I do note a difference between a ground,crude oil fire and a German diesel motor.

The "Door to Hell" (also known as the Gate to Hell, the Crater of Fire, Darvaza Crater) is a natural gas field in Derweze, Turkmenistan, that collapsed into an underground cavern in 1971, becoming a natural gas crater. Geologists set it on fire to prevent the spread of methane gas, and it has been burning continuously since then. The diameter of the crater is 69 metres (226 ft), and its depth is 30 metres (98 ft).
Diesel produces nitrous oxide and methane . Soot which is probably heat-retaining and radiating to the air. The dust mix would be cooling and sunlight-blocking so the result would be increasing coolness even with gases from burnt forests.

One theory I heard years ago, along similar lines, was that the server climate change led to them being born either all males, or all females.

This theory came from research gathered from croc farming where it was found that crocs, bred outside of their natural habitat, we born either all male or all female. So perhaps this has some merit as well.