Thursday, 6 November 2008

Gradually, the ice melts

This Scientific American article shows that we now have full house - all continents on Earth are showing signs of human caused global warming. If the Antarctic Western and Eastern ice sheets melt completely, global sea levels will eventually rise by around 230 feet. At my home in the North of St Lawrence, I will have a beachside house but unfortunately there won't be a Pizza Express to go to - so things won't be all Peroni and skittles.

http://www.sciam.com/article.cfm?id=warmer-antarctica-proves-global-climate-change&sc=CAT_SP_20081103

First paragraph follows: Humanity's impact on climate has been detected on every continent except Antarctica, or so said the United Nations Intergovernmental Panel on Climate Change (IPCC) in February 2007. No longer: scientists, comparing decades of records from 17 Antarctic weather stations with computer simulations of Earth's climate, found that human-induced global warming has been heating up the continent that is home to the South Pole, as well.

3 comments:

res nullius said...

Nick, is there a computer model or some other example to show the changing shape of this island when tides reach certain levels?

For example, I anticipate that St Clements and most of St Helier town will be completely underwater at some stage. However, there is something about the States Chambers being a good conger fishing spot that warms my heart...

ratleskutle said...

it's good to see diminishing uncertainty over anthropogenic causes of climate change. obama promises 25% of US electricity from renewables by 2025 and reduced greenhouse gas emissions by 80% by 2050. at least a step in the right direction. not sure how much climate change is an issue of interest to the jersey voting public though. i'd like to think there will be states members who understand it in place during the coming years and can work on suitable adaptation policies. good luck in st lawrence!

Nick Palmer said...

res - it would take a long time for the Antarctic's ice sheets to melt enough for St Helier to be under water, but a long time before that we would get very widespread and frequent flooding in storm surges - even a couple of feet rise would be catastrophic for St H.
Sea level rise happens for two reasons - firstly, any rise in temperature expands the water's volume but secondly (and much larger) if the Antarctic and Greenland ice sheets melt significantly then there will be a huge sea level rise eventually maxing out at around 250 feet - however this was forecast over a thousand years or so.

On the other hand, since the last IPCC report in 2007, evidence has come in http://www.technologyreview.com/energy/19504/?a=f (you might need to register to read this at M.I.T.'s technology review) that ice sheets are breaking up much faster than the figure that was put into the various computer models. The models assumed that the ice would melt from the top down but the sheets are actually breaking up faster than that because water from the surface gets to the bottom down cracks and lubricates the movement, thus breaking them up much earlier than expected. There is concern that sea level rise could start to affect us over just decades. If the methane starts coming out of the permafrost, then we are definitely snookered...