There is no doubt that the West Antarctic Ice Sheet has been melting, although the rate of melting has varied over time.

Climate scientists simply assumed that this was due to man-made global warming.  But scientists measuring the geothermal heat generated under the ice sheet found that the temperature was "surprisingly high," throwing the theory that global warming is responsible for the melt into a cocked hat.

The West Antarctic sheet is the part of the Antarctic ice cap thought to be easiest to melt and thus worries over global warming and sea-level rise lead to it being investigated much more than other parts of the frozen austral continent. Some parts of it, for instance the Pine Island Glacier, have appeared at times to be melting faster and faster, though it is not clear that this is due to global warming.

At other times, ice loss to the sea has appeared to slow right down.

Meanwhile all around the rest of Antarctica, the extent of sea ice has been growing not shrinking, such that there is nowadays much more Antarctic sea ice than there used to be - a circumstance which climate scientists admit has them stumped.

It's all a very confusing picture, then, and to make it worse nobody until now has had any idea how much heat might be reaching the possibly-troubled West Antarctic sheet not from the somewhat warmer seas and atmosphere, but from the rock beneath it.

That uncertainty has now been lessened somewhat, with instrumental readings from below the ice obtained and published at last in the journal Science Advances.

"It is important that we get this number right if we are going to make accurate predictions of how the West Antarctic ice sheet will behave in the future, how much it is melting, how quickly ice streams flow, and what the impact might be on sea level rise," says Professor Slawek Tulaczyk. "I waited for many years to see a directly measured value of geothermal flux from beneath this ice sheet."

Exactly what the new geothermal heating figures mean for the forecasts remains to be seen, but it is clear that the amount of geothermal heating is a good bit more than scientists had thought. Some of them are still hoping that it's a fluke result.

There has been a fierce debate over ice cap melting at both poles, with competing measurements.  The geothermal measurement may explain the disparity between the melting of the ice sheet and ice accumulating on the rest of the continent.

But have no fear: our intrepid global warming hysterics will cast about for an explanation that will blame humans for the volcanic activity.  That's the advantage of advocating "settled science."  Global warming means never having to say you're sorry...or that you're wrong.