An outstanding Four Corners show last night dealt with the melting of the summer pack ice in the Arctic as a consequence of global heating. The reality of a 'north west passage' could become a reality by 2013 as the Arctic becomes ice free during the summer months. The US, Soviet Union and Canada are engaged in a scramble for oil and other resources that will become accessible as a consequence of this climate change - the use of these resources will of course worsen the problem. Shipping companies and fishery businesses are likewise scrambling for business in the newly opened up areas.
More seriously, the possibility of positive climatic feedbacks from reduced ice cover - less reflection of heat energy back into space and the possible melting of the northern permafrost - raises the realistic prospect of a climate change catastrophe that might impact on people currently living. This would markedly increase world average temperatures and substantially increase sea levels.
Severe temperature increases in turn might lead to drought in the Amazon and fires there than would release huge amounts of carbon and destroy 15% of the world's carbon absorption capacity. The Greenland ice sheet and the ice cover in parts of the Antarctic also become vulnerable. It is an apocalytic scenario that would make an enjoyable feature film were it not so plausible and potentially destructive for our children.
The show reinforced views in the Stern Review which is excellent on these same issues and was one of the first policy oriented-documents to account seriously for the prospect of catastrophic change.
The issues raised have immense consequences for dealing urgently with global heating issues. Indeed one view is that we may have already gone too far. The dates at which the summer pack ice was forecast to disappear has progressively shifted back from 2100 to 2070 to 2050 to 2013 ominously suggesting that the prospect of substantial damage is coming more keenly into focus.
An incidental observation - the photography in this show was superb.
Tuesday, August 05, 2008
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We might have to be as careful as our ancestors were 14 million years ago about crossing one of those climate 'thresholds' Harry-
http://news.yahoo.com/s/ap/sci_southern_tundra
And from the UK Telegraph-
Scientists have uncovered a treasure trove of meteorological information contained in the detailed logs kept by those on board the vessels that established Britain's great seafaring traditition including those on Nelsons' Victory and Cook's Endeavour.
Every Royal Naval ship kept a detailed record of climate including air pressure, wind strength, air and sea temperature and major meteorological disturbances.
A group of academics and Met Office scientists has unearthed the records dating from the 1600s and examined more than 6,000 logs, which have provided one of the world's best sources for long-term weather data.
Their studies have raised questions about modern climate change theories. A paper by Dennis Wheeler, a geographer based at Sunderland University, recounts an increasing number of summer storms over Britain in the late 17th century.
Many scientists believe that storms are caused by global warming, but these were came during the so-called Little Ice Age that affected Europe from about 1600 to 1850.
The records also suggest that Europe saw a spell of rapid warming, similar to that experienced today, during the 1730s that must have been caused naturally.
"British archives contain more than 100,000 Royal Navy logbooks from around 1670 to 1850 alone," Mr Wheeler said. "They are a stunning resource. Global warming is a reality, but our data shows climate science is complex. It is wrong to take particular events and link them to carbon dioxide emissions.
"These records will give us a much clearer picture of what is really happening."
I think the long-term data is interesting but irrelevant to current debates about global warming. With respect to the experience post 1600 I agree with the scientists observa, global warming is a reality and climate science is complex. There are (of course) natural elements which drive climate change.
Indeed during 'The Tipping Point' show one Russian scientist made the same point - global warming is occurring but natural changes are as well and cannot be ignored.
Adaptation policies would need to address both natural and anthropogenic warming.
"I agree with the scientists observa, global warming is a reality"
That may well be the case, just like those naval logs show in the past, but the question remains, does rising CO2 satisfactorily explain the current observations? Some notable adherents are now having serious doubts, which may be justified by the careful analysis of what appears to be one of the greatest scientific records on climate we have. That seems to be the case at first glance (there are around 94000 logs to go though)
As well as the Stern report in the UK, a similar and equally hard-hitting economist's view of climate change and we should, nay must, do is the Garnaut report to the Australian government. It hit the headlines in the press down there a week or so ago and has been picked up, I note, at the triage discussion site of http://www.climatechangetriage.net
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