JUST ANOTHER NAIL-BITER

Runaway Global Warming 635 Million Years Ago

LiveScience Staff

LiveScience.comWed May 28, 4:16 PM ET

A sudden and extreme case of runaway global warming 635 million years ago was caused by an abrupt release of methane, a powerful greenhouse gas, scientists said today.

The methane seeped from ice sheets that covered much of the planet toward the end of a frigid era called Snowball Earth. The gas escaped gradually at first and then very quickly from clathrates, or methane ice that forms and stabilizes beneath water ice sheets. As the water ice melted, pressure was relieved on the clathrates and they began to de-gas.

The transition represents one of the earliest known cases of what scientists now call a climatic tipping-point.

The big question scientists are now pondering: Could it happen again?

"Our findings document an abrupt and catastrophic global warming that led from a very cold, seemingly stable climate state to a very warm, also stable, climate state - with no pause in between," said geologist Martin Kennedy of the University of California at Riverside, who led the research team.

"What we now need to know is the sensitivity of the trigger," Kennedy said. "How much forcing does it take to move from one stable state to the other - and are we approaching something like that today with current carbon dioxide warming?"

Also called marsh gas, methane is a colorless, odorless gas. As a greenhouse gas, it is about 30 times more potent than carbon dioxide.

Methane clathrates still exist in Arctic permafrost and beneath the oceans at continental margins. Kennedy said it's possible that very little warming could unleash this trapped methane, potentially warming the planet by tens of degrees.

Kennedy and colleagues collected hundreds of marine sediment samples in South Australia for stable isotope analysis, an important tool used in climate reconstruction. They found the broadest range of oxygen isotopic variation ever reported from marine sediments, which they attribute to melting waters in ice sheets as well as destabilization of clathrates by glacial meltwater.

"Today we're conducting a global-scale experiment with Earth's climate system," Kennedy said, "and witnessing an unprecedented rate of warming, all with little or no knowledge of what instabilities lurk in the climate system and how they can influence life on Earth."

He said Nature did a similar experiment 635 million years ago, "and the outcome is preserved in the geologic record. We see that strong forcing on the climate, not unlike the current carbon dioxide forcing, results in the activation of latent controls in the climate system that, once initiated, change climate to a completely different state."

The research, detailed in the May 29 issue of the journal Nature, was supported by the National Science Foundation and NASA's Exobiology Program.

Top 10 Ways to Destroy Earth Global Melt: Sea Ice Seen From Orbit How Lowly Bacteria Froze Earth Solid Original Story: Runaway Global Warming 635 Million Years Ago

Visit LiveScience.com for more daily news, views and scientific inquiry with an original, provocative point of view. LiveScience reports amazing, real world breakthroughs, made simple and stimulating for people on the go. Check out our collection of Science, Animal and Dinosaur Pictures, Science Videos, Hot Topics, Trivia, Top 10s, Voting, Amazing Images, Reader Favorites, and more. Get cool gadgets at the new LiveScience Store, sign up for our free daily email newsletter and check out our RSS feeds today!

RAIN, RAIN: GO AWAY!

It has been raining here for three days and nights. Not just rain, but downpours with high winds! Every tiny defect in the galvanized iron roofs of the people in Costa Rica has been exaggerated many fold. We've got big pots scattered all over the house and/or attic to collect the water from the leaks. It is impossible now to do any repairs because we haven't had even ten minutes of sunshine in which to work. This is a Central American country not far from the equator. And it has been COLD!

My wood-burning stove's chimney pipe burnt through a month ago, and I've been waiting for my neighbor and builder, Carlos, to finish another project so that he can come over here and make a new chimney. Now, with a big hole in the chimney pipe, I cannot use the stove to heat the house and dry out some of the air. And my solar hot water heater is no longer producing hot water. So no hot showers. I do have LP gas for my kitchen stove and we are only losing electricity sporatically (as usual) so no big problems with cooking or lights, etc. I have a huge back-up water tank holding potable water in case of national potable water service failures, but that doesn't look as though it will be a problem.

I have chronic sinus problems and now I've been having sinus bleeds and much pain for two days. A result of very low pressure systems over the country. Ouch!

But it could be much, much worse. We did have three little earthquakes a couple of days ago, but they caused no damage, thank goodness! Guanacaste Province in the north had been in the depths of a very serious drought! Cattle died and crops withered. Now they are suddenly dealing with major flooding.

I have just learned that this nasty weather system has been declared a tropical storm and is moving toward Nicaragua where it is expected to make landfall. Poor Nicas! The economy of Nicaragua is in shambles and Costa Rica is flooded with illegal immigrants fleeing starvation and seeking some kind of income to send to families in Nicaragua. So that poor nation certainly doesn't need more troubles! The tiny isthmus called Central America doesn't need more trouble. It has been plagued by war, disease, hunger, floods, earthquakes, and dictatorships! Costa Rica and Panama are making some progress toward a better life for its citizens, but the rest of Central America still has a long, long way to go.

Does it seem that this year has already been one of the most devastating in memory for natural disasters worldwide? Or am I seeing things with a jaundiced eye?

It is hard for people who have enough and more than enough security to carry them through any rough times to realize what the reality is for the people caught in the aftermath of a natural disaster. It is worse than a return to the stone age in terms of living day to day. It is surviving a minute at a time in constant fear and post-traumatic stress without enough food, water, or shelter and with the menacing possibilities that even worse tragedies lie ahead for survivors. We lucky few in this world who never have to live for months without bathing, with only enough water to sip a bit at a time, with scavenging for food, with cold, wet, and hunger gnawing at their bodies while grief and fear and anger battle in their souls - we lucky few cannot begin to imagine the true horror of these disasters.

And I wonder if this is not just a fluke of nature, but the beginning of the end. Is it too late to save life on this planet? Are we now facing another great extinction such as the one that wiped out the dinosaurs?

Don't just sit there shrugging! Do something useful! It's now or never, Folks!