In 2021, researchers at Purdue University announced that they had developed the whitest paint on Earth.

The color is so white that it can reflect over 98% of light. This is particularly useful because light generates heat – and we here on Earth are running a bit hot these days.

If used on a building, the researchers say, the paint would reduce the temperature on the surface, lowering the temps inside and decreasing the need for air conditioning. But what if there was an even bigger application, like reducing the temperature of the entire planet?

According to Jeremy Munday, a professor of electrical and computer engineering at the University of California, Davis, who researches clean technology, if a material like Purdue's paint covered 1–2% of the Earth's surface, the amount of light being bounced back into space would reduce the amount of heat being absorbed by the planet enough to stabilize global temperatures.

In other words, it could do a lot to solve climate change. Plus, Munday told The New York Times, the amount of light being bounced back into space wouldn't harm the cosmos very much. "It'd be like pouring a cup of regular water into the ocean," he told The Times.

But just how big is 1–2% of the Earth's surface? The total surface area of the Earth is right around 197 million square miles (and most of that is water), so the paint would need to cover between roughtly 2 million and 4 million square miles.

For reference, the total land area of the United States is just over 3.5 million square miles, so we'd need to cover the country in white paint from sea to paint-stained sea.

That would be a lot of paint. A LOT.

If we assume the new paint acts like commerical paint, as the Purdue researchers suggest, a gallon would cover about 400 square feet, we would need roughly 139 billion gallons of the super-duper white paint to cover just 1% of the Earth's surface.

Of course, that number doubles if we need to cover 2% of the surface. And none of this takes into account how hard it would be to paint oceans, deserts, and trees.

Painting things white to reduce temperatures is not a new concept. Just drive around my home state of Texas and see how many cars are white.

Many places around the world are already painting surfaces white, and Purdue's new paint will help. But it does show that we have a long way to go before the problem is solved.

This article was originally published by Business Insider.

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