Adélie penguin at the Mt Siple breeding colony, West Antarctica.
Climate change is set to expand Antarctica's ice-free area, potentially helping native species to flourish but also paving the way for invasive species to gain a foothold.
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.
Sea ice covering the Arctic Ocean during the winter peak in February 2015.
NASA's Scientific Visualization Studio
There is no doubt that 2016 has been a record-breaking year for the Earth’s climate.
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.
We still don’t know enough about questions such as where the tipping points are for Arctic ice melt.
Christine Zenino/Wikimedia Commons
The Paris agreement has given us some solid targets to aim for in terms of limiting global warming. But that in turn begs a whole range of new scientific questions.
Antarctica is vital to the planet’s climate system.
Antarctic image from www.shutterstock.com
Why should we care if the polar ice sheets melt hundreds of years in the future? Because they are vital for maintaining our current climate.
In some regions of the Arctic, polar bears will spend their entire lives on sea ice or the ocean.
Could polar bears slip into a hibernation-like state to tough out lean hunting during summers with little sea ice? Sadly, experiment suggests no.
Rising sea levels are one of the clearest and most widespread manifestations of climate change.
Since 1993, satellites have been used as well as tidal gauges to monitor sea level. A new calibration of this satellite record now shows that the rise in sea level is gathering pace.
The Totten Glacier, the largest in East Antarctica, has deep channels running beneath it that may allow relatively warm water into its belly.
Tas van Ommen
Researchers in East Antarctica have surveyed an area the size of New South Wales to study the behaviour of the region's biggest glacier - and the secrets below the ice that could speed up its melting.