Their report comes just days before President Barack Obama goes to Copenhagen, Denmark, to speak at a United Nations conference on climate change.
Rising temperatures over decades have prompted scientific concern, and the last decade has been the hottest in thousands of years, according to climate records. However, the warming eased a bit last year over North America, and groups seeking to deny climate change seized on that in an effort to challenge the idea of overall warming.
North America wasn't as warm as expected because of cooler water in the North Pacific, but the rest of the world continued to warm, the university and government researchers said Friday.