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Surface scientists coined the term 'Nuclear Winter' to describe the chilling effects of a significant nuclear war on our planet. This catastrophic event would trigger a miniature ice age, enveloping the majority of the world in freezing temperatures.
They believed the outcome of a large nuclear event could lead to the ignition of fires, releasing thick clouds of black smoke filled with chemicals and toxins from burning structures. These clouds would blanket the sky, preventing the sun's rays from penetrating and causing surface temperatures to plummet below freezing. The experts believed this scenario would be a global phenomenon, affecting all regions except those near the equator. They also predicted that a nuclear winter would last a maximum of two to three years, even in the worst-case scenario.
They were both right and wrong. The nuclear winter caused by the Catastrophe did indeed bring about that miniature ice age, but it happened everywhere; no place on the planet’s surface had temperatures above freezing. This resulted from the smoke rising so thickly into the sky that the sun heated the smoke which then rose above the atmosphere, unable to be cleared by the rain.
They were also wrong about how long it lasted. It lasted for a decade before finally clearing. By then, much of the living flora on the surface had died off, as had all vertebrates and most invertebrates. Even people who had access to other bomb shelters, both private and government-run, did not survive.