Over the course of the earth's history, the average
temperature of the planet has fluctuated greatly.
Orbital Changes Might Be The Key
To Some Changes.
The Tibetan Plateau's Rise
Probably Had A Major Impact.
Meteor/comet impacts, and volcanoes have had devastating effects.
Approximately 10,000 yrs, ago the U.S. was covered
w/ a sheet of ice as far south as Illinois.
Now the ice caps are receding.
This will mean higher sea levels in the future, and as most of the world's
people live on the ocean's coastlines, many will be flooded out of their homes.
About 3,000 yrs. ago there was no Sahara desert in North Africa.
Then The Earth's Axis Tilted.
Now an area as large as the continental U.S. is pure sand.
The Sahara has driven steadily south over the last 50 yrs. leaving
over 50 million Africans dead from drought/war-induced famine.
The natural temperature increase has been exacerbated by the
massive release of carbon monoxide into the atmosphere by
internal combustion engines, and other fossil fuel burning machines.
So far the world has done nothing about the problem.
The U.S. Congress unanimously passed a 'transportation' bill
that will make us even more dependant on the automobile.
I Guess They Weren't Looking At Our
This, as the world's politicians prepared to sign a treaty
to deal w/ global warming called the 'Kyoto treaty'.
The fact that many of the world's forests were ravaged by
drought that led to massive forest fires didn't make an impact.
Gas Hydrates Might
Be The Key