Timothy Naish, Te Herenga Waka — Victoria University of Wellington
The world is on track to exceed 2°C warming within the next five years, with dire consequences for polar ice, mountain glaciers and permafrost – and human society.
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.
Greenland’s ice made headlines in June, as warm weather made for unseasonably widespread melting. And though this summer is still unfolding, the human fingerprint on Greenland’s ice can’t be denied.
For everyone from traditional hunters to the military, the National Park Service to the oil industry, climate change is the new reality in Alaska. Government, residents and businesses are all trying to adapt.
What will Antarctica look like in 2070? Will the icy wilderness we know today survive, or will it succumb to climate change and human pressure? Our choices over the coming decade will seal its fate.
Since 1995, several ice shelves off the Antarctic Peninsula have abruptly disintegrated. A new analysis suggests that these events are triggered when ice shelves lose their buffer of floating ice.
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.
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.
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.
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.
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.
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.
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.
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.
Chief Investigator for the ARC Centre of Excellence for Climate Extremes; Deputy Director for the Australian Centre for Excellence in Antarctic Science; Deputy Director for the Centre of Excellence for 21st Century Weather, Australian National University