Re: Tropical 'hotspots' may get too warm to farm

[Guest guest]

Some of these areas have seen the advance of deserts since Roman times. They remarked on the visible advance of the Sudanese deserts more than 2,000 years ago. Other places have seen land become unusable because of a UN well drilling program. The UN drilled thousands of wells in dry areas for drinking and irrigation which improved the standard of living and crop yields for a while. The second cause, however, was that the water table dropped rapidly and even deep-rooted trees died for lack of water. Soon the land was useless and the people moved on.

Another thing that is happen is that because of rapidly expanding populations in many places, forests are being cut down for living space and farms. This soil is also usually of poor quality and so farm yields quickly fall off meaning they have to move on to new land before long. Taking out the trees cuts a link in the water cycle because the trees release a lot of water vapor into the air which can then fall back elsewhere as rain.

Some of the temperature increase is also likely because of this. Replacing forests with tin-roofed houses and bare dirt and the local temperature will go up. Then again there is probably also the usual problem with placing thermometers or even removing them and using computers to guess what the temperature is using sensors hundreds of miles away. Another point is the long term of the computer estimates, their lack of accuracy and just how they are programmed.

In a message dated 6/3/2011 11:56:57 A.M. Eastern Daylight Time, no_reply writes:

Tropical 'hotspots' may get too warm to farm