Today, August 9, 2021, the United Nations’ officially climate experts committee has released an updated report on climate change’s physical evidence and a list of solutions for policy makers. I’ve read over the policy maker’s report, and hope to explain what the document’s premises in terms that the layperson can comprehend. Since the International Panel on Climate Change’s last report, the AR5 (released in 2014), UN experts have made modifications in their modeling techniques and data analysis regarding anthropogenic climate change.
IPCC Sixth Assessment Report
The AR6 reports, with varying degrees of confidence, that the last few decades have been marked by increasing average surface temperature (0.8°C to 1.3°C for the years 1850-1900 to the years 2010-2019), increasing precipitation levels, melting Antarctic Ice Sheet and Greenland Ice Sheets, decreases in Arctic sea ice, rising upper ocean temperatures (depth of 0-700 meters) and rises in global sea levels. UN climate experts attribute relatively recent shifts in climate and weather to human influence.
Researchers also provide reconstructed data which simulates the mean surface temperature over the last 100,000 years. It is within the last 2000 years that an unprecedented spike occurs in mean surface temperature. Climate models suggest that rises in greenhouse gas levels, land use, ozone use and other human activities to explain the rise in global surface temperatures. The concentrations of carbon dioxide and methane exceed natural multi-millennial levels; these natural gases happen to be the some of the primary products of human industrial activities, such as agriculture, organic waste and energy.