In their book Dire Predictions, Penn State’s Lee Kump and Michael Mann describe just one local example of how drought, sea level rise and overpopulation may combine to pop the rivets of civilisation:
“Increasingly severe drought in West Africa will generate a mass migration from the highly populous interior of Nigeria to its coastal mega-city, Lagos. Already threatened by rising sea levels, Lagos will be unable to accommodate this massive influx of people. Squabbling over the dwindling oil reserves in the Niger river delta, combined with potential for state corruption, will add to the factors contributing to massive social unrest.”
“Massive social unrest” here being a rather bloodless phrase masking the utter chaos coming to a country already riven by corruption and religious violence.
“It’s sort of the nightmare scenario,” said Huber. “None of the economists is modelling what happens to a country’s GDP if 10% of the population is refugees sitting in refugee camps. But look at the real world. What happens if one person who was doing labour in China has to move to Kazakhstan, where they aren’t working? In an economic model, they’d be immediately put to work. But in the real world, they’d just sit there and get pissed. If people don’t have economic hope and they’re displaced, they tend to get mad and blow things up. It’s the kind of world in which the major institutions, including nations as a whole, have their existence threatened by mass migration. That’s where I see things heading by mid-century.”
And it doesn’t get any better after 2050. But forecasts about the disintegration of society are social and political speculations and have nothing to do with mass extinctions. Huber is more interested in the hard limits of biology. He wants to know when humans themselves will actually start to disintegrate. His 2010 paper on the subject was inspired by a chance meeting with a colleague.
“I presented a paper at a conference about how hot tropical temperatures were in the geological past and [University of New South Wales climate scientist] Steve Sherwood was in the audience. He heard my talk and he started asking himself the very basic question: ‘How hot and humid can it get before things start dying?’ It was literally just an order of magnitude kind of question. I guess he thought about it and realised that he didn’t know the answer and wasn’t sure anyone else did either… Our paper really wasn’t motivated by the future climate per se, because when we started we didn’t know if there was any kind of realistic future climate state that would fall within this habitability limit. When we started, it was just like, ‘We don’t know. Maybe you have to go to, like, 50C global mean temperature.’ Then we ran a whole set of model results and it was rather alarming to us.”
