Will Earth ever sizzle like Venus?
(Hubble Space Telescope image courtesy NASA/JPL.)
At the Lawrence Hall of Science in Berkeley, California, we recorded this question.
John Silva: My name is John Silva, and I’m from San Leondro, California. And my question is, could Earth’s climate in the future be similar to that of our sister planet Venus if we don’t start controlling pollution levels and global warming?
The Venus surface pressure is 90 times higher than Earth’s. Venus is blanketed by clouds of sulfuric acid. And it’s hot enough on Venus to melt lead. Several climate researchers told us that, although it seems plausible that Earth could go the way of Venus, it almost certainly won’t.
Today, the atmosphere of Venus consists of more than 96% carbon dioxide, a greenhouse gas. Long ago, some scientists think that Venus might have undergone a “runaway” greenhouse effect. Earth’s atmosphere has less than 1% carbon dioxide. Our distance from the sun, the composition and density of our atmosphere, and the presence of oceans on Earth all make a runaway greenhouse effect very unlikely. Even if we liberated all the carbon on Earth into the atmosphere – from fossil fuels, the ocean, the forests, and so on – our atmosphere still wouldn’t achieve the high concentration of carbon dioxide known to exist on Venus.
Still, scientists look to Venus as an extreme example of the greenhouse effect.
Our thanks to:
John Harte
Energy and Resources Group
University of California
Robert B. Jackson
Nicholas School of the Environment and Earth Sciences
Duke University
Andrea N. Hahmann
Institute of Atmospheric Physics
University of Arizona
Tom G Farr
Jet Propulsion Lab
Pasadena, CA
