Los Angeles painting city streets white in bid to combat climate change

Havana Moon said:
This made me laugh, painting roofs white can actually increase temperatures.


Seemed like a cool idea: paint the world's roofs white to reflect more sunlight, and it could help cool down both cities and the planet. A new study, however, finds it's a lot more complicated – even as it dispels climate change deniers' claims that urban "heat islands" are a major cause of apparent temperature increases.

The land covered by urban areas more than doubled between 1992 and 2005, to about 0.128% of Earth's surface, Mark Z. Jacobson and John E. Ten Hoeve of Stanford University report in the Journal of Climate. Roofs and roads cover about half of that land, and help heat up urban areas by preventing evaporation of water and absorbing sunlight. Exactly how these urban heat islands affect global temperatures, however, has been unclear. But Jacobsen says some skeptics of climate science have argued that heat islands – and not the buildup of warming gases in the atmosphere – may be responsible for observed temperature increases, since some monitoring stations are near urban areas.

In a bid to get a better handle on the issue, Jacobsen and Ten Hoeve developed a model that meshed data on land use, vegetation, albedo (the reflective capacity of different land uses) and soil-type. Then, they ran two 20-year-long simulations to see how much heat islands contributed to "gross global warming" (warming before cooling factors) – and what impact a lot of white paint might have.

Overall, "the urban heat island (UHI) effect may contribute to 2-4% of gross global warming," they found, "although the uncertainty range is likely larger than the model range presented, and more verification is needed." In contrast, greenhouse gases are responsible for about 79 percent of warming, Jacobsen told the Stanford News Service, and dark particulates about 18 percent.

Jacobson says his high-resolution study – which divided the world into 1 kilometer squares — was the first to calculate the impact of urban heat islands on global sea-surface temperatures, sea ice, atmospheric stability, aerosol concentrations, gas concentrations, clouds, and precipitation. "This study accounted not only for local impacts of the heat island effect, but also feedbacks of the effect to the global scale," he says.

"A worldwide conversion to white roofs," they found, could actually warm the Earth slightly due a complex domino effect. Although white surfaces are cooler, the increased sunlight they reflect back into the atmosphere by can increase absorption of light by dark pollutants such as black carbon, which increases heating. The study, however, did not account for how white roofs might reduce electricity use for cooling, which could help lower temperatures by reducing emissions from power plants.

"Cooling your house with white roofs at the expense of warming the planet is not a very desirable trade-off," Jacobson says. "There are more effective methods of reducing global warming."

Source: Jacobson, M., & Ten Hoeve, J. (2011). Effects of Urban Surfaces and White Roofs on Global and Regional Climate. Journal of Climate DOI:*10.1175/JCLI-D-11-00032.1

https://www.theguardian.com/environment/2011/oct/27/white-roofs-global-warming

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And what of the four articles I posted on wite rooftops?
 
How Painting Roofs White Can Help 'Turn Off The World For A Year ...

https://thinkprogress.org/how-painting-roofs-white-can-help-turn-off-the-world-for-a-...


May 30, 2012 - A NASA survey of New York City's rooftops last July showed that dark, heat-absorbing rooftops were up to 42 degrees F hotter than white rooftops. And that difference in heat can make a big difference in on-site energy use; painting a roof white can reduce air conditioning demand as much as 20 percent.


https://thinkprogress.org/how-paint...p-turn-off-the-world-for-a-year-e159dddc84c7/
 
How Painting Roofs White Can Help 'Turn Off The World For A Year ...

https://thinkprogress.org/how-painting-roofs-white-can-help-turn-off-the-world-for-a-...


May 30, 2012 - A NASA survey of New York City's rooftops last July showed that dark, heat-absorbing rooftops were up to 42 degrees F hotter than white rooftops. And that difference in heat can make a big difference in on-site energy use; painting a roof white can reduce air conditioning demand as much as 20 percent.


https://thinkprogress.org/how-paint...p-turn-off-the-world-for-a-year-e159dddc84c7/
 
Eagle Eye said:
Ok Stoned Ox just how does painting streets a reflective color help solve "global warming"? I'll tell you it doesn't!
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I screwed up earlier, Los Angeles county has over 23,000 miles of road. The 508 mile figure is for interstates. So to do the whole lot would cost in the region of a billion dollars!!!! Not even sure if that's just the special grey paint or a total figure. Not that it matters, as it's a truly enormous figure.

http://www.laalmanac.com/transport/tr01.php

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Havana Moon said:
I screwed up earlier, Los Angeles county has over 23,000 miles of road. The 508 mile figure is for interstates. So to do the whole lot would cost in the region of half a billion dollars!!!! Not even sure if that's just the special grey paint or a total figure. Not that it matters, as it's a truly enormous figure.

http://www.laalmanac.com/transport/tr01.php

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Not that expensive for California. I am sure the city of LA has a spare $1.12 billion laying around.
 
Eagle Eye said:
Not that expensive for California. I am sure the city of LA has a spare $1.12 billion laying around.
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Aren't they supposed to be insolvent? California has an unfunded pension liability estimated by some to be half a trillion dollars, and that's just for starters.

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Havana Moon said:
Aren't they supposed to be insolvent? California has an unfunded pension liability estimated by some to be half a*trillion*dollars, and that's just for starters.

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I was being sarcastic. I think every California city including the state government spends like drunken sailors.
 
we would be the 6th largest economy on the world if measured by ourselves

why do you hate economic success?
 
evince said:
we would be the 6th largest economy on the world if measured by ourselves

why do you hate economic success?
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California has an unfunded pension liability estimated to be around half trillion dollars and that's just for starters.

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California officials are hoping their latest attempt to stem the rising tides of climate change leads to a more socially conscious — and cooler — summer.

Officials in Los Angeles have been painting streets white to reduce the effect of urban “heat islands” and combat the effects of climate change.

The LA Street Services began rolling out the project last May, which preliminary testing shows has reduced the temperature of roadways by up to 10 degrees. The project involves applying a light gray coating of the product CoolSeal, made by the company GuardTop.

While each coasting could can last up to seven years, they are also pricey, with the estimated cost of $40,000 per mile, the L.A. Daily News reported.

Read more: http://www.foxnews.com/us/2018/04/10...te-change.html







its all sceincey so you right wing idiots wont understand


its a test of the idea

like any new project the cost will be the most in the beginning


you idiots don't realize how quickly the heat destroys the roads


its not just paint its sealer


if it works better than the resealing they MUST do every few years with a dark asphalt resurfacing and makes all the neighborhoods COOLER then it can be applied in a cheaper per mile cost if they decide to employ this idea city wide


and it will reduce the use of airconditioners in every neighborhood it is used in huh


the right hates news ideas


they cant think past their own noses


so they spew hate on any new ideas

trying to change the subject because you go your ass handed to you?
 
evince said:
California officials are hoping their latest attempt to stem the rising tides of climate change leads to a more socially conscious — and cooler — summer.

Officials in Los Angeles have been painting streets white to reduce the effect of urban “heat islands” and combat the effects of climate change.

The LA Street Services began rolling out the project last May, which preliminary testing shows has reduced the temperature of roadways by up to 10 degrees. The project involves applying a light gray coating of the product CoolSeal, made by the company GuardTop.

While each coasting could can last up to seven years, they are also pricey, with the estimated cost of $40,000 per mile, the L.A. Daily News reported.

Read more: http://www.foxnews.com/us/2018/04/10...te-change.html







its all sceincey so you right wing idiots wont understand


its a test of the idea

like any new project the cost will be the most in the beginning


you idiots don't realize how quickly the heat destroys the roads


its not just paint its sealer


if it works better than the resealing they MUST do every few years with a dark asphalt resurfacing and makes all the neighborhoods COOLER then it can be applied in a cheaper per mile cost if they decide to employ this idea city wide


and it will reduce the use of airconditioners in every neighborhood it is used in huh


the right hates news ideas


they cant think past their own noses


so they spew hate on any new ideas

trying to change the subject because you go your ass handed to you?
Click to expand...
You already posted that, are you senile?

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