Scientists to humans: Hey bozos, climate change could kill us all.

Part of the the protest camp. An experienced climate activist tunneller known as Digger, is currentl...
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Scientists say we haven't given enough thought to human extinction

We know that climate change, left unaddressed, will produce devastating results for the planet, including the extinction of many species that occupy it. While we spend most of our energy and figuring out how we’ll adapt to these new and challenging conditions, scientists say we aren’t giving enough thought to the very real possibility that humanity gets straight-up wiped out, too. A new study published in the journal Proceedings of the National Academy of Sciences (PNAS) argues that it’s time researchers start looking into human extinction as a potential “climate endgame.”

The study looked at other research that seeks to quantify the potential damages of the planet continuing to warm. They found that too often, researchers focus on the target temperatures for limiting climate change — keeping the planet from warming more than 1.5 to 2 degrees Celsius above industrial levels — instead of considering the more catastrophic end of the spectrum.

What happens if we miss our targets set by the Paris climate agreement? What happens if the planet warms by 3 degrees Celsius or more? For the most part, the study found, scientists have not really engaged with those possibilities. The most thorough examinations of these worst-case scenarios were mostly in non-fiction science books rather than scholarly texts or research papers.

This matters for a couple of reasons. First and foremost is the fact that extinction is not off the table for us, and we really don’t have a clear picture of what that looks like. No one wants to imagine just how brutal and calamitous it would be to get to the point of human extinction, but we might still have to seriously reckon with the idea. The paper calls for scientists to take a “four horseman” approach to considering the possibility to human extinction, examining the paths of famine, extreme weather, disease, and war. All would be disastrous, but we should know what each path looks like.

The other reason these researchers want more insight into the human extinction scenario is to avoid it. Publishing reports about just what that might look like might be enough to scare people straight. It worked with the threat of looming nuclear winter during the Cold War, the scientists reasoned in the paper, so why not try it with climate change?

Ideally, we never see what human extinction looks like. But we shouldn’t blind ourselves to the possibility of it happening. If we don’t change our behaviors and kick the fossil fuel habit, there is a non-zero chance that we doom ourselves to extinction. Let’s not rule out the possibility that humanity really is that self-destructive.