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

==== 12.3.7.1 Hazards ====

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Significant increases in the intensity and frequency of hot extremes and significant decreases in the intensity and frequency of cold extremes have ''likely'' been observed for the region (Skansi et al., 2013; [[#Ceccherini--2016|Ceccherini et al., 2016]] ; [[#Meseguer-Ruiz--2018|Meseguer-Ruiz et al., 2018]] ; [[#Vicente-Serrano--2018|Vicente-Serrano et al., 2018]] ; [[#Dereczynski--2020|Dereczynski et al., 2020]] ; [[#Dunn--2020|Dunn et al., 2020]] ; [[#Olmo--2020|Olmo et al., 2020]] ) (WGI AR6 Table 11.13) ( [[#Seneviratne--2021|Seneviratne et al., 2021]] ). In particular, a significant increment in the duration and frequency of heatwaves mainly in central Chile from 1961 to 2016 has been observed ( [[#Piticar--2018|Piticar, 2018]] ).

A robust drying trend for Chile (30°S–48°S) has been recorded ( ''medium confidence'' ) ( [[#Saurral--2017|Saurral et al., 2017]] ; [[#Boisier--2018|Boisier et al., 2018]] ) ''.'' However, inconsistent trends over the region in the magnitude of precipitation extremes with both decreases and increases ( [[#Chou--2014|Chou et al., 2014]] ; [[#Giorgi--2014|Giorgi et al., 2014]] ; [[#Heidinger--2018|Heidinger et al., 2018]] ; [[#Meseguer-Ruiz--2018|Meseguer-Ruiz et al., 2018]] ) (WGI AR6 Table 11.14) ( [[#Seneviratne--2021|Seneviratne et al., 2021]] ) have been observed ( ''low confidence'' ). The glacier equilibrium line altitude has presented an overall increase over central Chilean Andes ( [[#Barria--2019|Barria et al., 2019]] ).

For central Chile, a significant increase (5% to 20% in the last 60 years) in wave heights in the sea has been observed ( [[#Martínez--2018|Martínez et al., 2018]] ). From 1982 to 2016, sea levels at central Chile have increased 5 mm yr −1 , where El Niño events of 1982–1983 and 1997–1998 caused an extreme increase of 15 to 20 cm in the mean sea level ( [[#Campos-Caba--2016|Campos-Caba, 2016]] ; [[#Martínez--2018|Martínez et al., 2018]] ).

From 1946 to 2017, the number of fires and areas burned have increased significantly in Chile ( ''high confidence'' ) ( [[#González--2011|González et al., 2011]] ; [[#Jolly--2015|Jolly et al., 2015]] ; [[#Úbeda--2016|Úbeda and Sarricolea, 2016]] ; [[#de%20la%20Barrera--2018|de la Barrera et al., 2018]] ; [[#Urrutia-Jalabert--2018|Urrutia-Jalabert et al., 2018]] ). Fires are attributed to changes in temperature regimes ( [[#González--2011|González et al., 2011]] ; [[#de%20la%20Barrera--2018|de la Barrera et al., 2018]] ; [[#Gómez-González--2018|Gómez-González et al., 2018]] ) and precipitation regimes ( ''medium confidence'' ) ( [[#Gómez-González--2018|Gómez-González et al., 2018]] ; [[#Urrutia-Jalabert--2018|Urrutia-Jalabert et al., 2018]] ).

The glaciers of the southern Andes (including the SWS and SSA regions) show the highest glacier mass loss rates worldwide ( ''high confidence'' ) contributing to SLR ( [[#Jacob--2012|Jacob et al., 2012]] ; [[#Gardner--2013|Gardner et al., 2013]] ; [[#Dussaillant--2018|Dussaillant et al., 2018]] ; [[#Braun--2019|Braun et al., 2019]] ; [[#Zemp--2019|Zemp et al., 2019]] ). Since 1985, the glacier area loss in the sub-region is in a range of 20 up to 60% ( [[#Braun--2019|Braun et al., 2019]] ; [[#Reinthaler--2019b|Reinthaler et al., 2019b]] ).

Four sets of downscaling simulations based on the Eta Regional Climate Model forced by two global climate models ( [[#Chou--2014|Chou et al., 2014]] ) projected warmer conditions (more than 1°C) for the entire sub-region by 2050 under the RCP4.5 scenario ( ''medium confidence'' ). Extremely warm December–January–February days as well as the number of heatwaves per season are expected to increase by 5–10 times in northern Chile ( [[#Feron--2019|Feron et al., 2019]] ), ''likely'' increasing in the intensity and frequency of hot extremes over the entire region (WGI AR6 Table 11.13) ( [[#Seneviratne--2021|Seneviratne et al., 2021]] ). Drier conditions ( ''medium confidence'' ), by means of a decrease in total annual and extreme precipitation, are expected to increase for southern Chile, but inconsistent changes are expected in the sub-region ( ''low confidence'' ) ( [[#Chou--2014|Chou et al., 2014]] ) (WGI AR6 Table 11.14) ( [[#Seneviratne--2021|Seneviratne et al., 2021]] ) with ''high confidence'' upon an increase in fire weather and a decrease in permafrost and snow extent (WGI AR6 Table 12.6, [[#Ranasinghe--2021|Ranasinghe et al., 2021]] ).

Regional sea-level change for the region predicted by 2100 shows that total mean SLR along the coast will lie between 34 and 52 cm for the RCP4.5 scenario and between 46 and 74 cm for the RCP8.5 scenario with ''high confidence'' ( [[#Albrecht--2016|Albrecht and Shaffer, 2016]] ; WGI AR6 Table 12.6, [[#Ranasinghe--2021|Ranasinghe et al., 2021]] ).

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