Although climate change may now rank alongside ISIS as the world’s most feared security threat according to a new Pew report, the horrors that global warming will unleash in the future, are far “worse than you think” warns David Wallace-Wells.

In his sobering piece in New York Magazine, he says that “even within the lifetime of a teenager today .. parts of the Earth will likely become close to uninhabitable, and other parts horrifically inhospitable.”

He cites the melting Arctic permafrost as one alarming example: “It contains 1.8 trillion tons of carbon.” That’s twice as much CO2 that is currently trapped in our atmosphere from burnt fossil fuels. And, when it thaws, it will evaporate as methane, a greenhouse gas 34 times more potent than carbon dioxide in terms of cooking the planet.

And, methane is not the only thing that will be released: hidden within the ice lie diseases that have not circulated in the air for millions of years. And, as human beings have never been exposed to them, our immune systems will be woefully unprepared to deal with such “prehistoric plagues” when they finally emerge from the ice.

If that’s not terrifying enough, there are plenty of more recent viruses to contend, such as the 1918 flu which killed 100 million. Researchers discovered remnants of it in Alaska, and they suspect that the Siberian Ice holds both smallpox and bubonic plague.

And, to make matters worse, that permafrost may melt sooner than we think: the time scale on which climate change is happening only seems to grow faster and faster with each new report. According to the UN’s latest climate survey, the gold standard in global warming analysis, the world is not only warming faster, but its impacts are much worse than originally thought.

Two degrees of warming used to be regarded as the acceptable threshold for climate calamity: never mind that it will unleash “tens of millions of climate refugees upon an unprepared world”, writes Wallace-Wells. But, now there is only a small chance that we will stay under the 2C ceiling enshrined in the Paris climate deal. And, those odds are even bleaker since Donald Trump pulled the US out of the accord two months ago.

In fact, according to research out this week, there is only a 5 percent chance that Earth will stay under the 2C mark by century’s end: “We’re closer to the margin than we think. If we want to avoid 2C, we have very little time left,” warns Adrian Rafters, a University of Washington academic: “The public should be very concerned.”

According to the UN’s report, we will hit 4 degrees of warming within the next 80 years, and such a temperature rise will usher in changes not seen since the last Ice Age. And, to make matters worse, 4C is only the median projection: the upper end of the curve goes as high as 8C.

And, that doesn’t even include the impacts of permafrost melt; or the fact that less ice means that there will be less sun reflected and thus more warming; or that more cloud cover will trap more heat; or that forest dieback will mean that less CO2 is absorbed:

“Each of these promises to accelerate warming, and the history of the planet shows that temperatures can shift as much as five degrees Celsius within thirteen years,” says Wallace-Wells.

At 4C, the deadly 2003 European heat wave which killed 2,000 people a day, will be just a normal summer. At 7C of warming, it would be impossible to go outside, especially in the tropics where humidity routinely tops 90 percent:

“In the jungles of Costa Rica, for instance, simply moving around outside would be lethal,” writes Wallace-Wells: “And the effect would be fast: Within a few hours, a human body would be cooked to death from both inside and out.” At 11 or 12C of warming, “more than half the world’s population, as distributed today, would die of direct heat.”

And, it’s not just the heat that we have to contend with. For every degree that the planet warms up, food production falls by 10 - 15 percent. That means that if its 5C warmer by 2100, there will be 50% less food for a world population that has doubled in size.

Moreover, drought will only turn today’s lush agricultural lands into parched desert. Unless there is a dramatic fall in emissions by 2080, Southern Europe, most of the Middle East, parts of Australia, Africa, South America and China will all be in a permanent state of drought, drier than the American dust bowl.

There are already 800 million people starving across the globe today. Imagine what that number will be in 60 years time.

And, if that’s not alarming enough, warmer temperatures will also bring about more wars as people are forced to migrate from their homes whilst growing hungrier, thirstier, and more irritable in general with the heat. According to experts, every half-degree of warming will lead to a 10 to 20 percent increase in the chance of armed conflict.

That means that social conflict could more than double this century.

All of this begs the question: can we as a species survive this impending catastrophe?

In the past, the planet has witnessed five mass extinction events which have effectively wiped the evolutionary slate clean. And, all of them, except for the asteroid that killed the dinosaurs, were caused by climate change, the most notorious of which happened 252 million years ago.

That episode started when carbon dioxide warmed the planet by 5C, triggered by melting permafrost, culminating in the destruction of 97 percent of all life on Earth. And, according to scientists, this is the future that we are fast heading towards. Whilst this may smack of irrational panic to some, many of “the most credentialed scientists” that Wallace-Wells interviewed “have quietly reached an apocalyptic conclusion, too.”

Some have suggested that the lifespan of a civilization may only be several thousand years, and that of an industrial civilization only be a few hundred. Wallace-Wells muses whether this is why we’ve never found intelligent life from other galaxies:

“In a universe that is many billions of years old, with star systems separated as much by time as by space, civilizations might emerge and develop and burn themselves up simply too fast to ever find one another... the mass extinction we are now living through has only just begun.”

Although global warming started in England at the dawn of the Industrial Age, more than half of that carbon dioxide has been released in the past three decades. That means that climate change has brought us to the brink of planetary collapse within the span of a single generation.

And yet, in spite of all of this, many of the scientists that Wallace-Wells interviewed are optimists, asserting that humans will find a way to stop this madness simply because we must: our very survival depends on it. After all, as the old cliche goes: necessity is the Mother of all invention.