you may have noticed this is
my Reading the last 12 months of New Scientist month
This article, this month, has astounding implications, especially for Australia.
Unfortunately I left the article on the train. Fortunately most of it is on the web
Rainforests may pump winds worldwide - environment - 01 April 2009 - New Scientist
As I understand it the premise is that coastal forests cause rain.
The rain falls thus decreasing air pressure; this sucks in moist sea air further inland, where forests make more rain; this causes a drop in air pressure resulting in further inward movement of moist air. And this process just gets repeated and repeated. The magazine had a neat little graphic explaining it all much better than words.
This is how some Russian Scientist believe coastal forests suck precipitation (rain) further and further inland.
In Australia the forests we are chopping down are the coastal ones.
The inland is getting dryer.
Australia is like a huge wagon wheel with 'the mud on the edge' the major centres of population. We like to live on the coast, build hot cities made of concrete- spread out-a car oriented society- like LA.
It may be that aboriginal burning of coastal forests over 40-60,000 years (pick a number) may have dried out the continent.
Quote:
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The theory suggests that past civilisations could have had a much greater impact on global climate than we thought. Australia once had forests but is now largely desert. Gorshkov and Makarieva argue that Aborigines burning coastal forests may have switched the continent from wet to dry by shutting down its biotic pump.
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The implications of this theory/model are far reaching
- Oz Outback farmers can blame the city dwellers for their drought?
- We may need to green our cities post haste
- get those indoor plants going?
- should we be clearing coastalland to build a sea of concrete roofs, now, with new planning laws, no room to grow a tree-no "backyards."
- should we be wood-chipping coastal forests for the Japanese to make origami?
- how does this affect the Great Barrier reef and its aquifers?
- should we be moving city development inland (more Canberras ! Horror!)
Of course the implications may be similar in other countries.
However the implications may also be GLOBAL
Quote:
The implications are global, he adds. "We think some of the recycled Amazon moisture is taken on a jet stream to South Africa, and more maybe to the American Midwest. Gorshkov and Makarieva are looking at the front end of an absolutely critical process for the world's climate."
If their theory is correct, it means that large forests help kick-start the global water cycle.
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Quote:
Climatologists are already worried about the state of the Amazon rainforest. Last month, the UK's Met Office warned that if the planet warms by 4 degrees, 85 per cent of the forest could dry out and die.
If Gorshkov and Makarieva are right, the Amazon will be gone before warming kicks in.
They predict that even modest deforestation could shut down the pump and reduce rainfall in central Amazonia by 95 per cent.The same could happen in the world's other large rainforest regions, such as central Africa.
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Quote:
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It's not all bad news. If natural forests can create rain, then planting forests can, too. Sheil says, if forests attract rain, then replanting deforested coastal regions could re-establish a biotic pump and bring back the rains. "Once forests are established, the pump would be powerful enough to water them. Could we one day afforest the world's deserts? Makarieva and Gorshkov's hypothesis suggests we might."
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http://www.newscientist.com/article/...html?full=true
