The second part of this article gets really interesting, where the author speaks about the influence destruction of natural systems can have on a climate.  When these wetlands were destroyed, it not only displaced people from the area (and ruined their livelihoods) but also caused the region to become warmer overall - evaporating water from the surface and destroying agriculture. 

In truth, Saddam was not interested in the farmers. His real goal was to harm the Madan, also known as the Marsh Arabs. For thousands of years, the marshes had been the homeland of this ethnic group and their cows and water buffalo. They lived in floating huts made of woven reeds and spent much of their time in wooden boats, which they guided with sticks along channels the buffalo had trampled through the reeds. They harvested reeds, hunted birds and caught fish.

When the fishermen backed a Shiite uprising against the dictator, the vindictive Saddam turned their “Garden of Eden” into a hell. He had thousands of the Marsh Arabs murdered and their livestock killed. Any remaining water sources were poisoned and reed huts burned to the ground. Many people fled across the border into Iran to live in refugee camps, while others went to the north and tried to survive as day laborers. By the end of the operation, up to half a million people had been displaced.

via spiegel online