More on Global Dimming

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Posted by michael on Thursday May 13, 2004 @04:56AM from the future's-so-dark-I-don't-need-to-wear-shades dept.

dtolman writes "According to the New York Times (registration required) if the world seemed brighter to our grandparents 50 years ago, they were right. While the sun's output hasn't dropped, the amount of sunshine reaching the Earth's surface has dropped an average of 10% since the 1950's. In Hong Kong, the sunlight reaching the surface has decreased even more - 37%! Scientists are theorizing that this is mainly due to air pollution - so this trend might reverse if air pollution clears up." We had a another story on global dimming last year.

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Looks like we'll all be dead... by Neil+Blender · 2004-05-13 04:59 · Score: 3, Insightful

...the day after tomorrow. Next time an asteroid movie comes out, expect plenty of articles about about that in the media.
Less light - more heat? by drizst+'n+drat · 2004-05-13 05:00 · Score: 4, Insightful

Ok ... so less light is reaching the surface than did 50 years ago though the energy output has remained relatively the same. Is it safe to assume that the energy is being absorted by pollution and thus heating the planet?
1. Re:Less light - more heat? by rrkap · 2004-05-13 06:19 · Score: 3, Insightful
  
  Is it safe to assume that the energy is being absorted by pollution and thus heating the planet?
  
  Not really. The question is one of total energy ballance.
  
  Think about it as (mass)*(heat capicity)*(temperature change)=(incoming energy from radiation)-(reflected energy)-(re-emitted energy)
  
  The atmosphere could be becomming more reflective, too. The mechanism proposed for global warming ignores this in its simplest form. CO2 is pretty transparant to visible light, but likes to absorb heat, meaning that the total emissivity of the earth is assumed to be being reduced at long wavelengths and left the same at short ones. This research says that something is happening at the shorter wavelenghths as well.
  
  --
  I like my beverages with warning labels!
Headlines We Should be Wary Of by basking2 · 2004-05-13 05:10 · Score: 4, Insightful

So, after the ice age coming back, global warming destroying us, acid rain eating us and the oil supply being exhausted by 2010 I take science headlines with a grain of salt. The fact that this is from the NY Times just furthers my suspicion. That paper has destroyed its reputation over the years.
One thing that folks have to realize is that scientists are people. They get happy and sad, they are humble and proud, and they lie, steal, cheat and grab for headlines as reagularly as any normal person would.
This is not to discredit the publishers of this work, but to remind us all that headlines like this pop up often amount to a new natural trend or in the very rare case, us acctually damaging the environment in a way that it isn't designed to cope with.
I mention this because our geek culture has a way of worshiping the words of scientists and as a result some amusing lies have drifted in and out of school text books and around our little digital communities. Trust no one. The truth is out there. Now will I get sued by Fox or the aliens over Mexico??? Hmmm...

--
Sam
Re:Less light == less sunburns? by Scott+Richter · 2004-05-13 05:10 · Score: 3, Insightful

if UV rays aren't blocked by water clouds very well, why would they be blocked by pollution clouds? not cleaning up the air can never be considered a good thing.
First, water clouds DO block UV fairly well - you don't get a sunburn nearly as fast on a cloudy day. Second, pollution may not be absorbing UV - it's more likely scattering it.
Re:Let's just get this out of the way... by hak1du · 2004-05-13 05:18 · Score: 4, Insightful

Just because it's "dimmer" doesn't mean it isn't getting warmer.

Actually, it may be getting warmer because it is getting dimmer: if visible light is absorbed by something in the atmosphere, it would end up heating up the atmosphere. Think of a black solar collector used for water heating.
Obviously not by BESTouff · 2004-05-13 05:39 · Score: 4, Insightful

so this trend might reverse if air pollution clears up
This single utopic sentence should have told you it's only unrealistic babble.
Re:Let's just get this out of the way... by M1FCJ · 2004-05-13 05:48 · Score: 4, Insightful

Well, let's put it this way:
On Venus, it is around 400C degrees. On Venus, you can't see the sun because of the clouds.
Now, if we removed the clouds, would Venus get warmer or colder?
Re:Frustrated by dtolman · 2004-05-13 06:11 · Score: 3, Insightful

Perhaps because I read it on the front page of my physical New York Times first?