miércoles, 7 de diciembre de 2011

Human emissions could stretch around the Earth 63 times

Fred Pearce, consultant, Durban

Ever wonder how much carbon humans put into the air? Not the numbers, which are incomprehensible, but what it all looks like. Here goes. From burning carbon-based fuels like coal, oil and natural gas, we currently emit into the air every year 9 billion tonnes of carbon. Imagine that as a typical US coal train. How long would that it have to be to carry all that carbon?

The answer, according to Christopher Sabine of the US's National Oceanic and Atmospheric Administration, is 2,479,500 kilometres. A train that long would stretch around the planet 63 times. Remember that, while around half the emitted carbon is absorbed by oceans and land vegetation, the rest of it stays in the atmosphere for centuries. (Sadly, Sabine didn't calculate how many kilometres of coal train are still up there.)

What do we need to do to stop all that accumulating carbon from warming the planet by more than two degrees later this century? Nicholas Stern, author of the influential Stern Report on the economics of climate change, says we have to cut the rate at which we emit carbon by at least 60 per cent from business-as-usual. That's a tough ask, and it doesn't allow for accelerated economic development in poor nations. We ought to expect the poor world's emissions to triple as their wealth grows, says Stern. Factor this in and we have to find a way of cutting the amount of carbon we produce for every unit of economic activity by a factor of 7.5.

Stern, by the way, is an optimist. The transformation requires nothing less than a "new energy industrial revolution", he told a fringe meeting here in Durban. "The good news is that the revolution is beginning." Hold onto your hats.

my comment:

Look at the transport system, that being almost obsolete in U.S.A., and heavy oil dependent, is very much more eficient in many countries and cities of this same world. U.S.A. has now the great opportunity to stop this global war on oil, only by reconverting their "individual-car" based system. Microbuses, Vans, and collective taxis, and bici-taxis, would ameliorate, in so many cities, actual urban chaos. ¡Without new infrastructures!

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