Editing IPCC:AR6/WGII/Cross-Chapter-Paper-1 (section)

===== CCP1.2.1.2.1 Projected climatic hazards =====

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Comparison of climate warming projected for air and sea temperature shows biodiversity hotspots will continue to experience the greatest net increases in temperature at higher Northern Hemisphere latitudes, particularly in tundra regions (Figures CCP1.4; CCP1.5; Table CCP1.1). Generally, terrestrial and freshwater hotspots are projected to continue to warm more than marine (Figure CCP1.3). Modelled temperatures are projected to continue to be the highest in the tropics, indicating where there are more thermally stressful conditions for more species ( ''high confidence'' ) ( [[#Stuart-Smith--2015|Stuart-Smith et al., 2015]] ; [[#Stuart-Smith--2017|Stuart-Smith et al., 2017]] ; [[#Foster--2018|Foster et al., 2018]] ; [[#Waldock--2019|Waldock et al., 2019]] ). By the end of this century, all terrestrial biodiversity hotspots in Central and South America, Africa, India and southern and eastern Asia (including the Indo–West Pacific islands) are projected to experience climates unprecedented in their species’ evolutionary history ( ''medium confidence'' ) ( [[#Williams--2007|Williams et al., 2007]] ).

Based on WGI ''Interactive Atlas'' data (Gutiérrez et al., 2021), global warming is projected to affect terrestrial hotspots less than non-hotspot areas: 80% less for Myers and 95–96% less for G200 terrestrial and freshwater hotspots at global warming of 1.5°C–3°C ( ''medium confidence'' ) ( [[#Kocsis--2021|Kocsis et al., 2021]] ). In contrast, warming is projected to be 12–13% greater inside than outside marine hotspots ( ''medium confidence'' ) ( [[#Kocsis--2021|Kocsis et al., 2021]] ). Precipitation is generally projected to increase more in terrestrial and freshwater biodiversity hotspots compared to outside them ( ''low confidence'' ) ( [[#Kocsis--2021|Kocsis et al., 2021]] ). The exception is Myers hotspots, which are projected to have, on average, ~28% less precipitation at 1.5°C warming, but ~33% more at 2°C and ~65% more at 3°C ( ''low confidence'' ). However, precipitation changes are often difficult to assess as many hotspots cover large areas, with some areas projected to be wetter and some drier with wide differences between different climate models.

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'''Figure CCP1.4 |''' '''Projected loss of climatically suitable area in terrestrial biodiversity hotspots for a global average of 1.''' '''5°C (upper row, a–b), 2°C (middle, c–d) and 3°C (lower, e–f).''' Left-hand column displays the projected human impact using the five equal 20% categories of present-day impact (Figure CCP1.1). The right-hand column indicates the changes of impact categories compared to present-day impact. See Table SMCCP1.1 for more details.

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'''Figure CCP1.5 |''' '''Projected future warming in degrees Celsius for freshwater (left column, near-surface air temperature, panels''' '''a''' ''',''' '''c''' '''and''' '''e''' ''') and marine (right column as sea surface temperature, panels''' '''b''' ''',''' '''d''' '''and''' '''f''' ''')''' '''hotspots for a global average warming of +1.''' '''5°C (a, b), +2°C (c, d) and +3°C''' '''(e, f) compared to pre-industrial conditions.''' Values in text boxes in the figures indicate temperature increase from present-day (2005–2014) settings. Projected temperatures were calculated with averages of multi-model, yearly means across Shared Socioeconomic Pathways (SSP) 1.26 (only for +1.5°C), SSP2-45, SSP3-70 and SSP5-85.

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