The average surface temperature of the Earth rose approximately 1.53 degrees Fahrenheit between 1880 and 2012, according to the Intergovernmental Panel on Climate Change. The decade between 2000 and 2009 was the hottest on record.
According to NASA, the rate of increase has nearly doubled in the last 50 years. The rate is sped up by the greenhouse gases, such as carbon dioxide and methane, trapped in the Earth's atmosphere. When these gases absorb the heat energy from the Earth's surface, they radiate it back out in all directions, including back to the Earth. This is known as the greenhouse effect. The burning of fossil fuels has steadily increased the amount of greenhouse gases in the atmosphere, enhancing the greenhouse effect.