Saturday, March 30, 2013

Yet more on the flatlining

An interesting and disturbing paper from James Hansen et al. The message I get from this is that aerosol pollution has increased since 2000, mainly from increased coal-burning, and this has reduced global warming. The CO2 from the coal burning stays in the atmosphere for centuries but the aerosols fall out after about five days. This means that if we were to stop burning coal, or simply clean up the aerosol emissions from burning coal, the rate of global warming would increase immediately. However, if we don't stop burning coal, longer-term global warming will be all the greater because of the increased concentration of CO2 in the atmosphere.

Aerosol pollution is one possible contributor to the reduction in surface warming but there remain major uncertainties around the size of this contribution. These uncertainties would have been reduced by measurements from a satellite designed to measure aerosol concentrations. Unfortunately, the launch of this satellite failed and there are no plans to replace it.

Wednesday, March 27, 2013


In my last post but one I said I was trying to set up a local study group on sustainability issues. Since then we have had our first meeting and it went well. We decided to devote our next meeting to the subject of inequality. This was partly because the New Economics Foundation (nef) put on an event on the subject recently and one of our number attended it. A resume of the nef take on inequality can be found here.

What has inequality got to do with energy descent and sustainability - apart from the fact that they both appear to be causes associated with the left rather than the right in British politics? My gut feeling is: quite a lot.

More on the flatlining global temperature

I've commented before on the flatlining global surface temperature. This week I have found two very pertinent articles: first, from the website of The Economist, an extended discussion on that and related matters; second, on the Sceptical Science website, an article claiming that, far from flatlining, global warming has accelerated in recent years. The article, reporting a new paper by Balmaseda, Trenberth, and Källén, explains how much of the surplus heat from the sun is to be found deep in the oceans.

This would appear to confirm what some scientists were predicting five years ago, that natural fluctuations in ocean currents could depress the global surface temperature for about a decade.