Earth has warmed 0.4 C in 30 years

Globally, Earth's atmosphere warmed an average of about 0.4 C (or about 0.72 degrees Fahrenheit) in 30 years, according to data collected by sensors aboard NOAA and NASA satellites. More than 80 percent of the globe warmed by some amount.

Virtually all of the warming found in the satellite temperature record has taken place since the onset of the 1997-1998 El Nino. Earth's average temperature showed no detectable warming from December 1978 until the 1997 El Nino.