Global mean sea level increased by 0.20 
[0.15 to 0.25] m between 1901 and 2018. The average rate of sea level 
rise was 1.3 [0.6 to 2.1]mm yr-1 between 1901 and 1971, increasing to 
1.9 [0.8 to 2.9] mm yr-1 between 1971 and 2006, and further increasing 
to 3.7 [3.2 to –4.2] mm yr-1 between 2006 and 2018 (high conﬁdence). 
Human inﬂuence was very likely the main driver of these increases 
since at least 1971 (Figure 3.4). Human inﬂuence is very likely the main 
driver of the global retreat of glaciers since the 1990s and the decrease 
in Arctic sea ice area between 1979–1988 and 2010–2019. Human 
inﬂuence has also very likely contributed to decreased Northern Hemisphere 
spring snow cover and surface melting of the Greenland ice sheet. It is 
virtually certain that human-caused CO2 emissions are the main driver 
of current global acidiﬁcation of the surface open ocean. {WGI SPM A.1, 
WGI SPM A.1.3, WGI SPM A.1.5, WGI SPM A.1.6, WG1 SPM A1.7, 
WGI SPM A.2, WG1.SPM A.4.2; SROCC SPM.A.1, SROCC SPM A.2}
Human-caused climate change is already affecting many weather and 
climate extremes in every region across the globe. Evidence of observed 
changes in extremes such as heatwaves, heavy precipitation, droughts, 
and tropical cyclones, and, in particular, their attribution to human 
inﬂuence, has strengthened since AR5 (Figure 2.3).