Abstract
A couple of years ago, I realised that the professional military in various countries were taking an interest in climate change. They had grasped that the first and biggest impact of global warming, for human beings, is on the food supply – and as more and more people scrambled for less and less food, there was going to a growing demand for their services. So I set out on what turned into a two-year tour of the climate-change world, interviewing the scientists, the generals, the diplomats and the politicians. This is what I knew at the end that I didn’t know at the start.
First, this thing is coming at us a whole lot faster than the publicly acknowledged wisdom has it. When you talk to the people at the sharp end of the climate business, there is an air of suppressed panic in many of the conversations. We are not going to get through this without taking a lot of casualties, if we get through it at all.
Second, the generals are right. The key problem is that global warming cuts into food production, and some countries (mostly, those nearer the equator) are going to suffer from it much more than others. They will generate huge numbers of refugees, they may become “failed states”, and they could even end up at war with one another. The military will have plenty to keep them busy – and the more chaotic the world gets, the less chance there is for a global agreement on curbing greenhouse gases.
Third, there is a limit beyond which we must not go. If the rise in the average global temperature exceeds two degrees Celsius, we will probably trigger feedbacks that cause huge releases of naturally stored carbon dioxide and methane. Melting the permafrost would do it, or just warming the sea’s surface too much. Once those natural processes are set in motion, we could cut our own greenhouse gas emissions all the way back to zero and find out that the warming was still heading for five or six degrees Celsius. That would mean mass death.
Fourth, we are going to pass right through the two degree limit. Two degrees equates to 450 parts per million of carbon dioxide in the atmosphere, and we are already at 387 ppm. Our emissions are now raising that number by 3 ppm per year. It is very hard to believe that the talks for an international deal to replace the Kyoto accord will succeed soon enough, and mandate deep enough cuts, to stop the rise short of 450 ppm. The huge differences between the “old rich” countries and the newly industrialising ones will either delay a deal for years, or result in a bad compromise. We will be lucky to stop before 500 or even 550 ppm.
Fortunately, there is a way to cheat: various geo-engineering techniques that create an artificial sun-screen to keep the temperature below two degrees hotter. Putting sulphur particles into the stratosphere, or thickening low-lying marine clouds to make them more reflective, are only stop-gap measures. They don’t solve the problem. But they could win us extra decades to work at getting our emissions down without triggering the feedbacks. and we will probably be doing something like that within ten years.
This is a very big crisis, but there is a way through it.