Global temperatures are likely to rise beyond the critical 1.5 degrees Celsius threshold within the next few years, the United Nations Environment Program said Wednesday, warning that the breach would increase extreme weather and put further pressure on ecosystems, glaciers and low-lying coastal communities.
UNEP said returning global warming to below 1.5C remains possible, but is now highly uncertain. Doing so would require rapid reductions in greenhouse gas emissions alongside efforts to remove carbon dioxide already accumulated in the atmosphere.
Paris target increasingly likely to be exceeded
Under the 2015 Paris Agreement, governments committed to limiting the increase in global temperatures to 1.5C above pre-industrial levels in an effort to reduce the impacts of climate change and extreme weather.
UNEP said a temporary period above that threshold, known as “overshoot,” is now extremely likely. As a result, governments should focus not only on preventing further warming but also on minimizing the amount of time global temperatures remain above 1.5C.
“Every year of delay and every fraction of a degree above 1.5C increases risks and makes recovery harder,” UNEP said, warning that some losses could become irreversible even if temperatures eventually decline.
The agency’s most optimistic projection puts peak warming at 1.8C above pre-industrial levels, assuming countries fully implement their existing national climate pledges. However, UNEP said warming is likely to be significantly higher.
Under current policies, median global warming is projected to reach about 2.6C by 2100, according to the report.
Carbon removal needed alongside emissions cuts
As reported in Reuters, UNEP said removing carbon dioxide from the atmosphere will become critical to bringing temperatures back down after an overshoot.
Such measures include expanding forests and other approaches to removing carbon dioxide from the atmosphere. But the agency stressed that carbon dioxide removal cannot substitute for substantial reductions in current emissions.
Rapid cuts in emissions remain necessary to limit both the scale and duration of global warming above the 1.5C threshold.
