Increase in Atmospheric Moisture Tied to Human Activities

A new study by an international team of researchers has identified a human “fingerprint” on the climate in the increasing total moisture content of the atmosphere, despite the relatively short length (19 years) of the observed water vapor data. The study appears this week in the online edition of the Proceedings of the National Academy of Sciences.

Increased atmospheric water vapor—which is itself a greenhouse gas—amplifies the warming effect of increased atmospheric levels of carbon dioxide—a “positive feedback.”
When you heat the planet, you increase the ability of the atmosphere to hold moisture. The atmosphere’s water vapor content has increased by about 0.41 kilograms per square meter (kg/m