Recent extreme heatwaves are no match for future events.

Future 21st-century heatwaves are projected to be far more intense and longer than recent record-breaking events, with high-to-very-high emissions producing several-times more cumulative heat and up to several months duration.

• Why it matters: Recent extreme heatwaves have already caused serious impacts, but it is unclear whether today’s worst events represent a ceiling for what could occur later this century.
• What they did: The study compares multiple metrics for several observed exceptional heatwaves against potential 21st-century events under low-, medium-, and high-to-very-high-emissions scenarios, and also evaluates cases where Paris Agreement NDCs are not implemented.
• The result: Under low- and medium-emissions, some observed heatwaves remain unmatched, while under high-to-very-high emissions many regions are projected to exceed observed heatwave characteristics, and without NDCs most regions show a large share exceeding all analyzed characteristics at once.

AI summary of the abstract · may contain errors · not medical advice · read the paper.