A new Syracuse University study indicates climate change is natural and not caused by man.
A team of scientists found that the different parts of the Earth heated up during medieval times about 500 to 1,000 years ago.
They discovered the earth was warm from Europe down to Antarctica. After that, the Earth cooled back down.
The study, published recently online in the journal Earth And Planetary Science Letters, comes as the Environmental Protection Agency is issuing new regulations Tuesday on global warming.
The new rules are an attempt to limit greenhouse gasses, which some people say cause global warming.
Republicans warned that the rules will raise electricity prices and damage the coal industry.
The regulations will not apply to existing power plants, but some analysts say the rules will make it nearly impossible to build new power plants.