International Climate Change Panel (IPCC) is a part of the United Nations that assess climate change science. In 2023, they published a report that sums up the sixth round of assessment cycle. Here a few highlights after reading the report.
First, global surface temperature has increased by 1.1C compared to 1850-1900, and it’s very likely that human contribution is the main driver.
Second, trends from national policies show that GHG emissions might grow from above 50 to about 60 billion tonnes. Scenarios that show reduction of emissions to keep the temperature increase below 2 degrees would require a significant decay in emissions, which, while possible, is not very likely. And it is not very likely because, to limit the warming – absent of technological breakthroughs – developing countries would need to increase “green” spending at least by a factor of four, and developed – at least by a factor of 3.
Third, with current trends, and with current spending, it seems that we’re heading into 3.0-3.5-4.0(?) degree temperature increase. This is by 2100 – by 2050 the maximum projected is around 2.5 degrees. IPPC presents the risks of that as very high for unique and threatened systems (coral reefs, glaciers, biodiversity hotspots). As per the report, beyond 4 degrees extreme water shortages for something like half of word’s population, and without adaptation there would be more fires, more floods, and less food.
Source:
IPCC, 2023: Sections. In: Climate Change 2023: Synthesis Report. Contribution of Working Groups I, II and III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, H. Lee and J. Romero (eds.)]. IPCC, Geneva, Switzerland, pp. 35-115, doi: 10.59327/IPCC/AR6-9789291691647