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Section 2
Section 1
Section 2
2.1 Observed Changes, Impacts and Attribution
Human activities, principally through emissions of greenhouse gases, have unequivocally caused global warming, 
with global surface temperature reaching 1.1°C above 1850–1900 in 2011–2020. Global greenhouse gas emissions 
have continued to increase over 2010–2019, with unequal historical and ongoing contributions arising from 
unsustainable energy use, land use and land-use change, lifestyles and patterns of consumption and production 
across regions, between and within countries, and between individuals (high conﬁdence). Human-caused climate 
change is already affecting many weather and climate extremes in every region across the globe. This has led to 
widespread adverse impacts on food and water security, human health and on economies and society and related 
losses and damages63 to nature and people (high conﬁdence). Vulnerable communities who have historically 
contributed the least to current climate change are disproportionately affected (high conﬁdence).
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In this report, the term ‘losses and damages’ refers to adverse observed impacts and/or projected risks and can be economic and/or non-economic. (See Annex I: Glossary)
Section 2: Current Status and Trends
2.1.1. Observed Warming and its Causes
Global surface temperature was around 1.1°C above 1850–1900 in 
2011–2020 (1.09 [0.95 to 1.20]°C)64, with larger increases 
over land (1.59 [1.34 to 1.83]°C) than over the ocean 
(0.88 [0.68 to 1.01]°C)65. Observed warming is human-caused, with 
warming from greenhouse gases (GHG), dominated by CO2 and 
methane (CH4), partly masked by aerosol cooling (Figure 2.1). 
Global surface temperature in the ﬁrst two decades of the 21st century 
(2001–2020) was 0.99 [0.84 to 1.10]°C higher than 1850–1900.