Drought conditions have affected much of the U.S. Southwest and Central Plains in recent years. But scientists now believe future droughts in the last half of this century could be the worst in the past millennium.

An ultra-high-resolution NASA computer model has given scientists a stunning new look at how carbon dioxide in the Atmosphere travels around the globe. Plumes of carbon dioxide in the simulation swirl and shift as winds disperse the greenhouse gas away from its sources.

Fire is a powerful force on our planet. From South America's rainforests to Africa's savannas and Australia's highlands, fires touch 30 percent of the land surface. Yet whether naturally occurring or set by humans, fires' effects reach far beyond ravaged lands.