I don’t know about you but I kind of like the way the world was when civilization began, somewhere in the youth of this beautiful Indus valley. Now, I wasn’t around to see it, but that planet sounds pretty nice — our planet. So when James Hansen, Head of the Nasa Goddard Institute for Space Studies in New York and one of the world’s leading climate scientists, admitted that previous estimates of climate impact were grossly underestimated. That means that the UN Framework Convention on Climate Change’s international goal to prevent “dangerous anthropogenic interference” on climate systems will require us to drastically cut global emissions far more than previously expected.
As Hansen says in his recent report, “Target Atmospheric CO2: Where Should Humanity Aim?” 350 ppm of CO2 in the atmosphere is the only acceptable stabilization level of CO2 if “humanity wishes to preserve a planet similar to that on which civilisation developed.” I’m not afraid to say it — I WOULD like a level of CO2 that would allow us to preserve such a planet. Which is to say – the only one we’ve got. The one that all ecological systems evolved for. The one that all humans rely on for absolutely everything. The one planet that has tied, ties and will tie all of humanity together.
Which means – as some have recently said – that 350 might just be the most important number in our lifetime. And, in the lifetime of the planet. The problem, to put it in context, is that we’re already at 383 ppm, and it’s continuing to increase, because we’re continuing to add more carbon emissions to the atmosphere. His paper went on to say that if we allow CO2 to reach 550 (double the 280 ppm of the thousands of years before the Industrial Revolution — that is to say, the CO2 levels for all of civilization), we’ll be facing a 6 C increase in temperature, unlike the 3 C increase the IPCC predicts. This is because of the slow feedback loops in the climate system. For example, the glaciers and ice caps are melting much more quickly than researchers had anticipated and this melting is exposing more land and water for heat absorption rather than the reflection that ice provides. Even if we cut CO2 to 450 ppm, Hansen suggests that sea levels could rise several meters – by 2100!
But back to this 350. It’s easy to lose hope when you think we’re already well above that, with no clear international (or even any clear national) strategy to really turn that trend around. The global political community has talked for so long about how difficult it would be to even stabilize at 450 ppm; reaching 350 ppm will require a massive commitment from all nations to reaching 350. This has to happen if we want to preserve the planet – the same planet – on which civilization was born. And it has to happen fast. To stabilize at 350 (from our current rate and our current trajectory) means transforming the energy system from a heavily polluting one to a zero emissions system. Over night. No big deal. If you think the Earth itself (and the civilizations on it) are no big deal.
Hansen does give us hope in his article — that while we’ve underestimated the climate impacts, we’ve overestimated our fuel reserves, which may help in the shift to clean technology in the coming years. Prices of fossil fuels WILL go up and the market will force renewable energies into the leading role in the market. But we’ll need aggressive policies, we’ll need total creativity, we’ll need innovative technology, we’ll need changes in lifestyles, and most of all we’ll need action from all of us. To commit to 350, to encourage 350, to share 350… To make it 350.