Scientists are warning that a long-term temperature increase of more than two-degrees Celsius would have dangerous consequences for global climate systems. 

Meeting at a U.N. sponsored climate conference in Argentina Tuesday, a group of European experts said such an increase could threaten Latin American water supplies, reduce food yields in Asia and increase extreme weather conditions in the Caribbean.

Most scientists agree that global temperatures have already risen an average of more than half-a-degree Celsius over the past century.

The main focus of the two-week U.N. conference in Buenos Aires conference is the 1997 Kyoto Protocol, which mandates the reduction of carbon dioxide and other gas emissions believed to cause global warming.  The United States and Australia are the only major industrial countries that have failed to ratify the accord.  In rejecting the accord, President Bush said it would damage the U.S. economy.

Some information for this story provided by AP.