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