Cool Paint

Environmental & Science Education, STEM, Sustainability, Energy & Sustainability, Nature of Science, Climate Change

Ed Hessler

The Star Tribune in its Sunday (July 23, 2023) edition included a long feature titled "The Cooling Paint".

Xiulin Ruan, a Purdue University professor of mechanical engineering and students in his laboratory have "created the whitest paint on record, which can cool buildings. The paint has now been included in the Guinness World Records."

Cara Buckley, a reporter for the New York Times wrote the story from which the following is taken.

--The paint can "make surfaces as much as 8 degrees (F) cooler than its surrounding air temperature at midday and up to 19 degrees cooler at night."

--Can decrease A/C "needs by as much as 40%."

--The paint "doesn't warm the outside air."

--Jeremy Munday, a professor of electrical and computer engineering at the University of California, Davis had some criticisms.

If this paint "were to coat between 1% and 2% of the Earth's surface, the planet would no longer absorb more heat than it emits, and global temperatures would stop rising." Sounds good but Munday said this is not a good idea emphasizing "practicality, wildlife concerns, and weather disruptions caused by one region suddenly becoming much cooler. But spreading radiative cooling spots around the world could have global and local benefits, such as offsetting the urban heat island effect." 

--Another concern is that the major ingredient for both standard paint and the new, reflective paint must be mined.  There are always trade-offs and this choice is difficult.

--Buckley's final complaint is with Geoengineering (aka more accurately known as Climate Engineering) -- manipulating different processes to control the Earth's climate -- distracts from the root problem: burning fossil fuels. Munday said "This is definitely not a long-term solution to the climate problem...(perhaps) short term to mitigate worse problems while trying to get everything under control."

PBS News Hour did a feature on October 18, 2021. It is 5 m 44 s long.

The Buckley reporting is behind paywalls at both the Star Tribune and the New York Times. So if you are a subscriber you can find them. Here is a superb replacement, a thoughtful and thorough report from the Intelligencer by Eric Levitz which I prefer to the original.