Environment

Mini ice age could hit in a matter of months, not years

Mini ice age could hit in a ma...
New research indicates a mini ice age can be brought on in a matter or months (Image: NASA)
New research indicates a mini ice age can be brought on in a matter or months (Image: NASA)
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New research indicates a mini ice age can be brought on in a matter or months (Image: NASA)
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New research indicates a mini ice age can be brought on in a matter or months (Image: NASA)

Those who scoffed at the swiftness with which the world was plunged into an ice age in the film The Day After Tomorrow may need to rethink their disbelief with new research showing that such a scenario may not be so far from the truth. A new study reveals that switching off the North Atlantic circulation can force the Northern hemisphere into a mini ‘ice age’ in a matter of months rather than the tens of years indicated by previous research.

Around 12,800 years ago the northern hemisphere was hit by a mini ice-age, known by scientists as the Younger Dryas, and nicknamed the “Big Freeze”, which lasted around 1300 years. Geological evidence shows that the Big Freeze was brought about by a sudden influx of freshwater, when the glacial Lake Agassiz in North America burst its banks and poured into the North Atlantic and Arctic Oceans. This vast pulse, a greater volume than all of North America’s Great Lakes combined, diluted the North Atlantic conveyor belt and brought it to a halt.

Without the warming influence of this ocean circulation temperatures across the Northern hemisphere plummeted, ice sheets grew and human civilization fell apart. Previous evidence from Greenland ice cores has indicated that this sudden change in climate occurred over the space of a decade or so. Now new data shows that the change was amazingly abrupt, taking place over the course of a few months, or a year or two at most.

Using a mud core taken from an ancient lake, Lough Monreach, in Ireland, the researchers have created the highest resolution record of the Big Freeze event to date. Using a scalpel layers were sliced from the core, just 0.5mm thick, representing a time period of one to three months.

Carbon isotopes in each slice reveal how productive the lake was, while oxygen isotopes give a picture of temperature and rainfall. At the start of the Big Freeze their new record shows that temperatures plummeted and lake productivity stopped over the course of just a few years.

Meanwhile, their isotope record from the end of the Big Freeze shows that it took around two centuries for the lake and climate to recover, rather than the abrupt decade or so that ice cores indicate. “This makes sense because it would take time for the ocean and atmospheric circulation to turn on again,” says researcher William Patterson, from the University of Saskatchewan in Canada.

Looking ahead to the future Patterson says there is no reason why a “Big Freeze” shouldn’t happen again. “If the Greenland ice sheet melted suddenly it would be catastrophic,” he says.

The study was carried out by the European Science Foundation EUROCORES program ‘Histories from the North – environments, movements, narratives’, which was comprised of 38 individual research teams from Europe, Russia, Canada and the USA.

26 comments
bio-power jeff
so its an \'ice-age\' created by global warming?
Eletruk
So I guess nature would be self correcting. The global warming melts the Greenland ice sheet which stops the Gulf stream which freezes the northern hemisphere. So then the sudden ice age kills billions of humans who created this mess in the first place. But I wonder what happens to the southern hemisphere during all this? Should I move to Brazil?
jum
You are right Eletruk! 12,800 years ago them stupid humans with there coal fired power stations, and running around in their gas guzzling cars. lucky we have people like Al Gore now to show us the error of our ways, they could of done with someone like him 12,800 years ago.
Dalek
Yes, Jum, you have clearly demonstrated your aptitude for sarcasm and wit. And you have somehow stumbled upon the glorious revelation that Earth\'s localized temperature systems and CO_2 concentrations exhibit a naturally sinusoidal rhythm--but alas your brilliant discovery is nothing new to the scientific community as the data taken by hundreds of researchers already depicts that. But before you begin claiming that the unnaturally high levels of CO_2 and other greenhouse gasses that our technologies are known to produce in vast quantities are of little consequence, and expounding your myopic \"views\" in such an antagonistic manner, you might meditate on the definition of the word \'catalyst\'.
BillInStl
It\'s a feedback system: if you inject new inputs into the system it can oscillate - especially if you don\'t know what you\'re doing. In either case, the results are usually not good or predictable.
mrhuckfin
O.K. I have a question? Who decided that the amount of C0² that is now present is too much? It’s been MUCH higher in earths past and there is this little fact that C0² does not cause global warming but only goes up when the earth gets warm! Why doesn’t anybody every bring this up? C0² fallows the earths temperature not proceed it, AND even if it did cause any kind of temperature differential how about we just learn to adapt the way our ancestors did? I will not get put into a 3rd world life stile because somebody thinks my car had even the slightest effect on our earth!
Stuart21
Problems; Firstly it would only be a local ice age - affecting the countries now warmed by ocean circulation - GB, etc. Other areas (tropics particularly) would be HEATED by the reduction in outflow of heat, via ocean circulation. This would be on top of the anthropometric global warming. Secondly, & fortunately, there do not appear to be any lakes which could collapse at the current time - melting of the ice caps would be gradual and might slow the ocean circulation, but unlikely to stop it. MrHuck - I hope you don\'t have any kids. If you do, you can tell them to start \'adapting\' by remembering what beaches look like, and by making do without the food produced on the most productive soils - the river flats, which will go under. Yes, CO2 has been higher in the past - but last time it was as high as this, sea levels were 25 to 40 metres higher than now.
cgp
I would like to point out a couple of things: Yes, we live in a feedbacked system which tends to stability. This means two things: on an external input in one direction the system REACTS in an opposite way so as to go back to the previous state and to reduce the oscillation created; But the new stable point might not be exactly the previous one. And yes, some million years ago there was a lot more CO2 in the atmosphere, but average temperature on the planet was a lot higher, and possibly there were not the same oceanic circulations simply because the continents configuration was so different. And besides this, there were plants all over that were fixing all that CO2, with the aid of high temperatures converting CO2 in organic matter and releasing O2. When the CO2 was lowered and O2 was increased there was a certain point in which an equilibrium was broken and there was an ice age. After this plants were not the same any more and new species appeared (our modern plants, grass, flowers, and so on). So my conclusion is that ancient plants pumped CO2 underground (in form of coal, oil, etc.) for million years, and as we now are pumping it up again \"abruptly\" (in just three or four hundred years) it\'s quite possible that we get a temperature rise, and the global system will react more or less abruptly to reduce the oscillation.
Kavid
Wow Dalek, you are one incredibly sophisticated thinker, not to mention having your own unique brand of incredibly scathing wit. I bet your friends are intimidated as all hell by that mind of yours, fearing to venture even the most harmless of opinions in your presence. ...Can you say smarmy twerp? You passes the worst kind of gasses. Climate change, like all things on this planet, is inevitable, with or without the interference of human enterprise. Sure, we may exacerbate these changes to a minor extent, but it is my humble estimation this is merely the cause du jour on which sheeple are hanging their fears, most likely wrought by neocons and far left pinheads who are trying to level the playing field by bringing down the most productive nations through guilt, coercion and outright lies. Thanks to these anti-humans industrialized nations will be held as pariahs while third world cesspools will be lauded as representing humanity\'s finest endeavors.
Rangi
Jum, Dalek, mrhucfinn and Kavid, you are all just an antagonistic waste of space. Now listen to me, here\'s the way it really is.......