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

==== CCP1.2.3.2 Projected Impacts ====

<div id="h3-7-siblings" class="h3-siblings"></div>

Cold-water species are projected to lose habitat in Canada and this may apply in the Alaskan river (H143) and Russian Far East Lake Inle (H181) hotspots ( ''medium confidence'' ) ( [[#Comte--2013|Comte et al., 2013]] ). Water abstraction is significant in the Colorado river hotspot (H145) and reduces its resilience to climate change effects on flow rates ( [[#Grafton--2013|Grafton et al., 2013]] ).

In South America, in the Brazilian Amazon hotspot (H153, 154, 157), half the assessed fish species were considered sensitive to increased temperatures and reduced oxygen due to climate change ( ''low confidence'' ) ( [[#Frederico--2016|Frederico et al., 2016]] ). The use of protected areas was recommended to reduce the impacts of deforestation and water pollution ( [[#Jézéquel--2020|Jézéquel et al., 2020]] ). El Niño-related floods have led to declines in numbers of caiman, a top predator in the Brazilian Paraná river hotspot (H158), which indicates that increased floods due to climate change may reduce its population and alter food webs ( [[#Herrera--2015|Herrera et al., 2015]] ).

In Europe, including the Mediterranean freshwater hotspots, climate change is projected to result in reduced river flow, low oxygen in summer, salinity incursions, further eutrophication and spread of invasive species, compromising the survival of native biodiversity ( ''medium confidence'' ) ( [[#Moss--2009|Moss et al., 2009]] ). The longer growth season in the boreal and Arctic latitudes is projected to aid the invasion of exotic species, and increase lake stratification resulting in lower oxygen below the hypolimnion ( ''medium confidence'' ). In addition, strict cold-water species are projected to lose suitable habitat ( [[#Moss--2009|Moss et al., 2009]] ). An analysis of 1648 species of freshwater fish, amphibians, turtles, plants, molluscs, crayfish and dragonflies, projected ~6% of common and ~77% of rare species to lose 90% of their geographic range ( ''low confidence'' ) ( [[#Markovic--2014|Markovic et al., 2014]] ). Even if some species can spread to other areas and follow the climate, [[#Markovic--2014|Markovic et al. (2014)]] projected a loss of species, especially molluscs, from the southeastern Mediterranean, including the Balkan biodiversity hotspot (H162) ( ''medium confidence'' ). Similarly, within Europe, Mediterranean fish ( [[#Jarić--2019|Jarić et al., 2019]] ) and insects ( [[#Conti--2014|Conti et al., 2014]] ) are the most threatened by climate warming, droughts and floods. The fish species of the Danube river delta hotspot (H161) are less susceptible to climate change than in the Balkans (H162) and Anatolian (H163) hotspots. The rest of Europe, from the Iberian Peninsula to Scandinavia is not classified as a biodiversity hotspot. Thus, the areas where freshwater biodiversity is most threatened by climate change in Europe are in two of the three hotspots ( ''high confidence'' ).

The African Rift Valley Lakes (H171), including Lakes Tanganyika and Turkana, are suffering from climate change influenced drought, potentially impacting freshwater biodiversity ( ''medium confidence'' ) ( [[#Dudgeon--2006|Dudgeon et al., 2006]] ). Africa and Madagascar (H172) are projected to see a climate-driven 10% reduction in freshwater flow that is projected to threaten the survival of ~9% of freshwater-dependent fish and birds ( ''low confidence'' ) ( [[#Thieme--2010|Thieme et al., 2010]] ). Climate change is projected to increase the extinction vulnerability of most freshwater fish in the western South Africa Cape hotspot (H170) ( ''low confidence'' ) ( [[#Shelton--2018|Shelton et al., 2018]] ).

In Asia, although climate change impacts on the Yangtze (H183) and Mekong river (H186) biodiversity hotspots have not been reported, they are subject to the range of human impacts of over-exploitation, pollution, water abstraction, altered flow regimes, habitat loss and spread of invasive species, which makes them more vulnerable to climate effects ( ''medium confidence'' ) ( [[#Dudgeon--2006|Dudgeon et al., 2006]] ). The release of water from shrinking glaciers in Asia to some extent protects downstream freshwaters against drought, but half of these glaciers are projected to disappear by 2100 ( ''medium confidence'' ) ( [[#Pritchard--2019|Pritchard, 2019]] ).

In Australia, the Murray-Darling river basin occupies much of the Eastern Rivers hotspot (H195) and climate-related drought exacerbated by water abstraction is projected to drive declines in freshwater birds, fish and invertebrates ( ''high confidence'' ) ( [[#Grafton--2013|Grafton et al., 2013]] ). However, a national scale analysis projected climate change to cause freshwater species range shifts, but no losses of species in this hotspot ( ''low confidence'' ) ( [[#James--2017|James et al., 2017]] , WG2 Ch. 11).

<div id="CCP1.2.4" class="h2-container"></div>

<span id="ccp1.2.4-marine"></span>