sea level rise

The Greenland Ice Sheet could be lost without emissions cuts

A large iceberg has broken the surrounding layer of consolidated sea ice.
A large iceberg with areas of open water nearby. Photo: NASA/Linette Boisvert

Without significant near-term cuts to greenhouse gas emissions, all of the ice in Greenland could be lost within the next millennium, a new study finds.

Why it matters: The Greenland Ice Sheet is the second-largest ice sheet in the world, containing enough water to raise global sea levels by 23 feet if it were to melt completely. While a 1,000-year timeframe sounds extremely long, it is unusually speedy in geologic time, and the resultant sea level rise would drown many coastal megacities long before the year 3000.

Climate change visualized: How Earth's temperature has changed since 1970

Data: NASA GISS; Graphic: Harry Stevens/Axios

2018 was Earth's 4th-warmest year on record, coming in behind 2016, the planet's warmest recorded year, as well as 2015 and 2017, according to information released by NOAA, NASA and the U.K. Met Office.

Why it matters: The yearly rankings don't tell the whole story of long-term climate change, since natural variability can still push or pull an individual year up or down the rankings. However, the overall picture is growing starker with each passing year. Nine of the 10 warmest years on record since reliable data began in 1880 have occurred since 2005. At the same time, greenhouse gases from the burning of fossil fuels — as well as deforestation and intensive agriculture — have skyrocketed to levels not seen in more than 800,000 years.