Back in the 1970s before people were screaming about global warming, scientists were warning us that the next ice age may be just around the corner. Sometime between high school and the turning of the millennium, that fear of being crushed under a mile plus of glacier ice was replaced by being drowned under a mile of water melted from the polar ice caps.
According to a new study, the Ice Age was the right call but it is being delayed by global warming.
The last Ice Age ended about 11,500 years ago, and when the next one should begin has not been entirely clear.
Researchers used data on the Earth’s orbit and other things to find the historical warm interglacial period that looks most like the current one.
In the journal Nature Geoscience, they write that the next Ice Age would begin within 1,500 years – but emissions have been so high that it will not.
Prof Lawrence Mysak McGill University
“At current levels of CO2, even if emissions stopped now we’d probably have a long interglacial duration determined by whatever long-term processes could kick in and bring [atmospheric] CO2 down,” said Luke Skinner from Cambridge University.
Dr Skinner’s group – which also included scientists from University College London, the University of Florida and Norway’s Bergen University – calculates that the atmospheric concentration of CO2 would have to fall below about 240 parts per million (ppm) before the glaciation could begin.
The current level is around 390ppm.
Other research groups have shown that even if emissions were shut off instantly, concentrations would remain elevated for at least 1,000 years, with enough heat stored in the oceans potentially to cause significant melting of polar ice and sea level rise.
Then again there’s the study Dr. Skinner wont talk about.
Back in 2010 researchers took a look at what happened to the climate just before the last major glacier period, around 115,000 years ago and they found that there was a period of extreme climate fluctuations. They suggest that the period of global warming that plateaued fifteen years ago may just be one of those pre-glacier heat waves.
In Central and Eastern Europe, the slow transition from the Eemian Interglacial to the Weichselian Glacial was marked by a growing instability in vegetation trends with possibly at least two warming events. This is the finding of German and Russian climate researchers who have evaluated geochemical and pollen analyses of lake sediments in Saxony-Anhalt, Brandenburg and Russia. Writing in Quaternary International, scientists from the Helmholtz Centre for Environmental Research (UFZ), the Saxon Academy of Sciences (SAW) in Leipzig and the Russian Academy of Sciences say that a short warming event at the very end of the last interglacial period marked the final transition to the ice age.
The Eemian Interglacial was the last interglacial epoch before the current one, the Holocene. It began around 126,000 years ago, ended around 115,000 years ago and is named after the river Eem in the Netherlands. The followed Weichselian Glacial ended around 15,000 years ago is the most recent glacial epoch named after the Polish river Weichsel. At its peak around 21,000 years ago, the glaciers stretched as far as the south of Berlin (Brandenburg Stadium).
The results show a relatively stable climate over most of the time, but with instabilities at the beginning and end of the Eemian Interglacial. “The observed instability with the proven occurrence of short warming events during the transition from the last interglacial to the last glacial epoch could be, when viewed carefully, a general, naturally occurring characteristic of such transition phases,” concludes Dr Tatjana Boettger of the UFZ, who analysed the sediment profiles at the UFZ’s isotope laboratory in Halle. “Detailed studies of these phenomena are important for understanding the current controversial discussed climate trend so that we can assess the human contribution to climate change with more certainty,” explains Dr Frank W. Junge of the SAW.
The scientists got their results by examining ancient lake sediments exposed by modern open-cast mining in Russia and Germany. They believe that the end of the Eemian interglacial epoch saw “possibly at least two” warming events, according to a statement issued by the UFZ.
If History is to be our guide, the long past period of Global Warming has nothing to do with greenhouse gases, nor are high levels of CO2 delaying the next ice age. What is most likely is the natural fluctuations of global temperatures are an indication that things are about to get much colder around here (which might be worth it just to see Al Gore flip out).