NEW GLACIAL AGE: DID WE STALL IT WITH CO2?

 EARTH IS SLATED FOR A NEW “GLACIAL AGE”, HAS HUMAN CO2 WASTE STALLED IT?

The popular view of the Earth is that of a static unchanging “rocky planet”.  That is an erroneous perception. It is a dynamic  almost “living organism” which is in constant change and adaptation and still in the grip of its most recent glacial epoch. Yes the Earth remains in an Ice Age, not a simple cold spell—but many alternating periods of cold and expanding glaciers, followed by warm periods of glacial retreat.  Similar ice ages occurred in the Earth’s distant past.  The earliest known Ice Age dates from about 2 billion years ago, another at 800 million years ago, one at 460 million years ago, another 360 million years ago, and our most recent, beginning 2.6 million years ago. 

In this most recent Ice Age of the last three million years, the Earth has been subject to multiple advances and retreats of immense ice sheets.  These “continental glaciers” formed when snow accumulated year after year  and packed down to form continental-wide ice masses 3.5 kilometers (@2.2miles) thick which eventually spread out to cover all of Canada, and more than a third of the USA, as well as a similar area in Europe and Russia.  In the last 2.6 million years there have been at least 24 distinct, identifiable glacial advances and retreats with an average period (advance and retreat) of about 100,000 years each.  During that nearly three million period, scientists were able to identify at least four “interglacials” or warmer periods which were similar in temperature and other characteristics to our present day warm climate. So this present day warm spell —occurring over the last 15,000 years —is only a “warm break” in the mostly ice-dominated chilly period with alternating warm spells of the last three million years.

Our most recent ice age or Last Glacial Maximum (LGM),  began about 33 thousand years ago (33 kya), peaked at about 26-27 kya  and ended about 15 kya.  At its maximum extent,  ice covered more than a third of the USA under a sheet of ice more than 2 miles thick (max 3500 m).  In  North America a wide blanket of ice one to two miles thick covered most of eastern Canada, the USA from Maine to Manhattan, then west to northern Ohio and northern Indiana,  northern Illinois, northwest though the eastern half of North Dakota and then north into western Canada. Similar ice sheets covered Europe and Russia.  By 21,000 years ago the average global temperature had fallen to about 46F (or about about 6 C or (11 F) colder than at present)  See: “Last glacial Maximum”, Wikipedia, DL: May 1 2022)

But the glacial age was not just colder. During this last glacial maximum the world’s climate was drier too.  As the glacier advanced it tied up water in the form of solid ice that would have normally flowed back into the world ocean. Large expanses of permanent ice-cover helped reflect sunlight and induced a “feedback loop”which fostered cooler temperatures due to the fact that ice covered areas reflect sunlight very effectively. As snow cover expanded it caused temperatures to fall.  With moisture remaining in the solid state on land— ocean levels fell and were as much as 125 meters ( 410 feet lower) at the maximum extent of the ice.  Wide expanses of the continental shelves presently under seawater were exposed during the LGM.  In many places around the world, “land bridges” formed between continents or parts of continents formerly separated by deep water. (These were famously used by human migrants to populate areas formerly inaccessible to them—i.e. Australia, North and South America).  In many places the scarcity of atmospheric moisture caused droughts and produced desert like conditions with only sparse vegetative cover.  The steep variations in temperature and pressure along the glacial fronts also produced strong winds.  These winds lofted fine mineral matter or mineral dust into the atmosphere, as much as 25% more dust occurred during these times based or core evidences.  The higher concentrations of dust in the air also reduced incident solar radiation and also acted to cool  the Earth. 

Then,  beginning about 15,000 years ago (the cause or reason is not certain) the great ice sheets began to “retreat” or melt faster than they were formed. That event initiated the present “interglacial” or warm period. Temperatures increased, wind calmed down, sea level rose , air moisture increased, forests expanded northward as the ice retreated. Many lakes were formed in the wake of the retreating ice. An altered landscape was left as the ice melted back and deposited masses of rock and mineral debris into a wide array of glacial landforms.

  

Based on scientific data from the past, at the present time, we should expect, as this interglacial ends, the beginning of another glacial advance or cooling period. The onset of conditions which favor snow accumulating in northern regions where it is too cool to melt away during the summer.  So that the next winter’s snow builds on the previous season’s accumulation. In time the snow should pack down into ice and accumulate to great thickness to eventually form ice masses thick enough to expand and spread into a new glacial advance. The data of twenty-four previous glacial advances from our past supports such a future.

The Earth’s  past history seems to support this prediction.  But so far we have seen no evidence of the snow accumulation process—or the cooling.  In fact the Earth’s temperatures have been rising. Could it be that human activities—the dumping of massive amounts of CO2 gas—as a waste product of burning fossil fuels —has resulted in keeping the Earth warm enough to avoid a new ice age?  

Have we dodged a “glacial bullet”?  Have we humans avoided one terrible consequence—a new ice age,  and instigated another, a terrible heat wave and drought?  

Nature is often more complex than it seems. And the Earth is a not a simple rocky sphere, but a dynamic  body reacting to change …But time will tell.