A world with vastly shrunken inhabitable land mass, with its forced movements of millions of CC refugees, including I might add internal refugees in the US, is a disturbing picture. One that we MIGHT avoid if we pull our fingers out, beginning now. My concern is that concepts like the controversial white roofs one can too easily deflect some from the necessity of attaining carbon neutral societies by mid century at the latest.

People around the Globe have made a start – China and the US included. But we can’t afford to be diverted by controversial techno fixes.

…When the heat is reflected off the roof where does it reflect to, through a window?
Come on people think the process through this is not rocket science.

Hi Steve interesting point
In an urban environment you also have thermal mass to take into account, I don`t have the mathematics to put here, however a simple analogy would be if you painted a piece of concrete black and put it in the sun and had another identical piece painted white, the black piece would still be radiating heat longer after the sun has gone down.
Dry air radiates heat into space very quickly (far less so with damp air) that is why deserts have such a swing in temperature from day to night.
There are of corse a lot of other particles (man made usually as noted in the article) in air that can prevent that happening, that are found in urban in environments that are missing in deserts, so this is very patchy science I am presenting.
But at least on the heat loss of dry air compared to heat loss of moist air, there is some good science to back it up.
Most urban environment are made of high thermal mass products, Concrete, Bitumen Steel, these all will heat up more if they are darker colors and radiate back into the local environment after dark.
Where as if they radiated heat back into the air instead of absorbing it all day, there might be a better chance of a cool down before the sun comes up the next day.
As the article makes clear it is a lot more complicated than that, but it’s learning process

Jacobson and Ten Hoeve note that reflecting light from white roofs may lead to a decrease in cloud cover, thereby increasing, not decreasing, the urban heat effect. But they also note that their findings might change if they used different models. This is an ongoing research area not only for their group, but others, and ours as well. The findings should not be considered settled.

We have found that white roofs do provide a low-cost solution that can help buildings reduce energy costs, in a wide variety of climates, as well as cool the atmosphere regionally and globally. We have also found disadvantages. The reflective roofs may cause unwanted glare, for example, and may modestly increase heating costs in winter. But answers to these issues are exactly the ones we’re working hard to find.

Our work has shown that reflective roofs can lead to better air quality, reduce the strain on our electrical grid, improve comfort and decrease emissions from power plants. These are important considerations when evaluating all the available research.

In our opinion, all of these arguments and studies suggest that selective use of white and other reflective roofs makes sense as part of an integrated strategy for more sustainable human existence on Earth. But the potential benefits offered by cool roofs do not diminish the need for sustained reductions in greenhouse gas emissions to control global climate, or the need for increased use of renewable energy sources.

It’s important for the public to understand that scientific debate leads to better science. But it’s also important that the public receives—and the news media delivers—a message that properly conveys research news with all its many caveats and cautions. It’s not settled, until it’s settled.

For more information, go to: http://heatisland.lbl.gov/news/cool-roofs-and-global-cooling-heat-island-group-responds-jacobson-ten-hoeve-2011

Surabi Menon and Ronnen Levinson
Berkeley Lab Heat Island Group

In addition, white roofs aren’t always practical, especially because many people have ordinary shingle roofs and while shingles come in very light colors, I’ve never seen any that are white. That, and as has been mentioned, keeping them clean!

Low hanging fruit such as white roofs, more energy efficient buildings, and a better understanding of building envelope science can lower energy usage and costs. Storm water run-off is another issue but is related. Hey if they can clean the poop out of drinking water, taking out the hydrocarbons and aromatics of the roof run-off should not be a challenge when the need for clean water dictates that it be done

Just because we dont know HOW to fix a problem doesnt mean that the problem doesnt exist. If I have no clue what will cure my cancer, it does not logically follow that I therefore dont have cancer.

Climate is changing. Fact.

What to do. Multifaceted discussion … subject to change.

beaming.

After reading the headline I expected the problem would be the manufacturing of the paint—the actual cause is much more interesting (subtle & sophisticated).

It is a very difficult problem and we are working very hard to figure it out, those who simply fight it because of some misplaced idea that it’ll hurt our economy (which they also don’t understand) are invited to propose alternative methods of problem solving, because from where I sit, science is our only hope.

In the mean time please return all of the fruits of science you enjoy (virtually all technology, electronics, medical knowledge/treatment/equipment, advanced textiles, cars, computers, many synthetic materials, industrial farming, etc.).

Also, I’m skeptical that the evaporative effect (or lack thereof) would have nearly as much of an impact as the reduction in energy consumption from running air conditioners.

Agreed. Also, I don’t know how I’m going to die, so I’m not going to make any effort to eat healthy food or exercise. I also don’t plan on learning anything new either, since that will just be more wasted effort, since anything I learn about or experience might lead to my eventual death.

Seriously, though. The science of global climate is pretty tricky. Some things scientists are very sure about, and others they’re still working on. We don’t have all the answers, but we do have some of them, and not everything involves spending trillions of dollars.

We can’t even predict cloud cover to within one square mile, one hour into the future with any accuracy. When will the Left abandon ship here and move on to the next scare?