Stay up to date with notifications from The Independent

Notifications can be managed in browser preferences.

Global-warming Armageddon? It may be more likely than you thought

Calculations from Canadian and US scientists show runaway greenhouse effect is realistic possibility

John von Radowitz
Monday 29 July 2013 10:10 EDT
Comments
A runaway greenhouse Armageddon in which the oceans boil dry could theoretically happen on Earth, researchers claim. The good news is that human activity on its own will probably not be enough to trigger such an end-of-the-world scenario in the near futur
A runaway greenhouse Armageddon in which the oceans boil dry could theoretically happen on Earth, researchers claim. The good news is that human activity on its own will probably not be enough to trigger such an end-of-the-world scenario in the near futur (Julien Behal/PA Wire)

Your support helps us to tell the story

From reproductive rights to climate change to Big Tech, The Independent is on the ground when the story is developing. Whether it's investigating the financials of Elon Musk's pro-Trump PAC or producing our latest documentary, 'The A Word', which shines a light on the American women fighting for reproductive rights, we know how important it is to parse out the facts from the messaging.

At such a critical moment in US history, we need reporters on the ground. Your donation allows us to keep sending journalists to speak to both sides of the story.

The Independent is trusted by Americans across the entire political spectrum. And unlike many other quality news outlets, we choose not to lock Americans out of our reporting and analysis with paywalls. We believe quality journalism should be available to everyone, paid for by those who can afford it.

Your support makes all the difference.

A runaway greenhouse Armageddon in which the oceans boil dry could theoretically happen on Earth, researchers claim.

The good news is that human activity on its own will probably not be enough to trigger such an end-of-the-world scenario in the near future.

Previously it was thought more energy from the sun would be needed for global warming on Earth truly to spin out of control.

But new calculations from Canadian and US scientists show that catastrophic warming can occur more easily than had been assumed.

For a planet receiving the same amount of solar radiation as the Earth, a runaway greenhouse effect is a realistic possibility.

The team, led by Colin Goldblatt from the University of Victoria in Canada, wrote in the journal Nature Geoscience: "The runaway greenhouse may be much easier to initiate than previously thought.

"A renewed modelling effort is needed, addressing both Earth and planetary science applications."

To see what might happen to the Earth if it was ever caught in the grip of runaway global warming, it is only necessary to look next door.

Venus, our closest neighbour in space, is believed to have experienced a runaway greenhouse effect in the past.

Shrouded in a dense carbon dioxide atmosphere, it has an average surface temperature of around 460C - hot enough to melt lead.

The new study used a simplified model which did not take into account the effect of clouds. But it still suggests that under certain atmospheric conditions a stable Earth could switch to a runaway greenhouse state.

Looking back in the Earth's history reveals past episodes of global warming, but none involving a runaway greenhouse effect. There is no clue to the size of any "safety margin", said the scientists.

A carbon dioxide greenhouse effect caused the "hothouse" climate of the Eocene period 55 million years ago, when the Earth underwent more warming than at any previous time in its history. Average global temperature rose by up to 4C, and palm trees grew in the Arctic.

Eocene atmospheric carbon dioxide levels and temperature were both higher than what is expected in the foreseeable future from man-made greenhouse gas emissions, without triggering a runaway effect.

"This implies that an anthropogenic (human-caused) runaway greenhouse is unlikely," the scientists wrote.

PA

Join our commenting forum

Join thought-provoking conversations, follow other Independent readers and see their replies

Comments

Thank you for registering

Please refresh the page or navigate to another page on the site to be automatically logged inPlease refresh your browser to be logged in