Editing IPCC:AR6/WGI/Chapter-12 (section)

=== 12.4.9 Polar Terrestrial Regions ===

<div id="h2-16-siblings" class="h2-siblings"></div>

Several recent climate assessments of polar regions describe robust patterns of recent and future climatic changes driving impacts and risk for polar environmental, societal, and economic assets. These have included the IPCC SROCC ( [[#Meredith--2019|Meredith et al., 2019]] ), the Report on Snow, Water, Ice and Permafrost in the Arctic ( [[#AMAP--2017|AMAP, 2017]] ), and national assessments for the USA ( [[#Markon--2018|Markon et al., 2018]] ) and Canada ( [[#Derksen--2018|Derksen et al., 2018]] ). This section examines Greenland and Iceland, the Russian Arctic, Antarctica, and the Arctic portions of Northern Europe and North America (Figure 1.18c).

<div id="12.4.9.1" class="h3-container"></div>

<span id="heat-and-cold-8"></span>
==== 12.4.9.1 Heat and Cold ====

<div id="h3-70-siblings" class="h3-siblings"></div>

'''Mean air temperature:''' Atlas.11.2 shows ''high confidence'' in warming of the Arctic in observations and projections, measuring among the fastest-warming places at more than twice the global mean, with substantially higher temperature increases in the cold season (see also [[#AMAP--2017|AMAP, 2017]] ; [[#Meredith--2019|Meredith et al., 2019]] ). Atlas.11.1 assessed ''very likely'' warming in observations of West Antarctica from 1957 to 2016, but ''limited evidence'' of mean air temperature change across East Antarctica even as there is ''high confidence'' in future warming across the continent (Figure Atlas.29; [[#Meredith--2019|Meredith et al., 2019]] ).

'''Extreme heat, cold spell and frost:''' Ecosystem and societal temperature thresholds in polar regions often reflect lower tolerance to heat and higher tolerance to cold. Extreme heat events have increased around the Arctic and Iceland since 1979, including increases in cold season warm days and nights, melt days, and Arctic winter warm events (T &gt; –10°C) as well as decreases in cold days and nights ( [[#Mernild--2014|Mernild et al., 2014]] ; [[#Matthes--2015|Matthes et al., 2015]] ; [[#Vikhamar-Schuler--2016|Vikhamar-Schuler et al., 2016]] ; [[#Graham--2017|Graham et al., 2017]] ; [[#Sui--2017|Sui et al., 2017]] ; [[#Dobricic--2020|Dobricic et al., 2020]] ; [[#Peña-Angulo--2020|Peña-Angulo et al., 2020]] ). Heatwaves causing high temperature records have been recently documented in West and East Antarctica ( [[#Wille--2019|Wille et al., 2019]] ; [[#Robinson--2020|Robinson et al., 2020]] ). There is ''high confidence'' that polar amplification will drive increases in Arctic heat extremes as well as continuing declines in the magnitude and frequency of cold extremes ( [[#Matthes--2015|Matthes et al., 2015]] ; [[#Kharin--2018|Kharin et al., 2018]] ), although dynamical effects will still bring substantial cold air anomalies over the Arctic ( [[#Wu--2019|Wu and Francis, 2019]] ). There is ''medium confidence'' for equivalent changes in extreme heat in Antarctica based primarily on higher mean temperatures, with J.R. [[#Lee--2017|]] [[#Lee--2017|Lee et al. (2017)]] projecting more than 50 additional degree days above freezing (2098 RCP8.5 compared with 2014) over parts of the Antarctic Peninsula but smaller changes over mainland Antarctica.

<div id="12.4.9.2" class="h3-container"></div>

<span id="wet-and-dry-8"></span>
==== 12.4.9.2 Wet and Dry ====

<div id="h3-71-siblings" class="h3-siblings"></div>

'''Mean precipitation:''' Atlas.11.2 indicated ''medium confidence'' in observed increases in Arctic precipitation, with the largest rises in the cold season. Antarctic precipitation showed no significant overall trend since the 1970s, with a positive trend over the 20th century (Sections 9.4.2.1 and Atlas.11.1). Increases in Arctic and Antarctic precipitation during the 21st century are ''very'' ''likely'' , with projected percentage increases that are much higher than most subpolar regions of the world (Figure Atlas.29).

'''Floods and heavy precipitation:''' Observations and model projections indicate ''high confidence'' in increasing Arctic river runoff in response to increasing total precipitation ( [[#Box--2019|Box et al., 2019]] ; [[#Durocher--2019|Durocher et al., 2019]] ; [[#Meredith--2019|Meredith et al., 2019]] ) with a shift towards earlier meltwater flooding ( [[#AMAP--2017|AMAP, 2017]] ). Higher Arctic precipitable water totals are also connected with observed increases in heavy precipitation and convective activity ( ''high confidence'' ) ( [[#Ye--2015|Ye et al., 2015]] ; [[#Kharin--2018|Kharin et al., 2018]] ; [[#Chernokulsky--2019|Chernokulsky et al., 2019]] ). Higher flood magnitudes are also driven by future increases in rain-on-snow event days, amounts, and runoff, which are more significant in the Arctic than in mid-latitudes (where seasonal snow cover is often further reduced; [[#AMAP--2017|AMAP, 2017]] ; [[#Jeong--2018b|Jeong and Sushama, 2018b]] ).

'''Landslide and snow avalanche:''' There is a growing number of studies on mass movements in polar regions. Although there is ''low confidence'' in widespread observational trends for landslides or snow avalanches, a rise in the number of future landslides is supported by strong links to increases in heavy precipitation, glacier retreat, and thawing of ice-rich permafrost that can lead to retrogressive thaw slumps in Arctic regions ( [[IPCC:Wg1:Chapter:Chapter-2#2.3.2.5|Section 2.3.2.5]] ; [[#Kokelj--2015|Kokelj et al., 2015]] ; [[#Derksen--2018|Derksen et al., 2018]] ; [[#Lewkowicz--2019|Lewkowicz and Way, 2019]] ; [[#Patton--2019|Patton et al., 2019]] ; [[#Ward%20Jones--2019|Ward Jones et al., 2019]] ).

'''Aridity and drought:''' Recent decades have seen a general decrease in Arctic aridity, with projections indicating a continuing trend towards reduced aridity ( ''high confidence'' ) as increased moisture transport leads to higher precipitation, humidity and streamflow ( [[#Meredith--2019|Meredith et al., 2019]] ) and a corresponding decrease in dry days ( [[#Khlebnikova--2019a|Khlebnikova et al., 2019a]] ). There is ''low confidence'' overall of recent or projected drought changes in polar regions ( [[IPCC:Wg1:Chapter:Chapter-11#11.9|Section 11.9]] ) even as increasing evidence shows that drainage from permafrost thaw, higher potential evapotranspiration, and changing seasonal patterns of melt have caused lake reduction and soil moisture deficits in several areas that match with projections of future drought increase despite overall precipitation increases ( [[#Andresen--2015|Andresen and Lougheed, 2015]] ; [[#Bring--2016|Bring et al., 2016]] ; [[#Spinoni--2018a|Spinoni et al., 2018a]] ; [[#Feng--2019|Feng et al., 2019]] ; [[#Finger%20Higgens--2019|Finger Higgens et al., 2019]] ).

'''Fire weather:''' Fire season lengthened from 1979 to 2015 over Arctic portions of North America ( [[#Jain--2017|Jain et al., 2017]] ), corresponding also to a 1975–2015 increase in lightning-ignited fires in Arctic North-Western North America ( [[#Girardin--2013|Girardin et al., 2013]] ; [[#Veraverbeke--2017|Veraverbeke et al., 2017]] ). [[#Abatzoglou--2019|Abatzoglou et al. (2019)]] climate model simulations project significant fire weather index increases in boreal forests of Arctic Europe, Arctic Russia and Arctic North-Eastern North America ( ''medium confidence'' ). Trends towards more frequent fires in tundra regions are expected to continue, driven in particular by increasing potential evapotranspiration and changes in vegetation ( ''high confidence'' ) ( [[#Hu--2015|Hu et al., 2015]] ; [[#AMAP--2017|AMAP, 2017]] ; [[#Young--2017|Young et al., 2017]] ).

<div id="12.4.9.3" class="h3-container"></div>

<span id="wind-8"></span>
==== 12.4.9.3 Wind ====

<div id="h3-72-siblings" class="h3-siblings"></div>

'''Mean wind speed and severe storm:''' There is ''medium confidence'' of mean wind decrease over the Russian Arctic, Greenland and Iceland, and Arctic North-Eastern North America ( [[#Karnauskas--2018a|Karnauskas et al., 2018a]] ; [[#Jung--2019|Jung and Schindler, 2019]] ), but ''low confidence'' of changes in the other Arctic regions and Antarctica. [[#Bintanja--2014|Bintanja et al. (2014)]] projected that a strengthening of the Southern Annular Mode would decrease easterlies along Antarctica’s coasts with only small changes in katabatic winds (although this effect may diminish with stratospheric ozone recovery). In contrast, [[#Gorter--2014|Gorter et al. (2014)]] regional climate model projections indicated a reduction in mean winds over the interior of Greenland by RCP4.5 2100 while coastal winds increase. Reanalysis data and climate models indicate few coherent regional trends of polar cyclone frequency or relationships with cyclone depth and size ( [[#Akperov--2018|Akperov et al., 2018]] , 2019; [[#Day--2018|Day and Hodges, 2018]] ; [[#Zahn--2018|Zahn et al., 2018]] ).

<div id="12.4.9.4" class="h3-container"></div>

<span id="snow-and-ice-7"></span>
==== 12.4.9.4 Snow and Ice ====

<div id="h3-73-siblings" class="h3-siblings"></div>

'''Snow:''' Atlas.11.1 identified ''likely'' increases in surface mass balance (driven by snowfall) across Antarctica in the 20th century ( ''medium confidence'' ). In the Arctic, overall snow extent and seasonal duration are projected to continue recent declines ( ''high confidence'' ), although mid-winter snowpack increases in some of the coldest and high-elevation locations given higher precipitation totals ( ''medium confidence'' ) ( [[IPCC:Wg1:Chapter:Chapter-9#9.5.3|Section 9.5.3]] , Atlas.9 and Atlas.11.2; [[#Bring--2016|Bring et al., 2016]] ; [[#Danco--2016|Danco et al., 2016]] ; [[#AMAP--2017|AMAP, 2017]] ; [[#Meredith--2019|Meredith et al., 2019]] ). Higher temperatures result in a higher percentage of Arctic precipitation falling as rain (particularly in autumn and spring) ( ''high confidence'' ), with most land regions (outside of Greenland and Antarctica) becoming dominated by rainfall (more than 50% of total precipitation) by RCP8.5 2100 ( [[#Bintanja--2017|Bintanja and Andry, 2017]] ; [[#Irannezhad--2017|Irannezhad et al., 2017]] ).

'''Glacier and ice sheet:''' Section 9.5.1 and [[IPCC:Wg1:Chapter:Chapter-2#2.3.2.3|Section 2.3.2.3]] found that glaciers have lost mass in all polar regions since 2000 ( ''high confidence'' ), and [[IPCC:Wg1:Chapter:Chapter-9#9.4|Section 9.4]] assessed ''high confidence'' in Greenland Ice Sheet mass losses since 1980 and Antarctic Ice Sheet losses since 1992 (dominated by West Antarctica, with losses in parts of East Antarctica in the past two decades). New simulations from GlacierMIP ( [[#Marzeion--2020|Marzeion et al., 2020]] ) indicate glaciers in Iceland will lose 31 ± 35%, 41 ± 46% and 53 ± 45% of their mass in 2015 by the end of the century for RCP2.6, RCP4.5 and RCP8.5 scenarios, respectively. [[#Marzeion--2020|Marzeion et al. (2020)]] projected mass losses ( ''high confidence'' ) for those same scenarios in the Greenland Periphery: 22 ± 23%, 29 ± 26%, and 42 ± 28%; Svalbard: 35 ± 34%, 50 ± 36%, and 66 ± 35%; Russian Arctic: 26 ± 26%, 38 ± 28%, and 52 ± 30%; Northern Arctic Canada: 12 ± 13%, 18 ± 12%, and 27 ± 18%; Southern Arctic Canada: 23 ± 27%, 33 ± 29%, and 48 ± 32%; and Antarctic Periphery: 7 ± 12%, 13 ± 10%, and 16 ± 19%. Areas with receding glaciers are also potentially vulnerable to glacial lake outburst floods ( [[#Harrison--2018|Harrison et al., 2018]] ).

'''Permafrost:''' Observations from recent decades (assessed in [[IPCC:Wg1:Chapter:Chapter-9#9.5.2|Section 9.5.2]] and [[IPCC:Wg1:Chapter:Chapter-2#2.3.2.5|Section 2.3.2.5]] ) show increases in permafrost temperature ( ''very high confidence'' ) and active layer thickness ( ''medium confidence'' ) across the Arctic ( [[#AMAP--2017|AMAP, 2017]] ; [[#Derksen--2018|Derksen et al., 2018]] ; [[#Markon--2018|Markon et al., 2018]] ; [[#Biskaborn--2019|Biskaborn et al., 2019]] ; [[#Farquharson--2019|Farquharson et al., 2019]] ; [[#Meredith--2019|Meredith et al., 2019]] ; [[#Romanovsky--2020|Romanovsky et al., 2020]] ). [[IPCC:Wg1:Chapter:Chapter-9#9.5.2|Section 9.5.2]] noted that observations of active layer thickness in Antarctica are too limited to assess long-term trends (see also [[#Hrbáček--2018|Hrbáček et al., 2018]] ; [[#Biskaborn--2019|Biskaborn et al., 2019]] ). Future projections indicate continuing increases in permafrost temperature and active layer thickness with loss of permafrost across the Arctic ( [[IPCC:Wg1:Chapter:Chapter-9#9.5.2|Section 9.5.2]] ). [[#Streletskiy--2019|Streletskiy et al. (2019)]] noted that changes to Russian permafrost temperature and active layer thickness are most pronounced in areas where permafrost is continuous (underlying &gt;90% of landmass). CMIP5 analyses by [[#Slater--2013|Slater and Lawrence (2013)]] projected that, by RCP8.5 2100, shallow (&lt;3 m) permafrost would be most probable only in portions of the Canadian Arctic Archipelago and the Russian Arctic coastal and eastern upland regions.

'''Sea ice:''' Consistent with SROCC ( [[#Meredith--2019|Meredith et al., 2019]] ), [[IPCC:Wg1:Chapter:Chapter-9#9.3.1|Section 9.3.1]] and [[IPCC:Wg1:Chapter:Chapter-2#2.3.2.1.1|Section 2.3.2.1.1]] assess ''very high confidence'' that Arctic sea ice thickness, extent, and average age have significantly decreased over the past four decades, with largest declines in September (when sea ice is at an annual minimum). Declines in landfast ice are most rapid in the Laptev Sea ( [[#Selyuzhenok--2015|Selyuzhenok et al., 2015]] ), with warming also breaking perennial landfast ice blocking ocean channels (‘ice plugs’) in the Canadian Archipelago ( [[#Pope--2017|Pope et al., 2017]] ), and landfast ice declining in the cold season by 7% per decade across the Arctic (1976–2007; [[#Yu--2014|Yu et al., 2014]] ). Observed trends and projections suggest that perennial sea ice is being replaced by thin, seasonal ice, although multi-year ice will persist above the Canadian Archipelago and drift into sea transportation lanes ( [[#Howell--2016|Howell et al., 2016]] ; [[#Derksen--2018|Derksen et al., 2018]] ). Trends from 1979 to 2013 show slightly earlier spring melt for Arctic sea ice, but substantially delayed autumn freeze-up and a melt season lengthened by more than 3 days per decade off northern Alaska and Canada with the exception of portions of the Bering Sea ( [[#Parkinson--2014|Parkinson, 2014]] ; [[#Stroeve--2014|Stroeve et al., 2014]] ). [[IPCC:Wg1:Chapter:Chapter-9#9.3.2|Section 9.3.2]] assessed ''low confidence'' in long-term trends in sea ice extent or thickness near Antarctica.

Future declines in Arctic sea ice are ''virtually certain'' , although there is ''low confidence'' in declines of Antarctic sea ice given dynamical processes in the Southern Ocean and the recovery of stratospheric ozone ( [[IPCC:Wg1:Chapter:Chapter-9#9.3|Section 9.3]] ; [[#Meredith--2019|Meredith et al., 2019]] ). Projections of an ‘ice-free’ Arctic vary, depending on definitions representing transportation needs, however [[#Laliberté--2016|Laliberté et al. (2016)]] noted that the median of 42 CMIP5 models projected &lt;5% sea ice for the month of September by 2050, with equivalent conditions for the entirety of the August–October period by 2090. [[IPCC:Wg1:Chapter:Chapter-9#9.3.1|Section 9.3.1]] assessed ''high confidence'' that practically ice-free conditions (&lt;1 million km <sup>2</sup> in the September mean) would ''likely'' first appear before 2050 even under strong mitigation scenarios ( [[#Sigmond--2018|Sigmond et al., 2018]] ; [[#Stroeve--2018|Stroeve and Notz, 2018]] ; Notz and SIMIP Community, 2020).

'''Lake and river ice:''' There is ''high confidence'' in observations of significant declines in seasonal ice cover thickness and duration over most Arctic lakes, with many lakes projected to lose more than one month of ice cover by mid-century ( ''medium confidence'' ) ( [[#Meredith--2019|Meredith et al., 2019]] ; [[#Sharma--2019|Sharma et al., 2019]] ). Some lakes that previously froze to the bottom (‘bedfast’) now maintain liquid bottom water year round, and others shift from perennial to seasonal ice cover ( [[#Surdu--2016|Surdu et al., 2016]] ; [[#Engram--2018|Engram et al., 2018]] ). [[#Yang--2020a|Yang et al. (2020a)]] identified a decline in Arctic cold-season river ice extent in satellite observations (particularly in Alaska) and projected reductions in average Northern Hemisphere seasonal river ice duration of 6.10 ± 0.08 days per degree global surface air temperature.

'''Heavy snowfall and ice storm:''' There is ''limited evidence'' of changes in heavy snowfall due to competing influences of shortened snowfall seasonality with more intense (and larger overall) precipitation in the Arctic. Episodic heavy snowfall trends in Antarctica are difficult to separate from large interannual variability ( ''limited evidence'' ) (Gorodetskaya et al., 2014, Turner et al., 2020). ''Limited evidence'' also hinders clear signals in ice storms, although warming shifts the freezing line (around which ice storms occur) poleward and upslope ( [[#Bintanja--2017|Bintanja and Andry, 2017]] ). [[#Groisman--2016|Groisman et al. (2016)]] used 40 years of observations to identify an increase of freezing rain events in Norway, North America, and eastern and western Russia. Increases in winter rainfall have led to more frequent development of difficult wildlife and livestock grazing conditions as basal ice conditions coat the ground below snowpack ( [[#Peeters--2019|Peeters et al., 2019]] ).

<div id="_idContainer115" class="Basic-Text-Frame"></div>

'''Table 12.11''' '''|''' '''Summary of confidence in direction of projected change in climatic impact-drivers in the polar regions, representing their aggregate characteristic changes for mid-century for scenarios RCP4.5, SSP2-4.5, SRES A1B, or above within each AR6 region (defined in Chapter 1), approximately corresponding (for CIDs that are independent of sea level rise) to global warming levels between 2°C and 2.4°C (see [[#12.4|Section 12.4]] for more details of the assessment method).''' The table also includes the assessment of observed or projected time-of-emergence of the CID change signal from the natural interannual variability if found with at least ''medium confidence'' in [[#12.5.2|Section 12.5.2]] . Note that the Arctic portions of the NEU, NEN and NWN differ from the full AR6 regions assessed in the Europe and North America sections above (see also Figure 1.18c).

[[File:35c186ec3522c779e133883cf3c3179a IPCC_AR6_WGI_Chapter12_Table_12_11_1.jpg]]

<div id="12.4.9.5" class="h3-container"></div>

<span id="coastal-and-oceanic-7"></span>
==== 12.4.9.5 Coastal and Oceanic ====

<div id="h3-74-siblings" class="h3-siblings"></div>

'''Relative sea level:''' Satellite altimetry and tide data show that relative sea levels (with glacial isostatic adjustment) are rising in Arctic Europe and Arctic North-Western North America, declining in portions of southern Alaska and Arctic North-Eastern North America and no clear trend in Greenland and the Russian Arctic ( [[#Sweet--2018|Sweet et al., 2018]] ; [[#Rose--2019|Rose et al., 2019]] ), which is broadly consistent with findings in [[#Oppenheimer--2019|Oppenheimer et al. (2019)]] . Areas with low or negative change have substantial land uplift counteracting the global mean sea level trend ( [[#Greenan--2018|Greenan et al., 2018]] ; [[#Sweet--2018|Sweet et al., 2018]] ; [[#Madsen--2019|Madsen et al., 2019]] ). SROCC projections indicate ''high confidence'' in future rises in relative sea level for all Arctic regions other than areas of substantial land uplift in north-eastern Canada, the west coast of Greenland, and narrow portions of West Antarctica ( [[#Oppenheimer--2019|Oppenheimer et al., 2019]] ).

'''Coastal flooding and erosion:''' Higher sea levels and reduced coastal sea ice protection will increase future extreme sea levels in the Arctic ( ''high confidence'' for Arctic Northern Europe, the Russian Arctic, and Arctic North-Western North America ( ''medium confidence'' '')'' for Greenland and Iceland and Arctic North-Eastern North America given glacial isostatic adjustment). [[#Vousdoukas--2018|Vousdoukas et al. (2018)]] project that the current 1-in-100-year extreme total water level would have median return periods of 1-in-20-years to 1-in-50-years by 2050, increasing to 1-in-5-years to 1-in-20-years by 2100 under RCP4.5 along nearly the entire Arctic coastline by 2100 (excluding GIC for which projections are not available). Projections for RCP8.5 indicate that the present-day 1-in-100-year ETWL would have median return periods of 1-in-10-years to 1-in-50-years by 2050 and would occur once every five years (or more frequently) by 2100. Arctic coastal erosion is also expected to increase with climate change ( ''medium confidence'' ; ''high agreement'' but ''limited evidence'' of projections), accelerated in some regions by subsurface permafrost thaw and increased wave energy ( [[#Gibbs--2015|Gibbs and Richmond, 2015]] ; [[#Fritz--2017|Fritz et al., 2017]] ; [[#Oppenheimer--2019|Oppenheimer et al., 2019]] ; [[#Casas-Prat--2020|Casas-Prat and Wang, 2020]] ). A longer ice-free season for the RCP8.5 2080s is projected to help drive more than 100 m of shoreline retreat in North-Western North America Arctic coastal communities ( [[#Melvin--2017|Melvin et al., 2017]] ; [[#Greenan--2018|Greenan et al., 2018]] ; [[#Magnan--2019|Magnan et al., 2019]] ). Assessment of coastal flooding and erosion changes in Antarctica are limited by a lack of studies.

'''Marine heatwave:''' Recent years have seen marine heatwaves (MHWs) and increasing extreme coastal SSTs in Arctic systems ( [[#Lima--2012|Lima and Wethey, 2012]] ; [[#Collins--2019|Collins et al., 2019]] ; [[#Frölicher--2019|Frölicher, 2019]] ). 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 ( ''high confidence'' ). [[#Frölicher--2018|Frölicher et al. (2018)]] used 12 CMIP5 models to project median MHW days increasing about 25-fold and 50-fold at the 2°C and 3.5°C GWLs, respectively, in response to mean ocean warming and sea ice loss, and the smallest global changes still leading to increases in the Southern Ocean around Antarctica (see also Cross-chapter Box 9.1).

'''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''' ( high confidence '''), with similar changes in Antarctica but''' medium confidence '''for extreme heat increases and West Antarctic frost change decreases and''' low confidence '''for cold spell changes and East Antarctica frost. The water cycle is projected to intensify in polar regions, leading to more rainfall, higher river flood potential and more intense precipitation''' ( high confidence '''). 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''' ( medium confidence '''). 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''' ( high confidence '''), western Greenland, the northern Baltic Sea, and portions of West Antarctica. Higher sea levels also contribute to''' high confidence '''for projected increases of Arctic coastal flooding and higher coastal erosion (aided by sea ice loss)''' ( medium confidence ''') with lower confidence for those CIDs in regions with substantial land uplift.'''

<div id="12.4.10" class="h2-container"></div>

<span id="specific-zones-and-hotspots"></span>