Moderated Global Warming Discussion

[uke2se]

Somebody who knows physics could probably figure out how much how much white is needed to stop or reverse warming.

I remember in the seventies the talk about spreading black soot on the arctic to cause it to melt, to stop the coming ice age. They also talked about using nuclear bombs to blow up ice and change the global balance, to stop an ice age.

Who talked about either of these things?

 

[r-j]

If in fact we changed all homes to white roofs as they came around to roof renewal time, we could save a LOT of electricity.

I know! And it actually would make things so much cooler, especially in the summer. I want white roofs over all the parking lots. It's brutal coming out to your car after it sits in the sun all day. And the asphalt will burn your feet it's so hot.

Who talked about either of these things?

http://youtu.be/nprY2jSI0Ds about 6 minutes in.

 

[Warmer1]

I painted my old roof white, and am getting ready to do the new one. It lowers the temperature on the roof in the summer from 180 to around 110F. There is a noticeable cooling effect around the house as well. The energy saved on AC costs already paid for the cost of the paint

The US energy secretary Steven Chu advocates painting roofs white so Google this if you like and you are not alone by any means.

Painting roofs white was mentioned earlier in this thread but my forum search did not find the post. This was also mentioned in the national clean energy conference that was held in Las Vegas.

There were concerns about pilots being somewhat blinded by the reflected light but if areas surrounding landing strips were left dark that might actually help visual navigation.

On a YouTube video Steven Chu claims that white roofs can reduce air conditioning costs by 15% which is significant in the south. This is a meaningful reduction in CO2 production during hours of peak power demand.

I am not well versed in this area so hopefully others will chime in.

 

[uke2se]

http://youtu.be/nprY2jSI0Ds about 6 minutes in.

Fortunately Schneider realized his mistake and published a retraction for his paper in 1974.

By the way, that documentary is seriously dated. It seems to be popular among denialists from looking at the comments.

 

[Trakar]

I know! And it actually would make things so much cooler, especially in the summer. I want white roofs over all the parking lots. It's brutal coming out to your car after it sits in the sun all day. And the asphalt will burn your feet it's so hot.

Personally, I think covering all parking lots with solar panels would be a better option while actively generating usable power.

http://www.californiasolarcenter.org/solareclips/2002.05/20020528-4.html

 

[Trakar]

Who talked about either of these things?

Good question, I'd like to see some references associated with those claims.

 

[Trakar]

All quotes from http://www.cnn.com/2010/WORLD/americas/07/04/glacier.peru.paint.climate/index.html

cool, according to this video, Eduardo Gold began this paint project back in early 2009. Its now early 2012, we ought to be seeing some preliminary analyses of results anytime now! right?

Which is how experiments work. What is being reported is a lowering of temperatures where the rocks are white. It's called physics I thinl.

I don't think its a big controversy that albedo issues directly relate to energy/temperature differences, however, a subjective impression of the quantity and character of the difference is not terribly reliable when trying to figure out the practical value of projects such as this.

I painted my old roof white, and am getting ready to do the new one. It lowers the temperature on the roof in the summer from 180 to around 110F. There is a noticeable cooling effect around the house as well. The energy saved on AC costs already paid for the cost of the paint.

Most of my living space is moderately northern and at altitude, AC doesn't tend to be the issue that heating is. Though my business offices in Sacramento were converted from their black tar roofs to a white elastomeric spray resin coating back in 2006. We noticed a dramatic drop in electrical usage between 2005 and 2006, but the character of the summers was quite different as well.

This is the sort of thing that just seems like common sense. Yet I have had multiple people, who all express a great concern over warming, dismiss the idea of painting roof white.

"common sense" depends upon common experiences and common understandings. It would be wrong to dismiss any concept without an analysis of the facts and data. But suggesting that any concept has a practical and significant role to play, likewise requires supporting analyses and data.

I, personally, am of the opinion that now, while construction rates are in a lull, it would be a good time to create and enact some new, general residential and commercial building codes with an eye toward increased insulation, improved electrical and lighting standards, etc.,. There are a lot of steps like this that would create major efficiency improvements over the current hodge podge approach.

Either they say "it won't work", or "it looks horrible", or some other excuse. Then they drive off in their gas guzzling SUV with the AC on.

It is more about "change" than what direction such changes go, in many cases.

 

[Trakar]

Some people seem to just come up with an idea, build a computer model, then declare that is how things must be. In regards to cooling things down by making roofs white:



http://journals.ametsoc.org/doi/pdf/10.1175/JCLI-D-11-00032.1

"Lower local temperature means less water evaporates and rises up to eventually form clouds"

Do these experts not know anything about how the world even works? According to their ideas, cities cause clouds. Like a big city is some sort of source for water vapor. Now the particulate pollutants, that certainly could cause more clouds, but Hotlanta is not the source of rainfall in Georgia. Or the clouds.

What evidences do you bring to your argument against this study's findings?

 

[Trakar]

I have done my bit for albedo change; I installed white "Energy Star" roofs on my buildings last year.

Saved me quite a bit of air conditioning costs last summer.

If in fact we changed all homes to white roofs as they came around to roof renewal time, we could save a LOT of electricity.

Wouldn't this only be true in regions where it was hot a lot longer than it is cold? Perhaps in the mega-cities heat is always a bigger problem than cold due to heat island indexes.

 

[BenBurch]

Wouldn't this only be true in regions where it was hot a lot longer than it is cold? Perhaps in the mega-cities heat is always a bigger problem than cold due to heat island indexes.

Solar heating is relatively small in the winter due to sun angle and reduced hours of daylight, so though it rejects heat all year, it rejects most in the summer and the savings easily overcome any additional fuel required in the winter months.

 

[grokinhaze]

How can AGW be falsified?

If weather always changes and long term weather trends define climate, then how can AGW be falsified?

 

[Lowpro]

By determining that the climate change isn't from anthropic sources, or at least exacerbated by them ...that'd be my guess anyways.

 

[Pixel42]

As with any other scientific idea, it will be falsified (or not) by comparing its predictions with observations. Barring game changers like an asteroid collision or a supervolcano, natural forcings are expected to keep global temperatures fairly constant for at least the next 50,000 years before the Milankovich cycles initiate significant cooling and the next glaciation; take AGW into account and predicted climate trends are very different. So time will tell.

 

[r-j]

Personally, I think covering all parking lots with solar panels would be a better option while actively generating usable power.
http://www.californiasolarcenter.org/solareclips/2002.05/20020528-4.html

Hear hear!

There are so many things that are simple, make life better, and safe both fossil fuels and reduce pollution.

Why there is no huge effort towards this, it must be profit. If there was profit in saving the world, it would be already in action.

 

[CapelDodger]

Fortunately Schneider realized his mistake and published a retraction for his paper in 1974.

By the way, that documentary is seriously dated. It seems to be popular among denialists from looking at the comments.

They do like living in the past, even (especially?) an imaginary one. Of course, most of them are conservative so that's hardly surprising.

 

[CapelDodger]

Of course!

A friend of mine told me about it. Sources say it is already working.

Sources, eh? Well, I can't argue with that.

A performance artist is an excellent candidate for such a job. If a million mimes lay on their backs during daylight hours that might help a little as well.

Painting roof white is surely a good idea if they're not being used for anything else, such as solar panels. It could only be a palliative, of course.

 

[grokinhaze]

As with any other scientific idea, it will be falsified (or not) by comparing its predictions with observations. Barring game changers like an asteroid collision or a supervolcano, natural forcings are expected to keep global temperatures fairly constant for at least the next 50,000 years before the Milankovich cycles initiate significant cooling and the next glaciation; take AGW into account and predicted climate trends are very different. So time will tell.

So what we are seeing now could be due to some unknown factor or unexpected interaction of known natural factors but we wont suspect its natural unless global average temperatures trend downward?

 

[ehcks]

So what we are seeing now could be due to some unknown factor or unexpected interaction of known natural factors but we wont suspect its natural unless global average temperatures trend downward?

Sure... It could be because of something unknown and unexpected, or something known and expected.

I wonder which is more likely.

 

[Kestrel]

I have done my bit for albedo change; I installed white "Energy Star" roofs on my buildings last year.

Saved me quite a bit of air conditioning costs last summer.

If in fact we changed all homes to white roofs as they came around to roof renewal time, we could save a LOT of electricity.

As a nation, we should be jumping on this as easy way to save energy. A friend did this a couple years ago and found nobody in the area stocks light colored roofing material.

 

[CapelDodger]

Some people seem to just come up with an idea, build a computer model, then declare that is how things must be.

No, what they do is report the results of their model runs. That is not a declaration of how things must be.

In regards to cooling things down by making roofs white:

http://journals.ametsoc.org/doi/pdf/10.1175/JCLI-D-11-00032.1

"Lower local temperature means less water evaporates and rises up to eventually form clouds"

I don't see that in the abstract and I don't have access to the full article but that seems reasonable.

Do these experts not know anything about how the world even works?

Yes, they do, at least as well as you and very likely better.

According to their ideas, cities cause clouds. Like a big city is some sort of source for water vapor.

Most cities are on rivers and still get large amounts of water piped in. They also get rained on like anywhere else. So yes, they are a source of water vapour.

Now the particulate pollutants, that certainly could cause more clouds, but Hotlanta is not the source of rainfall in Georgia. Or the clouds.

What model are you basing that on? Does it model a range of particulate counts - from EPA level up to GOP-preferred level? Is Atlanta known as a cloudy place (like Chicago's known for being windy)? You need to build all this stuff in.