Is global warming saving mankind?
No, it isn’t! But it could be, as this somewhat tongue-in-cheek thought experiment postulates
I must say in advance that I am certainly not a climate denier. I was a skeptic, a decade or two ago, but a large number of profound and indisputable scientific studies convinced me that global warming was actually happening, and that it had very dire consequences for the future of humanity. The subsequent clear climate warming, and the incessant storms, proved that they were right.
Naturally global warming does not mean that every day will be warm. One cold day, walking to the car in freezing rain, and then scraping the ice off the windscreen with numb fingers, my son Tommy muttered: “Where’s this global warming thing they have been promising us for years?” That was flippantly remarked, but is it possible that humanity is being accidentally saved by greenhouse gases from a disastrous fate that could obliterate great areas of the northern hemisphere and cover major cities with a mile of ice?
Global warming is undoubtedly a reality, even if every aspect of the causes is not fully understood. Still, I want to jump into the debate with the following thought experiment: it is conceivable that, were it not for all the fossil fuels we’ve mindlessly burned, we’d right about now be headed into a new Ice Age. And it would be entirely possible that in fifty years from now we will be setting up factories to produce carbon dioxide in huge quantities, with countries being awarded bonuses for generating increased quantities of greenhouse gases. Look at it this way: the alternative for humanity at that point could be a mile of ice obliterating many countries in the northern hemisphere, leaving no brick on another in Boston, Amsterdam, Berlin, Moscow and other major cities.
There have been at least five major ice ages in Earth’s history, each lasting for millions of years. They are thought to be related to changes in Earth’s orbit around the sun, volcanic activity, and the amount of greenhouse gases in the atmosphere. The last three ice ages in northern central Europe: the Weichselian ice age, the Saale ice age and the Elster ice age.
The most recent ice age was the Weichselian glaciation. It began about 115,000 years ago and ended about 11,000 years ago. It covered much of northern Europe, northern Asia, and North America.
The Saale glaciation, which began 300,000 years ago and ended 130,000 years ago, was not as severe as the Weichselian, but it still covered a large area of Northern Europe. The Elster glaciation lasted from 450,000 to 300,000 years ago and was the most extensive glaciation.
Above is a schematic diagram shows the maximum glaciation during the last three cold periods in northern Germany. The red line show the extent of the Weichselian, the yellow line of the Saale, and the blue line of the Elster glaciation. Hamburg, where I live, was covered with more than a mile of solid ice during the latter two.
The Weichselian, Saale, and Elster glaciations carved out valleys, created lakes, and deposited moraines. They also caused the extinction of many plants and animals, and had a significant impact on human history. Humans had difficulty finding food and shelter, and were forced to migrate to warmer areas.
Further south there were glaciations in the Alps: the Günz, Mindel, Riss and Würm were the four main glaciations of a total of ten or twenty. The last, Würm, occurred from 115,000 to 10,000 years ago. J. Seguinot vividly illustrates the advance and retreat of Alpine glaciers during the last cycle:
Ice ages are a natural part of Earth’s climate history. For the last two million years variations in Earth’s orbit — a wobble in earth’s rotational axis relative to its orbital plane — have ushered in periods of glaciation on roughly a 100,000-year frequency. And we are overdue.
We actually live in an ice age known as the Quaternary glaciation. We know that the Arctic ice had been slowly growing for two millennia, advancing toward that “tipping point” beyond which glaciers begin their grinding, crushing sweep southward. However, the cooling abruptly reversed in the 20th Century. That is partially because, some 200 years ago, the Industrial Revolution began. Huge amounts of coal, and then oil, went up in smoke. The rising concentrations of CO₂ increased the atmosphere’s ability to hold heat. Humanity may have quite accidentally warded off another Ice Age — 50 millennia of advancing ice, followed by another 50 of de-icing. It is possible that the Quaternary glaciation is being interrupted by human-caused climate change.
So we might have hit a strange streak of good luck, by accidentally increasing the planet’s greenhouse effect just as another ice age was scheduled to begin and cover much of the northern hemisphere with ice sheets a mile thick. If somehow civilization had arrived at its current stage of development without burning fossil fuels, and if we were still at 280 parts per million and not the current 420 ppm of CO₂, it is entirely possible that we’d be having a different discussion about climate right now.
In the journal Geophysical Research Letters, scientists argued that fossil fuels are so valuable, as a source of climate-altering carbon, that we should stop burning them now and save them for later, when they are really needed. They have calculated that by releasing pulses of CO₂ from fossil fuels at the right time, we could maintain the current balmy interglacial conditions for another 500,000 years.
