Thread: Apparently Antarctica is warming after all.

This new (January - perhaps you've discussed it, if so I missed it) map from NASA uses satellite data, validated by the rather sparse ground station data to show that east Antarctica, which previously was thought to be staying the same or even cooling, probably has warmed since 1957. The new analysis method is described toward the bottom of the article.

http://earthobservatory.nasa.gov/IOTD/view.php?id=36736

Is a warming of 0.5 C in 50 years significant in a continent that averages minus 50 C, and has an average ice thickness of almost 2 kilometres?

Obviously warming of the ocean means ice melt around the edge, but what of the rest of the continent?

Depends what you mean by significant. I would think that the researchers were interested in reconciling their climate models with observations, and until now the observations seemed to suggest no change or slight cooling. Ocean circulation and the ozone layer depletion have been proposed as reasons for this, but it was still not clear that these effects ought to overwhelm the overall warming trend.

As the article describes, the limited ground station data that indicated no change or cooling has been used to validate much more extensive satellite data that indicate slight warming. This is significant to climate modelers since it is another empirical check of their models.

That's fine.

I have read elsewhere that the melting of the ice in Antarctica would release enough water to raise sea levels by 60 metres. However, there is nothing here to indicate anything other than localised melting at the edge of the sea.

No one is suggesting that all the ice in Antarctica is going to melt, but more realistically, look at the map of western Antarctica. It's warming more rapidly than the eastern part, and the loss of sea ice is allowing the glaciers to move faster into the sea. Antarctica is losing ice more rapidly than assumed in the IPCC scenarios. Exactly what this will mean for sea levels I'm sure is being studied. Not 60 metres though.