A puzzling, decade-long slowdown in summer warming across Greenland has been explained by researchers at Hokkaido University in Japan. Their observational analysis and computer simulations revealed that changes in sea surface temperature in the tropical Pacific Ocean, thousands of miles to the south, trigger cooler summer temperatures across Greenland. The results, published in the journal Communications Earth & Environment, will help improve future predictions of Greenland ice sheet and Arctic sea ice melting in coming decades.