It_is_the_Darkness wrote on Nov 5
th, 2010 at 5:17pm:
Quote:Oh for gods sake.....the Sahara region wasn't because of 'deforestation' it was because the climate dried out...logging had nothing to do with...
The same thing spelled the demise of the Mega-Fauna here in Australia...Changes in climate, leading to a reduction of the amount and type of vegetation is what killed the Mega Fauna....
Not even close Gizmo - you get rid of the Trees (etc) and you are drying the area out. You are removing that cool moist barrier between canopy and ground.
And BBQ (Carib) has been around for a long time with the Aboriginals doing it on a large scale. When the settlers arrived, Sydney Basin was neatly 'burnt' to keep underbrush to a minimum - resulting in nice forests of trees only.
There is so less many trees today (75% reduction I reckon) - coincidently bringing the idea of Global Warming.
Put in 6+Billion carbon dioxide producers and things a kinda warm indeed. Ever been in a small room with heaps of people - gets kinda stuffy and sweaty real fast
...common sense.
And if the Continent drifts closer to the Equator, then the summers become drier and the rainforests turn into deciduous, and then into savannah and finally into deserts...
The closer to the Equator, the hotter and drier the climate and the less lush the vegetation...
"The climate of the Sahara has undergone enormous variation between wet and dry over the last few hundred thousand years.[11] During the last glacial period, the Sahara was even bigger than it is today, extending south beyond its current boundaries.[12] The end of the glacial period brought more rain to the Sahara, from about 8000 BC to 6000 BC, perhaps due to low pressure areas over the collapsing ice sheets to the north.[13]
Once the ice sheets were gone, northern Sahara dried out. In the southern Sahara though, the drying trend was soon counteracted by the monsoon, which brought rain further north than it does today. The monsoon is due to heating of air over the land during summer. The hot air rises and pulls in cool, wet air from the ocean, which causes rain. Thus, though it seems counterintuitive, the Sahara was wetter when it received more insolation in the summer. This was caused by a stronger tilt in Earth's axis of orbit than today, and perihelion occurred at the end of July.[14]
By around 3400 BC, the monsoon retreated south to approximately where it is today,[15] leading to the gradual desertification of the Sahara.[16] The Sahara is now as dry as it was about 13,000 years ago.[11] These conditions are responsible for what has been called the Sahara pump theory."
What is this fascination you have with (75%)????
"humans caused a 75% reduction in Bison herds"
"humans caused a 75% reduction in tree numbers"...
Why is it always 75%???
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