Saturday, September 15, 2012

recent developments in Climate Change

We see that Russia and Canada, the big beneficiaries of global warming, are inclined to drag their feet. Note that this is a case where voters don't want to hear the politicians say "We plan to be bad". Instead they want to hear the politicians denying global warming. This is lying for the people, not lying to the people.

A recent scientific study showed how, hundreds of millions of years ago, there was a land-locked ocean over the North Pole. That lead to a massive decline in atmospheric CO2. That is nothing like the current situation, but it does show how feedbacks of warming can lead to reducing CO2 levels. Such negative feedbacks are likely to overshoot. For example if a warm ice-free Arctic does lead to something that reduces CO2 levels then it is likely to continue to do so for much longer than we would wish.

Another reason why I think global warming could lead to cooling is the history of recent inter-glacials. They have been warmer than this one, but have not lead to runaway warming when the Arctic melts. Instead each one spikes and then crashes:

Here's my graph of the global warming position:

We know there is a nice stable ice age waiting for us on the left. Many reckon that if we keep pushing up we will go over a bump down into a very warm climate to the right. I reckon that if we suddenly stop pushing that ball it might roll down and roll over the edge to the left. However this will only happen if we find an energy source cheaper than coal.

I also reckon that it is simplistic to imagine this 2d picture. Suppose we imagine this 2d graph embedded in a bigger 3d graph. We might role over the top to the right, but then get caught in a channel that leads back around to that waiting ice age.

In summary I want to see more science before we do any geo-engineering: including attempts to get CO2 levels all the way back to the "natural" 280ppm.