Anthrogenic Carbon Dioxide Has Averted the Worst Glacial Cycle Ever

Deep ice sheets would cover much of the Northern Hemisphere thousands of years from now—if it weren't for us pesky humans, a new study says.

Emissions of greenhouse gases—such as the carbon dioxide, or CO², that comes from power plants and cars—are heating the atmosphere to such an extent that the next ice age, predicted to be the deepest in millions of years, may be postponed indefinitely.

"Climate skeptics could look at this and say, CO² is good for us," said study leader Thomas Crowley of the University of Edinburgh in Scotland.

But the idea that global warming may be staving off an ice age is "not cause for relaxing, because we're actually moving into a highly unusual climate state," Crowley added.

In about 10,000 to 100,000 years, the study suggests, Antarctic-like "permanent" ice sheets would shroud much of Canada, Europe, and Asia.

"I think the present [carbon dioxide] levels are probably sufficient to prevent that from ever happening," said Crowley, whose study will appear tomorrow in the journal Nature.

For the past three million years, Earth's climate has wobbled through dozens of ice ages, with thick ice sheets growing from the poles and then shrinking back again.

These ice ages used to last roughly 41,000 years. But in the past half a million years, these big freezes each stretched to about a hundred thousand years long.

Meanwhile, the temperature swings during and between these ice ages became more extreme, soaring to new highs and lows.

The researchers found that between 10,000 and 100,000 years from now, Earth would enter into a period of permanent ice sheets—more severe than any seen in millions of years.

In some ways the ice age would be like those in the past few hundred thousand years, with a thick ice sheet covering North America, the study predicted.

But in the model, Europe and Asia also succumbed to ice sheets up to 2 miles (3.5 kilometers) thick, stretching from England to Siberia—something never before seen in models of past ice ages.

"We were surprised," Crowley said. "There's no evidence for this in Asia" during ice ages in the past few million years.

Just imagine the Sea Level Fall! QUICK! Buy the 'land rights' to the continental shelf! oh...ermm...

A bit more seriously, I have long felt that the interglacial-glacial cycle had not yet run its course and that calling us out of the Pleistocene a little premature. The Milkanovitch Cycles are certainly not over nor are the set conditions that prevented them from throwing the world into another ice age gone.

Or, at least, they wouldn't be without the industry generated carbon dioxide and other greenhouse gases (*cough*methane*cough*) were introduced to the atmosphere. The warming and the time period that will be necessary to sequester the amount of CO2 will probably put the next glacial cycle into the 100k+ year zone, if ever. We are doing major atmospheric engineering here whether we like it or not.

However, on a lighter note, should someone want to write a very different future, one that is near term happy, but long term not so good, this may be it. We fix the global warming problem, but X kiloyears in the future much of the planet is iced over. Not near term like Fallen Angels. bleh.