Averaged over all land and ocean surfaces, temperatures warmed roughly 1.53°F (0.85ºC) from 1880 to 2012, according to the Intergovernmental Panel on Climate Change. Because oceans tend to warm and cool more slowly than land areas, continents have warmed the most. In the Northern Hemisphere, where most of Earth's land mass is located, the three decades from 1983 to 2012 were likely the warmest 30-year period of the last 1400 years, according to the IPCC.