UN Climate Panel Shifts From Extreme Warming Scenario

The United Nations climate panel revised its modeling approach last month by replacing one high-emission pathway with seven alternative scenarios. The change affects a pathway that had projected warming of 4 to 5 degrees Celsius by the end of the century.

Officials said the scenario had become implausible based on trends in renewable energy costs, climate policy developments, and recent emission trends.

Background on the Scenario The pathway appeared in roughly 45,000 academic papers and served as the basis for forecasts of mass crop failure, rising seas, and extinction-level outcomes. Researchers published findings in Geoscientific Model Development stating the high-emission pathway had become outdated.

An agency scrapped an Obama-era greenhouse gas rule in February. Officials also removed signage at Glacier National Park in 2020 after predicted ice melt did not occur. A memo released before the COP30 summit stated that climate change will have serious consequences, particularly for people in the poorest countries, but will not lead to humanity's demise.