Antarctic ice sheet melting fast: scientists

[tristan]

Antarctic ice sheet melting fast: scientists

http://www.abc.net.au/news/newsitems/200603/s1583224.htm

Scientists say Antarctica's mammoth ice sheet is in "significant decline", probably due to climate change.

United States researchers at the University of Colorado at Boulder say online in the journal Science that the Antarctic ice sheet is losing up to 152 cubic kilometres of ice a year.

Dr Isabella Velicogna from the University's Cooperative Institute for Research in Environmental Sciences says it is the first study to indicate the total mass balance of the Antarctic ice sheet is in significant decline.

The team calculated the ice sheet lost 152 cubic kilometres a year from April 2002 to August 2005, give or take 80 cubic kilometres.

That is equivalent to global seas rising 0.4 millimetres a year, with a margin of error of 0.2 millimetres, the researchers say.

[kokonutmama]

mm hmm.  I'll remember that next time i'm tempted to machine dry my clothes or go to the store just for chocolate.

[kokonutmama]

Or print something I don't have to or buy something I don't need.

[tristan]

It seems there is now little doubt that climate  change is happening. Scientists now agree that temperatures are increasing and the icecaps and glaciers are in decline.

Since the EU has been enforcing stricter air pollution controls (about 5 years) temperatures in Europe have gone up significantly - about 2-3 degrees average temperature. This has led (among other things) to an improved understanding of the role of air pollution in global warming. CO2 is the biggest greenhouse gas (by volume) and until recently the extent of its affect was unknown.

It has been discovered that CO2 will warm the earth significantly more than was thought.

The warming effects of CO2 are being masked by particulate pollution (the dirty stuff) that actually helps to cool the earth. Since the EU reduced the particulate pollution, the full effects of the CO2 warming are being realised.

Another study that adds to this was done September 11 2001 when all air traffic in the US was grounded. The lack of particulate pollution from aircraft (particularly at high altitude) resulted in a significant short term temperature increase ( a couple of degrees).

So the problem then is if we clean up and reduce air pollution then we will experience significant and rapid global warming. If we don't then we are just delaying the inevitable problem.

So this would suggest that we are in for significant global warming at some stage, sooner or later.

BUT...

There is also evidence that global warming could result in an ice age!

The concept was popularised by a movie, but there is science behind the idea. The North Atlantic Current (NAC) that keeps NE America and Europe relatively warm is driven by a process that could be stopped by global warming. It has been estimated that the NAC keeps Europe 5 - 15 degrees warmer. Without it there would be mass crop failure, etc.

The process that keeps the NAC going is as follows. The warm water moves north and evaporates, becoming more and more saline, and therefore dense. When it gets somewhere off Greenland it becomes so dense it falls, like a big sink, sucking more water north to fill the gap. With global warming there will be a significant amount of fresh water flowing out of rivers in Canada and Greenland, diluting the salinity, and potentially stopping the NAC.

There are several other feeback loops like this that might result in cooling, not warming. And more dangerous, the idea of rapid climatic change - where temperatures change by many degrees almost overnight.

So then with this information, why are we not doing more to reduce the impacts?

I know personally I am going to sell my car and buy a hybrid car (to support the renewable/alternative industry and to reduce my fuel consumption). Individual actions are not enough, we need government to take action - particularly the US government!

[jnezmama02]

interesting...this is the first time I've ever heard of the relationship between particulate pollution, CO2 and global warming.  I think this explains a lot.  The problem is that it's something we all know we should do better, but until it directly affects our lives, we won't change. It's hard to change when we won't see a tangible result and that the problem and benefit to the solution wouldn't be seen for many many years still.

Thanks for posting this. Very insightful!