section_path: Geography/Climate change
section_name: Climate change
paragraph_text: Climate change
  
  The Greenland ice sheet always loses some mass from ice calving at its coasts, but it used to balance this on average by the accumulation of snowfall. However, Greenland has been warming since around 1900, and starting in the 1980s, the losses became larger than the gains. After 1996, Greenland has not had a single year when it did not lose mass on average. In the 2010s, the Greenland ice sheet melted at its fastest rate during at least the past 12,000 years, and is on track to exceed that later in the century. In 2012, 2019 and 2021, so-called "massive melting events" occurred, when practically the entire surface of the ice sheet was melting and no accumulation took place. During the 2021 event, rain fell at Greenland's highest point for the first time in recorded history, an event so unexpected that the research station at the summit had no rain gauges for the occasion.
  
  As with the ice loss elsewhere, the melting of Greenland contributes to sea level rise. Between 2012 and 2017, this melting added an average of 0.68 mm per year, equal to 37% of sea level rise from land ice sources (excluding thermal expansion of water from the continual increase in the ocean heat content). By the end of the century, the melting of Greenland alone will add between ~ 6 cm (2 + 1 ⁄ 2 in) if the temperature change is kept below 2 °C (3.6 °F), to around 13 cm (5 in) if the most intense climate change scenario with ever-increasing greenhouse gas emissions is followed.: 1302 Under this scenario, the worst case for Greenland melting could reach 33 cm (13 in) of sea level rise equivalent. The large quantities of fresh meltwater also affect the Atlantic meridional overturning circulation (AMOC) by diluting key currents, slowing it down. Due to this meltwater input, the circulation may even collapse outright with widespread detrimental effects, although research suggests this is likely only if the highest possible warming is sustained for multiple centuries.
  
  Greenland's ice sheet has a volume of ~ 2,900,000 cubic kilometres (696,000 cu mi). This means that if it were all to melt, global sea level would increase by ~ 7.4 m (24 ft) from that event alone. However, it also means that it will take at least 1,000 years for the ice sheet to disappear even with very high rates of global warming, and in around 10,000 years under lower rates of warming which still cross the threshold for the ice sheet's disappearance. This threshold likely lies for between 1.7 °C (3.1 °F) and 2.3 °C (4.1 °F). Reducing the warming back to 1.5 °C (2.7 °F) or lower above preindustrial levels (such as through large-scale carbon dioxide removal) would arrest the losses, but still cause greater ultimate sea level rise than if the threshold had never been exceeded. Further, 1.5 °C (2.7 °F) itself appears to commit the Greenland ice sheet to 1.4 m (4 + 1 ⁄ 2 ft) of sea level rise.
  
  A study published in January 2025 in the Proceedings of the National Academy of Sciences reported an "abrupt, coherent, climate-driven transformation" from "blue" (more transparent) to "brown" (less transparent) states of lakes in Greenland after a season of both record heat and rainfall drove a state change in these systems. This change was said to alter "numerous physical, chemical, and biological lake features", and the state changes were said to be unprecedented.
  
  The Greenland ice sheet always loses some mass from ice calving at its coasts, but it used to balance this on average by the accumulation of snowfall. However, Greenland has been warming since around 1900, and starting in the 1980s, the losses became larger than the gains. After 1996, Greenland has not had a single year when it did not lose mass on average. In the 2010s, the Greenland ice sheet melted at its fastest rate during at least the past 12,000 years, and is on track to exceed that later in the century. In 2012, 2019 and 2021, so-called "massive melting events" occurred, when practically the entire surface of the ice sheet was melting and no accumulation took place. During the 2021 event, rain fell at Greenland's highest point for the first time in recorded history, an event so unexpected that the research station at the summit had no rain gauges for the occasion.
  
  As with the ice loss elsewhere, the melting of Greenland contributes to sea level rise. Between 2012 and 2017, this melting added an average of 0.68 mm per year, equal to 37% of sea level rise from land ice sources (excluding thermal expansion of water from the continual increase in the ocean heat content). By the end of the century, the melting of Greenland alone will add between ~ 6 cm (2 + 1 ⁄ 2 in) if the temperature change is kept below 2 °C (3.6 °F), to around 13 cm (5 in) if the most intense climate change scenario with ever-increasing greenhouse gas emissions is followed.: 1302 Under this scenario, the worst case for Greenland melting could reach 33 cm (13 in) of sea level rise equivalent. The large quantities of fresh meltwater also affect the Atlantic meridional overturning circulation (AMOC) by diluting key currents, slowing it down. Due to this meltwater input, the circulation may even collapse outright with widespread detrimental effects, although research suggests this is likely only if the highest possible warming is sustained for multiple centuries.
  
  Greenland's ice sheet has a volume of ~ 2,900,000 cubic kilometres (696,000 cu mi). This means that if it were all to melt, global sea level would increase by ~ 7.4 m (24 ft) from that event alone. However, it also means that it will take at least 1,000 years for the ice sheet to disappear even with very high rates of global warming, and in around 10,000 years under lower rates of warming which still cross the threshold for the ice sheet's disappearance. This threshold likely lies for between 1.7 °C (3.1 °F) and 2.3 °C (4.1 °F). Reducing the warming back to 1.5 °C (2.7 °F) or lower above preindustrial levels (such as through large-scale carbon dioxide removal) would arrest the losses, but still cause greater ultimate sea level rise than if the threshold had never been exceeded. Further, 1.5 °C (2.7 °F) itself appears to commit the Greenland ice sheet to 1.4 m (4 + 1 ⁄ 2 ft) of sea level rise.
  
  A study published in January 2025 in the Proceedings of the National Academy of Sciences reported an "abrupt, coherent, climate-driven transformation" from "blue" (more transparent) to "brown" (less transparent) states of lakes in Greenland after a season of both record heat and rainfall drove a state change in these systems. This change was said to alter "numerous physical, chemical, and biological lake features", and the state changes were said to be unprecedented.