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1,300 | AR6_WGI | 1,106 | 8 | Most glaciers have lost mass more rapidly since the 1960s and in an unprecedented way over the last decade, thereby contributing to increased glacier runoff, especially from larger glaciers until a maximum is reached, which tends to occur later in basins with larger glaciers and higher ice-cover fractions | high | 2 | train |
1,301 | AR6_WGI | 1,106 | 11 | AR6 assesses that NH spring snow cover has been decreasing since 1978 (very high confidence) and that this trend extends back to 1950 | high | 2 | train |
1,302 | AR6_WGI | 1,106 | 29 | In summary, a decline in the spring NH snow cover extent, snow depth and duration has been observed since the late 1960s and has been attributed to human influence | high | 2 | train |
1,303 | AR6_WGI | 1,109 | 21 | Decreasing precipitation trends in the NH during the 1950s –1980s have been attributed to anthropogenic aerosol emissions from North America and Europe | high | 2 | train |
1,304 | AR6_WGI | 1,109 | 23 | In AR6, Chapter 2 (Section 2.3.1.4.1) states that the HC has very likely widened and strengthened since at least the 1980s, mostly in the NH | medium | 1 | test |
1,305 | AR6_WGI | 1,110 | 6 | As assessed in Section 3.3.3.1, GHG increases and stratospheric ozone depletion have contributed to the expansion of the zonal mean HC in the SH since around 1980, and the expansion of the NH HC has not exceeded the range of internal variability | medium | 1 | train |
1,306 | AR6_WGI | 1,110 | 11 | GHG increases and stratospheric ozone depletion have contributed to expansion of the zonal mean HC in the SH since around 1970, while the expansion of the NH HC has not exceeded the range of internal variability | medium | 1 | train |
1,307 | AR6_WGI | 1,110 | 14 | The causes of the observed strengthening of the WC during 1980 –2014 are not well understood due to competing influences from individual external forcings and since this strengthening is outside the range of variability simulated in coupled models | medium | 1 | train |
1,308 | AR6_WGI | 1,112 | 3 | The SAsiaM strengthened during past periods of enhanced summer insolation in the NH, such as the early-to-mid Holocene warm period around 9000 to 6000 years before the present (BP) (Masson-Delmotte et al., 2013; Mohtadi et al., 2016; Braconnot et al., 2019) and weakened during cold periods | high | 2 | train |
1,309 | AR6_WGI | 1,112 | 16 | Results from climate models indicate that anthropogenic aerosol forcing has dominated the recent decrease in summer monsoon precipitation, as opposed to the expected intensification due to GHG forcing | high | 2 | train |
1,310 | AR6_WGI | 1,112 | 17 | On paleoclimate time scales, the SAsiaM strengthened in response to enhanced summer warming in the NH during the early-to-mid Holocene, while it weakened during cold intervals | high | 2 | train |
1,311 | AR6_WGI | 1,112 | 18 | These changes are tightly linked to orbital forcing and changes in high-latitude climate | medium | 1 | train |
1,312 | AR6_WGI | 1,113 | 16 | The transition towards a positive PDV phase has been one of the main drivers of the EAsiaM weakening since the 1970s | high | 2 | train |
1,313 | AR6_WGI | 1,113 | 18 | On paleoclimate time scales, enhanced summer insolation in the Northern Hemisphere (NH) intensified the WAfriM precipitation during the early-to-mid Holocene | high | 2 | train |
1,314 | AR6_WGI | 1,113 | 21 | The WAfriM experienced the wettest decade of the 20th century during the 1950s and early 1960s | high | 2 | train |
1,315 | AR6_WGI | 1,113 | 25 | Wetter conditions of the WAfriM prevailed later from the mid-to-late 1990s, although the positive trend in precipitation started since the late 1980s (see also Section 10.4.2.1) over the Sahel (high confidence) and in the Guinean coastal region | medium | 1 | train |
1,316 | AR6_WGI | 1,114 | 12 | In summary, most regions of West Africa experienced a wet period in the mid-20th century followed by a very dry period in the 1970s and 1980s that is attributed to aerosol cooling of the NH | high | 2 | train |
1,317 | AR6_WGI | 1,114 | 13 | Recent estimates provide evidence of a WAfriM recovery from the mid-to-late 1990s, with more intense extreme events partly due to the combined effects of increasing GHG and decreasing anthropogenic aerosols over Europe and North America | high | 2 | train |
1,318 | AR6_WGI | 1,114 | 17 | The NAmerM strengthened until the mid-Holocene period, in response to ice-emsheet retreat and rising summer insolation, but probably did not exceed the strength of the modern system | low | 0 | train |
1,319 | AR6_WGI | 1,115 | 1 | The intensification recorded since about the 1970s has been partly driven by GHG emissions | medium | 1 | train |
1,320 | AR6_WGI | 1,115 | 27 | Paleoclimate reconstructions and simulations suggest a weaker SAmerM during warmer epochs such as the Mid-Holocene or the 900–1100 period, and stronger monsoon during colder epochs such as the LGM or the 1400–1600 period | high | 2 | train |
1,321 | AR6_WGI | 1,117 | 23 | In summary, no robust trend in atmospheric blocking has been detected in modern reanalyses and in CMIP6 historical simulations | medium | 1 | train |
1,322 | AR6_WGI | 1,117 | 24 | The lack of trend is explained by strong internal variability and/or the competing effects of low-level Arctic amplification and upper-level tropical amplification of the equator- to-pole temperature gradient | medium | 1 | train |
1,323 | AR6_WGI | 1,120 | 22 | Since the end of the 19th century, synchronous hydroclimate changes | medium | 1 | train |
1,324 | AR6_WGI | 1,120 | 31 | Over equatorial East Africa the IOD affects the short rain season | medium | 1 | train |
1,325 | AR6_WGI | 1,121 | 1 | The strength and frequency of the MJO have increased over the past century | medium | 1 | train |
1,326 | AR6_WGI | 1,121 | 17 | In summary, multiple water cycle changes related to ENSO and IOD teleconnections have been observed across the 20th century | high | 2 | train |
1,327 | AR6_WGI | 1,121 | 18 | The MJO amplitude has increased in the second half of the 20th century partly because of anthropogenic global warming | medium | 1 | train |
1,328 | AR6_WGI | 1,122 | 4 | In summary, while the attribution of 20th century variations of the NAM/NAO is still unclear, there is a strong relationship with precipitation changes over Europe and in the Mediterranean region | high | 2 | train |
1,329 | AR6_WGI | 1,122 | 5 | SAM teleconnections are associated with changes in moisture transport and extend to South America, Australia and Antarctica | high | 2 | train |
1,330 | AR6_WGI | 1,122 | 17 | In this Report, Chapter 4 provides an updated assessment of global annual precipitation (Section 4.3.1), finding that it is very likely that annual precipitation averaged over all land regions continuously increases as global surface temperatures increase in the 21st century | high | 2 | train |
1,331 | AR6_WGI | 1,125 | 12 | In general, there will be increases in moisture transport into storm systems, monsoons and high latitudes | medium | 1 | train |
1,332 | AR6_WGI | 1,125 | 16 | The AR5 assessed that the contrast of mean precipitation amount between dry and wet regions and seasons is expected to increase over most of the globe as temperatures increase | high | 2 | test |
1,333 | AR6_WGI | 1,127 | 6 | Beyond annual or seasonal mean precipitation amounts, an implication of the parallel intensification of the global water cycle and of the increased residence time of atmospheric water vapour (Section 8.2.1) is that the distribution of daily and sub-daily precipitation intensities will experience significant changes (Pendergrass and Hartmann, 2014b; Pendergrass et al., 2015; Bador et al., 2018; Douville and John, 2021), with fewer but potentially stronger events | high | 2 | train |
1,334 | AR6_WGI | 1,129 | 8 | Daily mean precipitation intensities, including extremes, are projected to increase over most regions | high | 2 | train |
1,335 | AR6_WGI | 1,129 | 9 | The number of dry days is projected to increase over the subtropics, Amazonia, and Central America | medium | 1 | train |
1,336 | AR6_WGI | 1,131 | 5 | In summary, the annual range of precipitation, water availability and streamflow will increase with global warming over subtropical regions and the Amazon (medium confidence), especially around the Mediterranean and across southern Africa | high | 2 | train |
1,337 | AR6_WGI | 1,131 | 6 | The contrast between the wettest and driest month of the year is likely to increase by 3–5% °C–1 with global warming in most monsoon regions, in terms of precipitation, water availability (P–E) and runoff | medium | 1 | train |
1,338 | AR6_WGI | 1,132 | 7 | CMIP5 models also project an increase in evapotranspiration over most land areas | medium | 1 | train |
1,339 | AR6_WGI | 1,133 | 8 | Evapotranspiration increases in most land regions, except in areas that are projected to become moisture-limited (due to reduced precipitation and increased evaporative demand), such as the Mediterranean, South Africa, and the Amazonian basin | medium | 1 | train |
1,340 | AR6_WGI | 1,133 | 9 | The patterns of change increase in magnitude from low to high-emissions SSP scenarios | medium | 1 | train |
1,341 | AR6_WGI | 1,133 | 10 | In summary, future projections indicate that anthropogenic forcings will drive an increase in global mean evaporation over most oceanic areas (high confidence) (Figure 8.17), an increase in global atmospheric demand (virtually certain) and an increase in evapotranspiration over most land areas, with the exception of moisture-limited regions | medium | 1 | train |
1,342 | AR6_WGI | 1,135 | 14 | There is a likely increase in drought occurrence | medium | 1 | test |
1,343 | AR6_WGI | 1,135 | 18 | Consistent with the coherent nature of warming in future projections, increases in vapour pressure deficit and evaporative demand are widespread and consistent across regions, seasons, and models, increasing in magnitude in accordance with the emissions scenario | high | 2 | train |
1,344 | AR6_WGI | 1,135 | 19 | Even under a low-emissions scenario (SSP1-2.6), projections of soil moisture show significant decreases in the Mediterranean, southern Africa, and the Amazonian basin | high | 2 | train |
1,345 | AR6_WGI | 1,135 | 20 | Under mid- and high-emissions scenarios (SSP2-4.5 and SSP5-8.5), coherent declines emerge across Europe, westernmost North Africa, south- western Australia, Central America, south-western North America, and south-western South America | high | 2 | train |
1,346 | AR6_WGI | 1,135 | 27 | The percentage of land area experiencing drying is slightly lower when runoff is used as an aridity metric instead (20–30%); taking this into consideration, it is estimated that about a third of global land areas will experience at least moderate drying in response to anthropogenic emissions, even under SSP1-2.6 | medium | 1 | train |
1,347 | AR6_WGI | 1,136 | 2 | The CORDEX South Asia multi-model ensemble projections indicate an increase in the frequency and severity of droughts over central and northern India during the 21st century, under the RCP4.5 and RCP8.5 scenarios | medium | 1 | train |
1,348 | AR6_WGI | 1,138 | 1 | In general, these regions are expected to become drier both due to reduced precipitation (medium confidence) and increases in evaporative demand | high | 2 | train |
1,349 | AR6_WGI | 1,138 | 2 | These same regions are likely to experience increases in drought duration and/or severity | high | 2 | train |
1,350 | AR6_WGI | 1,138 | 3 | The magnitude of expected change scales with emissions scenarios (high confidence) but even under low-emissions trajectories, large changes in drought and aridity are expected to occur | high | 2 | train |
1,351 | AR6_WGI | 1,138 | 4 | In the Mediterranean, Central Chile, and western North America, future aridification will far exceed the magnitude of change seen over the last millennium | high | 2 | train |
1,352 | AR6_WGI | 1,138 | 6 | The SROCC noted that these declines are projected to continue almost everywhere over the 21st century (high confidence), with complete glacier loss expected in regions with only small glaciers | very high | 3 | train |
1,353 | AR6_WGI | 1,138 | 8 | The SROCC concluded that cryosphere changes had already altered the seasonal timing and volume of runoff (very high confidence), which in turn had affected water resources and agriculture | medium | 1 | train |
1,354 | AR6_WGI | 1,138 | 14 | Because of their lagged response to warming, glaciers will continue to lose mass for decades even if global temperature is stabilized | very high | 3 | train |
1,355 | AR6_WGI | 1,138 | 30 | In summary, glaciers are projected to continue to lose mass under all emissions scenarios | very high | 3 | train |
1,356 | AR6_WGI | 1,138 | 31 | Runoff from glaciers is projected to peak at different times in different places, with maximum rates of glacier mass loss in low latitude regions taking place in the next few decades in all scenarios | high | 2 | train |
1,357 | AR6_WGI | 1,138 | 32 | While runoff from small glaciers will typically decrease because of glacier mass depletion, runoff from larger glaciers will increase with increasing global warming until glacier mass is similarly depleted, after which runoff peaks and then declines and which tends to occurs later in basins with larger glaciers and higher ice-cover fractions | high | 2 | train |
1,358 | AR6_WGI | 1,138 | 33 | Glaciers in the Arctic and Antarctic will continue to lose mass through the latter half of the century and beyond | high | 2 | train |
1,359 | AR6_WGI | 1,140 | 19 | It is likely that the zonal mean of the ITCZ will narrow and strengthen in the core region with projected surface warming | high | 2 | train |
1,360 | AR6_WGI | 1,140 | 20 | Distinct regional shifts in the ITCZ will be associated with regional changes in precipitation amount and seasonality | medium | 1 | train |
1,361 | AR6_WGI | 1,141 | 4 | The Hadley cells are projected to expand polewards with global warming, most notably in the SH | high | 2 | train |
1,362 | AR6_WGI | 1,141 | 20 | Discrepancies between observed and simulated changes in SSTs in the tropics indicate that a temporary strengthening of the Walker Circulation can arise from internal variability | medium | 1 | test |
1,363 | AR6_WGI | 1,143 | 5 | Since AR5, most studies have confirmed projected increases in South Asian monsoon precipitation | high | 2 | train |
1,364 | AR6_WGI | 1,146 | 6 | Changes in seasonality (Box 8.2) are projected with a later monsoon onset (high confidence) over the Sahel and a late cessation | medium | 1 | train |
1,365 | AR6_WGI | 1,146 | 9 | In summary, post-AR5 studies and newly available CMIP6 results indicate projected rainfall increases in the eastern-central WAfriM region but decreases in the west (high confidence), with a delayed wet season | medium | 1 | train |
1,366 | AR6_WGI | 1,146 | 10 | Overall, WAfriM summer precipitation is projected to increase during the 21st century but with larger uncertainty noted under high-emissions scenarios | medium | 1 | train |
1,367 | AR6_WGI | 1,147 | 27 | There is a projected increase in rainfall variability over northern Australia, with increased intensity of rainfall during the active or ‘burst’ phase | medium | 1 | train |
1,368 | AR6_WGI | 1,147 | 31 | Section 11.7.1.5 assesses that the average tropical cyclone rain-rate is projected to increase with warming (high confidence), and peak rain rates are projected to increase at greater than the Clausius–Clapeyron scaling rate of 7% °C–1 warming in some regions due to increased low-level moisture convergence | medium | 1 | train |
1,369 | AR6_WGI | 1,150 | 16 | This is projected to increase the intensity of heavy precipitation events on the west coast of the USA and in western Europe | high | 2 | train |
1,370 | AR6_WGI | 1,151 | 6 | In summary, even though there is low confidence in how the tropical MoVs will change in the future (Sections 4.3.3.2 and 4.5.3.3), their regional hydrological consequences, in terms of precipitation, are projected to intensify | medium | 1 | train |
1,371 | AR6_WGI | 1,151 | 7 | For example, the ENSO influence on precipitation over the Indo–Pacific sector is projected to strengthen and shift eastward | medium | 1 | train |
1,372 | AR6_WGI | 1,151 | 8 | The MJO is projected to intensify in a warmer climate, with increased associated precipitation | medium | 1 | train |
1,373 | AR6_WGI | 1,151 | 16 | In summary, projected changes in the intensity, frequency and phase of extratropical MoVs (see also Sections 4.3 and 4.5) may amplify regional changes in precipitation and contribute to an increase in their intra-seasonal and interannual variability | medium | 1 | train |
1,374 | AR6_WGI | 1,151 | 17 | Regionally, there are potentially significant precipitation and atmospheric circulation changes associated with changes in extratropical dynamics | low | 0 | train |
1,375 | AR6_WGI | 1,159 | 2 | For example, internal variability will continue to play an important role in the variability of river flows over France in coming decades | medium | 1 | train |
1,376 | AR6_WGI | 1,160 | 8 | Major volcanic eruptions temporarily reduce total global and wet tropical region precipitation (high confidence) (Iles and Hegerl, 2014), can weaken or shift the ITCZ (Iles and Hegerl, 2014; Colose et al., 2016; Liu et al., 2016), and reduce summer monsoon rainfall | medium | 1 | train |
1,377 | AR6_WGI | 1,160 | 9 | Monsoon precipitation in one hemisphere can be enhanced by the remote volcanic forcing occurring in the other hemisphere | medium | 1 | train |
1,378 | AR6_WGI | 1,160 | 16 | The occurrence of volcanic eruptions in the coming century, either as single large events or clustered smaller ones, can alter the water cycle (see also Cross-Chapter Box 4.1), and regional drought events may be enhanced by co-occurring volcanic (Liu et al., 2016; Gao and Gao, 2017; Zambri et al., 2017) and GHG (e.g., Cook et al., 2018) forcing | low | 0 | train |
1,379 | AR6_WGI | 1,160 | 17 | Volcanic eruptions may also lead to widespread precipitation anomalies up to several years following an eruption through their potential influence on the El Niño Southern Oscillation | low | 0 | train |
1,380 | AR6_WGI | 1,160 | 18 | In summary, large volcanic eruptions reduce global mean precipitation, as well as precipitation in tropical wet regions | high | 2 | train |
1,381 | AR6_WGI | 1,164 | 10 | In summary, there is both numerical and process-based evidence that terrestrial water cycle changes can be non-linear at the regional scale | high | 2 | train |
1,382 | AR6_WGI | 1,164 | 11 | Non-linear regional responses of runoff, groundwater recharge and water scarcity have been documented based on both CMIP5 and CMIP6 models, and highlight the limitations of simple pattern-scaling techniques | medium | 1 | train |
1,383 | AR6_WGI | 1,164 | 12 | Water resources fed by melting glaciers are particularly exposed to such non-linearities | high | 2 | train |
1,384 | AR6_WGI | 1,166 | 12 | Observed transitions into and out of Green Sahara states are always faster than the underlying forcing, in agreement with theoretical considerations | high | 2 | train |
1,385 | AR6_WGI | 1,166 | 14 | Both paleoclimate data and modelling experiments suggest that the timing and speed of the transition was spatially heterogeneous | high | 2 | train |
1,386 | AR6_WGI | 1,166 | 17 | CMIP5 and CMIP6 models, some of which include dynamic vegetation schemes, cannot simulate the magnitude, nor the spatial extent, of greening and precipitation change associated with the last Green Sahara under standard mid-Holocene (6,000 years ago) boundary conditions | high | 2 | train |
1,387 | AR6_WGI | 1,167 | 17 | In contrast, cirrus cloud thinning, a longwave radiation technique, results in increased global precipitation as it causes enhanced radiative cooling in the troposphere | medium | 1 | train |
1,388 | AR6_WGI | 1,167 | 25 | The additional global warming caused by SRM termination may result in a rapid increase in global mean precipitation | medium | 1 | train |
1,389 | AR6_WGI | 1,230 | 8 | Since the 1950s, the fastest surface warming has occurred in the Indian Ocean and in western boundary currents, while ocean circulation has caused slow warming or surface cooling in the Southern Ocean, equatorial Pacific, North Atlantic, and coastal upwelling systems | very high | 3 | train |
1,390 | AR6_WGI | 1,230 | 13 | The long time scale also implies that the amount of deep-ocean warming is irreversible over centuries to millennia | very high | 3 | test |
1,391 | AR6_WGI | 1,230 | 14 | On annual to decadal time scales, the redistribution of heat by the ocean circulation dominates spatial patterns of temperature change | high | 2 | train |
1,392 | AR6_WGI | 1,230 | 15 | At longer time scales, the spatial patterns are dominated by additional heat, primarily stored in water masses formed in the Southern Ocean, and by weaker warming in the North Atlantic where heat redistribution caused by changing circulation counteracts the additional heat input through the surface | high | 2 | train |
1,393 | AR6_WGI | 1,230 | 17 | Since the 1980s, they have approximately doubled in frequency (high confidence) and have become more intense and longer | medium | 1 | train |
1,394 | AR6_WGI | 1,230 | 19 | The largest changes will occur in the tropical ocean and the Arctic | medium | 1 | train |
1,395 | AR6_WGI | 1,230 | 22 | Based on recent refined analyses of the available observations, the global 0–200 m stratification is now assessed to have increased about twice as much as reported by SROCC, with a 4.9 ± 1.5% increase from 1970 to 2018 | high | 2 | train |
1,396 | AR6_WGI | 1,230 | 32 | Western boundary currents have shifted poleward since 1993 | medium | 1 | train |
1,397 | AR6_WGI | 1,231 | 1 | In the 21st century, consistent with projected changes in the surface winds, the East Australian Current Extension and Agulhas Current Extension will intensify, while the Gulf Stream and Indonesian Throughflow will weaken | medium | 1 | train |
1,398 | AR6_WGI | 1,231 | 2 | Eastern boundary upwelling systems will change, with a dipole spatial pattern within each system of reduction at low latitude and enhancement at high latitude | high | 2 | train |
1,399 | AR6_WGI | 1,231 | 4 | There is no tipping point for this loss of Arctic summer sea ice | high | 2 | train |
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