In the XX Century, humanity became aware for the first time of the possibility of causing the end of the world by nuclear war. Dr. Strangelove made fun of total war but in the back of our minds we did not laugh and some thought we should prepare.
Those who studied the consequences of nuclear war knew very well that it would be the end of humanity as we know it. Others tried to figure out how humanity could communicate after nuclear war;
Paul Baran, the link between nuclear war and the internet
The Doomsday Clock is back to 3 minutes before midnight, the worst since 1984 and 1949.
But now, the reason why the clock has been moved 2 minutes by the Atomic Scientists is because of global warming;
Extreme weather, such as long-lasting droughts, outsized storm systems, and increasingly erratic monsoon seasons --is already reducing agricultural yields, causing fresh water sources to dry up, and leading to increased flooding of coastal cities around the world. While these are the kinds of effects from global warming that environmental scientists have been predicting, government policies have yet to encourage the changes in energy use and human settlement that could stave off the very worst results and mitigate the suffering that is now bound to occur. More bellow the orange mushroom cloud.