Expansion of aquatic vegetation in northern lakes amplified methane emissions

Aquatic vegetation contributes to lake methane emissions, but changes in aquatic vegetation in northern (>40° N) lakes remain unknown, hindering evaluations of its importance in estimating lake emissions. Here we use Landsat imagery to monitor aquatic vegetation (mainly emergent and floating vegetation) in 2.7 million northern lakes from 1984 to 2021. Vegetation was observed in 1.2 million lakes, with a total maximum vegetation area of 12.0 × 104 km2, a mean vegetation occurrence of 1.68 ± 3.8% and a greenness of 0.66 ± 0.05. From the 1980s–1990s to 2010s, significant (P