We have some very strange weather at the moment, but what’s interesting is that some of the research we’ve done shows that there have been times in the past when the jet stream has been as far south as it is now. In the 1680s and 1690s the jet stream was as far south as it is today, but all that really does is demonstrate how incredibly complicated predicting weather is. Our climate in the 1690s and 1690s wasn’t as it is now, that period is known as The Little Ice Age.
Dennis Wheeler, Emeritus Professor of Climatology, University of Sunderland, 6 march 2014
The forecast reflects the slightly cooler conditions currently prevailing associated with the recent ‘pause’ in global surface warming…There are also indications of a developing pattern of cooling in the north Atlantic sub-polar gyre…
Met Office, Latest Decadal Forecast: 2014-2018, January 2014
…when the atmosphere cools, the jet stream becomes more erratic, swinging in zigzags, first north then south, and becoming very weak and susceptible to disturbances caused by sea temperature and by snow and ice on land and sea…Recent severe weather conditions in North America and elsewhere are a result of this weaker, more erratic pattern of windflow. High pressure building over the southwestern United States seaboard, aided by ocean temperature conditions, zigzags the jest stream so that it is too weak to push the “blocking high” system away. A dominant flow from northwest to southeast is established across the whole of the United States east of the Rockies, encouraging the southward flow of the jet stream and cooling a great area of ocean south of Newfoundland.
Douglas Orgill and John Gribbin, “The Sixth Winter”, 1979
As the planet was warming (1979-2001) the jet stream was moving north, at a speed of 12-13 miles per year (the polar convective cells were shrinking). Now that it has stopped warming, the jet stream is gradually shifting southward (the polar convective cells are growing): “Instead of circling the earth in the far north, the jet stream has begun to meander, like a river heading off course. This has brought chilly Arctic weather further south than normal, and warmer temperatures up north. Perhaps most disturbingly, it remains in place for longer periods of time” (“Jet Stream Shift Could Mean Harsher Winters”, Discovery)
Jet streams trending equatorially are a phenomenon linked to cooling poles (a greater differential between tropical and polar temperatures) and to low solar activity (an active sun flattens the jet stream: more latitudinal (“zonal”) jet stream; a quiet sun makes it more meandering: more meridional jet stream) (cf. Brian Fagan, “The Little Ice Age: How Climate Made History 1300-1850“).
What will likely occur over the next few years is that heat will be pulled from the tropics to the poles to offset their cooling trend. This means more powerful storms, overall windier conditions and maximum precipitation (i.e. snow), as it normally happens when warm meets cold. When mid latitudes will be cool enough, nothing will stop the Arctic cooling and the northern hemisphere will plunge into an ice age.
So, no matter how counterintuitive this may sound, global warming produces global cooling and triggers glaciations. Every ice age has been preceded by an upward spike in global temperatures increasing oceanic evaporation and precipitations falling as snow, feeding glaciers at high latitudes and high elevations. This is why French and Swiss glaciers are growing, the northern hemisphere winter snow cover is also growing, and Antarctic sea ice is dramatically expanding.
If this is the beginning of a cooling phase or even the end of the current interglacial (which is indeed nearing its expiring date), then we are to expect snowy winters and shorter, hot summers keeping the oceans warm, with more evaporation.
This is how it works:
The beginning of the last glacial period was characterized in the Northern hemisphere by major accumulation of snow at high latitudes and the formation of a huge polar ice sheet. For climatologists this was paradoxical, since snowfall is always associated with high humidity and relatively moderate temperatures. Now, a French team coordinated by MaríaFernanda Sánchez-Goñi, a researcher at EPHE working in the ‘Oceanic and Continental Environments and Paleoenvironments’ Laboratory (CNRS/Universités Bordeaux 1 & 4) has solved this paradox. By analyzing sediment cores dating from 80 000 to 70 000 years ago, the researchers have shown that during this period water temperatures in the Bay of Biscay remained relatively high, whereas temperatures in mainland Europe gradually fell. Carried northwards by wind, the humidity released by this thermal contrast appears to have caused the snowfall that formed the polar ice sheet.
Scientists analyzing the geological and ice records tell us that ice ages take place in a regular cyclic pattern and normally last about 100,000 years, with intervening interglacial periods of 10 to 15,000 years which “tend to occur during periods of peak solar radiation in the Northern Hemisphere summer”.
According to the Danish Niels Bohr Institute, the last ice age ended circa 11,711 years ago, “as if a button was pressed”. According to research conducted at the Max Planck Institute for Solar System Research, between 1940 and the end of solar cycle 23 (2008), the sun reached its peak of activity for the past 8000 years.
Now, instead, “solar activity is declining… faster than at any time in the last 9300 years” (Mike Lockwood, professor of space environmental physics at Reading University), with substantial effects on Earth’s climate.
We are about to find out whether large portions of the northern hemisphere will be made suddenly uninhabitable by an increasingly dry and freezing climate and, eventually, by the advancing ice sheets.
One thing we know for sure: ice core data show that CO2 changes lag behind global warming changes.
This is because warm water retains less CO2 than cold water.
Carbon dioxide increases are therefore, if anything, an effect, not the primary cause of global warming.
This also means that global CO2 levels will keep increasing even as global temperatures drop.
The demonization of CO2 has been one of the most outrageous fallacies in the history of science. The rate of photosynthesis, and therefore the flourishing of life on this planet, is determined by the concentration of CO2 in the atmosphere. The more, the better: plants grow faster, healthier, stronger.
Photosynthesis counters entropy, that is to say, life extinction. Deliberately cutting CO2 concentration is like draining the biosphere’s blood. Our carbon emissions are, as it were, a profoundly innovative way for Gaia to sustain its biosphere and, possibly, forestall some of the effects of the forthcoming ice age.
A human civilization committed to fighting off glacial inception through CO2 emissions, greening the deserts and melting the ice to lower Earth’s albedo would be the most expedient ecological invention ever devised by Mother Nature: humans as a cure for the ice cancer.