I got to thinking that some of the simpler strategies, like some variation on using sulfur dioxide to cool the Earth, or Black Carbon or even CO2 to warm it might have been within the technical capabilities of the combatants. Certainly some climate engineering strategies, like dumping iron in iron-deficient parts of the ocean to increase plankton and supposedly to reduce CO2 in the atmosphere would have been within the capabilities of the Great Powers with access to the oceans if they had figured out the potential impact.

The questions are: (1) How do you get from where climate science actually was in the 1940s to an understanding sophisticated enough to influence climate? (2) Which, if any, of the Great Powers would feel that it was in their interest to deliberately change the climate? (3) Are there ways that the combatants might have accidentally altered climate?

I’m going to toss out a few scenario seeds and then leave the issue open for you to explore or ignore.

1. Stalin explores ways to warm the Soviet Union. If somehow Soviet scientists stumbled across the role of Greenhouse gases in the mid 1930s I could see the Soviets trying to climate-engineer for greater warmth. Could they actually pull it off? I’m somewhat skeptical of their ability to actually make much difference. Could they have somehow artificially released large deposits of methane in the huge Siberian peat bogs? Methane is around 20 times as potent a greenhouse gas as CO2, so messing with large deposits of it could have interesting consequences.

This wouldn’t have to be a deliberate thing, actually. The Soviets were into grandiose schemes. Maybe they decide to do a massive exploitation of the peat bogs for fuel or fertilizer.That would probably make zero economic sense, but then again a lot of things the Soviets did were economic nonsense.

So let’s say that sometime in the late 1930s the Soviets somehow release a heck of a lot of methane, enough to make some difference in world-wide climate. What happens next?

That innocent little question is frankly beyond my capability to answer. So many parts of World War II were weather-influenced—the horrible winter of 1939/40 that kept postponing the German offensive against France, but also minimized French opportunities to do badly needed training of their ‘B’-series divisions, the cloud cover over Dunkirk during the British evacuation, coupled with calm seas that allowed small ships to participate in the evacuation, the lateness of the fall rains that Poland counted on to slow down the Germans in September 1939, the big block of perfect, clear blitzkrieg weather that maximized the impact of German tanks and planes in the battle for France, the coming of the fall rains in 1940 that slowed the German rush to Moscow. And those are just small micro-effects. An actual change in climate patterns would probably have even larger impacts.

2. Stalin goes seriously scorched earth. This wouldn’t be a deliberate climate-change gambit, but it might have the same impact. Let’s say he decides to leave a wasteland whenever the Germans approach—burning town forests, towns, and cities, starting fires in coalmines and oil wells. Essentially, as much as possible anything that couldn’t be evacuated would be destroyed. Now that would have all kinds of impacts post-war. It might actually be counterproductive in terms of Soviet public support for the war effort. It might also be counterproductive in terms of diverting resources from the war effort. In terms of climate there would be a couple of possible impacts. All of the burning could toss enough debris into the atmosphere to create a small-scale version of nuclear winter. On the other hand, coal mine and oil field fires might toss out enough CO2 to make the winter of 1941 relatively mild. Not good from a Soviet point of view.

3. Hitler tries to use weather as a vengeance weapon. If the Hitler regime somehow figured out that sulfur dioxide had a cooling affect I could see them trying to pump it into the air as a way of striking back at their enemies in late 1944-early 1945. They probably wouldn’t have the resources to do anything major, but if the infrastructure was in place I could see the adversaries of the cold war continuing to play with it.

4. The Shah of Iran torches his oil wells in 1941. Britain and Russia invaded Iran in the summer of 1941 and overthrew the original Shah of Iran. The oil industry was in the hands of British companies, but that might not keep the Iranians from torching the fields. I doubt that the fires would have a major impact on climate, but they might hamper British use of the oil and force them to ship more oil in from outside the Middle East. The Iraqi revolutionaries could have done the same thing to their oil wells as it became obvious that their revolt in the spring of 1941 was going to fail.

5. The Germans (or the Soviets) Could Have Torched the Caucasus Oil Fields. If the Germans temporarily grabbed a major part of the fields or looked like they would, the Soviet could have torched them, or the Germans could have when it became obvious that they were going to have to leave. Again, I’m not sure the resulting fires would have a significant impact on climate, though they might have an impact on the rest of the war.