Scientific evidence for warming of the climate system is unequivocal. Ice cores drawn from Greenland, Antarctica, and tropical mountain glaciers show that Earth's climate responds to changes in greenhouse gas levels.

United Nations legal instruments The UN family is at the forefront of the effort to save our planet. In 1992, its “Earth Summit” produced the United Nations Framework Convention on Climate Change (UNFCCC) as a first step in addressing the climate change problem. Today, it has near-universal membership.

FACT: Climate change is caused by human activity Burning fossil fuels creates a blanket of pollution trapping the sun's heat on Earth and raising global temperatures.

Some 97 percent of scientists involved in climate research agree that it is extremely likely that much of the warming observed since the early 1900s results from human activities.