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Reflective ultra-white paint could help to cool the planet

Academic researchers have reportedly produced the brightest ever white paint, capable of reflecting 98% of sunlight and radiating infrared heat into space. Could this be key to tackling the climate crisis?

My fellow Thred enthusiasts, we’re quite possibly looking at a game changing all-natural air conditioner, and it comes straight from a tin.

Academic researchers have reportedly developed a white paint so bright it could prevent us from emitting between 600 million and 1.1 billion tons of carbon dioxide by 2050 through artificial cooling systems.

If you’re privy to a bit of travelling, or a villa holiday in the summer somewhere with heights of 30+ degrees, you’ll no doubt have noted how white paint is used to keep the exterior – and thus the interior – of buildings cool.

This reflective method has been employed for centuries and is widely effective, but as global temperatures continue to rise it is becoming less so. White outdoor paints available on the market today reflect 80% to 90% of sunlight but unfortunately cannot cool a roof to below air temperature.

Xiulin Ruan, a Purdue University professor of mechanical engineering, poses with a sample of the new, sunlight reflecting paint.
Image Credit: Purdue University/Jared Pike

A new grade of what’s being described as the ‘whitest paint on record’ may not just be the answer to mitigating this issue, but could position us to one day replace powered air conditioning almost entirely.

Developed by Scientists at the University of Purdue in India, this ultra-white paint is capable of reflecting up to 98% of sunlight and crucially can cool surfaces by up to 4.5 degrees.

For context, if you were to cover the exterior of a roof area around 1,000 square feet in this paint, leading professor Xiulin Ruan claims ‘you could get a cooling power of 10 kilowatts.’

This far exceeds the effectiveness of most central air conditioners and all that’s required to achieve it, is a bit of good old-fashioned of elbow grease.

So, what exactly makes this paint pigment so white then?

Easily the closest counterpart to the blackest black ‘Vantablack’ which is capable of absorbing 99.9% of sunlight, this climate friendly paint is extremely white thanks to one vital compound.

Known as barium sulphate, this super reflective ingredient is deliberately comprised of varying sized particles which scatter different parts of the light spectrum so it isn’t directly absorbed. Ah, Science.

The barium sulphate paint enables surfaces to be below air temperature, even in direct sunlight, because it reflects so much of the sun’s light and also radiates infrared heat at a wavelength that is not absorbed by air.

‘The radiation can go through the atmosphere, being directly lost to deep space, which is extremely cold,’ said Ruan at a press release.

While this all sounds extremely promising, there are a number of logistical kinks to figure out before this can hit the shelves. With billions of tons of barium sulphate required to make a meaningful difference, researchers are working to thin their paint as much as feasibly possible without hindering its efficiency.

This innovative new product, which to the naked eye is being described as ‘a bit brighter than snow,’ is being patented by the University regardless, and the team is targeting a rollout in the next two years.

If your lucky enough to live somewhere with hot summers, I’d start digging out your old roller and ladder.