We are almost certainly going to see a two degree Celsius rise in global temperatures – we are already about half way there. The tipping point for two degrees is about 450 ppm of CO2 in the atmosphere. This year we will likely pass 400 and since we add about 2 ppm every year, the math is easy. We are on track to hit 450 by the year 2040, give or take a couple of years.
Carbon stays in the atmosphere for a very long time and even if we were to stop emitting greenhouse gases next year – an impossible task – we would still see another half degree rise. They say 1.5 is unpleasant but manageable. Given that we are unlikely to stop emitting carbon; the question is no longer if we will hit two degrees but when.
Most scientists are saying that even with an aggressive plan we are probably looking at 2.5 to 3 degree rise in temperatures; with the proposals on the table in Paris, it may be a degree above that. This may not seem like a lot but we’ve already seen an increase in droughts and massive storms so it is more than you think. And it may be enough to trigger feedback loops over which we will have little or no control. Runaway climate change won’t end life on earth – life is resilient. But it will probably end human life or at least human civilization. And those of us who are left will live lives that are truly nasty brutish and short.
But not all is doom and gloom. One thing we can do is buy time. Reducing our emissions by half over the next decade – something that we can do – would delay the arrival of 450ppm by 20 or even 40 years. Which would give us time to get down to zero by say 2060 or 2070. It will be too little to stop us from crossing the 2 degree barrier but it may save us from 3.5.
But the models tell us that this is still too much for our current economies and much of our infrastructure to survive. Certainly sea level rise itself will destroy many countries and cities and put a massive strain on economies struggling to adapt. And if we get feedback loops kicking in, we’re all doomed anyway.
So what are the options? On the one hand we could be even more aggressive in reducing emissions – get down to zero by 2040, for example. It won’t be cheap but neither is building a dike around New York City. Sadly we would have been there already if we had listened to Al Gore in 2000 and not spent trillions of dollars fighting wars in the Middle East over oil – the thing that ironically is going to kill us now. Still, humans eventually wake up – I hope – and zero by 2040 is something we could shoot for.
And, on the other hand, there is always technology. Nobody really wants to go there but geo-engineering is an option. Which I’ll explore tomorrow. But in the meantime ask yourself this: do you really want to experiment on the only planet we know we can survive on?
And that’s ten minutes.