Playing devil’s advocate for a moment, what if some of the more extreme climate predictions turn out to be nothing more than hyperbole? What if we ignore things like feedback loops and energy demand? What if we take the IPCC scenarios at face value, new carbon capture technologies and all, and operate on the basis that there is still time to turn things around without substantially changing our Western lifestyles?
According to the Global Catastrophic Risks Report, using just the IPCC figures, scholars have scientifically estimated the probability of reaching a 6°C global average increase in temperature by 2100 at around 10% (with medium to high emission scenarios, the trajectory we are currently on). Would you get on an airplane that had a 10% chance of crashing? Of course not. Yet playing that kind of Russian roulette with humanity’s future somehow seems reasonable.
What does a 6°C average global temperature increase really mean for humanity? To answer that question, British author and journalist Mark Lynas spent 3 years of his life poring over 10,000 scientific papers and found that, although it doesn’t sound like a lot, a 5ºC or 6ºC temperature would be devastating. The National Geographic documentary based on Lynas’ work describes how at 5ºC, two massive uninhabitable zones spread into once temperate regions of Northern and Southern hemispheres. The snow packs and aquifers that feed the great cities would dry up. And climate refuges would number in the hundreds of millions.
“I think in a world that is much warmer than now, 5ºC, it is going to be inconceivable that human civilization can withstand that kind of climatic shock,” said Lynas.
At 5ºC, suggested National Geographic, we in essence enter the twilight zone of climate change, a nightmare vision of life on Earth where traditional social systems break down. And at 6ºC, Lynas suggests, we reach what has been called a Doomsday scenario.
“Warmings of 6°C over longer periods have been associated with some of the most devastating mass extinctions that have taken place,” said Lynas. “So it’s certainly fair to assume that if temperatures soar by six degrees within less than a century, we are going to face nothing less than a global wipe out.”
It is our past climate history that shows more clearly than any computer model how the climate system works, which is not through gradual change, but rather periods of stability broken by sudden lurches. Greenhouse gas concentrations are already at their highest level in millions of years and temperatures will soon join them. “Humanity faces a genuinely new situation,” notes environmental journalist Fred Pearce. “It is not an environmental crisis in the accepted sense. It is a crisis for the entire life-support system of our civilization and species.“ In the relative climate stability of the last 10,000 years, civilizations have plundered and destroyed their local environments. But as a civilization fell in one place, another rose somewhere else.
“In the past, if we got things wrong and wrecked our environment, we could pack up and move somewhere else,” said Pearce. “Migration has always been our species’ great survival strategies. Now we have nowhere else to go, No new frontier. We only have one atmosphere; only one planet.”
But it isn’t all doom and gloom. James Lovelock points out that extreme temperatures don’t necessarily mean that there are not areas when people could still live. The Arctic might again become tropical, as it was in the past, but it would probably still be habitable, for instance. After years of being one of the environmental movement’s most influential figures (according to one British newspaper), an honest assessment led Lovelock to conclude that our best strategy might be not sustainable development, but rather sustainable retreat.
We suspect that we have little time left to deal with climate change, overpopulation, food and water shortage, and other adverse consequences of our accelerated way of living. But how do we choose between the remedies on offer? Do we try sustainable development and renewed energy? Or do we bite the atom and rely on nuclear energy? Some offer to geoengineer the Earth to an ideal composition and climate. I think we might do worse than have trust in Gaia to regulate the Earth as she has done since life began, and retreat to the best [cooled] cities that we can design and build with the objective of saving as many of us as we can; and entirely abandon the absurdly hubristic idea of saving the planet.