Climate-related risks to health, 
livelihoods, food security, water supply, human security, and economic 
growth are projected to increase with global warming of 1.5°C. In 
terrestrial ecosystems, 3 to 14% of the tens of thousands of species 
assessed will likely face a very high risk of extinction at a GWL of 1.5°C. 
Coral reefs are projected to decline by a further 70–90% at 1.5°C of 
global warming (high conﬁdence). At this GWL, many low-elevation 
and small glaciers around the world would lose most of their mass or 
disappear within decades to centuries (high conﬁdence). Regions at 
disproportionately higher risk include Arctic ecosystems, dryland regions, 
small island developing states and Least Developed Countries (high 
conﬁdence). {WGII SPM B.3, WGII SPM B.4.1, WGII TS.C.4.2; SR1.5 SPM A.3, 
SR1.5 SPM B.4.2, SR1.5 SPM B.5, SR1.5 SPM B.5.1} (Figure 3.3)
At 2°C of global warming, overall risk levels associated with the unequal 
distribution of impacts (RFC3), global aggregate impacts (RFC4) and 
large-scale singular events (RFC5) would be transitioning to high (medium 
conﬁdence), those associated with extreme weather events (RFC2) would 
be transitioning to very high (medium conﬁdence), and those associated 
with unique and threatened systems (RFC1) would be very high (high 
conﬁdence) (Figure 3.3, panel a).