Himalayan Glaciers Not Shrinking as Much as Expected
A news report yesterday in NATURE that the Himalayan glaciers are not disappearing as anticipated has caused a flurry of discussion in the scientific community — and also fueled those that want to assert global warming is not happening.
My take is that while interesting, and good science, it is not that surprising, nor does it in any way contradict the larger climate change scenario. Consider:
97% of the world’s water is locked up in Antarctica and Greenland (the “cryosphere”). Since those two ice sheets are in melt mode, the impact is clear in terms of the trend for the amount of ice, and the impact on sea level.
Fundamentally, as the oceans warm, more moisture will evaporate, and will come down as rain or snow, depending on the temperature of the region at the time. (In other areas we have droughts not seen in decades.) We have already seen record snowfalls and rain in specific parts of the planet. What is happening is that the PATTERNS of usual cold and warm areas by seasons are changing — precisely BECAUSE of the overall warming planet during the last century. While it may be colder in some areas, many other areas, like the Arctic are warmer than in millions of years — and that’s a problem — since that is what is causing the ice sheets to melt at an unprecedented rate.
As reported in a great piece “Bundle Up, It’s Global Warming” by Judah Cohen in the NYT on 12-25-10, excessive snow was noted as piling up in Siberia, due to the phenomenon of unusual moisture. The effect was identified that the unusual snow, had caused a standing wave in the atmosphere, that was effectively diverting the jet stream, putting a colder than usual airmass in place. It is a good example how warming temperature, is consistent with greater snowfall in some places.
The fact that the 2-3% of the ice represented by the glaciers — in the lower latitudes — may not be diminishing as expected, is very interesting — and needs to be understood quantitatively for better modeling — but in no way negates the larger warming trend. The fact that the Himalayas are NOT in net melt mode, does not change the larger picture