0.6 to 0.9 degrees Celsius (1.1 to 1.6° F)
According to an ongoing temperature analysis conducted by scientists at NASA’s Goddard Institute for Space Studies (GISS), the average global temperature on Earth has increased by about 0.8° Celsius (1.4° Fahrenheit) since 1880. This graph illustrates the change in global surface temperature relative to 1951-1980 average temperatures. The 10 warmest years in the 134-year record all have occurred since 2000, with the exception of 1998. The year 2014 ranks as the warmest on record. (Source: NASA/GISS). Global Warming is the increase of Earth's average surface temperature due to effect of greenhouse gases, such as carbon dioxide emissions from burning fossil fuels or from deforestation, which trap heat that would otherwise escape from Earth. This is a type of greenhouse effect. Global warming is the unusually rapid increase in Earth’s average surface temperature over the past century primarily due to the greenhouse gases released as people burn fossil fuels. The global average surface temperature rose 0.6 to 0.9 degrees Celsius (1.1 to 1.6° F) between 1906 and 2005, and the rate of temperature increase has nearly doubled in the last 50 years. Temperatures are certain to go up further. Despite ups and downs from year to year, global average surface temperature is rising. By the beginning of the 21st century, Earth’s temperature was roughly 0.5 degrees Celsius above the long-term (1951–1980) average. (NASA figure adapted from Goddard Institute for Space Studies Surface Temperature Analysis. ).
http://earthobservatory.nasa.gov/Features/WorldOfChange/decadaltemp.php http://climate.nasa.gov/vital-signs/global-temperature/ http://www.nmsea.org/Curriculum/Primer/Global_Warming/fossil_fuels_and_global_warming.htm http://earthobservatory.nasa.gov/Features/GlobalWarming/page2.php http://earthobservatory.nasa.gov/Features/GlobalWarming/page2.php
global warming average temperature increase