the wrong type of dust – airborne particles and climate change

In the past week there have been 2 pieces of news, both about the effects of particulates (ie dust) on the atmosphere and climate, and both challenge the commonly held belief that CO2 in the atmosphere is the prime cause of climate change.

To put it briefly, different particles act differently depending on size and composition. Soot is dark and tends to absorb sunlight and re-emit it as heat while other particles like sulphur compounds tend to reflect heat. Industrialization has caused massive increases in particulates caused by construction, combustion, and urbanization. The scientists are saying is that it is this that has caused climate change and not the increase in CO2 emissions. According to these theories, the efforts to reduce sulphur emissions to combat acid rain have reduced the reflectivity of the atmosphere causing an increase in heating as there’s less to counteract soot.

This is interesting because it addresses the fact that the arctic is heating faster than the antarctic. The northern hemisphere is much more industrialized and the majority of particulate emissions happen here, the scientists are saying that black soot is coating the ice which makes it absorb heat more, and with reductions in sulphur more sunlight is reaching the ice for it to absorb, causing the alarming arctic melting.

The suggestion here is that in order to stabilize temperature we need to reduce soot emissions and possibly think about increasing sulphur emissions. The trouble with the second part of that is that sulphur forms acid rain which causes deforestation. hmmmmmm.

Are they right about particulates as opposed to CO2? There’s insufficient data to be sure, but I doubt that’s the whole story. The issue I have with both camps is that there ARE camps in the first place. The earth’s climate is extremely complex and in all likelihood both sides are right to a certain extent, yet both say one is completely right and the other completely wrong. This attitude is common in science but this is like 2 people fighting in a burning house. The point to take from this is that there’s a lot about the climate we don’t know, and before we invest massively in a solution we really need to more fully understand the problem.

It’s time to launch more climate study satellites and to mandate that all new commercial aircraft carry scientific instruments to study the air. There also needs to be a fully-funded international initiative to investigate geo-engineering to find and test better alternatives to dumping millions of tons of pollution into the air, although in the near future we may see the phrase “give a hoot – pollute”.