core). The pooled standard deviation is 1.0 ppm on the final CO2 values, with no significant difference in pooled standard deviation observed between the two replicate types. The CO2 record, ages and errors are presented in Supplementary Data File 1.

Continuous CH4 analysis
16.5 metres of ice from Skytrain was measured for continuous CH4 throughout 1426 to 1617 CE. Samples were measured over a single day using the Continuous Flow Analysis (CFA) system at BAS22. Sample gas was extracted from a continuous steam of melt by applying a pressure decrease across an Idex Transfer Line Degasser. The sample was then dehumidified in a Nafion dryer before continuous injection into a SARA (Spectroscopy by Amplified Resonant Absorption) analyser37,38, where concentration data are acquired at 4 Hz. Gas measurements were bracketed by calibration routines using NOAA primary air standards to place data on the WMO X2004A reference scale36 and to correct for the dissolution of CH4 in the melted ice stream27. Average CH4 dissolution was 11.7 ± 0.5% and a correction factor of 1.13 is applied to all data. Data presented in this study are binned at 30 s intervals and the bins have a pooled relative standard deviation of 0.9% (1σ), equivalent to an average 6.3 ppb. Over the section analysed, a sum total 3.8 m was unavailable due to previous sampling requirements, compounding gaps in the data relating to ice quality (ca. 3 breaks per metre). The CH4 record, ages and errors are presented in Supplementary Data File 1.

Smoothing splines
Smoothing splines for each CO2 record, the Skytrain continuous CH4 record, and our final CO2 compilation were generated using a bootstrapped Monte Carlo simulated cubic smoothing spline procedure. We applied a random sampling with replacement bootstrap over 10,000 iterations of our dataset. For each iteration, the MATLAB cubic smoothing spline function, ‘csaps’, generates a spline based on the input data, x and y, and the smoothing parameter, p. The smoothing parameter is sensitive to the input records’ time-resolution (e.g., 13 years at Law Dome), so an individual parameter is tuned for each record to produce a spline at half height of the amplitude of a generic cosine test function. Cut-off frequencies for the individual records were set at 50 years, in the mid-range of previous studies2,39. This value allows preservation of distinct features in the records, such as the 1610 CE minimum in the CO2 records, while not being overly affected by sample variation from intrinsic measurement errors. A longer frequency of 100 years is used for the spline based on a compilation of the datasets. The final spline for each record is a mean of these 10,000 iterations and the spline error, or confidence interval, is the standard deviation of the iterations. Spline parameters are summarised in Table S1. Smoothing splines for each ice core record are presented in Supplementary Data File 1.

Firn filter modelling
We use the Oregon State University Firn Air Model to generate firn filters for the WAIS Divide and Skytrain ice cores40–42. These may also be seen referred to as age distributions and/or Greens Functions in similar studies. Broadly, the model allows input of the individual site characteristics of accumulation rate, site temperature, atmospheric pressure, and snow densities at surface and close-off for a choice of gases and over a specified time, calling the Herron-Langway43 model for densification. The model incorporates physical processes of diffusion, advection, mixing, bubble closure and bubble compaction. The model has been validated using reproduction of Greenland firn air measurements and intercomparison with multiple other firn models shows good agreement in their depiction of smoothing under the same conditions40. For specific details on parameterisations please see references40–42. Additionally, the model firn filters are sensitive to the assumed diffusivity parameter for the gas of interest (in this case CO2). We adopt a previously used approach41 which assumes a value for CO2 diffusivity of 0.10 cm2/s. We note that these firn-filters-the starting point for our enhanced smoothing experiments-are not trained on data, they are purely the consequence of our current, best knowledge of firn smoothing. To check validity of these parameters for our sites, we compare our WAIS Divide firn filter to the previously published WAIS Divide filter23, which was generated using the Centre for Ice and Climate (CIC), University of Copenhagen, firn air transport model. The CIC firn filter accounts for more complex processes of bubble closure, for example due to layering, in comparison to the OSU model which more simply defines bubble closure following the rate of bulk firn compaction41. Despite these differences the two firn filters very closely agree (Fig. 2b), helping to validate our firn filters and indicating that differences in parameterisations between firn models are not impacting our results. The same diffusivity is thus assumed for Skytrain.

Log-logistic distributions (y) can also be used to represent ice core firn filters45 using the equation:

y=((β/α)(x/α)^(β-1))/(1+(x/α)^β)^2 (1)

which requires the inputs of gas age, x, distribution width, α, and distribution shape, β. Other distributions can be used, for example log-normal distributions24,25, but a comparative study found them to give virtually the same results while log-logistic functions were the most mathematically tractable45. Our firn smoothing experiments require an artificially enhanced amount of smoothing for the WAIS Divide and Skytrain distributions (See ‘Results and discussion’ Fig. 3) to eliminate the 1610 CO2 minimum from the Law Dome record during convolution. We firstly tuned the width and shape parameters to create a single function that best represents both the WAIS Divide and Skytrain firn filters. From here the shape parameter value is maintained while applying increasing values of width to force a function of increased firn smoothing. Functions are terminated at three times the median age of the distribution to prevent very long tails44,45. The start points of the generated functions are also offset by 75 yrs to match the WAIS Divide and Skytrain model firn filters. Repeating the convolution of the Law Dome CO2 record with the artificial firn filters allows us to identify the level of firn smoothing required to eliminate the CO2 minimum from the Law Dome record, and better reproduce the WAIS Divide and Skytrain CO2 records (Fig. 3b). Three filters are chosen which best reproduce these records, which were the three filters calculated to have the lowest offset to the CO2 splines of WAIS Divide and Skytrain (see Supplementary Information and Fig. S1).

One thing to consider is that we are using firn filters generated for the diffusion of CO2 in our ice core records, but the diffusion of CH4 through the firn column will have a slightly different behaviour and therefore diffusivity parameter, potentially increasing the firn smoothing (CH4 diffusivity = 1.367*CO2 diffusivity). We test the effect of this by generating a firn filter for Skytrain using the same OSU Firn Air Model and parameters as previously and changing only the diffusion parameter from that of CO2 to that of CH4. We repeat the convolution process using this filter and the Law Dome CH4 record. Comparing each of the new and previous filters and convolutions shows negligible differences (Fig. S2). Each of our generated firn filters are presented in Supplementary Data File 1.

Convolutions
All convolutions use MATLAB ‘conv’ where an input function, the firn filter, is convolved with an input time series, the ice core record. The convolution requires that the filter functions are normalised to a sum of one, and functions and time series are of matching time resolution. This is 0.2 yrs, the same as the output of the OSU Firn Model. CO2 records are interpolated linearly to this time step preceding convolution.

Compilation CO2 record
To account for the various offsets in the final compilation, we adjust each of the Law Dome and WAIS Divide records in the direction of their average spline offsets to the Skytrain spline, as in Fig. 1. For the Law Dome—Skytrain offset, data through the 1610 CE CO2 minimum are excluded from the average offsets so as not to artificially enlarge the average offset, which equates to the exclusion of three data points. The resulting adjustment for all Law Dome data is +1.4 ppm, and for WAIS Divide is −1.3 ppm. The final compilation spline is generated using a compilation CO2 dataset incorporating the original Skytrain CO2 values and the adjusted values for Law Dome and WAIS Divide, using the same bootstrapped cubic smoothing spline as previously but with an increased cut-off frequency of 100 years (Fig. S3).

Peer review rounds
[{"round": 1, "reviewer_comments": {"reviewer_1": "This study uses a new ice-core CO2 record (Skytrain) and modelling to suggest that a previously reported brief dip in atmospheric CO2 seen around 1600 in the much-used Law Dome CO2 record is likely an artifact. Instead, although a drop did occur around that time, it was more gradual. This more gradual drop is more in line with some prior estimates of land CO2 fluxes that followed from (tragic) decimation of native American populations in around 1600 and resulting land abandonment.\nI found the paper to be quite interesting, with implications for both anthropology and climate sciences, e.g. the 1600 dip has been previously highlighted as a marker for defining the Anthopocene (Lews and Manslin, 2015). I appreciated the (mostly) very clear writing and presentation. The argument is well crafted and generally convincing, especially because the new Skytrain core corroborates the CO2 record from the WAIS divide core, which I surmise was previously discounted because it disagreed with the favored Law Dome record. In effect, the Law Dome record is now outvoted. The authors skillfully address complications caused by smoothing of the different ice-core records by diffusion in the firn column. Overall, very nice work!\nMy only substantive concern relates to error analysis. Although the general agreement between the Skytrain and WIAS cores makes other details of error analysis less critical, I nevertheless feel the need to point out some issues. For one thing, the presentation wasn’t super clear. But if I understood correctly, they apply a fixed +/- 1 ppm uncertainty to each data point, and propagate errors via a Monte Carlo scheme. The problem here is that the +/- 1 ppm estimate is by itself not well justified (see below) and may not fully capture relevant errors. I suggest that a better approach would be to use a resampling method, such as a bootstrap, using random picks of the data to feed into the spline fitting. There is no perfect method, but I believe a bootstrap will at least involve fewer arbitrary assumptions. I suggest that they do bootstrapping for all three ice cores.\nDetailed comments:\n184-185. I’m not sure this is correct. I believe the key requirement is for a regularly spaced atmospheric times series, whether smoothed or not. An interpolation method is thus needed, but it’s not required that the resulting time series by highly smoothed.\nFigure 4. I would appreciate seeing the time axis for these plots extending over a larger time frame, so that the dip around 1600 can be seen in the context of longer-term variability. Why not use the 1300-1800 timeframe shown in Figure 2?\n236. The double negative and the phrase “high per-capita land use”, which I found ambiguous on first reading, makes this hard to parse. I suggest rephrasing avoiding the double negative and using previously defined terms “high-end” and “low-end”.\n250-252. This needs some editing for clarity. As currently written, the 1600 cooling doesn’t appear within the summary of cooling periods. I suggest simply ranking the cooling around 1600 in relation to other periods. I’m also not clear what is meant by coldest (non overlapping) decades.\n309. NOAA revised its CO2 scale recently. What NOAA scale is being used?\n316. See general point above about error analysis. It’s unclear why pooled standard deviation is being used as an error metric. If errors were truly random, the pooled standard error (across replicates) would be more relevant, which would be sqrt(2) or sqrt(3) times more precise. As far as I can tell, using the +/- 1 ppm number for replicate averages has no real justification, or at least not one that has been disclosed. More to the point, it’s clear from comparing the records in Figure 2 that other errors are dominating, such as systematic differences between the true atmospheric value and what’s preserved in the ice or something to do with the extraction. A sensible error analysis would quantify these aspects rather than reporting a statistic related to random error on a single point that is then applied to a replicate average. As I suggested earlier, a bootstrap would be more inclusive of different types of error with fewer assumptions.\n347. What’s a compilation spline?\n348. See earlier point. I don’t follow this method. Was a constant with sigma +/- 1 ppm added for each sample point? Based on my earlier comment, I doubt these addresses relevant errors.\n361. Not clear what is meant by “conservative value”. High or low?\n368. What is y in this equation?", "reviewer_3": "Review of “Reconciling ice core CO2 and land-use change following New World-Old World contact”\nKing, A.C.F. et al., submitted to Nature Communications.\nThis manuscript by Amy King et al. assesses atmospheric CO2 changes measured in ice cores during the pre-industrial centuries. This is an important period as it shows variations in the carbon cycle before large emissions from fossil fuel that may be evidence of natural, likely climate-driven, causes or early anthropogenic land use change. It has been the focus of several ice core measurement surveys and modelling interpretation studies, in particular the CO2 minimum at about 1590-1630 AD. King et al. present another ice core record through this period from the relatively new Skytrain ice core. They question whether the CO2 minimum observed in the Law Dome DSS ice core is an artefact as opposed to an actual atmospheric change.\nAs the authors note, variations in CO2 at this time have been widely used in quantifying climate, carbon cycle and anthropogenic roles and as such we need to be sure of their accuracy.\nThe main requirements to produce a CO2 record from ice cores that best represents rapid atmospheric variations are that the measurements are an accurate measure of the CO2 concentrations of the air in the ice, that the CO2 in the ice has not changed since enclosure in bubbles and that the enclosure of air in the bubbles has minimal effect on the CO2 concentration of the atmosphere of the time.\nThe measurements by King et al. appear to be done well and have replicates and high measurement density through this period. However, the resulting scatter of CO2 concentrations appears to be rather large compared to their measurement precision, the likely atmospheric variability and, importantly, the likely variability that would remain after the smoothing effect of air enclosure in the ice at the Skytrain site. This is discussed further next.\nVariations in the Skytrain CO2 measurements are sometimes quite large and appear difficult to reconcile as being atmospheric in origin given our knowledge of likely variations in atmospheric CO2 and additionally the attenuation of rapid atmospheric signals by the ice core air enclosure process. For example, point-to-point differences (separated by less than a decade) of 4-5 ppm occur at around 1540 and (importantly) 1610-1630 AD. Almost as much CO2 variability is seen in WAIS in the early 1600s. Is this evidence that these cores are affected in some way? This variability is comparable to the difference between the measured CO2 minimums in the Skytrain and WAIS cores and the expected CO2 minimum if the Law Dome record were convolved by their respective air age distributions (blue and red data and lines in Figure 3). Note also that both Skytrain and WAIS are slightly elevated in CO2 compared to many other ice core records: Law Dome, DML, EPICA/DML (Rubino et al., ESSD, 2019) and South Pole (Siegenthaler et al., 2005). Is this revealing anything important about CO2 retention in WAIS or Skytrain? The WAIS-Law Dome difference was found not to be caused by inter-laboratory measurement differences (Ahn et al., GBC, 2012). So while it is reasonable to question some of the lower values within the DSS record, a similar level of scrutiny could also be applied to the Skytrain CO2 measurements, especially if they align with the WAIS record that is likely elevated.\nA key question is how an ice core with an accumulation of only 13.5 cm/yr can retain atmospheric composition variations that can be used to verify a rapid variation observed in the higher accumulation rate ice from Law Dome (DSS, 60 cm/yr)? The spread of air age in ice is a result of the diffusion of air in the firn column and additional smoothing as the air deep in the firn is enclosed into bubbles. That additional smoothing can be significant and would be larger for low accumulation sites. It is not clear from the manuscript how this additional smoothing has been included for Skytrain, if at all, in the resulting air age distributions used in the analysis and comparison of potential CO2 changes observed in these different ice cores. There are many references in the text to the advantages of high accumulation and temporal resolution (for example, paragraph staring at line 38) and then testing of Law Dome CO2 through the firn based smoothing (section at line 114). But I couldn’t find what was included in the “firn-filters” (line 129). Firn-filter modelling is described at line 353, and mentions densification and close-off, but does it include bubble close-off, either measurement or parameterisation, and its effect on air age spread?\nValidation of ice core air age distributions is useful to quantify the effect of enclosure smoothing on atmospheric variations. One approach is to test the air age distributions derived for the air in ice core bubbles against rapid atmospheric changes of gas species with independently found histories. For example, 14CO2 measurements of Law Dome ice core and firn air, including the DSS ice core, were compared with measurements of the “bomb-pulse” 14CO2 in the atmosphere smoothed by the model of firn diffusion and bubble close-off (Smith et al., NIMB, 2000). Have measurements of any gas species other than CO2 or CH4 been used to check the Skytrain ice core air age distributions?\nKing et al. test whether the smoothing required to remove all of the 1610 CO2 minimum signal is compatible with the CH4 measurements (from line 149). This makes good sense as there are CH4 data through these periods for the 3 cores and CH4 is generally reliably enclosed and stored in air in ice. However, this comparison depends on how well constrained are the WAIS and Skytrain age distributions (“firn filters”). If they are trained on matching the CO2 datasets would they be potentially in error due to the variability that both cores’ CO2 measurements show especially in the 1600s? It’s also difficult to see how well the increased smoothing functions fit the data (Fig 3B). These are quite radical increases in smoothing and it would help to see the CO2 data and their uncertainties plotted alongside. The CH4 data could also be shown in Fig 3C as well as the spline.\nIt should be noted that there are rapid CH4 variations in Law Dome DSS that are not observed in either Skytrain or WAIS, curiously also around 1600AD. It would be unlikely that these CH4 differences were caused by the same artefact that is proposed to have affected CO2.\nThe general approach of King et al. is similar in many ways to that used by Rubino et al., Nature Geo 2016, who compared the CO2 changes in the WAIS and DML (also lower accumulation than Law Dome) ice cores with those in the Law Dome DSS core. The CO2 measurements were consistent with the DSS CO2 record convolved through the bubble air age distributions for both those ice cores but neither could confirm or rule out the 1610 minimum in DSS. Without evidence that the Skytrain bubble air age distribution is sufficiently narrow and not broadened by its relatively low accumulation rate, it is difficult to see how it could offer a significant improvement.\nA final general comment regards the comparison of the Law Dome 1610 minimum with carbon fluxes from land use change scenarios. The authors interpret the inability of land use models to account for the measured 1610 minimum as evidence that it is implausibly large. It is interesting to make model-data comparisons like these but I think the land use estimates for that time could also be uncertain. More importantly, this claim seems to ignore the CO2, 13CO2 and COS measurements and modelling presented by Rubino et al. (Nature Geo., 2016) as evidence for a climate role in the Little Ice Age CO2 drop (~1600-1800).\nArguing that a low accumulation ice core can better record rapid atmospheric CO2 variations than a higher accumulation counterpart requires convincing demonstration that the air age distribution has been fully accounted for and that there are no artefacts in the ice core measurements- of both high and low accumulation cores. King et al. go some of the way in doing this for their Skytrain study but more is required to make their claims more robust. Given the importance of ensuring that past CO2 variations are accurately reconstructed from ice cores I hope that they can make the suggested improvements. Their final statement that new very high accumulation (air age resolution) Antarctic ice cores are needed must stand as a high priority.\nOther, specific notes on the manuscript:\nLines 45, 46, 53, 55. Please say whether and how bubble close off is accounted for in these estimates, and later on in the analysis.\nLine 56. 0-6 ppm is given in Ahn et al.\nLine 60. Is this saying that both records could have artefacts?\nLine 68, 77. Should also say that the other interpretation is climate-CO2 feedback.\nLine 80. Prefer “interpretation” or “understanding” to accounting.\nLine 94. More information on Skytrain relevant to ice core CO2 would be helpful: temperature, melt events, age and uncertainty, locations, how drilled…. Either here or in Methods/Supplementary.\nLine 100. The first part of the CO2 decrease actually looks comparable to Law Dome.\nLine 109. As in general comments above, regions of large variability in both Skytrain and WAIS.\nLine 117. Low pass filtering occurs in firn and bubble close of region.\nLine 119. Are all air age distributions using the same statistic?\nLine 122. For clarification: …(about 40 years) was ana actually atmospheric CO2 change recorded in Law Dome ice but smoothed away in both Skytrain and WAIS?...\nLine 128. “Firn filters” are also referred to as Greens Functions for the purpose of convolutions and forward and inverse modelling signals.\nLine 131, 132. The convolved minimums are much more subtle than the originals, and are actually not much different from the data, especially Skytrain, given the stated uncertainties and the additional variability.\nLine 138. Again, what is included in the firn filters?\nLine 150. If it is a true signal and if it is enclosed and preserved without unexpected changes…\nLine 158. Could the Skytrain CH4 data be plotted please?\nFigure 3B. Could the CO2 data be plotted to see how well the convolutions fit?\nFigure 3C. Please show Skytrain data points.\nFigure 4. It would be help if the ocean-atmosphere fluxes were shown or at least mentioned.\nLine 161. Given the points raised above this would be better stated as “a plausible”.\nLine 232. Also as stated above, there are other possible reasons for the CO2 change.\nLine 261, 262. Based on the reasons given above, this statement is possibly too confident. Suggest removing the word “strong” unless more evidence as mentioned earlier can be shown.\nLine 292. What is the range/uncertainty of the CH4 blank?\nSection at line 355. Please be clear about what processes are included in the firn filter modelling, especially bubble close off and how it interacts with the diffusion in the firn column. This is crucial to the resulting air age spread and the conclusions of this work."}, "author_response": "Thank you very much to the reviewer for the positive feedback, and for the constructive comments given below.\nMy only substantive concern relates to error analysis. Although the general agreement between the Skytrain and WIAS cores makes other details of error analysis less critical, I nevertheless feel the need to point out some issues. For one thing, the presentation wasn’t super clear. But if I understood correctly, they apply a fixed +/- 1 ppm uncertainty to each data point, and propagate errors via a Monte Carlo scheme. The problem here is that the +/- 1 ppm estimate is by itself not well justified (see below) and may not fully capture relevant errors. I suggest that a better approach would be to use a resampling method, such as a bootstrap, using random picks of the data to feed into the spline fitting. There is no perfect method, but I believe a bootstrap will at least involve fewer arbitrary assumptions. I suggest that they do bootstrapping for all three ice cores.\nWe have updated our analysis to include bootstrap for producing our smoothing splines of all ice core records and the confidence intervals (error) on these splines.\nWe use a ‘true’ bootstrap method, random sampling with replacement, and include the analytical uncertainties in the bootstrap. We chose this over random sampling without replacement as this method would be overly sensitive for shorter time series, which our Skytrain data set is. The generated splines and their confidence intervals now replace all previous splines used in the figures, smoothing experiments, and land carbon modelling in our manuscript, but do not change any of the conclusions of our work. To demonstrate this, Figure R1A shows a comparison between our previous splines and their confidence intervals and the new bootstrap method splines and their confidence intervals. The figure shows the increased capture of data variability in the confidence intervals as requested by the reviewer, while overall splines remain virtually the same. Figure R1B highlights the similarity of the splines in our period of interest, the same as they are used in manuscript Figure 2 for our convolution experiments. These new splines do not impact the conclusions of any of our smoothing experiments. Finally, Figure R1C shows the new land carbon modelling outputs, based on the bootstrap splines and confidence intervals, alongside the previous outputs. There are subtle differences in the confidence intervals of calculated land - atmosphere fluxes due to the now wider input confidence intervals of our splines, but overall trends in the fluxes are not changed.\nA note that the confidence intervals on our new bootstrap splines may become very wide at the end of the datasets as shown in Figure R1A for Skytrain since this time series is shorter. The ends of the time series are constrained by fewer data points resulting in wider errors here. This does not affect the data or splines/confidence intervals in our specific period of interest in the core. The same end-effects occur for all records but lie outside the window of this particular plot, and are reduced in the case of WAIS Divide and Law Dome given they are longer datasets overall.\nThe methods section which reports the generation of our smoothing splines has been updated to reflect the new bootstrap methodology used.\nFigure R1A: CO data for each of the three cores in this study, with their previous monte carlo 2 smoothing splines and confidence intervals shown in black/grey bands, and the new bootstrapped smoothing splines and confidence intervals in coloured bands. Confidence intervals become very wide at the end of the datasets as shown for Skytrain here since this time series is shorter. The ends of the time series are constrained by fewer data points resulting in wider errors. The same end-effects occur for all records but lie outside the window of this particular plot, and are reduced in the case of WAIS Divide and Law Dome given they are longer datasets overall.\nFigure R1B: CO data for each of the three cores through the period of interest to this study, in the 2 style of manuscript Figure 2 for comparison. The graph plots the previously used splines generated using the monte carlo (MC) method (dashed lines), with the new splines generated using the bootstrapped (BS) method (solid lines). There is a strong similarity between both versions of the splines, thus the conclusions of our later smoothing experiments are not affected.\nFigure R1C: A comparison of results from the deconvolution experiments for the various ice core records showing the change in CO and the inferred land-atmosphere carbon flux based on our 2 previous splines and confidence intervals (coloured shading) and fluxes based on our updated bootstrapped splines and confidence intervals (bold lines). There are some subtle differences in the confidence intervals of the calculated fluxes due to the new confidence intervals of our splines being generally of increased width, however overall trends in fluxes remain the same.\nDetailed comments:\n184-185. I’m not sure this is correct. I believe the key requirement is for a regularly spaced atmospheric times series, whether smoothed or not. An interpolation method is thus needed, but it’s not required that the resulting time series by highly smoothed.\nGood point. We have modified the sentence to read ‘This technique requires a continuous record of atmospheric CO , interpolated to the model timestep, which we take from the suite of bootstrapped 2 spline fits.’\nFigure 4. I would appreciate seeing the time axis for these plots extending over a larger time frame, so that the dip around 1600 can be seen in the context of longer-term variability. Why not use the 1300-1800 timeframe shown in Figure 2?\nThank you for the suggestion. We have retained the original time axis range as this covers the full extent of out new Skytrain record. A fuller Common Era picture is outside the scope of our dataset and this study.\n236. The double negative and the phrase “high per-capita land use”, which I found ambiguous on first reading, makes this hard to parse. I suggest rephrasing avoiding the double negative and using previously defined terms “high-end” and “low-end”.\nThanks for pointing out the confusion. We have reworded as follows‘This challenges previous work which, based on the longer-term carbon balance over the last millennium 4, suggested the “high-end” scenarios were implausible, as well as recent work which revised downward the per-capita land use in the Americas 11.’\n250-252. This needs some editing for clarity. As currently written, the 1600 cooling doesn’t appear within the summary of cooling periods. I suggest simply ranking the cooling around 1600 in relation to other periods. I’m also not clear what is meant by coldest (non overlapping) decades.\nWe have added further description to clarify:\n‘Intriguingly, many tree-ring based reconstructions of Northern Hemisphere temperature record a strong cooling around 1600 CE, but this oscillation is not particularly exceptional in the wider context of decadal-scale cold periods of the last millennium. For context, the two coldest decades of the last millennium are in the 1800s followed by 1462-1471, 1695-1704 and 1452-1461 as the 3rd, 4th and 5th coldest, respectively31. Thus, if the terrestrial carbon cycle was particularly sensitive to rapid coolings, most crucially, with a response time capable of driving a decadal-scale drop in CO as observed in the 2 Law Dome ice core, we would expect similarly large CO decreases following 1450/60s and the early 2 1700s. Instead, CO is either stable or even increasing during these intervals. More likely, a series of 2 coolings starting as early as the 1300’s in the Northern Hemisphere (in particular the Arctic) contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE.’\nChanged ‘discrete CH ’ to ‘Discrete (non continuous) samples…measured for CH ’.\n4 4\n309. NOAA revised its CO2 scale recently. What NOAA scale is being used?\nAdded to sentence: ‘(WMO scale X2019)’.\n316. See general point above about error analysis. It’s unclear why pooled standard deviation is being used as an error metric. If errors were truly random, the pooled standard error (across replicates) would be more relevant, which would be sqrt(2) or sqrt(3) times more precise. As far as I can tell, using the +/- 1 ppm number for replicate averages has no real justification, or at least not one that has been disclosed. More to the point, it’s clear from comparing the records in Figure 2 that other errors are dominating, such as systematic differences between the true atmospheric value and what’s preserved in the ice or something to do with the extraction. A sensible error analysis would quantify these aspects rather than reporting a statistic related to random error on a single point that is then applied to a replicate average. As I suggested earlier, a bootstrap would be more inclusive of different types of error with fewer assumptions.\nWe now use a bootstrap method for generation of splines and confidence intervals as suggested (please see more detailed response to error analysis above). The pooled standard deviation remains to indicate analytical error bars on our individual CO data points. The pooled standard deviation 2 was chosen as it is widely used in reporting of error on ice core gas measurements, and because of our variation in replicate numbers across data points.\n347. What’s a compilation spline?\nChanged to ‘...the spline based on a compilation of the datasets.’\n348. See earlier point. I don’t follow this method. Was a constant with sigma +/- 1 ppm added for each sample point? Based on my earlier comment, I doubt these addresses relevant errors.\nAs in previous comments, this method has been updated to include bootstrap and appropriately address errors.\n361. Not clear what is meant by “conservative value”. High or low?\n‘Conservative’ has been removed to avoid introducing confusion.\n368. What is y in this equation?\ny is the term used to represent the log logistic distribution here. To clarify this we have added in brackets in line 366: ‘Log logistic distributions (y) can also be….’\nThank you to the reviewer for their insightful comments on our manuscript and further discussion of the points raised. We have improved the manuscript as suggested, with the details of these changes found below.\nVariations in the Skytrain CO2 measurements are sometimes quite large and appear difficult to reconcile as being atmospheric in origin given our knowledge of likely variations in atmospheric CO2 and additionally the attenuation of rapid atmospheric signals by the ice core air enclosure process. For example, point-to-point differences (separated by less than a decade) of 4-5 ppm occur at around 1540 and (importantly) 1610-1630 AD. Almost as much CO2 variability is seen in WAIS in the early 1600s. Is this evidence that these cores are affected in some way? This variability is comparable to the difference between the measured CO2 minimums in the Skytrain and WAIS cores and the expected CO2 minimum if the Law Dome record were convolved by their respective air age distributions (blue and red data and lines in Figure 3). Note also that both Skytrain and WAIS are slightly elevated in CO2 compared to many other ice core records: Law Dome, DML, EPICA/DML (Rubino et al., ESSD, 2019) and South Pole (Siegenthaler et al., 2005). Is this revealing anything important about CO2 retention in WAIS or Skytrain? The WAIS-Law Dome difference was found not to be caused by inter-laboratory measurement differences (Ahn et al., GBC, 2012). So while it is reasonable to question some of the lower values within the DSS record, a similar level of scrutiny could also be applied to the Skytrain CO2 measurements, especially if they align with the WAIS record that is likely elevated.\nFigure R3A, below, shows a running three-point standard deviation of the CO data from each of our 2 three cores alongside the CO records of the cores as originally shown in manuscript Figure 1. The 2 standard deviations show that all three cores display periods of higher and lower variability (or, point-to-point differences) with comparable overall ranges of this variability. Throughout the ‘1610’ period in particular, variability of Skytrain is not outside the range of the other two cores. Highlighted in the boxes overlying the CO records are periods where each core record shows high 2 variability even though the suggested background atmospheric CO record is relatively unchanging. 2 Data variability above that of the analytical precision, and presumably not of atmospheric origin, is something that persists across ice core records and is not fully explained. However, given that each of the three cores used in this study show good analytical precision and evidence of overall faithful capturing of atmospheric trends, they all maintain as excellent atmospheric records. It is difficult to analyse variability between the cores any further than this due to differences in sample resolution and analytical methods applied.\nWe certainly agree with the reviewer that a similar level of scrutiny can be applied to variability in each of the cores, but we hope this demonstrates that the Skytrain record is of comparably good quality to both Law Dome and WAIS Divide, in particular through the ‘1610’ time period. To more markedly capture the observed variability in the cores through our error analysis, as suggested by Reviewer 1, we now include bootstrapping in our spline procedure for confidence intervals. Thus, we show a fair reporting of the variability seen in each of the cores. Please see the description in response to Reviewer 1 for this, and Figure R1A.\nAs the reviewer points out, the offset between absolute values of the WAIS Divide and Law Dome records could not be connected to analytical differences, and no conclusion on the reason behind this has been drawn with certainty. The new Skytrain record does appear to be closer to WAIS Divide values preceding the CO drop through the 1600s, but throughout the drop is not elevated alongside 2 WAIS Divide and agrees with Law Dome in the short period measured following the CO drop (also 2 evidenced in Figure 1 showing the offset between WAIS Divide and Skytrain). Extension of the Skytrain CO record outside of this time window was beyond the scope of this study and therefore it 2 is not possible to call where the absolute values of Skytrain sit in the wider picture of the Common Era. It is thus difficult to further the discussion on the absolute offsets. However, in the rest of our study we present robust analyses to demonstrate that both WAIS Divide and Skytrain are faithfully recording the trends in atmospheric CO at the time. Further, with the weighting of both the WAIS 2 Divide core and the Skytrain core, which are from different locations, different coring, transport and storage conditions, and different analytical conditions, now in favour of a more reduced drop in CO 2 into the Little Ice Age despite their different absolute offsets, we demonstrate that absolute values are unlikely to be impacting our conclusions.\nFigure R3A: Figure showing the CO records (top) of Law Dome, WAIS Divide and Skytrain and 2 (bottom) the corresponding running three-point standard deviation of each record, to capture point-to-point variability of the data. Overlying boxes highlight periods of high variability in sections of each of the three cores where background CO trends otherwise appear relatively stable. 2\nA key question is how an ice core with an accumulation of only 13.5 cm/yr can retain atmospheric composition variations that can be used to verify a rapid variation observed in the higher accumulation rate ice from Law Dome (DSS, 60 cm/yr)? The spread of air age in ice is a result of the diffusion of air in the firn column and additional smoothing as the air deep in the firn is enclosed into bubbles. That additional smoothing can be significant and would be larger for low accumulation sites. It is not clear from the manuscript how this additional smoothing has been included for Skytrain, if at all, in the resulting air age distributions used in the analysis and comparison of potential CO2 changes observed in these different ice cores. There are many references in the text to the advantages of high accumulation and temporal resolution (for example, paragraph staring at line 38) and then testing of Law Dome CO2 through the firn based smoothing (section at line 114). But I couldn’t find what was included in the “firn-filters” (line 129). Firn-filter modelling is described at line 353, and mentions densification and close-off, but does it include bubble close-off, either measurement or parameterisation, and its effect on air age spread?\nTo address these concerns, we have improved our description of the firn air modelling procedure, better emphasised our existing tests which show the accuracy of our firn filters, and implemented additional description in the manuscript constraining the accuracy further.\nAs a first step, we acknowledge that in the main text it was not explicitly stated how the firn filters were generated when they are first mentioned, nor was it explicitly linked to the methods section which describes this, and therefore we have added: ‘These firn filters, or age distributions, were generated using the Oregon State University (OSU) firn model (see methods) and mimic the firn smoothing specific to each ice core site.’\nAs a second step, we discuss here some further detail on the firn filter methodology, and include additional information in the manuscript to make the generation of our firn filters clearer. The Oregon State University (OSU) Firn Model is a comprehensive firn model but, as in all firn models, the precise parameterisations will vary in comparison to other firn models. The performance of the OSU firn model in accurately reproducing firn smoothing on gas records was validated by testing reproducibility of firn air measurements in a Greenland borehole as reported in Buizert et al. 2012. This work also provided an intercomparison of multiple firn air models, including the OSU firn model, the CIC firn model (which produced the published WAIS Divide firn filter in Mitchell et al. 2015, to which we compare our OSU firn filter for our own reproducibility test as described in our manuscript), and the CSIRO firn model which was used to produce the Law Dome firn filter of Rubino et al. 2016. The intercomparison study of Buizert et al. 2012 shows good reproducibility between all models, and details their individual parameterisations.\nFor bubble closure specifically, the OSU firn model uses the bubble closure parameterisation of Buizert 2011, and as further detailed in Rosen et al. 2014, “concentrations are calculated assuming that closed bubbles pressurize at the same rate as bulk firn compaction”. The OSU model therefore does not include more complex processes such as layering or other mechanisms which would result in variation in close-off depth. However, Mitchell et al. 2015 undertake an extensive investigation into these more complex processes, which are included in their (CIC) WAIS divide firn filter, and to which our (OSU) WAIS divide firn filter output shows very close reproducibility (Figure 2B). Thus, differences in bubble closure processes in the firn models do not appear to affect our results.\nIn the manuscript methods we have further added: ‘The model incorporates physical processes of diffusion, advection, mixing, bubble closure and bubble compaction. The model has been validated using reproduction of Greenland firn air measurements and intercomparison with multiple other firn models shows good agreement in their depiction of smoothing under the same conditions 41. For specific details on parameterisations please see references 41-43.’This is to give an overview of the included parameters and to reference the existing literature more clearly on the model.\nWhere we describe the WAIS Divide firn filter comparison in the methods, we also add: ‘The CIC firn filter accounts for more complex processes of bubble closure, for example due to layering, in comparison to the OSU model which more simply defines bubble closure following the rate of bulk firn compaction 42. Despite these differences the two firn filters very closely agree (Figure 2b), helping to validate our firn filters and indicating that differences in parameterisations between firn models are not impacting our results.’\nWe have also highlighted the different bubble closure parameterisation of the comparison CIC WAIS Divide firn filter in the main manuscript where we present the firn filter comparison in Figure 2, adding to the caption ‘alongside a previously published WAIS Divide filter that includes a stochastic model of bubble closure to mimic layering to show reproducibility’.\nWe accept an error is present in all firn models due to an imperfect knowledge of firn processes. We have already built this assumption into our work with experiments of artificially enhanced smoothing. To state this potential error more explicitly at the first reporting of our smoothing experiments in the manuscript we have added ‘could our firn filters be underestimating the degree of smoothing in the cores?’. To connect these potential errors to specific model parameterisations, we further add ‘For example, our firn model does not account for small-scale (cm-scale) density variations from layering and associated effects on bubble closure which can drive some pores to close-off about the traditional lock-in zone and thus lead to age-reversals and slightly broader firn age distributions.’\nOur tests of artificially enhanced smoothing account for error in the firn models which would result in an underestimation of the amount of smoothing of our records, or, place an upper limit on the firn filter widths. The results of these tests show that significantly increased smoothing, or width of our firn filters, is not compatible with the gas records we have measured. To further improve the constraints on the accuracy of our firn filters, we now also add to the manuscript a discussion on constraining the lower limit of the firn filter widths, adding confidence that out filters are within an accurate window:\n‘In an alternative approach, one could use the CH records from all three cores to determine age 4 distributions of WAIS Divide and Skytrain independently of the CO record and provide not only 2 estimates of the upper limits of the firn age widths (as done here), but also the lower limits. However, this would require high-resolution, continuous CH data from Law Dome. Tentatively, we can place 4 some constraints on the lower limit of the firn age distributions by examining a CH4 minimum that immediately precedes the CO drop (~1590 CE). This minimum is fortuitously nearly coincident with 2 the CO drop of interest (Figure S4 (or R3B here), about half the width of the CO drop (~20 years 2 2 versus ~40 years), and about the same width as the gas age distribution of Skytrain and WAIS Divide. If our original estimates of smoothing based on firn models were accurate, we would predict that CH 4 minimum would be absent in WAIS Divide and Skytrain. This is clearly the case in the WAIS Divide record and most likely the case in the Skytrain record (although our measurement unfortunately did not extend to the predicted levelling off in CH post 1600 CE (Figure 3). However, other features 4 present in the low-resolution Law Dome data are not obviously comparable to the WAIS Divide and Skytrain features such as divergence in the preceding CH bump of the 1500s CE. Measurements of 4 CH and other gases at the Law Dome site via continuous flow analysis (CH CFA publications) are 4 4 thus a crucial prerequisite for future work on understanding the smoothing imparted on ice core gas records by firn processes.’\nFigure R3B: Comparison plot of CO and CH in Law Dome to highlight that a short, rapid drop in CH4 2 4 is also present around 1600 CE, which is not present in the WAIS Divide (shown for reference) and Skytrain records.\nWe hope that these new details have reassured the reviewer on the quality of our age distribution/firn filter modelling, and that the additions to the manuscript ensure other readers have a clearer description to utilise. In answer to the overview question ‘A key question is how an ice core with an accumulation of only 13.5 cm/yr can retain atmospheric composition variations that can be used to verify a rapid variation observed in the higher accumulation rate ice from Law Dome (DSS, 60 cm/yr)?’; our extensive smoothing experiments indicate that both the Skytrain and WAIS Divide cores are capable of recording high resolution CO changes and in particular the ‘1610’ atmospheric 2 CO variations, and we have now demonstrated that these experiments are based on accurate age 2 distributions.\nValidation of ice core air age distributions is useful to quantify the effect of enclosure smoothing on atmospheric variations. One approach is to test the air age distributions derived for the air in ice core bubbles against rapid atmospheric changes of gas species with independently found histories. For example, 14CO2 measurements of Law Dome ice core and firn air, including the DSS ice core, were compared with measurements of the “bomb-pulse” 14CO2 in the atmosphere smoothed by the model of firn diffusion and bubble close-off (Smith et al., NIMB, 2000). Have measurements of any gas species other than CO2 or CH4 been used to check the Skytrain ice core air age distributions?\nFurther gas species have not been measured in this section of the Skytrain core, however our continuous CH record was measured specifically to test the compatibility of our CO findings on an 4 2 independent, high-resolution gas species. Further analysis was outside the scope of this study.\nKing et al. test whether the smoothing required to remove all of the 1610 CO2 minimum signal is compatible with the CH4 measurements (from line 149). This makes good sense as there are CH4 data through these periods for the 3 cores and CH4 is generally reliably enclosed and stored in air in ice. However, this comparison depends on how well constrained are the WAIS and Skytrain age distributions (“firn filters”). If they are trained on matching the CO2 datasets would they be potentially in error due to the variability that both cores’ CO2 measurements show especially in the 1600s?\nWe note that the firn-filters - the starting point for our enhanced smoothing experiments - are not trained on data, they are purely the consequence of our current, best knowledge of firn smoothing. There is thus no circular logic regarding our starting point for the firn smoothing experiments. To answer this, as above, we have improved our descriptions of the production of our firn filters and added to the discussion on the accuracy of our filters.\nIt’s also difficult to see how well the increased smoothing functions fit the data (Fig 3B). These are quite radical increases in smoothing and it would help to see the CO2 data and their uncertainties plotted alongside.\nTo clarify this process, we have now added the below description to the supplement alongside FigureR3B (subsequently Figure S1).\nTo choose the correct level of increased smoothing in our log-logistic distributions (i.e. those that best fit the ‘no 1610 dip’ scenarios of the Skytrain and WAIS Divide ice core CO records) we generated a 2 wide range of log-logistic functions and then calculated the offsets to the Skytrain and WAIS Divide CO splines for each function, looking for the closest fit. The offset was calculated over a specific time 2 window covering the CO drop. The average offset for each spline and function is then plotted to find 2 the optimal functions, where the offset is lowest (Figure R3B). The different functions are represented *=90-17@GA;)2:-><01+01890-6)7)3-9-75.90-25/B25/1891+.:4+915490)9+549752890-<1,905.90- function and therefore the degree of smoothing. For Skytrain, the three best-fit functions, 7-67-8-4914/)7)4/-5.5691548814+-454-)7-6-7.-+9><-7-GED>GFC)4,GFD?$57(\"%&#1;1,-90- *-89B.19.:4+91548<-7-GEC>GED)4,GFC>)+258-)/7--3-49?'0-7-1821992-,1..-7-4+-*-9<--490-8- two options, so we chose to take forward the range for Skytrain based on our later experiments being used to investigate other Skytrain gas records specifically.\nWe refer to this in both our main manuscript (‘We increase the width of the smoothing until the convolution output best matches the measured CO records of WAIS Divide and Skytrain using a test 2 which calculates the offset between the convolutions and datasets (See supplement and Figure S1’)) and our log-logistic function methods section (‘Three filters are chosen which best reproduce these records, which were the three filters calculated to have the lowest offset to the CO2 splines of WAIS Divide and Skytrain (see Supplement Figure S1)).\nfeatures such as divergence in the preceding CH bump of the 1500s CE. Measurements of CH and 4 4 other gases at the Law Dome site via continuous flow analysis (CH CFA publications) are thus a 4 crucial prerequisite for future work on understanding the smoothing imparted on ice core gas records by firn processes.’\nDue to the large differences in data resolution between each of the three CH records, it is difficult 4 to give a precise enough comparison between records to comment on artefacts. Future work in high resolution CH analysis in cores for this time period, as suggested, would be needed. 4\nThe general approach of King et al. is similar in many ways to that used by Rubino et al., Nature Geo 2016, who compared the CO2 changes in the WAIS and DML (also lower accumulation than Law Dome) ice cores with those in the Law Dome DSS core. The CO2 measurements were consistent with the DSS CO2 record convolved through the bubble air age distributions for both those ice cores but neither could confirm or rule out the 1610 minimum in DSS. Without evidence that the Skytrain bubble air age distribution is sufficiently narrow and not broadened by its relatively low accumulation rate, it is difficult to see how it could offer a significant improvement.\nRubino et al. 2016 do indeed follow a similar approach in proposing the use of a third, independent, ice core record of CO through this time to resolve the difference between the existing Law Dome 2 and WAIS Divide records. However, a key difference to this study is that the age distribution of the core they utilise, DML, is significantly broader, and thus the record significantly more smoothed, than that of Skytrain, the core used in this study. Thus, we present a record which has the capability of recording the ‘1610 dip’, while the Rubino study acknowledges themselves that the DML record would not have the capability to record this feature. As in our earlier responses, we have improved the description of the generation of our age distributions/firn filters and thus hope to have answered the doubts around the capability of the Skytrain record to record the ‘1610 dip’. Thus, we can reliably compare the various age distributions to highlight the improvement in comparison to DML of our record; the age distribution width of Law Dome is lowest, at 8 years, with both WAIS and Skytrain having similar distributions at 19 and 23 years, respectively. The age distribution of DML is three times higher than this, at 65 years. This would increase the smoothing significantly. Indeed, the DML distribution is wider than the Law Dome ‘1610 CO drop’ in its entirety, and thus would not 2 capture such an event in its record even if it were a real atmospheric signal. In contrast, as our extensive smoothing investigations demonstrate, while the WAIS Divide and Skytrain distributions are not as high in resolution as Law Dome, they are still at a high enough resolution that they would faithfully capture the 1610 drop if it were a true atmospheric signal. With our improved justification that our Skytrain age distribution is accurate, this holds true. Additional robustness to this conclusion is added by demonstrating that this holds true in both the WAIS Divide and Skytrain cores.\nA final general comment regards the comparison of the Law Dome 1610 minimum with carbon fluxes from land use change scenarios. The authors interpret the inability of land use models to account for the measured 1610 minimum as evidence that it is implausibly large. It is interesting to make model-data comparisons like these but I think the land use estimates for that time could also be uncertain.\nWe certainly agree on the uncertainty with land use estimates, and we discuss this in the text: ‘It is important to note that underlying the state-of-the art land use and carbon cycle models are based on population estimates that are very coarse resolution (100 years until 1700 CE). Now that our new data precisely define the timing and magnitude of carbon uptake, further work modelling population dynamics, land-use change and carbon cycle changes during the New World Pandemics is warranted.’\nMore importantly, this claim seems to ignore the CO2, 13CO2 and COS measurements and modelling presented by Rubino et al. (Nature Geo., 2016) as evidence for a climate role in the Little Ice Age CO2 drop (~1600-1800).\nWe have added this citation to the beginning of the existing discussion on potential climatic influence at 1610 CE: ‘Alternatively, the CO decrease could be due in some part to natural carbon 2 cycle feedbacks that were triggered by a cooling in the Northern Hemisphere 5.’\nArguing that a low accumulation ice core can better record rapid atmospheric CO2 variations than a higher accumulation counterpart requires convincing demonstration that the air age distribution has been fully accounted for and that there are no artefacts in the ice core measurements- of both high and low accumulation cores. King et al. go some of the way in doing this for their Skytrain study but more is required to make their claims more robust.\nIn summary for the more detailed responses above, we have improved the reporting of how our age distributions were generated and demonstrated their accuracy, and combined with the response to Reviewer 1, have improved the error analysis on our CO data, to report variability in the records 2 more realistically.\nGiven the importance of ensuring that past CO2 variations are accurately reconstructed from ice cores I hope that they can make the suggested improvements. Their final statement that new very high accumulation (air age resolution) Antarctic ice cores are needed must stand as a high priority.\nWe appreciate the support of the reviewer in moving this study forward to publication. A new high-resolution core would be an exciting move forward in the field which we hope this study can help to motivate.\nOther, specific notes on the manuscript:\nLines 45, 46, 53, 55. Please say whether and how bubble close off is accounted for in these estimates, and later on in the analysis.\nWe have improved our description of firn filter modelling, as detailed above, throughout the manuscript.\nLine 56. 0-6 ppm is given in Ahn et al.\nChanged to ‘range from 0-6 ppm higher….’.\nLine 60. Is this saying that both records could have artefacts?\nThis line refers to the WAIS Divide values being elevated, and has been rephrased to more clearly relate to this: ‘the absolute mixing ratios of WAIS Divide are ~2-4 ppm higher than those of Law Dome between 750 - 1800 CE 3,4, though the exact cause of this artefact remains elusive.’\nLine 68, 77. Should also say that the other interpretation is climate-CO2 feedback.\nThis has been added: ‘...,as well as inferred climate-CO feedback’with reference to the work of 2 Rubino 2016 as mentioned by the reviewer above.\nLine 80. Prefer “interpretation” or “understanding” to accounting.\nChanged to ‘interpretation’.\nLine 94. More information on Skytrain relevant to ice core CO2 would be helpful: temperature, melt events, age and uncertainty, locations, how drilled…. Either here or in Methods/Supplementary.\nSite temperature has been added to the existing details on age scale and accumulation rates given in the methods. Details of the drilling of the Skytrain ice core and the site characteristics have been previously published in reference 32, while the details of chemistry and dating in the top 2000 years of the core have been published in 33, and the gas age scale for the entire core published in 34. Each of these are referenced in the methods section alongside some overview data for each, however a sentence has been added to clarify: ‘For further detailed information on drilling, site characteristics and age scale generation please see references 32,33,34.’\nLine 100. The first part of the CO2 decrease actually looks comparable to Law Dome.\nIn this section we give values that consider the total CO decline in each core for the entire ‘CO 2 2 drop’. It is correct that within this decline there may be very shorter, decadal-scale, periods where rates of change agree with both WAIS Divide and Law Dome. However, this is tricky to compare in a robust way due to differences in sample resolution between cores. The main focus for this manuscript is the comparison in the overall change between cores.\nLine 109. As in general comments above, regions of large variability in both Skytrain and WAIS.\nPlease see earlier detailed discussion on additional error/variability analysis.\nLine 117. Low pass filtering occurs in firn and bubble close of region.\nAdded ‘...and during bubble close off’.\nLine 119. Are all air age distributions using the same statistic?\nYes, all distributions are given at Full Width Half Maximum (FWHM). The first distribution presented in the manuscript has been changed to ‘(gas age distribution width of 8 years at Full Width Half Maximum (FWHM)’ and all others follow the style of ‘(gas age distribution width of 19 years FWHM)’.\nLine 122. For clarification: …(about 40 years) was ana actually atmospheric CO2 change recorded in Law Dome ice but smoothed away in both Skytrain and WAIS?...\nThis has been added: ‘...CE (about 40 years) was an atmospheric CO change that was recorded at 2 Law Dome…’.\nLine 128. “Firn filters” are also referred to as Greens Functions for the purpose of convolutions and forward and inverse modelling signals.\nAdded to the methods section on firn filter modelling: ‘These may also be referred to as age distributions and/or Green's Functions in similar studies.’\nLine 131, 132. The convolved minimums are much more subtle than the originals, and are actually not much different from the data, especially Skytrain, given the stated uncertainties and the additional variability.\nThe reviewer correctly highlights that it is difficult to compare the new convolved histories to the original data in the existing figure, which we believe is due to both the offsets and the faded colour of the original data in the background. If the offsets are removed, as in Figure R3D below, it becomes evident that the convolved histories are recreating much of the dip in the Law Dome spline. In the figure, we feel it better to maintain the offsets to allow close comparison to the original datasets.\nWe have therefore adapted the figure in the manuscript by making the splines of the original data bold, rather than faded, as Figure R3E below, so that a clearer comparison can be seen. We have also now included the updated spline confidence intervals on the plot, with the increased capture of variability, so that it can be observed how the convolutions are differentiated from the original records by being beyond the scope of variability in the datasets.\nFigure R3D: Convolved histories overlying original CO records, as in manuscript Figure 2, but with 2 offset adjustments removed.\nFigure R3E: Convolved histories overlying original CO records, as in manuscript Figure 2, but with 2 smoothing splines of the original CO records in bold to allow easier comparison between these and 2 the convolved histories, and with additional confidence intervals of the splines. Figure R3C has replaced Figure 2A in the manuscript.\nLine 138. Again, what is included in the firn filters?\nPlease see earlier discussion on firn filters for more detail.\nLine 150. If it is a true signal and if it is enclosed and preserved without unexpected changes…\nAdded ‘...if it is a true paleo-atmospheric signal, assuming no unexpected changes have occurred, but is this robust…’\nLine 158. Could the Skytrain CH4 data be plotted please?\nThe Skytrain continuous CH data is plotted in Figure S2, and we have updated the caption of Figure 4 3 to reference this directly: ‘For reference, the full Skytrain continuous CH record is shown in Figure 4 S2.’ The Skytrain data was continuously measured using CFA analysis, thus is presented in a smoothed spline form on the main manuscript plot for best comparability to the discrete measurements of Law Dome and WAIS and so as not to overfill the plot.\nFigure 3B. Could the CO2 data be plotted to see how well the convolutions fit?\nAs in our earlier response, we have now added a new section and figure to the supplement to improve the description of how we chose our increased smoothing functions and convolutions, which plots the CO data alongside the convolutions. This new figure allows this to be seen more 2 clearly than if we were to also plot it on Figure 3B as the latter figure is very small and becomes difficult to read with further lines plotted.\nFigure 3C. Please show Skytrain data points.\nThe Skytrain CH data is plotted in Figure S2, and we have updated the caption of Figure 3 to 4 reference this directly: ‘For reference, the full Skytrain continuous CH record is shown in Figure S2.’. 4 The Skytrain data was continuously measured using CFA analysis, thus is presented in a smoothed spline form on the main manuscript plot for best comparability to the discrete measurements of Law Dome and WAIS Divide and so as not to overfill the plot.\nFigure 4. It would be help if the ocean-atmosphere fluxes were shown or at least mentioned.\nThank you for the suggestion. We have included the ocean-atmosphere fluxes in a supplemental figure (as Figure R3E below, or therein Figure S5) along with a comparison to previously published results to show the good agreement between the OSU box model (this study) and previous work using the HILDA model (Bauska et al., 2015). This is referenced in the manuscript: ‘The ocean-atmosphere carbon flux (Figure S5) is allowed to evolve freely…’\nFigure R3F: A comparison of the land and ocean carbon fluxes predicted in this study (shaded bands) with the OSU Carbon Cycle Model and a previous study using just the WAIS Divide ice core data and the HILDA model (Bauska et al. 2015) (darker lines). All experiments are single deconvolution experiments and thus use only the atmospheric CO data (A) to predict the land-atmospheric carbon 2 flux (C). The atmospheric d13C-CO (B) and ocean-atmosphere fluxes (D) are allowed to freely evolve 2 in the model. The single deconvolutions fail to capture the d13C-CO minimum that precedes the 1610 2 drop but do capture the broader maximum within the top itself.\nBauska, T. K. et al. Links between atmospheric carbon dioxide, the land carbon reservoir and climate over the past millennium. Nat Geosci 8, (2015).\nLine 161. Given the points raised above this would be better stated as “a plausible”.\nChanged to ‘plausible’.\nLine 232. Also as stated above, there are other possible reasons for the CO2 change.\nWe have added the citation of Rubino et al. 2016 as suggested earlier: ‘Alternatively, the CO 2 decrease could be due in some part to natural carbon cycle feedbacks that were triggered by a cooling in the Northern Hemisphere 5.’\nLine 261, 262. Based on the reasons given above, this statement is possibly too confident. Suggest removing the word “strong” unless more evidence as mentioned earlier can be shown.\nWe have made all suggested revisions to show that our data and analysis is of high and reliable quality, thus we do not completely remove the wording here but do change ‘strong’ to ‘robust’.\nLine 292. What is the range/uncertainty of the CH4 blank?\nAdded: ‘An average blank correction of 8.3 ± 2.7 SD ppb…’\nSection at line 355. Please be clear about what processes are included in the firn filter modelling, especially bubble close off and how it interacts with the diffusion in the firn column. This is crucial to the resulting air age spread and the conclusions of this work.\nWe have improved our description of firn filter modelling, and indicated references to other published work reporting further detail on the model validation and the detailed parameterisation which is outside the reporting scope of this study."}, {"round": 2, "reviewer_comments": {"reviewer_1": "I'm happy with the revisions and have only one concern which is easily addressed by minor wording changes. This and a few other minor suggestions are detailed below. The concern relates to the claim that the Law Dome dip in CO2 around 1610 is incompatible with land use scenarios.\nSpecific points:\n26-29. Needs rewording because it doesn't recognize that the Law Dome dip might have had a cause other than land use. I think the valid point is that the more gradual CO2 decrease seen in Skytrain and WAIS is easily explained by CO2 uptake driven land-use following new-world old-world contact and helps valid some land-use reconstructions. In contrast, the Law Dome dip, if real, requires some unknown process.\n82. I'd expect references to the Skytrain core (32, 33) here.\n268-270. Needs rewording for the same reason as above.\n307. Needs rewording for the same reason as above.\nFigure 3. I urge that the actual Skytrain CH4 dataset be shown in Figure 3, and not just the spline. Perhaps the authors were concerned this would clutter the figure? This could be easily addressed by using a faint color for the actual data.", "reviewer_3": "Second review, “Reconciling ice core CO2 and land-use change following New World-Old World contact”\nKing, A.C.F. et al., resubmitted to Nature Communications.\nDecember 2023\nThank you to the editor of Nature Communications for the opportunity to review this resubmission and to the authors for the considered comments they have made to both reviews and their careful revisions. I think the manuscript has improved significantly.\nMy main concern remains with the quantification of the ice core air age distributions, or at least their uncertainties, and how that may impact the confidence of the conclusions. The new paragraph (line 181) says that tuning age distribution widths using CH4 records would require higher resolution CH4 data from Law Dome (the same also applies to the WAIS CH4 data which have low sampling resolution) from CFA measurements of CH4 and other gases. Indeed this is one limit of intercomparing ice core gas records. The use of independent atmospheric gas measurements is preferred for tuning air age distributions of ice core gas records (not just firn air records), as was done for Law Dome using 14CO2 and mentioned in my first review. The authors note in their rebuttal that, for the Skytrain and WAIS cores, “We note that the firn-filters - the starting point for our enhanced smoothing experiments - are not trained on data…”. Given that a main thrust of this manuscript relies on accurately quantified air age distributions I think this point should be made in the manuscript, as it is an important difference between the records. Together with the observation that WAIS, and less so Skytrain, have relatively elevated CO2 concentrations, and the variability within each of the ice core CO2 records, I think there are good reasons to reword the multiple claims about the Law Dome CO2 being (the only?) artefact data during the 1610 event (lines 24, 177, 178, 301).\nThe abstract of the revised version appears unchanged. I think it should be updated to include some of the changes made to the manuscript following the points raised in the reviews. In particular, saying that the sudden 1610 CE decrease is most likely an artefact, seems too strong given the potential uncertainties in all of the ice core records discussed in the manuscript. Also, the decrease at 1610 being too rapid to be explained by land use change should be accompanied by the point in the review that a climate influence on terrestrial carbon is also compatible with lower CO2 as well as the previously published evidence of 13CO2, COS and CH4 changes. This last point is important because much of the focus on the 1610 CO2 minimum of this manuscript and some of the publications it cites is on the event being ascribed to an anthropogenic cause and a potential marker of the Anthropocene (the Orbis spike), whereas a climatic cause is also possible."}, "author_response": "REVIEWERS' COMMENTS\nReviewer #1 (Remarks to the Author):\nI'm happy with the revisions and have only one concern which is easily addressed by minor wording changes. This and a few other minor suggestions are detailed below. The concern relates to the claim that the Law Dome dip in CO2 around 1610 is incompatible with land use scenarios.\nSpecific points:\n26-29. Needs rewording because it doesn't recognize that the Law Dome dip might have had a cause other than land use. I think the valid point is that the more gradual CO2 decrease seen in Skytrain and WAIS is easily explained by CO2 uptake driven land-use following new-world old-world contact and helps valid some land-use reconstructions. In contrast, the Law Dome dip, if real, requires some unknown process.\nWe have reworded this to: ‘This challenges previous work which, based on the longer-term carbon balance over the last millennium, suggested the “high-end” scenarios were implausible, as well as recent work which revised downward the per-capita land use in the Americas. In contrast, the Law Dome dip, if real, requires some unknown process outside the land-use scenarios that are the focus of this study. Our focus in this study has been to reconcile the land use change scenarios to ice core data, because the land use scenarios have been presented and debated in a number of studies, whereas the Law Dome dip has been previously highlighted as a marker for defining the Anthropocene. In our concluding remarks, we also discuss the potential for natural carbon cycle feedbacks that were triggered by a cooling in the Northern Hemisphere. In the case of the 1610 CE CO2 minimum this would require a sudden cooling and similarly rapid warming…’. \nTo expand this further in response to the reviewer requests, we have added:\n‘Whether the CO2 decrease resulted from natural or anthropogenic processes, it is possible that large-scale land abandonment, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. Whether the CO2 decrease resulted from natural or anthropogenic processes, it is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a gradual uptake of carbon on land and no exceptional carbon cycle feedback is required around 1610 CE. It is possible that large-scale land abandoned, in tandem with a cooling in the Northern Hemisphere, contributed to a"}]

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