We now know how much global warming has delayed the next ice age

Without human induced climate change, the Earth may have been on its way to throwing itself into another ice period within 11,000 years. This long -term prognosis of the planet’s “natural” climate is based on a new analysis of how winges in the form of its orbit and the slope of its axis are combined to change the love of solar energy reaching the planet.

For millions of years, these orbitaloscillations – known as Milankovitch -Cycles – B3Wer have the planet in and out of grace periods about 41,000 years. But the last 800,000 years have seen these freezer cycles, also known as ICE, only occurs every 100,000 yes or so. The term ice age can be used to trace at any time there were at the Earth’s poles, as there are now, although it often means periods of widespread glaciation.

Improvements in the record of when ice sheets advanced and re -induced meant that it was possible to explain how they changed us involved in driving this long cycle, a mystery Nown to palee -climate climate as “100 thousand years of problem”.

Where previous studies tried to connect changes in orbiting to specific periods as the beginning of an age, Stephen Barker took at Cardiff University, UK and his colleagues a new tack. They looked at the overall patterns of how ice periods, also called ice, faded and returned during the intervention “interglacials”. This enabled them to connect changes in orbit with changes in ICI – despite the fuzziness in the ice record in the last millions of years.

They found that these 100,000-year-old cycles appear to follow a straightforward rule. For the past 900,000 years, each interglacial has occurred after the Earth’s axis winged at the longest point from the sun as the planet also tilted closer to the sun after the most circular phase of its orbit.

This suggests all three of these aspects of the Earth’s orbit, known as Precence, Sloping and Eccentricity Combin to create the 100,000 -year -old ice cycle, Barker says. “Sayte 900,000 years ago, this simple rule predicts every one of these major glacial events. This tells us that it’s really easy to predict, ”he says.

Based on this rule and absent the heating influence of our greenhouse gas emissions, we could expect the next interglacial period after the one we currently live in – known as Holocene – to begin around 66,000 years from now. But it “could only start if there was an ice period before then,” says Barker.

The phaseing of sloping and precessive that preceded the Holocene suggests that glaciation would probably be well underway between 4300 and 11,100 years from now. We may even live on what would have been the beginning of this next ice period. “Of race it is only in a natural scenario,” says Barker.

The more than 1.5 trillion tons of carbon dioxide people have emitted in atmospheric sales, which the industrial revolution is expected to cause enough warming to interfere with this long -term freezer cycle.

“The love we have already put into the atmosphere is so great that it will take hungs to thousands of years to sweater it through natural processes,” says Barker. However, he says there is a need for more research to define the Earth’s future natural climate in more detail.

This is in line with previous modeling that suggests increasing CO2 levels due to anthropogenic emissions will prevent the next glacier period for tens of thousands of thousands of years, says Andrey Ganopolski at the Potsdam Institute for Climate Peat in Germany.

However, he says that even pre-industrial levels of CO2 in the atmosphere may have been high enough to delay the ice sheets by 50,000 years. This is due to the unusually less orbital variations expected in the coming millennia and the unpredictable way the earth responds to these changes.