Global Dimming

[A Spoonful Supreme]

http://en.wikipedia.org/wiki/Global_dimming
http://www.globalissues.org/EnvIssues/GlobalWarming/globaldimming.asp#Whatisglobaldimming

Have you guys heard about this? I just saw a d0cumentary on it and I didn't even know it existed, it sounds really serious. Apparently some guy brought it to light after 9/12/2001 when Bush grounded all airplanes. Researchers claim it's responsible for enviornmental disaster and death etc.

[Already_Taken]

we will live in a cold, dark place in a few years :-|

[Cybergasm]

Originally Posted by Already_Taken

we will live in a cold, dark place in a few years :-|

Actually it will be a hot, dark place. Just because the light is getting refracted back, the heat energy is still reaching us and getting trapped=global warming.

Thus, we are under going both global dimming and warming.

[Reaganista]

it'll be at least 5 years before I believe this bull****

[WhoDidTheElf]

Sweet it will be like a hot Alaska in it's 24 our dark times.

[A Spoonful Supreme]

Originally Posted by The Tway

it'll be at least 5 years before I believe this bull****

idk if 5 years is enough time to decide or believe anything in the timeline of the world

[Reaganista]

idk if 5 years is enough time to decide or believe anything in the timeline of the world

I didn't mean I was going to analyze the next five years' worth of empirical data

[A Spoonful Supreme]

Originally Posted by The Tway

I didn't mean I was going to analyze the next five years' worth of empirical data

why would it take u 5 years then

[Reaganista]

because I'm going to completely ignore this and never think of it again for the next five years

if it still hasn't been disproven by that point then I'll say it's probably true, or at least has some truth to it

[A Spoonful Supreme]

Originally Posted by The Tway

because I'm going to completely ignore this and never think of it again for the next five years

if it still hasn't been disproven by that point then I'll say it's probably true, or at least has some truth to it

thats why i said it probably isnt enough time to disprove or prove these theories, you arent going to analyze the data, other people are

[Reaganista]

well they should hurry the hell up then.

usually these crazy-*** theories are pretty far along the development line before I start accidentally hearing about them

[A Spoonful Supreme]

i dont disagree with you


btw are all people from philly hard asses like you?

[Reaganista]

some of them. i guess.

[davser]

There was a good d0cumentary on UK television that looked at this. It seems that clean burn technology could actually have an adverse effect as there is a reduction in soot in the atmosphere leading to more sunlight getting through which can't escape due greenhouse gases etc.
Discovered due to some evaporation test I believe.

[coheneran]

So if we used more aerosols, we could potentially balance up the heating effects of global warming with the cooling effects of global dimming?

Seems like nowadays anyone can be an environmentalist critic if they find a word to go after "global". You guys better watch out, because if you don't stop your corrupt and immoral ways of life, we'll all die from global indigestion!

And davser, awesome avatar!

[davser]

Cheers re avatar!

Yeah quite bizarre that some pollution may have a cooling effect after the recevied wisdom that it is all bad.

From http://www.bbc.co.uk/sn/tvradio/programmes/horizon/dimming_prog_summary.shtml

We are all seeing rather less of the Sun. Scientists looking at five decades of sunlight measurements have reached the disturbing conclusion that the amount of solar energy reaching the Earth's surface has been gradually falling. Paradoxically, the decline in sunlight may mean that global warming is a far greater threat to society than previously thought.

The effect was first spotted by Gerry Stanhill, an English scientist working in Israel. Comparing Israeli sunlight records from the 1950s with current ones, Stanhill was astonished to find a large fall in solar radiation. "There was a staggering 22% drop in the sunlight, and that really amazed me," he says.

Intrigued, he searched out records from all around the world, and found the same story almost everywhere he looked, with sunlight falling by 10% over the USA, nearly 30% in parts of the former Soviet Union, and even by 16% in parts of the British Isles. Although the effect varied greatly from place to place, overall the decline amounted to 1-2% globally per decade between the 1950s and the 1990s.

Gerry called the phenomenon global dimming, but his research, published in 2001, met with a sceptical response from other scientists. It was only recently, when his conclusions were confirmed by Australian scientists using a completely different method to estimate solar radiation, that climate scientists at last woke up to the reality of global dimming.

Dimming appears to be caused by air pollution. Burning coal, oil and wood, whether in cars, power stations or cooking fires, produces not only invisible carbon dioxide (the principal greenhouse gas responsible for global warming) but also tiny airborne particles of soot, ash, sulphur compounds and other pollutants.

This visible air pollution reflects sunlight back into space, preventing it reaching the surface. But the pollution also changes the optical properties of clouds. Because the particles seed the formation of water droplets, polluted clouds contain a larger number of droplets than unpolluted clouds. Recent research shows that this makes them more reflective than they would otherwise be, again reflecting the Sun's rays back into space.

Scientists are now worried that dimming, by shielding the oceans from the full power of the Sun, may be disrupting the pattern of the world's rainfall. There are suggestions that dimming was behind the droughts in sub-Saharan Africa which claimed hundreds of thousands of lives in the 1970s and 1980s. There are disturbing hints the same thing may be happening today in Asia, home to half the world's population. "My main concern is global dimming is also having a detrimental impact on the Asian monsoon," says Prof Veerhabhadran Ramanathan, one of the world's leading climate scientists. "We are talking about billions of people."

But perhaps the most alarming aspect of global dimming is that it may have led scientists to underestimate the true power of the greenhouse effect. They know how much extra energy is being trapped in the Earth's atmosphere by the extra carbon dioxide (CO2) we have placed there. What has been surprising is that this extra energy has so far resulted in a temperature rise of just 0.6°C.

This has led many scientists to conclude that the present-day climate is less sensitive to the effects of carbon dioxide than it was, say, during the ice age, when a similar rise in CO2 led to a temperature rise of 6°C. But it now appears the warming from greenhouse gases has been offset by a strong cooling effect from dimming - in effect two of our pollutants have been cancelling each other out. This means that the climate may in fact be more sensitive to the greenhouse effect than thought.

If so, then this is bad news, according to Dr Peter Cox, one of the world's leading climate modellers. As things stand, CO2 levels are projected to rise strongly over coming decades, whereas there are encouraging signs that particle pollution is at last being brought under control. "We're going to be in a situation, unless we act, where the cooling pollutant is dropping off while the warming pollutant is going up. That means we'll get reduced cooling and increased heating at the same time and that's a problem for us," says Cox.

Even the most pessimistic forecasts of global warming may now have to be drastically revised upwards. That means a temperature rise of 10°C by 2100 could be on the cards, giving the UK a climate like that of North Africa, and rendering many parts of the world uninhabitable. That is unless we act urgently to curb our emissions of greenhouse gases

[A Spoonful Supreme]

ya thats the d0cumentary I saw, the BBC one, man that was really good