DENVER (CBS4) – With an estimated 17,000 nuclear weapons in the world, we have the power to exterminate humanity many times over.

But it wouldn’t take a full-scale nuclear war to make Earth uninhabitable, reports Live Science.

Even a relatively small regional nuclear war, like a conflict between India and Pakistan, could spark a global environmental catastrophe, says a new study.

“Most people would be surprised to know that even a very small regional nuclear war on the other side of the planet could disrupt global climate for at least a decade and wipe out the ozone layer for a decade,” said lead author Michael Mills, an atmospheric scientist at the National Center for Atmospheric Research in Colorado.

Researchers developed a computer model of the Earth’s atmosphere and ran simulations to find out what would happen if there was a nuclear war with just a fraction of the world’s arsenal.

What they saw was the stuff of nightmares:

Firestorms would belch over 5 million tons of ash into the sky.

The ash would absorb the sun’s rays, causing deadly cooling on the surface.

Global temperatures would plummet my nearly 3 degrees Farenheit on average, with most of North America experiencing winters that would be colder by 4 to 10 degrees.

Lethal frosts would cover the Earth and reduce the growing seasons bu about a month for several years.

Rainfall and other precipitation would be reduced by about 10 percent, triggering worldwide droughts and leading to wildfires in the Amazon, which would spew more smoke into the atmosphere.

The sky ash would heat the stratosphere and accelerate the chemical reactions that destroy the ozone layer.

The intense ultraviolet radiation that would get through to the surface would be a dramatic threat to human health and damage fragile ecosystems on land and sea.

“All in all, these effects would be very detrimental to food production and to ecosystems,” Mills said.

The findings are published in the journal Earth’s Future.

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