Monday, March 21, 2005
Global dimming
Despite the almost Biblical (I don’t mean fictional, but ‘dramatic’ or ‘apocalyptic’) representation of a flooded Trafalgar Square, BBC’s programme on ‘global dimming’ underlined the precarious nature of the environment we are creating for ourselves.

Essentially, global dimming is thus: increased levels of particulates in the atmosphere - ‘smog’ - and vapour trails from jets, prevent solar radiation from reaching the planet’s surface, therefore having ‘cooling’ effect on global temperatures.

This does not imply that the ‘greenhouse effect’, from increasing CO2 concentrations, is not occurring and we are immune from global warming. Au contraire, it suggests that the impact of anthropogenic CO2 has been masked by human pollution and the damage caused so far is far worse than we realise.

Global dimming may also result in huge changes in weather patterns, resulting in widespread trauma from too many people living in what could become an inappropriate environment. It has even been blamed for making Bob Geldoff more famous than he ought to have been, had his reputation been based on his musical ability alone. The Ethiopian famine in 1984 may well have been a result of these changing weather patterns.

So all we’ve got to do is keep on polluting, right?

Err no, actually. As we begin to burn our fossil fuels more cleanly, we generate fewer particulates, which will reduce the main cause of global dimming and intensify the effects of global warming. None of this has yet been adequately modelled, but the early postulations are quite alarming.

Worse, increasing the levels of both particulates and CO2 has amplified climate instability, meaning small changes in one will be hugely magnified.

Therefore the programme’s conclusion is that combating the effects of global dimming (cutting particulate pollution, for example) cannot be considered without tackling the causes of global warming – ie burning fossil fuels and clearing vegetation.

Personally, I think the researchers and the scientists have it all wrong.

I conclude that ‘global dimming’ can be attributed to the prevalence of reality TV on commercial television channels.


See:
www.realclimate.org (Global Dimming II)
www.realclimate.org (Global Dimming I)
Program symopsis at BBCi

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