Global Warming: Get the Facts According to a recent report from the Intergovernmental Panel on Climate Change (IPCC) the Earth's average surface temperature has increased 1.3 degrees F over the past 100 years. Most scientists agree that this increase is caused by human activity - primarily the burning of fossil fuels. What may seem like a small temperature change has devastating consequences - rising sea levels, loss of Arctic habitat, extinctions, increasingly intense hurricanes, and drought and famine.