The weather systems of the Earth are a complex thing, enough that we have a hard time predicting it - check out the supercomputers used by the Met Office in the UK! While Al Gore is on his mission to warn the world about Global Warming, late last year the BBC show Horizon brought another issue to light, Global Dimming. At first it sounds like a bit of a contradiction, things are cooling down when they’re warming up? You have to dig a little deeper though, which the show does.

Global Dimming is a situation created by pollution - not greenhouse gases. The water molecules in clouds tend to build around elements in the air such as pollen, but when polluted air is involved, there are 10x as many particles for those water molecules to build around, making the clouds much denser. As a result, they reflect more sunlight back into space. Studies found that sunlight hitting various countries around the world had dropped from 5 - 30% between the 1950’s and the 90’s. As you can imagine, these findings were mostly dismissed, but then further corroborative evidence was found, water evaporation rates in Australia had dropped a significant amount during the same period.

We are now starting to feel the effects of lower Global Dimming, as pollutant levels decrease from our own efforts to ‘clean up’, but without removing the real source of the danger, carbon dioxide. As a result, temperatures rise faster, and now some scientists claim we may see temperatures rise 10 degrees in the next 100 years, a major difference from previous models which didn’t factor in the effects of Global Dimming.

Of course, I’m not a scientist, but this still concerns me, and I hope it concerns you. Is it all a load of codswallop? I only have to look at recent extreme weather events to know things are changing fast: Hurricane Katrina, massive snowfall in NY State, record-breaking temperatures in Europe in 2003. The list goes on.

I’m now laughingly waiting for comments claiming left or right wing tactics - the climate does not give a damn if you’re democrat or republican, change is afoot and we must sort something out, not banter politically.

Tags: global warming, global dimming, weather, climate