Global environmental challenges
Antarctic ice expands — global warming at work?
Ice getting bigger hardly sounds like a sign of global warming but that’s apparently what is happening in the seas around Antarctica.
Leading climate scientists say that a tiny trend towards bigger ice in winter floating on the oceans around the frozen continent since the late 1970s — the maximum extent is around now, in September — is consistent with models of climate change that predict harsher winds and less warmer water at the surface.
It may even be that there’s more snow and rain falling onto the southern oceans because of climate change — that can raise the amount of fresh water on the surface and, hey presto, fresh water freezes at a higher temperature than salt water.
At Reuters News my colleagues and I often write stories about the shrinking of summer ice at the other end of the world, in the Arctic, as one of the clearest signs of global warming that is blamed by the U.N. Climate Panel on human use of fossil fuels.
In response to those stories, I often get e-mails from people sceptical about climate change who say that ice at the other end of the earth, around Antarctica, is expanding.
But it turns out that leading scientists at NASA, the British Antarctic Survey and Norway’s Nansen Center say the two things are not contradictory — the world reacts to greenhouse gases in different ways.
Antarctica is a gigantic frozen continent and winds sweep around it in the southern oceans, without drawing in much warmer air from further north. The Arctic is an open ocean ringed by continents, and more vulnerable to currents and winds blowing up from the south.
So you really can have your ice and melt it, depending on which pole you’re talking about.
What do you think?