There is an endless list of personal concerns that confront individuals, such as relationships, career, children, health, etc. From the mundane to the serious, these things consume most of our waking hours. However, for many people there remains enough bandwidth to concern themselves with problems beyond their immediate sphere. I suspect that it is probably the need for a distraction from one’s personal life that we turn to concerning ourselves with global problems. For many in our educated, credentialed class, impending Climate Armageddon from man-made CO2 is an overriding concern. While Climate Armageddon as they envision it is a fantasy, there is one in humanity’s future that is very real.

Geologists in the 19th century discovered to their surprise that glaciers had existed on a large portion of North America and Northern Europe at repeated intervals in the recent geological past. It was a mere 12,000 years ago that a glacier sat where New York City is today. In fact, if one goes to New York City’s Central Park, one can see the surfaces of granite outcroppings that bear the marks of subglacial debris. These glaciers grew because of snow accumulation on the Canadian Shield where snow failed to melt completely in summer. It did not melt completely because the insolation reaching Northern latitudes was diminished. Over several millennia, it grew into a sizable mass and extended itself south into the present-day northern portion of the United States.

Although geologists knew about it, they were perplexed as to why it happened. It took the Serbian scientist, Milutin Milankovitch, with a lot of time on his hands while interned as a POW during World War I to figure it out. He was let out daily from his POW confinement to pursue his studies in Budapest’s public library. Milankovitch performed intricate calculations on changes in Earth’s orbit around the Sun and the tilt and direction of its axis, and found that it correlated with the periodicity of glacial growth and retreat in the Northern Hemisphere. In 2006, Gerard Roe perfectly correlated Milankovitch’s findings with time rate of change of global ice volume, affirming Milankovitch’s discovery.

Milankovitch’s work emphasizes the inevitability that the glaciers will return and in the not-too-distant future. Interglacial periods average between 10,000 – 15,000 years, and we are 12,000 years into the current Holocene interglacial period. So, we are about due. Will it be the fate of future generations to squeeze into the Southern states not covered with ice and snow?

Another thing that the last Ice Age brought was a precipitous drop in the level of CO2. With the glaciers came cooler ocean waters, which sequestered a significant amount of atmospheric CO2. Before those demonizing CO2 start cheering, it would be worthwhile for them to consider that during the Last Glacial Maximum, when CO2 was ~180 ppm, meaning C3 plants comprising all temperate crops were strongly CO2-limited with significantly slower growth and lower water-use efficiency. So not only will we have less arable land on which to grow crops in North America, the crop yield will be considerably less than it is today.

One can imagine a future in which people will be thankful for whatever man-made CO2 that is emitted. Thank you for emitting will replace today’s scornful look.

Image generated by ChatGPT.