Runaway greenhouse is when the Earth takes up more energy from the sun than can run off to space, putting the planet out of thermal balance. That explains what had happened to the planet Venus, who is once believed to be just like Earth. There’s water everywhere but its oceans boiled off as a result of runaway greenhouse. And as the sun's solar radiation continues to exaggerate in the future, similar things will happen to the Earth.
According to new calculations, this “runaway greenhouse” can commence easily than perceived.
Colin Goldblatt, a professor of Earth system evolution at the University of Victoria in British, Columbia, Canada, and lead author of the study, told NBC News, "We could go into the runaway greenhouse today if we could get the planet hot enough to get enough water vapor into the atmosphere."
Though, the reality is that burning all Earth’s fossil fuels like oil and coal is very improbable to cause the uncontrollable warming.
“Our estimate is that it would take 30,000 parts per million of carbon dioxide in the atmosphere to make it warm enough to trigger this runaway greenhouse,” Goldblatt wrote in the July 28 issue of the online journal Nature Geoscience.
Reaching 30,000 parts per million seems really unlikely because burning all fossil fuels on Earth would just lead to 2,000 to 3,000 parts per million. The outlier chance of a runaway greenhouse due to human activity, he noted, stems from the inherent uncertainty in the calculations.
The ambiguity directed the researchers to conclude that “anthropogenic emissions are probably insufficient” to trigger a runaway greenhouse.
David Grinspoon, the curator of astrobiology at the Denver Museum of Nature and Science, said in an e-mail to NBC News, “The calculations are significant and done by a very capable team. I find their conclusion that the danger of humans triggering a runaway is remote to be both sound and vaguely reassuring. However, this work also reminds me of how much more we need to do to really understand long-term climate change and that makes me uncomfortable."
“Venus shows us what we will be like in the future, and it’s not pretty,” Goldblatt said.
Turning out to be like Venus may seem improbable but let’s not wait for it to happen. Being mindful of what we do won’t hurt much, so start caring for the only planet that is known to be habitable.
