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More on Global Dimming
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.
...the day after tomorrow. Next time an asteroid movie comes out, expect plenty of articles about about that in the media.
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?
Plants get their energy from the sun's light. Insufficient light means no plants. No plants means no food. (Meat isn't plants, but it's powered by plants, so no plants, no meat either.)
One unfortunate thing about polution is that the wind blows it everywhere. A coal factory darkens the skies in antartica no matter if it's location is in Denver, Stockholm, or Bejing.
Isn't global dimming a good thing? Sunlight isn't exactly compatible with the nerd life...
Actually, the pollution tends to let the heat through but then trap it.
"Have you ever thought about just turning off the TV, sitting down with your kids, and hitting them?"
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
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.
Ok, so scientists are pissed off about the following things:
1) Global warming: It's getting hotter!
2) Global dimming: It's getting darker!
3) Global light pollution: It's too bright at night!
4) Global noise pollution: It's too noisy!
Why don't we all stop bemoaning all the crap that's supposed to have killed us within 10 years over the past 50 years and just get back to doing something useful with our time. Measuring fractions of changes on a global scale is like stating that my Linux server crashed because of the price of tea in China yesterday! Sheesh.
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.
"It's a heck of a lot worse to, say, invade a country on another continent than to attack a neighboring village."
You're measuring human 'dimness' by the acts of a gov't under motivations we don't have all the facts on?
"Derp de derp."
"Why, oh why, do people choose to link to a page that requires registration when it's totally unnecessary? "
Because most of us don't give a flying fuck and just registerred with them. Seeing as how they don't send spam etc, it's a small price to pay for a free service.
This crusade against NYT is redudant, lame, and very tiring. More embarrasingly, they don't even check to see if you have a valid email. You want to complain about a site? Go glance around IGN.com. Bet you find at least 5 things to bitch about within the first 5 page loads.
"Derp de derp."
Experts may disagree about the extent of global warming and human-induced climate change, but few can dispute that we are changing the planet's atmosphere in measurable ways. There is objectively more carbon dioxide and pollutants in general floating around. One is hard-pressed to claim that these will not have ANY affect on weather. The left/right fights are over what the specific changes are.
There seems to be a recent up-ward warming trend. If this trend continues, it will cause economic problems such as shoreline movements, droughts, and others. Whether this is caused by SUV's or not, we should understand the causes and be prepared. The warming could be just coincidental with pollution, but to make that the primary candidate is sticking your head in the sand IMO.
Table-ized A.I.
This single utopic sentence should have told you it's only unrealistic babble.
peak power in the green - coincidence that chlorophyll is chemical of choice for providing energy to plants? I think not...
The problem with that statement is that something colored green absorbs all the light except for the green frequencies, so the plants would be reflecting away the most powerful frequency and not absorbing it.
AntiFA: An abbreviation for Anti First Amendment.
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The measuring instrument, a radiometer, is simple, a black plate under a glass dome. Like asphalt in summer, the black plate turns hot as it absorbs the sun's energy. Its temperature tells the amount of sunlight that has shone on it.
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It's not really that simple. The nature of the black plate will change how the temperature is affected. Temperature is a measure of average kinetic energy. The profile of (vs wavelength) and magnitude of the energy which is absorbed, dispersed, and reemitted will change depending upon the composition of the metal or ceramic of the plate and the nature of the coating material which makes it black.
Consider several black objects underneath a glass dome: a block of obsidian, a block of slate (as in blackboard slate), a stainless steel plate painted black, a badly tarnished silver plate, a lump of charcoal, or crushed up charcoal suspended in an epoxy resin over a stainless steel plate.
I can't begin to rank and categorize the profiles of the above objects but to illustrate the principle try the following: on a hot summer day leave a piece of charcoal out in the sun and then pick it up. On the same day place your hand on the black asphalt of a freshly laid blacktop highway. Paint a stainless steel plate in glossy black and in flat black and feel both on the same hot day.
Even if they are still using the _exact_ same radiometer today that they were using 50 years ago its absorption and reemission profile will have changed unless they've kept the glass dome sealed and either evacuated or filled with some inert gas. Even at that level there could be a change in absorptive and emissive properties from surface phenomenon.
On top of all of that there's also the cooling rate of the glass dome. On humid days the water in the air will carry kinetic energy away from the glass more quickly and could cause the interior temperature to be lower than on dry days.
It's all a crapshoot. I don't buy the doom and gloom.
+++ATHZ 99:5:80
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?
Because the costs of the damage are paid for indirectly. It is the same reason oil is so "cheap" in America compared almost any other country - our taxes subsidize the true cost of oil (pollution, maintaining the supply, etc). If we received an itemized list of where our tax dollars go, you can bet a lot of priorities wrt to the planet's ecology would suddenly be increased. But since most people don't "see" it, they don't think the problems even exist.
Perhaps because I read it on the front page of my physical New York Times first?
I'm not sure about the exact figures, but human eyes begin to sense less light after the age of 20. I think everything is around 20% darker every 10 years thereafter. By the age of 60 you would expect on average 45-50% darker vision. Sounds like he's right on schedule.
The "inconclusive" (according to CNNHN, right now) 10% over 50 years would be well under any human's ability to detect.
All true wisdom can be found in sigs.
so this trend might reverse if air pollution clears up.
Well, lets see there is less light, and probably heat too. That isnt going to really help matters, people will just use more electricity to compensate. That translates to more pollution.
Oh dear it looks like we are all doomed.
nick..
Electronic Music Made Using Linux http://soundcloud.com/polyp
Seems to me that one of the largest concerns is that plant life will be receiving less light which would obviously decrease the amount photosyntesis that occurs. That would mean less oxygen and more carbon dioxide in the atmosphere. And where is the tipping point be between less photosynthesis and a massive dying off of plants and trees? Scary to think about.
---Technology will liberate us if it doesn't enslave us first.
Say, Have you ever heard of calibration? The article even references it. This is why they know the data is consistent.
I'm a software engineer... when will my rickets set in??
Funny, but unlikely. Vitamin D is added to many things, including milk. Anyone in the US, including goth-like only come out at night wanna-be vampires is unlikely to suffer the softening of the bones associated with rickets because of dietary additives.
GF.
Lots of petrified grits