Satellites verify greenhouse-gas effects

Comparisons of data obtained from satellites that orbited Earth more than 25 years apart provide rare, direct evidence that the planet’s greenhouse effect increased significantly during the closing decades of the 20th century. These new findings support abundant indirect indications that greenhouse gases, such as carbon dioxide and methane, are warming Earth’s atmosphere.

Spectrometers showed that more of the infrared radiation emitted by Earth and leaving the atmosphere was blocked by heat-absorbing greenhouse gases in 1997 than in 1970.