Editing IPCC:AR6/WGI/Chapter-4 (section)

=== Precipitation ===

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'''Annual global land precipitation will increase over the 21st century as GSAT increases''' ( ''high confidence'' '''). The''' ''likely'' '''range of change in globally averaged annual land precipitation during 2081–2100 relative to 1995''' '''–2014 is –0.2 to +4.7% in the low-emissions scenario SSP1-1.9 and 0.9–12.9% in the high-emissions scenario SSP5-8.5, based on all available CMIP6 models.''' The corresponding ''likely'' ranges are 0.0–6.6% in SSP1-2.6, 1.5–8.3% in SSP2-4.5, and 0.5–9.6% in SSP3-7.0. {4.3.1, 4.5.1, 4.6.1, 8.4.1}

'''Precipitation change will exhibit substantial regional differences and seasonal contrast as GSAT increases over the 21st century''' ( ''high confidence'' ''').''' As warming increases, a larger land area will experience statistically significant increases or decreases in precipitation ( ''medium confidence'' ). Precipitation will ''very likely'' increase over high latitudes and the tropical oceans, and ''likely'' increase in large parts of the monsoon region, but ''likely'' decrease over large parts of the subtropics in response to greenhouse gas-induced warming. Interannual variability of precipitation over many land regions will increase with global warming ( ''medium confidence'' ). {4.5.1, 4.6.1, 8.4.1}

'''Near-term projected changes in precipitation are uncertain, mainly because of natural internal variability, model uncertainty, and uncertainty in natural and anthropogenic aerosol forcing''' ( ''medium confidence'' ''').''' In the near term, no discernible differences in precipitation changes are projected between different SSPs ( ''high confidence'' ). The anthropogenic aerosol forcing decreases in most scenarios, contributing to increases in GSAT ( ''medium confidence'' ) and global mean land precipitation ( ''low confidence'' ). {4.3.1, 4.4.1, 4.4.4, 8.5}

'''In response to greenhouse gas-induced warming, it is''' ''likely'' '''that global land monsoon precipitation will increase, particularly in the Northern Hemisphere, although Northern Hemisphere monsoon circulation will''' ''likely'' '''weaken.''' In the long term (2081–2100), monsoon rainfall change will feature a north–south asymmetry characterized by a greater increase in the Northern Hemisphere than in the Southern Hemisphere and an east–west asymmetry characterized by an increase in Asian-African monsoon regions and a decrease in the North American monsoon region ( ''medium confidence'' ). Near-term changes in global monsoon precipitation and circulation are uncertain due to model uncertainty and internal variability such as Atlantic Multi-decadal Variability and Pacific Decadal Variability ( ''medium confidence'' ). {4.4.1, 4.5.1, 8.4.1, 10.6.3}

'''It is''' ''likely'' '''that at least one large volcanic eruption will occur during the 21st century. Such an eruption would reduce GSAT for several years, decrease global mean land precipitation, alter monsoon circulation, modify extreme precipitation, and change the profile of many regional climatic impact-drivers.''' A low-likelihood, high-impact outcome would be several large eruptions that would greatly alter the 21st century climate trajectory compared to SSP-based Earth system model projections. {Cross-Chapter Box 4.1}

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