1445. Record-Sized Melt of the Greenland Ice Sheet

In the climate change debate, the melting of the Greenland ice sheet and Arctic sea ice, along with permafrost melt, Antarctic ice sheet melt, and Amazon deforestation, are considered to be tipping elements (subsystems where the Earth is likely to pass a tipping point due to anthropogenic activities, where large-scale, gradual, and irreversible changes occur).

According to a study published in Nature Communications, climate change is significantly altering the nature of extreme melt events on the Greenland Ice Sheet, making them more frequent, widespread, and intense. Since 1990, the area affected by extreme melt events has expanded at a rate of 2.8 million km² per decade. Furthermore, the amount of water produced by ice sheet melt has increased more than sixfold, from 12.7 gigatonnes per decade to 82.4 gigatonnes per decade. Seven of the 10 most extreme melt events have occurred since 2000, including record-breaking events in August 2012, July 2019, and July 2021. These events are unique and without dynamic precedents, highlighting their exceptional nature.

The study analyzed extreme melt events recorded between 1950 and 2023 using an innovative classification method that combined anticyclonic and cyclonic air mass circulation types with regional climate models. This approach made it possible to distinguish between the role of thermodynamic factors (related to atmospheric warming) and dynamic factors (related to atmospheric circulation) in the intensification of melt events.

The study found a clear thermodynamic intensification of extreme melt events, with more water being produced during each event. Since 1990, meltwater production has increased by 25% compared to the 1950-1975 period when comparing events with anticyclonic and cyclonic air mass circulation, and by up to 63% when analyzing all extreme events.

The most affected region is northern Greenland, which has emerged as one of the major hotspots. Future projections under high greenhouse gas emissions scenarios indicate that extreme anomalies in meltwater production could increase by up to three-fold by the end of this century.

(Reference)
Josep Bonsoms et al., Record-breaking Greenland ice sheet melt events under recent and future climate, Nature Communications (2026). https://www.nature.com/articles/s41467-026-69543-5

Contributor: IIYAMA Miyuki, Information Program