White is the Coolest Color

It's basic physics that darker colors absorb more heat than lighter ones or, more technically, darker colors absorb more of the different wavelengths of light energy, while white or light-colored objects reflect the light of most wavelengths:

So, many walls and roofs are often painted white in warmer climates to deflect more heat and keep homes cooler. That's a good thing but it's also not enough, particularly when temperatures are rising around the world. Industrialization is contributing to climate change (bad!), but it's also pulled billions of people around the world into the middle class (good!), who now seek relief from that heat by more buying ACs (bad?). See...all those ACs, not so good for the environment. In fact, they may be really bad for the environment, like really, really bad, according to a WEF report:

"...the typical window and split units used in most homes - are set to account for over 130 gigatons (GT) of CO2 emissions between now and 2050. That would account for 20-40% of the world’s remaining “carbon budget” (the most we can emit while still keeping global warming to less than 2˚C above pre-industrial levels - the goal set at the Paris Climate Conference in 2015)."

In other words, if the heat doesn't get us, comforting cooling probably will. Hmm, if only there was an uber-white color we could paint on our buildings. Well now there may be...scientists at Perdue University have developed a type of white paint that reflects up to 98.1% of sunlight. What does that mean? Let the researchers explain:

“If you were to use this paint to cover a roof area of about 1,000 square feet, we estimate that you could get a cooling power of 10 kilowatts,” said Xiulin Ruan, a Purdue professor of mechanical engineering. “That’s more powerful than the central air conditioners used by most houses.”

Whoa! Go on..."typical commercial white paint gets warmer rather than cooler. Purdue says its product repels infrared heat from a surface and reflects up to 98.1% of sunlight. This outperforms 80%-90% of comparable products and beats the 95.5% of sunlight reflected by the researchers’ previous ultra-white paint." It could mean we may not need ACs or at least as many of them in the future. That would be a good great thing because there are already a lot of ACs in the world:

Not to mention, a climate hack like this would be great for everyone's utility bills...a win/win/win. The research team Perdue are looking for backers to commercialize their product...so in the not too distant future these companies could be at the forefront of the climate change fight: