I realize this is not exactly breaking news, but 18,000 years ago, it was really chilly here. Canada was covered in a thick layer of ice. In some places, it was more than one kilometre deep. The mean temperature of planet Earth was about four degrees centigrade lower than it was from 1960 to 1991.
Homo sapiens have been around for about 300,000 years. But when Canada was last covered in ice, members of our species were living in warmer regions.
Some 18,000 years ago, gradual shifts in the tilt of the planet and the shape of its orbit around the sun increased the amount of sunshine in the northern hemisphere, setting off many slow global warming processes. Reflection of sunlight would gradually decrease. The atmospheric blanket would thicken as it retained more water vapour and began absorbing carbon dioxide and methane released from storage in land and oceans.
Over the next 3,600 years, the planet's mean temperature rose two degrees, and the ice started melting. The temperature continued to rise. Within 900 years, it was up a further 0.4 degrees. Then, about 13,500 years ago, it began cooling down as ice-cold freshwater pouring off the glaciers into the oceans changed the pattern of circulating currents. Within 800 years, the 0.4-degree temperature gain had been lost. But warming resumed, and over the next 1,900 years, the global temperature rose another two degrees.
By then – 10,600 years ago – the planet was as warm as it was in the last century. The northern glaciers had retreated to form a white beanie on the globe. People began living here, closely connected to nature and deeply attuned to the spirit world.
Since that time, the global temperature has been relatively stable. It has never been more than 0.6 degrees higher or 0.4 degrees lower than it was then.
Global warming after an ice age is to be expected. However, alarm bells are ringing, and red lights are flashing because of the astounding speed of the recent temperature change.
It takes Mother Nature at least 900 years to raise the global temperature by one degree. Homo sapiens have managed a one-degree rise in just 100 years. How? Easy as falling off a log. The trick is to burn fossil fuels, day and night, year after year, all around the globe, thus continually pumping carbon dioxide, methane and nitrous oxide into the atmosphere.
When informed about global warming and climate change, a shaman in a tribe in the Amazon rainforest said, "Something is wrong with the world."
Michael Obrecht is a resident of Wakefield, QC