The big wildcard for sea level rise is Antarctica.
If emissions continue at their current pace, Antarctica will cross a threshold into runaway sea rise when today’s kids are raising families. Pulling CO2 out of the air later won't stop the ice loss.
Aerial view of a glacier in the Antarctic peninsula region.
Getty Images/Mario Tama
Two centuries after it was first sighted by Russian explorers, Antarctica is a key site for studying the future of Earth's climate – and for global scientific cooperation.
Meltwater on the ice shelf near the McMurdo research station, Antarctica.
Nicholas Bayou / UNAVCO
These lakes could threaten the future stability of parts of the Antarctic ice sheet.
Rivers of melted ice on a Western Greenland ice sheet drain into the ocean beneath the ice.
Photo via Caspar Haarløv/AP
Studies show that the Arctic is heating up twice as fast as the rest of the planet.
A small boat in the Illulissat Icefjord is dwarfed by the icebergs that have calved from the floating tongue of Greenland’s largest glacier, Jacobshavn Isbrae.
Sea levels could rise by two metres by 2100, sparking a refugee crisis unlike anything the world has ever seen.
The research vessel must dodge dangerous icebergs as it drills for sediment core samples.
A paleooceanographer describes her ninth sea expedition, this time retrieving cylindrical 'cores' of the sediment and rock that's as much as two miles down at the ocean floor.
The northeast edge of the Venable Ice Shelf, near Antarctica’s Allison Peninsula.
Last summer one of Antarctica's floating ice shelves calved an iceberg the size of Delaware – but scientists say other less dramatic changes reveal more about how and why Antarctica is changing.
Scientists on Arctic sea ice in the Chukchi Sea, surrounded by melt ponds, July 4, 2010.
Climate change is transforming the Arctic, with impacts on the rest of the planet. A geographer explains why he once doubted that human actions were causing such shifts, and what changed his mind.
Melting Antarctic ice can trigger effects on the other side of the globe.
The climate secrets contained in an ancient tree that lived through abrupt global change reveal how Antarctica can trigger rapid warming in the north by dumping cold water into the Southern Ocean.
Water mass enters the ocean from glaciers such as this along the Greenland coast.
Greenland's ice is largely responsible for the accelerating pace of sea-level rise. A new analysis shows that, while Greenland accounted for just 5% of the rise in 1993, that figure rose to 25% by 2014.
An icebreaker makes its way through Antarctica’s sea ice.
After record-breaking amounts of sea ice in Antartica, this year we're seeing record lows.
Melting ice sheets – such as this one in Greenland – are one way the Earth amplifies global warming.
Ice sheet image from www.shutterstock.com
New projections suggest the world could warm 3-7 degrees over coming centuries.
The crew of scientists prepare to put the drill stem into the Greenland ice sheet to probe water flows about a half of a mile below.
A glaciologist develops a lightweight method for probing the depths of Greenland's ice sheet to answer a crucial question: How fast is it melting?
What lies beneath: bedrock peeks through the Antarctic ice.
Russ Hepburn, Kenn Borek Air
Buried beneath kilometres-thick slabs of ice are rivers and huge lakes - some of which are teeming with microbes that thrive in a world without light or oxygen.
Knowing where the ice comes from can help work out what it will do to sea levels.
Polar ice isn't all the same - it can be divided roughly into "land ice" and "sea ice". What matters most for sea levels is how much ice slides off the land and melts in the sea.
Some parts of Antarctica’s Totten Glacier are more stable than others.
New mapping shows how Antarctica's huge Totten Glacier has retreated far inland, raising sea levels by more than a metre. Rising temperatures could trigger it to do so again.
Glaciers have been a major contributor to sea-level rise.
Could sea levels really rise by several metres this century. Probably not, although this century's greenhouse emissions could potentially set the stage for large rises in centuries to come.
Where the ice meets the sea: Antarctica’s ice shelves play a key role in how fast ice sheets melt.
Antarctica image from www.shutterstock.com
As the world warms, Antarctica's melting ice will likely reach the point of no return.
Million-year-old ice likely lies more than 3km below Antarctica’s surface.
Tas van Ommen
Ice cores tell us vital information about how the world's climate has changed - and how it will change in the future.
A portion of the East Antarctic Ice Sheet, called Wilkes Land, flowing into the ocean.
Michael Hambrey/Glaciers online net
The way ice sheets respond to global warming may be more predictable than previously thought