Skip to comments.Clear skies end global dimming. Earth's air cleaner, but may worsen the greenhouse effect.
Posted on 05/06/2005 7:19:39 AM PDT by .cnI redruM
Our planet's air has cleared up in the past decade or two, allowing more sunshine to reach the ground, say two studies in Science this week.
Reductions in industrial emissions in many countries, along with the use of particulate filters for car exhausts and smoke stacks, seem to have reduced the amount of dirt in the atmosphere and made the sky more transparent.
That sounds like very good news. But the researchers say that more solar energy arriving on the ground will also make the surface warmer, and this may add to the problems of global warming. More sunlight will also have knock-on effects on cloud cover, winds, rainfall and air temperature that are difficult to predict.
The results suggest that a downward trend in the amount of sunlight reaching the surface, which has been observed since measurements began in the late 1950s, is now over.
The researchers argue that this trend, commonly called 'global dimming', reversed more than a decade ago, probably following the collapse of communist economies and the consequent decrease in industrial pollutants.
The widespread brightening has remained unnoticed until now simply because there wasn't enough data for a statistically significant analysis, says Martin Wild, an atmospheric scientist at the Swiss Federal Institute of Technology in Zurich and an author on one of the reports.
Wild and his team looked at data on surface sunshine levels from hundreds of devices around the planet. They found that since the 1980s there has been a transition from decreasing to increasing solar radiation nearly everywhere, except in heavily polluted areas such as India and at scattered sites in Australia, Africa, and South America1.
A second study, led by Rachel Pinker from the University of Maryland, College Park, found a similar trend by looking at satellite data, although their research suggests the extent of the brightening is smaller2. Unlike ground stations, satellites can sample the whole planet, including the oceans. However, satellite data are difficult to calibrate, and so are considered less accurate than measurements from the ground.
Surprisingly, Wild's study shows a brightening trend in China, despite the fact that there is a booming, fossil-fuel-intensive industry in that country. Wild says he can only speculate that the use of clean-air technologies in China might be more widespread and efficient than has been thought.
In contrast, India's vast brown clouds of smog, which result from wildfires and the use of fossil fuels, have reduced the sunlight reaching the ground.
Just warming up
Researchers will now focus on working out the long-term effects of clearer air. One thing they do know is that black particulate matter in the air has been contributing a cooling effect to the ground. "It is clear that the greenhouse effect has been partly masked in the past by air pollution," says Andreas Macke, a meteorologist at the Leibniz Institute of Marine Sciences in Kiel, Germany.
Uncertainties remain part of the game because scientists have only a limited ability to track cloud cover and particulates, says Macke. Increased cooperation in programmes such as the NASA-led International Satellite Cloud Climatology Project should help to close the gaps in our knowledge of how dirty air affects climate, he says.
What else can you do?
Is it just me or are all these scientists just full of crap ?
EVERYTHING that happens means global warming... how odd
Stop global warming, pollute more.
Some days you just can't win.
So pollution is good for us!
>>>>EVERYTHING that happens means global warming... how odd
True, or else the temperature would pretty much stay at or around 0 Kelvin.
Imagine that! And here I thought by reading many posts on this forum to the contrary, global warming was just a myth. Oh those pesky melting polar icecaps. [/sarcasm]
This article deserves framing! WTF!
I don't know what your involvement might be, but yes, these scientists are in fact, as you so eloquently put it, "full of crap!"
We could prevent this tragic warming by all visiting our local dumps and setting huge piles of rubber tires on fire....That would solve polar melting.
Besides, Greenland was several degrees warmer, and hence named Greenland, hundreds of years before anthrogenic pollution was even a blip on the radar screen.
I would submit that people greatly exaggerate the ability of humans to influence the climate in an effort to control the actions of others.
It's good to see that the MSM still knows how to wrest bad news from the jaws of good news.
The obvious conclusion is that government research grants cause global warming.
In May, June, July and August, we will each carry opened umbrellas (cloud blue)....raining or not. This will prevent the sun's rays from hitting the surface of the earth.
In the winter, we'll pray for more snow. If it doesn't happen, we'll all make ice cubes and bring them outside to cool mother nature who apparently can't handle the workings of a populated earth.
WE'RE DOOMED!!!! No matter what we do, our human hi-tech civilization is DOOMED!
The government needs to start euthanizing people now so that Mother Gaia can start re-processing their corpses before our DOOM hits. Our poor Mother Gaia cannot process the billions of corpses that will be lying about if we do not reduce our population right now! Mandantory abortion for 99.99% of all pregnant women, only committed Gaians may be allowed to reproduce, and then only one child per mother. Only less than 1 million humans will be permitted. Mandantory dismantling of all industrial infrastructure. Mandantory re-education camps for all people so that they may accept their fate with pleasure for their final service to Mother Gaia.
(I wonder how many of those enviro-whackos really believe this?)
These poor f*cks just don't know when to quit. A few years ago, I remember one liberal telling me that she KNEW global warming was happening because, "every summer it keeps getting hotter and hotter..."
Then, a year or two later, Boston was just slammed with one of the coldest winters on record. I commented to another liberal friend, "Hey, I thought the world was getting hotter and hotter."
His response, "well... extra cold winters are just one symptom of global warming..."
Personally, I'm still waiting for the ice age we were promised back in the 70s.
"Is it just me or are all these scientists just full of crap ?"
Well, I don't know if you are full of crap, but the scientists certainly are full of crap. :)
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.