99% Less Ambitious than Sherwin Williams

April 23, 2021 12:56 PM

Researchers at Purdue University have developed a new ultra-white paint that reflects 98.1 percent of sunlight and can keep surfaces up to 19 degrees Fahrenheit cooler than their ambient surroundings. This new paint, which may become available for purchase in the next year or two, could someday help combat global warming and reduce our reliance on air conditioners.

Using statistical modeling, the researchers estimated that their ultra-white paint could reduce air conditioning use by up to 70 percent in hot cities like Reno, Nevada, and Phoenix, Arizona. In a rather extreme model, they also found that covering 0.5 to 1 percent of the Earth’s surface—buildings, roads, unused land, just about everything—with the ultra-white paint would be enough to stop the global warming trend.

posted by gusottertrout (48 comments total)

Soundtrack option for post.
posted by gusottertrout at 12:57 PM on April 23, 2021 [2 favorites]

Huh, Daisyworld. Which is nifty!
posted by clew at 1:03 PM on April 23, 2021

Another soundtrack option.
posted by The Tensor at 1:03 PM on April 23, 2021 [2 favorites]

In a rather extreme model, they also found that covering 0.5 to 1 percent of the Earth’s surface—buildings, roads, unused land, just about everything—with the ultra-white paint would be enough to stop the global warming trend.

"I see a hot world and I want to paint it...white?"
posted by The Tensor at 1:04 PM on April 23, 2021 [28 favorites]

I assume that in the "extreme model" temps would stabilize but the atmosphere would keep carbonizing and the ocean would keep acidifying. Better than nothing.
posted by paper chromatographologist at 1:09 PM on April 23, 2021

Can we all agree to keep Anish Kapoor in the dark about this one?
posted by theory at 1:09 PM on April 23, 2021 [31 favorites]

I wonder if they’ve heard from Anish Kapoor yet.
posted by zamboni at 1:10 PM on April 23, 2021 [3 favorites]

If this catches on I bet a bunch of people are going to paint whatever they can Vantablack
posted by any portmanteau in a storm at 1:10 PM on April 23, 2021 [2 favorites]

Someone is taking the Sherwin Williams logo too seriously.

Also, doesn’t it get... dirty?
posted by yeti at 1:11 PM on April 23, 2021 [10 favorites]

Somewhere, ski goggle manufacturers are popping a bottle of champagne
posted by zeptoweasel at 1:11 PM on April 23, 2021 [6 favorites]

Boy it doesn't take long for us to trot out the same joke.
posted by any portmanteau in a storm at 1:11 PM on April 23, 2021 [5 favorites]

Can we all agree to keep Anish Kapoor in the dark about this one?

The darkest dark?
posted by zeptoweasel at 1:12 PM on April 23, 2021 [4 favorites]

Don't worry, Stuart Semple is already on the case with NFTs to cancel out any and all pigment-related efficiency gains.
posted by CrystalDave at 1:13 PM on April 23, 2021 [2 favorites]

This is really intriguing to me. The easiest way to affect the surface temperature of the planet is to change the albedo. That's what's behind the proposals to inject sulfides into the stratosphere to cool the climate. IMHO, painting a whole lot of stuff ultra-white is a much more palatable option than yet another mega-scale atmospheric chemistry experiment.
posted by vibrotronica at 1:20 PM on April 23, 2021 [4 favorites]

There’s a joke in there somewhere re: The whitest white being created in Indiana.
posted by Thorzdad at 1:20 PM on April 23, 2021 [20 favorites]

K.
"In 1954, Americans Were Told to Paint Their Houses to Increase Their Chances of Surviving an Atomic Bomb'
posted by clavdivs at 1:25 PM on April 23, 2021

This is great. However, the typical roof now reflects about 32 percent of light. So going from average roof to regular white paint is about 6 times as effective as going from regular white paint to this.

Developing new technologies is crucially important. But applying the technologies we have available today is often more important.
posted by Mr.Know-it-some at 1:26 PM on April 23, 2021 [20 favorites]

Boy it doesn't take long for us to trot out the same joke.

Came for the Anish Kapoor; was not disappointed at all.

Sometimes I *want* to see the ol' reliable MetaFilter gags.
posted by tzikeh at 1:30 PM on April 23, 2021 [11 favorites]

They didn't really say but I wish they would have gotten it on some houses and cars to see the effect in action. I recently redid my roof, and got the lightest shingles you could buy that were normal priced (actual white shingles are like 3X the cost and most big box stores don't sell them), but they don't seem to make much difference in my summer cooling load.
posted by The_Vegetables at 1:34 PM on April 23, 2021 [3 favorites]

Things like this fascinate me partly because I live in extreme temperatures - Minnesota - but our heat is miserable due to humidity more than ambient temp. I'd like a white roof in the summer and a black roof in the winter.

I wonder, does the reflection actually reduce the energy absorbed by the Earth or does this just displace it from the building? I understand the air conditioning efficiency gains would be similar in both cases, but would painting an asphalt parking lot keep the air around it from heating up? I read that things painted with vanta black heat up very quickly in sunlight and wonder the same thing - is that stealing energy from nearby things or actually absorbing more energy directly from the sun?
posted by soelo at 1:34 PM on April 23, 2021 [3 favorites]

From 2009 at PhysOrg.com: Color-changing roof tiles absorb heat in winter, reflect it in summer. A team of recent MIT graduates has developed roof tiles that change color based on the temperature. The tiles become white when it's hot, allowing them to reflect away most of the sun's heat. When it's cold they turn black and absorb heat just when it's needed. The team's company, Thermeleon, was founded the same year.
posted by Iris Gambol at 1:41 PM on April 23, 2021 [6 favorites]

does the reflection actually reduce the energy absorbed by the Earth or does this just displace it from the building

The wavelengths of solar radiation that pass through the atmosphere coming in can pass through it going out, so reflection does reduce planetary heating, not just move it around.
posted by clew at 1:56 PM on April 23, 2021 [3 favorites]

I was about to say that it’ll get dingy like any other paint and won’t stay amazingly white for long but that’s not quite what they’re saying. This paint isn’t likely to be noticeably whiter in visible light, but is reflecting a lot of the UV too. So even if it gets a bit dirty it’ll still be reflecting more UV. Additionally they’ll be doing durability testing, which will surely get into the issue of cleaning (or not).

The principal new component, barium sulfite, is said to be relatively cheap but I wonder if it would stay that was in the face of extreme demand.
posted by sjswitzer at 1:56 PM on April 23, 2021 [1 favorite]

OK but hear me out with this and some vantablack we could make the FASTEST CROOKES RADIOMETER IN HISTORY
posted by ook at 1:57 PM on April 23, 2021 [31 favorites]

And who doesn't want a faster Crookes radiometer I mean really
posted by ook at 1:57 PM on April 23, 2021 [14 favorites]

OK but hear me out with this and some vantablack we could make the FASTEST CROOKES RADIOMETER IN HISTORY

Or we could mix them and make the grayest gray! None more gray!
posted by TedW at 2:00 PM on April 23, 2021 [27 favorites]

I got my flat-ish roof replaced with white EPDM + 1.5 inches of insulation and it was a giant difference. The really white roof materials are very very reflective. It makes the material last longer, too. And this stuff adds up - parts of Philadelphia can be 20 degrees warmer than others from lack of trees and older black roofs.
posted by sepviva at 2:20 PM on April 23, 2021 [1 favorite]

This sounds pretty neat, but the last time someone made a "whiter than white" paint, they left the rest of us with a risk of lead poisoning.
posted by basalganglia at 2:45 PM on April 23, 2021

I'm already way cooler than my ambient surroundings, maaaan, and I'm definitely not whiter than white.
posted by Harvey Kilobit at 2:49 PM on April 23, 2021 [1 favorite]

Barium sulfate is non-toxic.
posted by seanmpuckett at 2:50 PM on April 23, 2021

If this gets wide spread use, someone is going to need to invent better sunglasses to counter-act all the glare.
posted by 3j0hn at 3:03 PM on April 23, 2021 [1 favorite]

Thank you for reminding me of Stuart Semple, who has a Whitest White already on the way.

(I confirm that I am not Anish Kapoor, am in no way affiliated with Anish Kapoor, am not making this comment on behalf of Anish Kapoor or an associate of Anish Kapoor. To the best of my knowledge, information and belief this comment will not make its way to the eyes of Anish Kapoor unless he is a very dedicated Google Alerts reader.)
posted by trig at 3:31 PM on April 23, 2021 [4 favorites]

A previous owner painted the tile roof of our house white. When our maintenance to-do list finally makes it 'round to the roof, I guess I know what I should look for.
posted by krisjohn at 3:40 PM on April 23, 2021

> covering 0.5 to 1 percent of the Earth’s surface with the ultra-white paint

1x Australia is about 1.5% of the Earth's surface area (including the oceans). So let's say we paint 1/3 to 2/3 of Australia white. Assume someone first grades Australia flat and sands away the bumps. That gives a nice flat paintable surface area of around 2.5x to 5x 10^12 m^2.

How much paint do we need? Let's say we only want to apply one coat. The internet reliably informs me that the amount of paint we need depends on the spreading rate, available on the paint's product data sheet. Let's assume that 1 litre of this paint can cover around 10 m^2 of surface. So we'll need 2.5x to 5x 10^11 litres of paint.

Is that a lot of paint or not very much? We can compare to another popular liquid, oil. Global oil consumption is about 3.5 x 10^10 barrels / year = about 5.6 x 10^12 litres / year.

We'd need about 1/20th -- 1/10th as much volume of paint to do one coat as the volume of oil we consume in a year. Might need to give australia another coat every 10 years or so, depending on wear and tear.
posted by are-coral-made at 4:15 PM on April 23, 2021 [12 favorites]

There’s a joke in there somewhere re: The whitest white being created in Indiana.

To my mind, the better approach is along these lines: if Vantablack is the darkest pigment, that suggests Vantawhite is maybe the sensible name for this. That is very close indeed to Vanna White, an American celebrity who is close to maximum Caucasianness herself.

All the components of the joke are there. It’s like I can see the pitch coming in but I just cannot get the bat off my shoulder.
posted by ricochet biscuit at 4:38 PM on April 23, 2021 [10 favorites]

The 'Wheel of Fortune' co-host is half Puerto Rican, on her biological paternal side; White is her stepfather's surname. (Maybe you're at a basketball game?)
posted by Iris Gambol at 4:48 PM on April 23, 2021 [2 favorites]

I would suggest Dixie White...
posted by jim in austin at 5:07 PM on April 23, 2021

my joke bombed. Article didn't say but I assume powered Teflon is off the ingredients list.
posted by clavdivs at 5:13 PM on April 23, 2021 [1 favorite]

Eh, just use mirrored roof tiles.



(Take THAT, pilots!)

(And neighbors.)
posted by darkstar at 6:06 PM on April 23, 2021 [2 favorites]

What, another new paint?

I'm still waiting to hear back about buying some of that new blue they approved recently.
posted by hippybear at 6:26 PM on April 23, 2021

The swatch that the scientist is holding for the picture looks like a square that was deleted with MS Paint.
posted by Countess Elena at 7:57 PM on April 23, 2021 [2 favorites]

So the whitest white is not as white as the blackest black is black. Sounds like a potentially great breakthrough though.
posted by blue shadows at 9:01 PM on April 23, 2021

Okay, 1% of the Earth's surface in paint. That seems doable. What fraction of the world’s buildings is that? Just to get a rough estimate of how many roofs we are talking about here.

Oh, it’s all of them.

although it can seem like our expanding cities take up a lot of land, only around 1% of global land is defined as built-up area;
posted by Jawn at 9:58 PM on April 23, 2021 [7 favorites]

Barium sulfate is non-toxic.

The CDC says barium sulfate is not toxic only because of its insolubility:

There is little quantitative information regarding the extent of barium absorption following inhalation, oral, or dermal exposure. Available evidence indicates that barium is absorbed to some extent following inhalation, oral, and dermal exposure; however, in some cases, absorption is expected to be limited. For example, there is some evidence that gastrointestinal absorption of barium in humans is 5–30% of the administered dose. The general population can be exposed to barium via inhalation, oral, or dermal exposure; under most circumstances, oral exposure would be the predominant route of exposure.
2.2 SUMMARY OF HEALTH EFFECTS
An important factor affecting the development of adverse health effects in humans is the solubility of the barium compound to which the individual is exposed. Soluble barium compounds would generally be expected to be of greater health concern than insoluble barium compounds because of their greater potential for absorption. The various barium compounds have different solubilities in water and body fluids and therefore serve as variable sources of the Ba2+ ion. The Ba2+ ion and the soluble compounds of barium (notably chloride, nitrate, hydroxide) are toxic to humans. Although barium carbonate is relatively insoluble in water, it is toxic to humans because it is soluble in the gastrointestinal tract. The insoluble compounds of barium (notably sulfate) are inefficient sources of Ba2+ ion and are therefore generally nontoxic to humans. The insoluble, nontoxic nature of barium sulfate has made it practical to use this particular barium compound in medical applications as a contrast media for x-ray examination ofthe gastrointestinal tract. Barium provides an opaque contrasting medium when ingested or given by enema prior to x-ray examination. Under these routine medical situations, barium sulfate is generally safe. However, barium sulfate or other insoluble barium compounds may potentially be toxic when it is introduced into the gastrointestinal tract under conditions where there is colon cancer or perforations of the gastrointestinal tract and barium is able to enter the blood stream.

Note that inhalation has not been studied all that much, and god knows what would happen if a building painted and roofed with it caught fire.

I got really sick after drinking a barium sulfate contrast dye, and I happen to have a leaky gut thanks to small intestine scarring caused by celiac disease.
posted by jamjam at 10:05 PM on April 23, 2021 [3 favorites]

I see a red door and I Vanta (paint it) Black.
posted by AugustWest at 10:59 PM on April 23, 2021 [5 favorites]

If someone opens the door while you're painting it we'll finally know where that scene's from.
posted by trig at 1:46 AM on April 24, 2021 [3 favorites]

What a good idea! I hope it works out, we need as many low-cost solutions as we can get.
posted by harriet vane at 3:54 AM on April 24, 2021

Did not expect a Vanna White factoid.
posted by Don.Kinsayder at 7:37 AM on April 25, 2021 [3 favorites]