[telegraph.hill]

Has anyone here heard of the phenomenon of global dimming? I saw a Horizon program about it, (in the UK), about a year ago.

The theory goes that pollution, especially from planes, has dimmed the sky significantly, so much so that there is less light reaching the earth. The perturbing part about the whole program was that it was suggested that global dimming has actually masked the effects of global warming, which is actually worse than we think! Now, that I did find worrying.

So has anyone else heard of this? What do you think?

[Raptor235]

I've heard similar things... also when big volcanoes in the past exploded they have lowered the global temperature of the earth for a year or so....

some people have actually suggested using nuclear Winter from hydrogen weapons as a way to combat global warming by lowering temperature... very interesting..

[horselover]

An A bomb? Wouldn't that do more damage?

[Matc]

You'd have to use an H bomb (probably several) the idea being that the particles sent up into the atmosphere would reflect a good deal of the incoming radiation back out into space stopping the Earth from being warmed by the suns rays. Hence cooling it down. For an explosion of that magnitude you'd want a clean H bomb (our current ones are detonated using what is basically an A bomb) so as not to cause and problems with harmful radiation - so it is a bit beyond as at the moment.

I've heard similar ideas for terraforming the moon.

[flaja]

One of the episodes of the PBS series Secrets of the Dead discusses the effects of volcanic eruptions on climate and the resulting effects on human society. The theory goes that in the 6th century AD a massive eruption sent so much ash into the sky that sunlight was blocked enough to cause global cooling. The resulting famines, plagues and social upheaval lead to the Dark Ages in Europe. So let’s hear it for global warming!