'Cooling glass' could fight climate change by reflecting solar radiation back into space

the sun rises above Earth as seen from a space station in orbit
New "cooling glass" has shown to reflect 99 percent of solar radiation into space. (Image credit: NASA)

As the world continues to experience a worsening climate crisis with record-breaking temperatures, scientists have developed a new, highly reflective glass coating that may help cool a rapidly warming Earth.

In theory, the coating — a slurry-like mixture of inexpensive glass and aluminum oxide particles — could reflect high amounts of sunlight off of the surfaces on which it is painted, such as roofs of buildings and roads. 

Laboratory tests have shown it to reflect up to 99 percent of solar radiation back into space. If it pans out, the "cooling glass" could be a promising way to lower temperatures across Earth, researchers behind the new glass say.

"This 'cooling glass' is more than a new material — it's a key part of the solution to climate change," Xinpeng Zhao, a research scientist at the University of Maryland who led the new study, said in a statement. "This could change the way we live and help us take better care of our home and our planet."

Related: These scientists want to put a massive 'sunshade' in orbit to help fight climate change

While most surfaces release heat naturally — Earth, too, cools itself by shedding heat into space, especially on clear nights — the newly developed coating accelerates that process by reflecting sunlight within the so-called atmospheric transparency window. That window is a range of the electromagnetic spectrum that can pass through Earth's atmosphere and escape into space without increasing its temperature, effectively using space as a heat sink. 

Cooler weather created by the cooling effect of the glass and/or other climate change-fighting measures could help create would then prompt people to reduce using air conditioners, Zhao told Space.com.

The team's new ceramic-based paint, which comes in four colors, is novel in that it is durable for at least 30 years, thanks to its ability to withstand temperatures up to 1,832 degrees Fahrenheit (1,000 degrees Celsius) as well as exposure to water and even flames, according to the new study.

"In that sense, I think this is certainly an interesting, potentially effective strategy," Aaswath Raman, a professor of materials science at the University of California, Los Angeles, who was not involved in the new study, told Space.com. 

Ultimately, the new coating will have to "compete with a range of existing approaches that have also shown potential for long durability."

The new research is described in a paper published in the journal Science. 

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Sharmila Kuthunur
Space.com contributor

Sharmila is a Seattle-based science journalist. She found her love for astronomy in Carl Sagan's The Pale Blue Dot and has been hooked ever since. She holds an MA in Journalism from Northeastern University and has been a contributing writer for Astronomy Magazine since 2017. Follow her on Twitter at @skuthunur.

  • Pogo
    If this stuff is durable as a road surface, we could just paint this stuff on blacktop and concrete surfaces.
    Reply
  • Unclear Engineer
    That would probably create an extremely dazzling effect on people trying to navigate the roads and even sidewalks. Think "snow blindness" and all of the gear and techniques people have had to develop to travel in sunny and snowy locales.

    But, putting it on roofs would probably be a good idea. And, as I posted elsewhere, putting roofs over big parking areas with solar cells on them could provide cooler parking areas, the ability to charge parked cars during office time or shopping visits, and left-over energy to power the offices and shopping malls, at least during the days (and when there isn't much snow on the solar panels). Unfortunately, solar panels are designed to not reflect light, so about 75-to-80% of the solar energy hitting them would be released as heat. But the rest of the roof areas could be coated in this paint.
    Reply
  • Helio
    Roads require frictional functions that I doubt any glass-like product would have. It also must not be a road hazard when it breaks.

    Reflective roofs, however, have always been a good idea, IMO.

    Also, we’re not in a “crisis” stage, or has the IPCC capitulated?
    Reply
  • George²
    The quotation marks in the title are very appropriate. Another stupidity that will drain the budget, if adopted, with much more (harmful) effect than benefits it could bring.
    Reply
  • MIT BOY
    While the glass painted on roofs is a good idea, I don't think it will be much help in small towns and may be a waste of money. It is a good idea for big cities, however.
    Reply
  • Unclear Engineer
    Depending on how inexpensive and easy to apply it can be made, it might be attractive at an individual homeowner level. First, it should substantially reduce heating costs in the summer. And, if it is really as durable as the article indicates, it would probably last twice as long as asphalt shingles. So, especially in areas where cooling is the dominant energy use, this could make a difference in energy demand, and thus in greenhouse gas emissions.
    Reply
  • Pogo
    I wonder if this would have an adverse effect on pilots, highly reflective surfaces blinding those in the air.
    Reply
  • Unclear Engineer
    I don't think that is likely. Pilots already have the sun shining down on them, which is sometimes blocked by the opaque roof over commercial cockpits, but not by the clear canopies of fighter aircraft. And what light does get reflected from the ground would usually be blocked by the aircraft's body. Maybe on landing approach some highly reflective surfaces would be more of a problem than the usual situation, but I would expect that could be dealt with using the same policies as for building height restrictions, etc. around airports.
    Reply
  • George²
    Birds, insects, including bees, all life that flies will be affected. Even today, many bees are lost due to disorientation.
    Reply
  • DomainRider
    Reflective white paint on roofs has been a big success in India, dropping indoor temperatures by up to 5℃. For those that can't afford A/C, this is a significant benefit.
    Reply