Editing IPCC:AR6/SR15/TS (section)

==== Terrestrial and Wetland Ecosystems ====

'''Risks of local species losses and, consequently, risks of extinction are much less in a 1.5°C versus a 2°C warmer world (''high confidence'').''' The number of species projected to lose over half of their climatically determined geographic range at 2°C global warming (18% of insects, 16% of plants, 8% of vertebrates) is projected to be reduced to 6% of insects, 8% of plants and 4% of vertebrates at 1.5°C warming (''medium confidence''). Risks associated with other biodiversity-related factors, such as forest fires, extreme weather events, and the spread of invasive species, pests and diseases, would also be lower at 1.5°C than at 2°C of warming (''high confidence''), supporting a greater persistence of ecosystem services. {3.4.3, 3.5.2}

'''Constraining global warming to 1.5°C, rather than to 2°C and higher, is projected to have many benefits for terrestrial and wetland ecosystems and for the preservation of their services to humans (''high confidence'').''' Risks for natural and managed ecosystems are higher on drylands compared to humid lands. The global terrestrial land area projected to be affected by ecosystem transformations (13%, interquartile range 8–20%) at 2°C is approximately halved at 1.5°C global warming to 4% (interquartile range 2–7%) (''medium confidence''). Above 1.5°C, an expansion of desert terrain and vegetation would occur in the Mediterranean biome (''medium confidence''), causing changes unparalleled in the last 10,000 years (''medium confidence''). {3.3.2.2, 3.4.3.2, 3.4.3.5, 3.4.6.1, 3.5.5.10, Box 4.2}

'''Many impacts are projected to be larger at higher latitudes, owing to mean and cold-season warming rates above the global average (''medium confidence'').''' High-latitude tundra and boreal forest are particularly at risk, and woody shrubs are already encroaching into tundra (''high confidence'') and will proceed with further warming. Constraining warming to 1.5°C would prevent the thawing of an estimated permafrost area of 1.5 to 2.5 million km2over centuries compared to thawing under 2°C (''medium confidence''). {3.3.2, 3.4.3, 3.4.4}