The global temperature change during the Younger Dryas, a period of cooling that occurred approximately 12,800 to 11,500 years ago, is believed to have been quite rapid. The Younger Dryas is believed to have started with a cooling of several degrees Celsius in a matter of decades. The cooling was caused by a change in the Atlantic Meridional Overturning Circulation (AMOC), which is a large ocean current system that carries warm water northward from the tropics and cold water southward from the poles. The change in the AMOC is thought to have caused a decrease in the amount of warm water that flowed into the North Atlantic, which in turn cooled the region and caused a cooling of the climate in Europe and North America.

The cooling during the Younger Dryas is believed to have been quite severe, with temperatures dropping by as much as 5 to 10 degrees Celsius in some areas. This cooling caused a number of changes in the environment, including the extinction of large mammals such as the woolly mammoth and the reindeer, changes in the distribution of plant and animal species, and a reduction in the amount of precipitation in many areas.

Overall, the cooling during the Younger Dryas is believed to have been a rapid and dramatic change in the global climate, and it serves as an important example of how climate can change quickly and have significant impacts on the environment and human populations.

Plus of how spending much of the world’s wealth and labour on trying to control CO2 over decades and centuries is absolute folly…