Carbonbrief hade hösten 2021 en mycket bra genomgång av WG1 på sin sida.
https://www.carbonbrief.org/in-depth-qa-the-ipccs-sixth-assessment-report-on-climate-science/
Där många frågor kring vad klimatförändringarnas konsekvenser som ofta diskuteras mer i pop-media tas upp.
Några utdrag:
Citat:
The authors conclude that it is “unequivocal” that humans have warmed the planet, causing “widespread and rapid” changes to Earth’s oceans, ice and land surface. They warn that the present state of many parts of the climate system is “unprecedented over many centuries to many thousands of years”.
Citat:
Many of these changes – particularly to the oceans, ice sheets and global sea levels – are “irreversible”, the authors say. Abrupt changes and “tipping points” – such as rapid Antarctic ice sheet melt and forest dieback – “cannot be ruled out”.
Citat:
One of the key developments since the IPCC’s last assessment report in 2013-14 is the strengthening of the links between human-caused warming and increasingly severe extreme weather, the authors say. This is now “an established fact”, they write
Citat:
With high confidence, the report concludes that global average precipitation and evaporation are increasing with global warming – very likely with a range of 1-3% per degree C.
“Widespread, non-uniform human-caused alterations of the water cycle, which have been obscured by a competition between different drivers across the 20th century that will be increasingly dominated by greenhouse gas forcing at the global scale”.
Citat:
Wetter wet seasons and events.
More severe “very wet” and “very dry” events.
More intense heavy precipitation events and greater flood hazards during such events.
Increased severity of droughts as warming over land drives an increase in evaporation.
Drying in some regions as greater warming over land than over oceans shifts atmospheric circulation patterns and reduces relative humidity (although the report also notes that humidity has very likely increased over land and likely over the oceans as well, a phenomenon explained in this Carbon Brief guest post.)
A slowdown of tropical circulation that partly offsets the warming-induced strengthening of precipitation in monsoon regions.
Citat:
For example, it says that, since the 1980s, the global-scale atmospheric circulation known as the Hadley cell has very likely widened, monsoon rains have likely increased and the northern stratospheric polar vortex – which was behind the much-discussed “Beast from the East” that struck the UK in 2018 – has weakened and experienced “more frequent excursions towards Eurasia”.
Citat:
“So it is a statement of fact, we cannot be any more certain; it is unequivocal and indisputable that humans are warming the planet…And every government agreed to that [wording in the SPM].”
Citat:
The chapter’s executive summary leads with the conclusion that it is an “established fact” that human-caused emissions of greenhouse gases “have led to an increased frequency and/or intensity of some weather and climate extremes”.
