Some of the climate changes will be irreversible for millennia. But some can be slowed and even stopped if countries quickly reduce their greenhouse gas emissions, including from burning fossil fuels.

A particularly stormy winter has pushed perennial sea ice into the Arctic melt zone.

Emperor penguins survive in a ‘Goldilocks zone’ between too much sea ice and too little. A new study shows the risk they face from climate change.

Emperor penguins survive in a ‘Goldilocks zone’ between too much sea ice and too little. A new study shows the risk they face from climate change.

Emperor penguins survive in a ‘Goldilocks zone’ between too much sea ice and too little. Global warming is raising risks.

Emperor penguins survive in a ‘Goldilocks zone’ between too much sea ice and too little. Global warming is putting their chicks at risk and setting almost every colony on a path toward extinction.

The world's ice is shrinking by 33,000 square miles a year, according to the first ever global asessment of the Earth's cryosphere.

An area once considered to be a potential last refuge for ice-dependent animals in the Arctic is already showing signs of ice loss.

Almost all the world's glaciers, about 220,000 in total, are are rapidly becoming thinner and losing mass, a new study shows.

Russia is attempting to claim more of the Arctic seabed – an area rich in oil, gas and minerals – and its fleet of icebreakers is helping shipping expand. The US needs some creative ideas to catch up.