rlacombe/ClimateX huggingface dataset:
For most RKRs, potentially global and systemically pervasive risks become severe in the case of high levels of warming, combined with high exposure/vulnerability, low adaptation or both (IPCC AR6_WGII, confidence: high)
Under these conditions there would be severe and pervasive risks associated with water scarcity and water- related disasters (IPCC AR6_WGII, confidence: high)
Tropical and polar low-lying coastal human communities are experiencing severe impacts today (IPCC AR6_WGII, confidence: high)
Some systems will experience severe risks before the end of the century (medium confidence), for example critical infrastructure affected by extreme events (IPCC AR6_WGII, confidence: medium)
Food security for millions of people, particularly low-income populations, also faces significant risks with moderate to high warming or high vulnerability, with a growing challenge by 2050 in terms of providing nutritious and affordable diets (IPCC AR6_WGII, confidence: high)
Priority areas for regions are indicated by the intersection of hazards, risks and challenges, where, in the near term, challenges to SDGs indicate probable systemic vulnerabilities and issues in responding to climatic hazards (IPCC AR6_WGII, confidence: high)
Since IPCC AR5, human influence on the Earth’s climate has become unequivocal, increasingly apparent and widespread, reflected in both the growing scientific literature and in the perception and experiences of people worldwide (IPCC AR6_WGII, confidence: high)
The total risk in any location may thus differ from the sum of individual risks if these interactions, as well as risks from responses themselves, are not considered (IPCC AR6_WGII, confidence: high)
Many recent impacts are not detected, due to a shortage of monitoring and robust attribution analysis (IPCC AR6_WGII, confidence: high)
Since AR5, a growing literature provides initial inventories of adaptation plans and implementation worldwide, but information on effectiveness remains scare (IPCC AR6_WGII, confidence: high)
Adaptation is urgent to the extent that soft adaptation limits are currently being approached or exceeded and that achieving levels of adaptation adequate to address these soft limits requires action at a speed and scale faster than that represented by current trends (IPCC AR6_WGII, confidence: high)
As described in this report, however, current climate policies and actions alone are not sufficient to meet stated policy goals (Section 1.1.3) (IPCC AR6_WGII, confidence: high)
While understanding regarding the extent of adaptation gaps remains limited, the available evidence suggests significant adaptation gaps exist (IPCC AR6_WGII, confidence: high)
The other half of the 10-year difference arises because, for central estimates of climate sensitivity, most scenarios show stronger warming over the near term than was assessed as ‘current’ in SR1.5 (IPCC AR6_WGII, confidence: medium)
However, uncertainties in regional climate responses at a given GWL are large (Cross-Chapter Box CLIMATE in Chapter 1, Table CLIMATE.3a) and natural climate variability occurs in parallel with ongoing warming, so the potential for impacts higher than central estimates could be a more urgent consideration for risk assessments and adaptation planning than the earlier projected timing of reaching 1.5°C (IPCC AR6_WGII, confidence: high)
Climate has always changed, often with severe effects on nature, including species loss Observations provided by the historical, archaeological, and palaeontological records, together with paleoclimatic data, demonstrate that climatic variability has high potential to affect biodiversity and human society (IPCC AR6_WGII, confidence: high)
The evolution of the Earth’s biota has been punctuated by global biodiversity crises often triggered by rapid warming (IPCC AR6_WGII, confidence: high)
Mass extinctions, each with greater than 70% marine species extinctions, occurred when the magnitude of temperature change exceeded 5.2°C (Song et al., 2021), albeit species extinctions occurred at lower magnitudes of warming (IPCC AR6_WGII, confidence: medium)
Responses of biota to rapid climate change have included range shifts (very high confidence), phenotypic plasticity (high confidence), evolutionary adaptation (medium confidence), and species extinctions, including mass extinctions (IPCC AR6_WGII, confidence: very high)
While knowledge about the relative roles of these processes in promoting survival during times of climate change is still limited (Nogués-Bravo et al., 2018), they have influenced the evolutionary trajectories of species and entire ecosystems (high confidence), and also the course of human history (IPCC AR6_WGII, confidence: medium)
Temperature and deoxygenation were key drivers of past biotic responses in the oceans (Gibbs et al., 2016; Penn et al., 2018; Section 3.3) (high confidence), whereas on land the interplay between temperature and precipitation is less well established in ancient hyperthermals (Frank et al., 2021) (IPCC AR6_WGII, confidence: medium)
Marine invertebrates and fishes are at greater extinction risk in response to warming than terrestrial ones because of reduced availability of thermal refugia in the sea (Pinsky et al., 2019) (IPCC AR6_WGII, confidence: high)
Terrestrial plants showed reduced extinction during past rapid warming compared to animals (IPCC AR6_WGII, confidence: high)
Population range shifts including migrations are common adaptations to climate changes across multiple time scales and ecological systems in the past and in response to current warming (IPCC AR6_WGII, confidence: high)
During warming periods, diversity loss was common near the equator (IPCC AR6_WGII, confidence: medium)
This variability may have favoured key hominin adaptations such as bipedality, increased brain size, complex sociality, and more diverse tools (Potts, 1998; Potts et al., 2020) (medium confidence), but extinctions of five species of Homo have also been attributed partly to climate change (Raia et al., 2020) (IPCC AR6_WGII, confidence: low)
Most late Pleistocene megafaunal extinctions are attributed to direct and indirect human impacts (Sandom et al., 2014), although some were likely accelerated by climate change (Wan and Zhang, 2017; Westaway et al., 2017; Carotenuto et al., 2018; Saltré et al., 2019) (IPCC AR6_WGII, confidence: low)
Variability in resource availability and agricultural production, entrained by climatic variability, is implicated in the disruption and decline of numerous past human societies (IPCC AR6_WGII, confidence: medium)
This will overturn the long-lasting stability of interactions between humans and domesticated plants and animals as well as challenge the habitability for humans in several world regions (Horton et al., 2021) (IPCC AR6_WGII, confidence: medium)
Medium confidenc e In many regions, changing preciptiation or melting snow and ice are altering hydrological systems, affecting water resources in terms of quantity and quality (IPCC AR6_WGII, confidence: medium)
Articulating the goals of adaptation at the international, national and local levels thus requires engaging with the concepts of equity, justice and effectiveness (IPCC AR6_WGII, confidence: high)
Without recognition, actors may not benefit from the two other aspects of justice (IPCC AR6_WGII, confidence: medium)
Soft limits are usually associated with human systems whereas hard limits are more proximate for natural systems due to inability to adapt to biophysical changes (Chapter 16) (IPCC AR6_WGII, confidence: medium)
Technology-led, market-led or state-led transitions aimed at meeting Paris Agreement and SDGs may fail without integrating dimensions of social justice and addressing the social and political exclusion that prevent the disadvantaged from accessing such improvements and increasing their incomes (Burkett et al., 2014; Scoones et al., 2015) (IPCC AR6_WGII, confidence: medium)
However, incremental strategies can fail to move fast enough, can succumb to path-dependency that locks in initially helpful but long-term adverse responses (such as the well-known levee effect) (Sadoff 2015; Haasnoot 2019) or can result in a transition that meets some goals (e.g., environmental) but not others (e.g., equity) (IPCC AR6_WGII, confidence: high)
A focus on single or overly aggregated measures (Section 1.4.1.2) and single scenarios can privilege some actors’ views over others, reduce transparency and make it more difficult to identify resilient and equitable solutions to complex, deeply uncertain, non-linear and contested problems (Schoen and and Rein, 1994; Renn, 2008; Jones et al., 2014; Lempert and Turner, 2020) (IPCC AR6_WGII, confidence: medium)
The norms, institutions and power relationships that mediate such choices determine the extent to which the process unfolds consistent with principles of equity and social justice (IPCC AR6_WGII, confidence: high)
The most severe impacts are occurring in the most vulnerable species and ecosystems, characterised by inherent physiological, ecological or behavioural traits that limit their abilities to adapt, as well as those most exposed to climatic hazards (IPCC AR6_WGII, confidence: high)
Where attribution was assessed (>4,000 species globally), approximately half of the species had shifted their ranges to higher latitudes or elevations and two-thirds of spring phenological events had advanced, driven by regional climate changes (IPCC AR6_WGII, confidence: very high)
Shifts in species ranges are altering community make-up, with exotic species exhibiting a greater ability to adapt to climate change than natives, especially in more northern latitudes, potentially leading to new invasive species (IPCC AR6_WGII, confidence: medium)
New analyses demonstrate that prior reports underestimated impacts due to the complexity of biological responses to climate change (IPCC AR6_WGII, confidence: high)
Changes in flow have led to reduced connectivity in rivers (IPCC AR6_WGII, confidence: high)
Indirect changes include alterations in river morphology, substrate composition, oxygen concentrations and thermal regime in lakes (IPCC AR6_WGII, confidence: very high)
Warming and browning (increase in organic matter) have occurred in boreal freshwaters, with both positive and negative repercussions on water temperature profiles (lower vs. upper water) (high confidence) and primary productivity (medium confidence) as well as reduced water quality (IPCC AR6_WGII, confidence: high)
Climate change has increased wildlife diseases (IPCC AR6_WGII, confidence: high)
Many vector-borne diseases and those caused by ticks, helminth worms and the chytrid fungus (Batrachochytrium dendrobatidis, Bd) have shifted polewards and upwards and are emerging in new regions (IPCC AR6_WGII, confidence: high)
Local population extinctions caused by climate change have been widespread among plants and animals, detected in 47% of 976 species examined and associated with increases in the hottest yearly temperatures (IPCC AR6_WGII, confidence: very high)
The white sub-species of the lemuroid ringtail possum (Hemibelideus lemuroides) in Queensland, Australia, disappeared after heat waves in 2005 (IPCC AR6_WGII, confidence: high)
The Bramble Cay melomys (BC melomys, Melomys rubicola) was not seen after 2009 and was declared extinct in 2016, with sea-level rise (SLR) and increased storm surge associated with climate change being the most probable drivers (IPCC AR6_WGII, confidence: high)
Additionally, the interaction of climate change and chytrid fungus (Bd) has driven many of the observed global declines in amphibian populations and the extinction of many species (IPCC AR6_WGII, confidence: high)
A growing number of studies have documented genetic evolution within populations in response to recent climate change (IPCC AR6_WGII, confidence: very high)
To date, genetic changes remain within the limits of known variation for species (IPCC AR6_WGII, confidence: high)
Controlled selection experiments and field observations indicate that evolution would not prevent a species becoming extinct if its climate space disappears globally (IPCC AR6_WGII, confidence: high)
Climate hazards outside of those to which species have adapted are occurring on all continents (IPCC AR6_WGII, confidence: high)
More frequent and intense extreme events, superimposed on longer-term climate trends, have pushed sensitive species and ecosystems towards tipping points that are beyond the ecological and evolutionary capacity to adapt, causing abrupt and possibly irreversible changes (IPCC AR6_WGII, confidence: medium)
New studies are documenting the changes that were projected in prior IPCC reports have now been observed, including upward shifts in the forest/alpine tundra ecotone, northward shifts in the deciduous/boreal forest ecotones, increased woody vegetation in the sub-Arctic tundra and shifts in the thermal habitat in lakes (IPCC AR6_WGII, confidence: high)
A combination of changes in grazing, browsing, fire, climate and atmospheric CO 2 is leading to observed woody encroachment into grasslands and savannah, consistent with projections from process-based models driven by precipitation, atmospheric CO 2 and wildfires (IPCC AR6_WGII, confidence: high)
Observed changes impact the structure, functioning and resilience of ecosystems as well as ecosystem services, such as climate regulation (IPCC AR6_WGII, confidence: high)
Regional increases in the area burned by wildfire (up to double natural levels), tree mortality of up to 20%, and biome shifts of up to 20 km latitudinally and 300 m up-slope have been at- tributed to anthropogenic climate change in tropical, temper -ate and boreal ecosystems around the world (IPCC AR6_WGII, confidence: high)
This degrades the survival of vegetation, habitat for biodiversity, water supplies, carbon sequestration, and other key aspects of the integrity of ecosystems and their ability to provide services for people (IPCC AR6_WGII, confidence: high)
Field evidence shows that anthropogenic climate change increased area burned by wildfire above natural levels in western North America in the period 1984–2017: a doubling above natural for the western USA and 11 times higher than natural in one extreme year in British Columbia (IPCC AR6_WGII, confidence: high)
Wildfires generate up to one-third of ecosystem carbon emissions globally, a feedback that exacerbates climate change (IPCC AR6_WGII, confidence: high)
Increase in wildfire from the levels to which ecosystems are adapted degrades vegetation, habitat for biodiversity, water supplies and other key aspects of the integrity of ecosystems and their ability to provide services for people (IPCC AR6_WGII, confidence: high)
It has also potentially contributed to over 100 other cases of drought-induced tree mortality across Africa, Asia, Australia, Europe, and North and South America (IPCC AR6_WGII, confidence: high)
Field observations have documented post-mortality vegetation shifts (IPCC AR6_WGII, confidence: high)
Increases in forest insect pests driven by climate change have contributed to tree mortality and shifts in carbon dynamics in many temperate and boreal forest areas (IPCC AR6_WGII, confidence: very high)
The direction of changes in carbon balance and wildfires following insect outbreaks depends on the local forest insect communities (IPCC AR6_WGII, confidence: medium)
Intact tropical rainforests, Arctic permafrost, peatlands and other healthy high-carbon ecosystems provide a vital global ecosystem service of preventing the release of stored carbon (IPCC AR6_WGII, confidence: high)
Terrestrial ecosystems contain stocks of ~3500 GtC in vegetation, permafrost, and soils, three to five times the amount of carbon in unextracted fossil fuels (high confidence) and >4 times the carbon currently in the atmosphere (IPCC AR6_WGII, confidence: high)
Deforestation, draining, burning or drying of peatlands, and thawing of Arctic permafrost, due to climate change, has already shifted some areas of these ecosystems from carbon sinks to carbon sources (IPCC AR6_WGII, confidence: high)
The median values for percentage of species at very high risk of extinction (categorized as “critically endangered” by IUCN Red List categories)(IUCN, 2001) are 9% at 1.5°C rise in GSAT, 10% at 2°C, 12% at 3.0°C, 13% at 4°C and 15% at 5°C (IPCC AR6_WGII, confidence: high)
All groups fare substantially better at lower warming of 2°C, with extinction projections reducing to <3% for all groups, except salamanders that reduced to 7% (IPCC AR6_WGII, confidence: medium)
As species become rare, their role in the functioning of the ecosystem diminishes (IPCC AR6_WGII, confidence: high)
Loss of species locally reduces the ability of an ecosystem to provide services and lowers its resilience to climate change (IPCC AR6_WGII, confidence: high)
At 1.58°C GSAT warming, >10% of species are projected to become endangered (median estimate, with “endangered” equating to a high risk of extinction, sensu IUCN), and at 2.07°C this rises to >20% of species, representing a high and very high risk of biodiversity loss, respectively (IPCC AR6_WGII, confidence: medium)
Biodiversity loss is projected for more regions with increasing warming, and will be worst in northern South America, southern Africa, most of Australia and at northern high latitudes (IPCC AR6_WGII, confidence: medium)
Climate change increases risks of biome shifts on up to 35% of global land at ≥4°C GSAT warming, that emission reductions could limit to <15% for <2°C warming (IPCC AR6_WGII, confidence: medium)
Under high-warming scenarios, models indicate shifts of extensive parts of the Amazon rainforest to drier and lower- biomass vegetation (medium confidence), poleward shifts of boreal forest into treeless tundra across the Arctic, and upslope shifts of montane forests into alpine grassland (IPCC AR6_WGII, confidence: high)
Area at high risk of biome shifts from changes in climate and land use combined can double or triple compared to climate change alone (IPCC AR6_WGII, confidence: medium)
Novel ecosystems, with no historical analogue, are expected to become increasingly common in the future (IPCC AR6_WGII, confidence: medium)
With 4°C GSAT warming by 2100, wildfire frequency is projected to have a net increase of ~30% (IPCC AR6_WGII, confidence: medium)
For ecosystems with an historically low frequency of fires, a projected 4°C global temperature rise increases the risk of fires, with potential increases in tree mortality and the conversion of extensive parts of the Amazon rainforest to drier and lower-biomass vegetation (IPCC AR6_WGII, confidence: medium)
This includes minimising additional stresses or disturbances; reducing fragmentation; increasing natural habitat extent, connectivity and heterogeneity; maintaining taxonomic, phylogenetic, and functional diversity and redundancy; and protecting small-scale refugia where micro-climate conditions can allow species to persist (IPCC AR6_WGII, confidence: high)
There is also new evidence that species can persist locally because of plasticity including changes in phenology or behavioural changes that move an individual into cooler micro-climates, and genetic adaptation may allow species to persist for longer than might be expected from local climatic changes (IPCC AR6_WGII, confidence: high)
There is no evidence to indicate that these mechanisms will prevent global extinctions of rare, very localised species already near their climatic limits or species inhabiting climate/habitat zones that are disappearing (IPCC AR6_WGII, confidence: high)
Many proposed adaptation measures have not been implemented (IPCC AR6_WGII, confidence: low)
Adaptation can reduce risks but cannot prevent all damaging impacts so is not a substitute for reductions in greenhouse gas (GHG) emissions (IPCC AR6_WGII, confidence: high)
An increasing body of evidence demonstrates that climatic risks to people including floods, drought, fire and overheating, can be lowered by a range of EbA techniques in urban and rural areas (IPCC AR6_WGII, confidence: medium)
Interdisciplinary scientific information and practical expertise, including Indigenous and local knowledge (IKLK), are essential to effectiveness (IPCC AR6_WGII, confidence: high)
There is a large risk of maladaptation where this does not happen (IPCC AR6_WGII, confidence: high)
Ecosystem services that are under threat from a combination of climate change and other anthropogenic pressures include climate change mitigation, flood risk management, food provisioning and water supply (IPCC AR6_WGII, confidence: high)
Land use and land cover change (LULCC) as well as the unsustainable exploitation of resources in terrestrial and freshwater systems continue to be major factors contributing to the loss of natural ecosystems and biodiversity (IPCC AR6_WGII, confidence: high)
Likewise, for biodiversity, invasive alien species have been identified as a major threat, especially in freshwater systems, on islands and in coastal regions (IPCC AR6_WGII, confidence: high)
Non-climatic hazards such as LUC, habitat fragmentation, pollution and invasive species have been the primary drivers of change in terrestrial and freshwater ecosystems in the past (IPCC AR6_WGII, confidence: high)
Increased temperatures and changes to rainfall and runoff patterns; greater variability in temperature, rainfall, river flow and water levels; and rising sea levels and the increased frequency of extreme events means that greater areas of the world are being exposed to climate hazards outside of those to which they are adapted (IPCC AR6_WGII, confidence: high)
Extreme events are a natural and important part of many ecosystems, and many organisms have adapted to cope with long-term and short-term climate variability within the disturbance regime experienced during their evolutionary history (IPCC AR6_WGII, confidence: high)
However, climate changes, disturbance regime changes and the magnitude and frequency of extreme events such as floods, droughts, cyclones, heat waves and fire have increased in many regions (IPCC AR6_WGII, confidence: high)
These disturbances affect ecosystem functioning, biodiversity and ecosystem services (IPCC AR6_WGII, confidence: high)
Increases in the frequency and severity of heat waves, droughts and aridity, floods, fires and extreme storms have been observed in many regions (Seneviratne et al., 2012; Ummenhofer and Meehl, 2017), and these trends are projected to continue (IPCC AR6_WGII, confidence: high)
High climate velocity (Loarie et al., 2009) is expected to be associated with distribution shifts, incomplete range filling and species extinctions (IPCC AR6_WGII, confidence: high)
It is generally assumed that the more rapid the rate of change, the greater the impact on species and ecosystems, but responses are taxonomically and geographically variable (IPCC AR6_WGII, confidence: high)
The ability to track suitable climates is substantially reduced by habitat fragmentation and human modifications of the landscape such as dams on rivers and urbanisation (IPCC AR6_WGII, confidence: high)
Many species, both terrestrial and freshwater, are not expected to be able to disperse fast enough to track suitable climates under mid- and high-emission scenarios (IPCC AR6_WGII, confidence: medium)
Rivers already under stress from human activities such as urban development and farming on floodplains are prone to reduced resilience to future extreme events (IPCC AR6_WGII, confidence: medium)
If instream habitat is strongly affected, recovery, if it occurs, takes much longer, resulting in a decline of biodiversity (IPCC AR6_WGII, confidence: medium)
In summary, extreme events (heat waves, storms and loss of ice) affect lakes in terms of water temperature, water level, light, oxygen concentrations and nutrient dynamics, which, in turn, affect primary production, fish communities and GHG emissions (IPCC AR6_WGII, confidence: high)
Droughts have a negative impact on water quality in streams and lakes by increasing water temperature, salinity, the frequency of algal blooms and contaminant concentrations, and reducing concentrations of nutrients and dissolved oxygen (IPCC AR6_WGII, confidence: medium)
For RCP8.5, warming increases to 5.4°C and duration increases dramatically to 95.5 days (IPCC AR6_WGII, confidence: medium)