rlacombe/ClimateX huggingface dataset:
Glacier and ice sheet: Section 9.5.1 and Section 2.3.2.3 found that glaciers have lost mass in all polar regions since 2000 (IPCC AR6_WGI, confidence: high)
Permafrost: Observations from recent decades (assessed in Section 9.5.2 and Section 2.3.2.5) show increases in permafrost temperature (very high confidence) and active layer thickness (IPCC AR6_WGI, confidence: medium)
Projections show increases in MHW intensity, frequency and duration will be larger over the Arctic Ocean than mid-latitude oceans due in part to low interannual variability under current sea ice (IPCC AR6_WGI, confidence: high)
Climate change has caused and will continue to induce an enhanced warming trend, increasing heat-related extremes and decreasing cold spells and frosts in the Arctic (IPCC AR6_WGI, confidence: high)
The water cycle is projected to intensify in polar regions, leading to more rainfall, higher river flood potential and more intense precipitation (IPCC AR6_WGI, confidence: high)
Projections indicate reductions in glaciers at both poles, with sea ice loss, enhanced permafrost warming, decreasing permafrost extent, and decreasing seasonal duration and extent of snow cover in the Arctic (high confidence) even as some of the coldest regions will see higher total snowfall given increased precipitation (IPCC AR6_WGI, confidence: medium)
Projections indicate relative sea level rises in polar regions (high confidence), with the exception of regions with substantial land uplift including North-Eastern North America (IPCC AR6_WGI, confidence: high)
Higher sea levels also contribute to high confidence for projected increases of Arctic coastal flooding and higher coastal erosion (aided by sea ice loss) (IPCC AR6_WGI, confidence: medium)
Marine ecoregions will experience ocean acidification and temperatures that increase faster in high latitudes (IPCC AR6_WGI, confidence: high)
Longer dry seasons also extend the seasonal length and geographical extent of fire weather in all future scenarios (IPCC AR6_WGI, confidence: medium)
Box 10.3 identified a continuing strong role of the urban heat island in amplifying heat extremes in cities, although changes in the urban heat island are an order of magnitude smaller than projected localized warming trends (IPCC AR6_WGI, confidence: very high)
Coastal cities’ proximity to the sea somewhat mitigates the effect of urban heat islands (IPCC AR6_WGI, confidence: high)
Such threshold exceedances are projected to increase for many coastal areas (IPCC AR6_WGI, confidence: high)
Climate change-related variations in oceanic drivers (e.g., relative sea level, storm surge, ocean waves), combined with tropical cyclones, extreme precipitation and river flooding, are expected to lead to more frequent and more intense coastal flooding and erosion (IPCC AR6_WGI, confidence: very high)
Compound flooding due to simultaneous storm surges and high river flows have been found to be increasingly frequent in several cities and/or low- lying areas in Europe and the USA (IPCC AR6_WGI, confidence: high)
Chapter 11 found that the frequency of such compound flood events is projected to increase (IPCC AR6_WGI, confidence: high)
These include increases in extreme heat, pluvial floods, coastal erosion and coastal flood (IPCC AR6_WGI, confidence: high)
Increasing relative sea level, compounding with increasing tropical cyclone storm surge and rainfall intensity, will increase the probability of coastal city flooding (IPCC AR6_WGI, confidence: high)
In general, droughts have increased in several arid and semi-arid areas over the last decades (IPCC AR6_WGI, confidence: medium)
Dust loadings are expected to decrease over most of the Sahara and Sahel (low confidence) (Section 12.4.1), increase over Mexico and the south-west USA (IPCC AR6_WGI, confidence: medium)
These included an observed general decline in low-elevation snow cover, glaciers and permafrost (high confidence), which induced changes in natural hazards such as decrease in slope stability (IPCC AR6_WGI, confidence: high)
Warming is also affecting mountain lake surface temperatures, increasing probabilities of ice-free winters and the frequency and duration of ‘lake heatwaves’ (IPCC AR6_WGI, confidence: high)
Elevation-dependent warming could speed up the observed, rapid upward shifts of the freezing level height (FLH) in several mountainous regions of the world and lead to faster changes in the snowline, the glacier equilibrium-line altitude and the snow/rain transition height (IPCC AR6_WGI, confidence: high)
These events are projected to increase in major mountainous regions (Alps, parts of the Andes, British Columbia, North- Western North America, Calabria, Carpathian, Hindu-Kush-Himalaya, Rocky Mountains, Umbria; medium to high confidence depending on location), with potential cascading consequences of floods, landslides and lake outbursts in mountainous areas in all scenarios (IPCC AR6_WGI, confidence: medium)
Declines in low-elevation snow depth and seasonal extent are projected for all SSP-RCPs (see Sections 12.4.1–12.4.6), along with reductions in mountain glacier surface area, increases in permafrost temperature, decreases in permafrost thickness, changes in lake and river ice, changes in the amount and seasonality of streamflows and hydrologic droughts in snow-dominated and glacier-fed river basins (e.g., in Central Asia; Sorg et al., 2014; Reyer et al., 2017b) (IPCC AR6_WGI, confidence: medium)
Glacier recession could lead to the creation of new glacial lakes in places like the Himalaya-Karakoram region (Linsbauer et al., 2016) and in Alaska and Canada (Carrivick and Tweed, 2016; Harrison et al., 2018) (IPCC AR6_WGI, confidence: medium)
With increasing temperature and precipitation these can increase the occurrence of glacier lake outburst floods and landslides over moraine-dammed lakes (IPCC AR6_WGI, confidence: high)
In conclusion, mountains face complex challenges from specific climatic impact-drivers drastically influenced by climate change: regional elevation-dependent warming (high confidence), low-to-mid-altitude snow cover and snow-season decrease even as some high elevations see more snow (high confidence), glacier mass reduction and permafrost thawing (high confidence), and increases in extreme precipitation and floods in most parts of major mountain ranges (IPCC AR6_WGI, confidence: medium)
The SRCCL assessed an enhanced risk and severity of wildfires in tropical rainforests (IPCC AR6_WGI, confidence: high)
In conclusion, most tropical forests are challenged by a mix of emerging warming trends that are particularly large in comparison to historical variability (IPCC AR6_WGI, confidence: medium)
Water cycle changes bring prolonged drought, longer dry seasons, and increased fire weather to many tropical forests, with plants also responding to CO 2 increases (IPCC AR6_WGI, confidence: medium)
All regions will experience, before 2050, increased warming, an increase of extreme heat and a decrease in cold spells, regardless of the emissions trajectory (IPCC AR6_WGI, confidence: high)
Several global-scale studies have shown that high temperature extremes will increase everywhere (IPCC AR6_WGI, confidence: high)
Increases in temperatures will result in reductions in heating degree days (Arnell et al., 2019; Coppola et al., 2021b) and a widespread reduced frequency of cold extremes (IPCC AR6_WGI, confidence: high)
One cluster of regions – East Southern and West Southern Africa regions, the Mediterranean, Northern Central America, Western North America, several regions in South America and Australia – will experience, in addition to the aforementioned globally changing CIDs, increases in either drought/ aridity or fire weather (IPCC AR6_WGI, confidence: high)
A second cluster of regions including mountainous areas or regions with seasonal snow cover will experience (in addition to increases in heat extremes, more intense short-duration rainfall, and increases in coastal hazards where coasts exist) reductions in snow and ice cover and/or increases in river flooding in many cases (Western, North- Western, Central and Eastern North America, Arctic regions, Andes regions, Europe, Siberia, Central and East Asia, Southern Australia and New Zealand) (IPCC AR6_WGI, confidence: high)
For instance, emergence is reached by 2050 under RCP8.5 in most areas of Europe, Australia or East Asia, but it does not occur within the 21st century under RCP2.6 (IPCC AR6_WGI, confidence: medium)
However, even under RCP2.6, mean temperatures in tropical regions that have not already emerged are projected to emerge before 2050 (IPCC AR6_WGI, confidence: medium)
Extreme heat and cold: An increase in heat extremes has emerged or will emerge in the coming three decades in most land regions (IPCC AR6_WGI, confidence: high)
In other regions emergence is projected at the latest in the first half of the 21st century under RCP8.5 (IPCC AR6_WGI, confidence: high)
Relative to the end of 20th-century conditions, changes in humid heat stress as characterized by wet bulb temperature, indicates a ToE as early as in the first two decades of the 21st century in RCP8.5 at least in many tropical regions (most of Africa in the band 20°S–20°N, South Asia and South East Asia) (IPCC AR6_WGI, confidence: medium)
Mean precipitation: Mean precipitation changes only emerged over a few regions in the historical period (increase in Northern and Eastern Europe and decrease in West Africa and Amazonia) from observations with an S/N ratio larger than one (IPCC AR6_WGI, confidence: low)
The emergence of increasing precipitation before the middle of the 21st century is found across scenarios in Siberian regions, Russian Far East, Northern Europe, Arctic regions and the northernmost parts of North America (IPCC AR6_WGI, confidence: high)
In climate projections, the emergence of increase in heavy precipitation strongly depends on the scale of aggregation (Kirchmeier-Young et al., 2019), with, in general, no emergence before a 1.5°C or 2°C warming level, and before the middle of the century (IPCC AR6_WGI, confidence: medium)
Emergent increases in heavy precipitation are found in several regions when aggregated at a regional scale in Northern Europe, Northern Asia and East Asia, at latest by the end of the century in SRES A1B or RCP8.5 scenarios or when considering the decadal variability as a reference (IPCC AR6_WGI, confidence: medium)
Even though significant drought trends are observed in several regions with at least medium confidence (Sections 11.6 and 12.4), agricultural and ecological drought indices have interannual variability that dominates trends, as can be seen from their time series (IPCC AR6_WGI, confidence: medium)
The snow cover duration period is projected to emerge over large parts of Eastern and Western North America and Europe by the mid-century both in spring and autumn, and emergence is expected in the second half of the 21st century in the Arctic regions in the high RCP8.5 scenario (IPCC AR6_WGI, confidence: medium)
Sea ice: Sea ice area decrease in the Arctic in all seasons has already emerged from the interannual variability (IPCC AR6_WGI, confidence: high)
Relative sea level, coastal flood and coastal erosion: Near- coast RSLR will emerge before 2050 for RCP4.5 along the coasts of all AR6 regions (with coasts) except East Asia, the Russian Far East, Madagascar, the southern part of Eastern North America and the Antarctic regions (IPCC AR6_WGI, confidence: medium)
Under RCP8.5, emergence of near-coast RSLR is projected by mid-century along the coasts of all AR6 regions (with coasts), except WAN where emergence is projected to occur before 2100 (Section 9.6.1.4; Lyu et al., 2014) (IPCC AR6_WGI, confidence: medium)
Heat and cold CIDs (excluding frost) that have not already emerged will emerge by 2050 whatever the scenario in almost all land regions (IPCC AR6_WGI, confidence: medium)
The emergence of increasing precipitation before the middle of the century is also projected in Siberian regions, Russian Far East, Northern Europe and the northernmost parts of North America and Arctic regions across scenarios with the various methods and emergence definitions used (IPCC AR6_WGI, confidence: high)
In all ocean basins, the signal of ocean acidification in the surface ocean is projected to emerge before 2050 (IPCC AR6_WGI, confidence: high)
Regional-to-continental scale trends generally consistent with global-scale trends (IPCC AR6_WGI, confidence: high)
Extreme Precipitation EventsAll RKRs; RFC2, RFC3Frequency and intensity of heavy precipitation events increased at the global scale over a majority of land regions with good observational coverage (IPCC AR6_WGI, confidence: high)
Larger percentage increases in heavy precipitation observed in the northern high latitudes in all seasons, and in the mid-latitudes in the cold season (IPCC AR6_WGI, confidence: high)
Regional increases in the frequency and/or intensity of heavy rainfall also observed in most parts of Asia, north-west Australia, northern Europe, South-Eastern South America, and most of the USA (high confidence), and West and Southern Africa, Central Europe, the eastern Mediterranean region, Mexico, and North-Western South America (IPCC AR6_WGI, confidence: medium)
Increase in frequency of heavy precipitation events accelerates with warming, higher for rarer events (IPCC AR6_WGI, confidence: high)
DroughtAll RKRs; RFC2, RFC3Increased atmospheric evaporative demand in dry seasons over a majority of land areas due to human-induced climate change (IPCC AR6_WGI, confidence: medium)
Especially observed in dry summer climates in Europe, North America and Africa (high confidence).Upward trend with GSAT (IPCC AR6_WGI, confidence: high)
Increase in the frequency and magnitude of pluvial floods (IPCC AR6_WGI, confidence: high)
Increasing flood potential in urban areas where heavy precipitation projected to increase, especially at high GWLs (IPCC AR6_WGI, confidence: high)
Tropical Cyclones (TCs)All RKRs; RFC2, RFC3Human contribution to extreme rainfall amount from specific TC events (IPCC AR6_WGI, confidence: high)
Global proportion of major TC intensities likely increased over the past four decades.Increase in precipitation from TC with GSAT; average peak TC wind speeds, proportion of intense TCs, and peak wind speeds of most intense TCs increase globally with GSAT (IPCC AR6_WGI, confidence: high)
Decrease or lack of change in global frequency of TCs (all categories) with GSAT (IPCC AR6_WGI, confidence: medium)
Spatial heterogeneity with larger changes in the tropical oceans and Arctic Ocean (IPCC AR6_WGI, confidence: medium)
Increasing trend in more frequent concurrent heatwaves and droughts with GSAT (IPCC AR6_WGI, confidence: high)
More frequent concurrent (in time) extreme events at different locations with increasing GSAT, for GWLs > 2°C (IPCC AR6_WGI, confidence: high)
Compound flooding risk (storm surge, extreme rainfall and/or river flow) increasing with GSAT (IPCC AR6_WGI, confidence: high)
Trends Fire Weather TrendsRKR-B, C; RFC1,2,3Weather conditions that promote wildfire (compound hot, dry and windy events) more probable in some regions over the last century (IPCC AR6_WGI, confidence: medium)
Patterns of Mean WarmingRKR-B, D, F, RFC1,3,4Spatial patterns of temperature changes associated with the 0.5°C difference in GMST warming between 1991–2010 and 1960–1970 consistent with projected changes under 1.5°C and 2°C of global warming.Temperatures scale approximately linearly with GSAT, largely independently of scenario (IPCC AR6_WGI, confidence: high)
Antarctic polar amplification smaller than Arctic (IPCC AR6_WGI, confidence: high)
In the Southern Hemisphere relatively high rates of warming in subtropical continental areas of South America, Southern Africa and Australia (IPCC AR6_WGI, confidence: high)
Arctic Warming TrendsRKR-A,C,G,H; RFC1, RFC3 Emerged already from internal variability.Very likely more pronounced (2–2.4 times faster) than the global average over the 21st century (IPCC AR6_WGI, confidence: high)
Patterns of Precipitation ChangeRKR-B, D, F, RFC1, RFC3Regional patterns of recent trends, over at least the past three decades, consistent with documented increase in precipitation over tropical wet regions and decrease over dry areas.Changes in large-scale atmospheric circulation and precipitation with each 0.5°C of warming (IPCC AR6_WGI, confidence: high)
Some departures from linearity possible at regional scale (IPCC AR6_WGI, confidence: medium)
Precipitation increases in large parts of the monsoon regions, tropics and high latitudes, decreases in the Mediterranean and large parts of the subtropics (IPCC AR6_WGI, confidence: high)
Ocean Acidification/ pHRKR-A,B; RFC1, RFC4Virtually certain decline of surface pH globally over the last 40 years at a rate of 0.017–0.027 pH units per decade; decline also in the subsurface over the past 2–3 decades (IPCC AR6_WGI, confidence: medium)
Surface pH now the lowest of at least the last 26,000 years (very high confidence).Increase of net ocean carbon flux throughout the century irrespective of the emissions scenario considered (IPCC AR6_WGI, confidence: high)
Decrease of ocean surface pH through the 21st century, except for SSP1-1.9 and SSP1-2.6 where values increase slightly starting from 2070–2100 (IPCC AR6_WGI, confidence: high)
No clear evidence shifts in ENSO or associated features or its teleconnections.No change in the amplitude of ENSO variability (medium confidence); enhanced ENSO-related variability of precipitation under SSP2-4.5 and higher (IPCC AR6_WGI, confidence: high)
Sea Ice LossRKR-A, B, H; RFC1,3,5Arctic sea ice area decreased for all months since 1970s; strongest decrease in summer (IPCC AR6_WGI, confidence: very high)
Arctic sea ice younger, thinner and faster moving (IPCC AR6_WGI, confidence: very high)
Current pan-Arctic sea ice levels unprecedented since 1850 (IPCC AR6_WGI, confidence: high)
Antarctic sea ice area experienced little net change since 1979 (IPCC AR6_WGI, confidence: high)
The Arctic Ocean will likely become sea ice-free in September before 2050 in all considered SSP scenarios; such disappearance including several months in most years at 3°C–5°C (IPCC AR6_WGI, confidence: high)
Permafrost ThawRKR-A,C; RFC3,5Increases in permafrost temperatures in the upper 30 m over the past three to four decades throughout the permafrost regions (IPCC AR6_WGI, confidence: high)
Relative to 1995–2014: at 1.5°C and 2°C decreasing by less than 40% (medium confidence), at 2°C and 3°C by less than 75% (medium confidence), at 3°C and 5°C by more than 60% loss (IPCC AR6_WGI, confidence: medium)
Sea Level ChangeRKR-A,C,D,E,F, G,H; RFC1,3,4Gobal mean sea level (GMSL) is rising at an accelerated rate since the 19th century (IPCC AR6_WGI, confidence: high)
GMSL increase over the 20th century faster than over any preceding century in at least the last three millennia (IPCC AR6_WGI, confidence: high)
By 2100, likely GMSL rise with respect to 1995–2014 of 0.51 (0.40–0.69) m, 0.62 (0.50–0.81) m and 0.70 (0.58–0.91) m for, respectively, GWLs of 2.0°C, 3.0°C, and 4.0°C (IPCC AR6_WGI, confidence: medium)
Spring Snow Cover has seen substantial reductions in spring snow cover extent in the Northern Hemisphere since 1978 (IPCC AR6_WGI, confidence: very high)
Since 1981, general decline in NH spring snow water equivalent (IPCC AR6_WGI, confidence: high)
Relative to 1995–2014: at 1.5°C–2°C NH spring snow cover extent likely decreases by less than 20% (IPCC AR6_WGI, confidence: medium)
Current global glacier mass loss highly unusual over at least the last 2000 years (IPCC AR6_WGI, confidence: medium)
Increased rate of glacier mass loss over the last 3 to 4 decades (IPCC AR6_WGI, confidence: high)
For 1.5°C–2°C about 50–60% (IPCC AR6_WGI, confidence: low)
At 2°C–3°C about 40–50% (IPCC AR6_WGI, confidence: low)
At sustained 3°C–5°C 25–40% (IPCC AR6_WGI, confidence: low)
Ice Sheets RFC5Greenland Ice Sheet mass-loss rate increased substantially since the turn of the 21st century (IPCC AR6_WGI, confidence: high)
The Antarctic Ice Sheet has lost mass between 1992 and 2017 (very high confidence), with an increasing mass-loss rate over this period (medium confidence).At sustained warming levels between 1.5°C and 2°C, the ice sheets will continue to lose mass (high confidence); on time scales of multiple centuries, the Greenland and West Antarctic ice sheets will partially be lost (medium confidence); there is limited evidence that the Greenland and West Antarctic ice sheets will be lost almost completely and irreversibly over multiple millennia; at sustained warming levels between 2°C and 3°C, there is limited evidence that the Greenland and West Antarctic ice sheets will be lost almost completely and irreversibly over multiple millennia, and high confidence in increasing risk of complete loss and increasing rate of mass loss for higher warming; At sustained warming levels between 3°C and 5°C, near- complete loss of the Greenland Ice Sheet and complete loss of the West Antarctic Ice Sheet will occur irreversibly over multiple millennia (medium confidence); substantial parts or all of Wilkes Subglacial Basin in East Antarctica will be lost over multiple millennia (IPCC AR6_WGI, confidence: low)
Observed decline since the mid-2000s cannot be distinguished from internal variability (IPCC AR6_WGI, confidence: high)
Arctic Sea Ice RFC5 Abrupt change already observed.Reversible within years to decades; no tipping point or threshold beyond which loss of ice becomes irreversible (IPCC AR6_WGI, confidence: high)
Global Monsoon RFC5Has likely increased over the last 40 years (IPCC AR6_WGI, confidence: medium)
User needs and decision-making contexts are very diverse and there is no ‘one size fits all’ solution to climate services (IPCC AR6_WGI, confidence: very high)
Climate services require user engagement and can take various forms in which climate information and data are delivered or communicated to the users (IPCC AR6_WGI, confidence: very high)
Three specific examples that elaborate in more detail on specific practices and products related to those general categories are provided in Cross-Chapter Box 12.2.12.6.3 Challenges Climate services set new scientific challenges to physical climate research (IPCC AR6_WGI, confidence: high)
Climate services require a sustained engagement between scientists, service providers and users that is often hindered by limited resources for the co-design and co-production process (IPCC AR6_WGI, confidence: high)
Observed Trends and Projections in Regional Climate Most land areas have warmed faster than the global average (IPCC AR6_WGI, confidence: high)
Significant negative trends have been observed in the Horn of Africa and south-west of the state of Western Australia (high confidence), parts of the Russian Far East, some parts of the Mediterranean and of the Caribbean, south-east and north-east Brazil, and southern Africa (IPCC AR6_WGI, confidence: medium)
In many other land areas there are no significant trends in annual precipitation over the period 1960–2015 though increases in average precipitation intensity have been observed in the Sahel and South East Asia (IPCC AR6_WGI, confidence: medium)
Across each of the continents, higher warming is likely to occur in northern Africa, the central interior of southern and Western Africa; in North Asia; in Central Australia; in Amazonia; in Northern Europe and northern North America (IPCC AR6_WGI, confidence: high)
Changes in monsoons are likely to result in increased precipitation in eastern and northern China and in South Asia in summer (IPCC AR6_WGI, confidence: high)
Precipitation intensity will increase in many areas, including in some where annual mean reductions are likely (e.g., southern Africa) (IPCC AR6_WGI, confidence: high)
Snow cover has declined over Australia as has annual maximum snow mass over North America (IPCC AR6_WGI, confidence: medium)
Antarctic precipitation and surface mass balance showed a significant positive trend over the 20th century, while strong interannual variability masks any existing trend over recent decades1 (IPCC AR6_WGI, confidence: medium)
Significant warming trends are observed in other West Antarctic regions and at selected stations in East Antarctica since the 1950s (IPCC AR6_WGI, confidence: medium)