Researchers at Purdue University have developed the whitest paint ever produced, capable of reflecting more than 98 percent of the light that strikes it, a quality that could reduce the need for air conditioning for buildings coated in the brilliant pigment. But perhaps even more ambitiously, another researcher calculates that if a mere one to two percent of the Earth’s surface were colored by this paint, the light reflected back into space could be enough to stabilize our decidedly out of control global temperatures.

“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,” according to Purdue professor of mechanical engineering, Xiulin Ruan. “That’s more powerful than the central air conditioners used by most houses.”

Although current commercially-available white paints can be used to reflect sunlight away from the surfaces they’re applied to, they still absorb about 10 to 20 percent of the light that strikes them, meaning the surface absorbs enough energy to become warmer than its surroundings. But instead of using regular pigments, the Perdue paint uses a barium sulfate compound, a chemical already used to make photo paper and cosmetics white.

Additionally, the barium sulfate particles in the paint vary in size, allowing them to reflect different wavelengths of light, meaning the paint can reflect a broader spectrum of sunlight. These two qualities enable the new paint to reflect enough sunlight—98.1 percent—for the surface it’s applied to to lose more energy than it’s receiving, cooling it below the surrounding temperature.

“A high concentration of particles that are also different sizes gives the paint the broadest spectral scattering, which contributes to the highest reflectance,” explains Purdue Ph.D. candidate Joseph Peoples.

But what if this paint were used on a portion of the planet to increase the Earth’s albedo, its ability to reflect light? According to the calculations of University of California professor of electrical and computer engineering Jeremy Munday, we would only need to cover between one and two percent of the Eart... to reflect enough sunlight back into space to offset the energy trapped by global warming.

While this doesn’t seem like it would require a huge effort to accomplish, this means we would have to cover a portion of the Earth that is between five and ten million square kilometers (1,930,000 to 3,860,000 square miles)—an area close to the size of Canada—requiring between 139 and 278 billion gallons of Perdue’s paint to complete the job.

Even if we don’t resort to covering large swaths of the planet in super-pale pigments, simply painting surfaces white can help control rising heat levels at a local level; for instance, Los Angeles is painting streets and roadways white, to prevent the dark asphalt from absorbing sunlight; and simply coating one’s roof with ordinary white paint can reduce the temperature of the house by a number of degrees, with some houses in Indonesia seeing temperature reductions of over 10°C (18°F) as part of the Million Cool Roofs Challenge.