Paint your roof white to reduce global warming

In summary, the global initiative to change the colour of roofs, roads and pavements so that they reflect more sunlight and heat could play a big part in containing global warming, according to Professor Chu. He said that this approach could have a vast impact by reducing carbon emissions by as much as taking all the world’s cars off the roads for 11 years. However, there is some concern about the amount of CO2 produced by concrete processing.
  • #71
People who address issues of long-term climate variability by cherry-picking yearly data should be called to task. Many places in the US experienced record heat and drought and others got drowned and buried in cloud-cover for weeks. Invoking short-term variations to "disprove" long-term trends is intellectually suspect.
 
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  • #72
turbo-1 said:
Invoking short-term variations to "disprove" long-term trends is intellectually suspect.
And the same is true if you replace "disprove" with "prove".
 
  • #73
Hurkyl said:
And the same is true if you replace "disprove" with "prove".
You're right. Can you see where the climate-change nay-sayers might have a weakness, using logical arguments?
 
  • #74
turbo-1 said:
You're right. Can you see where the climate-change nay-sayers might have a weakness, using logical arguments?
:confused: I don't understand the question -- too vague.



It looks to me like Ivan was saying "Hey look -- record high temperatures. See? Global warming!" to which mhsleep retorted "That's not a valid argument. Look -- record lows too! :-p"

Of course, we have no idea what Ivan and mhsleep actually meant with their two comments -- neither offer any explanation, and Ivan's doesn't obviously relate to anything over the past page or so. (mhsleep's is presumably a direct reply to whatever he thought Ivan meant)

We're supposed to have guidelines against merely posting a link and/or a quote without any further comment...
 
  • #75
HurkylI said:
t looks to me like Ivan was saying "Hey look -- record high temperatures. See? Global warming!" to which mhsleep retorted "That's not a valid argument. Look -- record lows too! :-p"
Yes that is what I meant, and how I meant it.

Hurkyl said:
We're supposed to have guidelines against merely posting a link and/or a quote without any further comment...
Yes you are right of course, deleted post.
 
  • #76
Ivan Seeking said:

Ah, yes, I had seen that elsewhere. It sounds pretty problematic to me. As I understand it, it would increase albedo of *existing cloud cover*, but that's already pretty high, so I don't know how much you can win. On the other hand, cloud cover works both ways (as "greenhouse" and as albedo) so it is not clear who wins (you also reflect back more efficiently IR radiation). Finally, you increase, at least locally, the vapor pressure of water, which is a strong greenhouse gas (although I reckon that this is not a big problem given the short duration of the water cycle).

So to me it is not obvious *what* it could do, and moreover, *what way* it would work (more or less warming) ?
 
  • #77
Skyhunter said:
The biggest carbon offset from painting your roof white is a reduction in energy expended for cooling. A lot of energy is used to heat and cool buildings. Living roofs are even better, they provide insulation, evaporative cooling, particulate scrubbing, and an environment for butterflys and other native fauna.

Yeah, this is a great idea and has a huge range of environmental benifits.

I think it is worth the fire risk and bad karma of not cleaning my gutters, but only for the environmental payoffs of course! :P
 
  • #78
Ivan Seeking said:
http://www.timesonline.co.uk/tol/news/environment/article6366639.ece

That should read that it would yield the same benefit as removing all of the cars for 11 years...

https://www.youtube.com/watch?v=pLlxjYACa5U

If the results would be that significant, why not paint the center and edges of roads white - everything except the tire tracks?

We already have the painting equipment - just need to modify a bit. I'm sure there's some loose change in the stimulus Bill that could be diverted.
 
  • #79
I bought a white metal roof and it helps a lot in summer. It also helps to use a fan to "sample and hold" the cool night air around 4 AM. Add that to digging 10 feet down for a basement and migrating there for the summer and the result is about three days worth of air conditioning for the whole summer in West Virginia.

In winter the trombe wall helps warm the South side. I use about a fourth of the gas that others burn for heat. Electricity is normally 250 KWH/month.
 
  • #80
My car is white, i must say, its the best 'color' ever.
 
  • #81
I guess we will know if this will work when the polar ice caps melt. All that ice has a large albedo.
 
  • #82
bassplayer142 said:
I guess we will know if this will work when the polar ice caps melt. All that ice has a large albedo.

It's difficult to say. The total projected effect (there's not much reason to doubt it) comes down to 1 extra year delay. It comes down to offsetting the effect of the emissions of about 1 year. Even if there's 50% error on it, it will mean that it comes down to offsetting the effect between 6 months and 1 year and a half.
 
  • #83
Has anyone explained why we can't just paint the roads white - except for the tire track lines?
 

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