A news release from the University of Southampton, UK:
Next Ice Age delayed by rising CO2 levels
Future ice ages may be delayed by up to half a million years by our burning of fossil fuels. That is the implication of recent work by Dr Toby Tyrrell of the University of Southampton’s School of Ocean and Earth Science at the National Oceanography Centre, Southampton.
According to New Scientist magazine, which features Dr Tyrrell’s research this week, this work demonstrates the most far-reaching disruption of long-term planetary processes yet suggested for human activity.
Dr Tyrrell’s team used a mathematical model to study what would happen to marine chemistry in a world with ever-increasing supplies of the greenhouse gas, carbon dioxide.
The world’s oceans are absorbing CO2 from the atmosphere but in doing so they are becoming more acidic. This in turn is dissolving the calcium carbonate in the shells produced by surface-dwelling marine organisms, adding even more carbon to the oceans. The outcome is elevated carbon dioxide for far longer than previously assumed.
Computer modelling in 2004 by a then oceanography undergraduate student at the University, Stephanie Castle, first interested Dr Tyrrell and colleague Professor John Shepherd in the problem. They subsequently developed a theoretical analysis to validate the plausibility of the phenomenon.
The work, which is part-funded by the Natural Environment Research Council, confirms earlier ideas of David Archer of the University of Chicago, who first estimated the impact rising CO2 levels would have on the timing of the next ice age.
Dr Tyrrell said: ‘Our research shows why atmospheric CO2 will not return to pre-industrial levels after we stop burning fossil fuels. It shows that it if we use up all known fossil fuels it doesn’t matter at what rate we burn them. The result would be the same if we burned them at present rates or at more moderate rates; we would still get the same eventual ice-age-prevention result.’
Ice ages occur around every 100,000 years as the pattern of Earth’s orbit alters over time. Changes in the way the sun strikes the Earth allows for the growth of ice caps, plunging the Earth into an ice age. But it is not only variations in received sunlight that determine the descent into an ice age; levels of atmospheric CO2 are also important.
Humanity has to date burnt about 300 Gt C of fossil fuels. This work suggests that even if only 1000 Gt C (gigatonnes of carbon) are eventually burnt (out of total reserves of about 4000 Gt C) then it is likely that the next ice age will be skipped. Burning all recoverable fossil fuels could lead to avoidance of the next five ice ages.
Dr Tyrrell is a Reader in the University of Southampton’s School of Ocean and Earth Science. This research was first published in Tellus B, vol 59 p664.
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
Would skipping the next five ice ages be a good thing?
The UK is looking forward to being mostly covered in a several Km thick glacier.
Dr Tyrell should start out by showing that his “mathematical model” is absolutely complete and absolutely accurate.
Without this proof his assertions can be bundled with all the other unsubstantiated claims … but I dare say it’s got him funding for more studies!!
Jen – could be a while off though – like 100,000 years – might be good for humanity to get unscathed through the next 200 or so first.
Of course the ice ages were involved in a lot of soil development processes too. Not that the civilised northern hemisphere as we now know it, would survive under an ice sheet, but humanity has reaped some of the benefits of all that grinding post glaciation.
I wish you guys could make up your mind. Are we causing warming or not. It appears we are, if it’s good, but not if it’s bad.
We don’t seem to be sure when the next ice age is due – could be another 50,000 years – either way, we are in a long interglacial regardless of CO2 levels. Interglacials are obviously preferable to glacial periods:
http://news.bbc.co.uk/1/hi/sci/tech/5317762.stm
Eight times humans came to try to live in Britain and on at least seven occasions they failed – beaten back by freezing conditions.
Scientists think they can now write a reasonably comprehensive history of the occupation of these isles.
It stretches from 700,000 years ago and the first known settlers at Pakefield in Suffolk, through to the most recent incomers just 12,000 years or so ago.
Australian aboriginals have been in Australia longer, continuously than the British people have been in Britain.
The Tyrrell paper is idiotic. Ice ages have come every 100,000 years for the last million years, like clockwork. You can’t delay them by 0.5 million years – they are either skipped or keep coming. And they are going to keep coming for at least a few more million years.
Shit now I’ve got to worry about missing my next ice age and I was so looking forward to it.
Bought a parka, six sled dogs and an Igloo construction manual.
Damn, bloody AGW and humans.
“Ice ages have come every 100,000 years for the last million years, like clockwork”
Jeez David – being a serious climate researcher like you are, I would have thought you’d be across this issue. And you see that illustrates the entire problem we mutually have doesn’t it – how cycles can appear that aren’t cycles. That’s why sometimes you need models instead of statistics 🙂 !!
http://amper.ped.muni.cz/gw/articles/html.format/orb_forc.html
http://campus.udayton.edu/~physics/rjb/PHY399Winter2007/Berger%20-%20Long%20Interglacial.pdf
Fifty years ago Dr Toby Tyrrell would have made a living writing for ‘Galaxy’ magazine.
http://en.wikipedia.org/wiki/Galaxy_Science_Fiction
I found the abstract to the paper:
http://www.ingentaconnect.com/content/mksg/teb/2007/00000059/00000004/art00003
The long-term legacy of fossil fuels
Abstract:
Fossil fuels will have large impacts on ocean chemistry and climate during the period while they are being burnt (and carbon dioxide emitted) in large amounts. It is frequently assumed that these impacts will fade away soon thereafter. Recent model results, by contrast, suggest that significant impacts will persist for hundreds of thousands of years after emissions cease. We present a new analysis that supports these model findings by elucidating the cause of this `fossil fuel hangover’ phenomenon. We explain why the carbonate compensation feedback is atypical, compared to other feedbacks, in the sense that convergence is back towards a new steady-state that is distinct from the starting state. We also calculate in greater detail the predicted implications for the future ocean and atmosphere. The post-fossil fuel long-term equilibrium state could differ from the pre-anthropogenic state by as much as 50% for total dissolved inorganic carbon and alkalinity and 100% for atmospheric pCO2, depending on the total amount of future emissions.
Have you ever considered an ice age, of dry ice; frozen carbon dioxide