KEY POINTS
  • On Friday, the government of Mexico issued a statement that it plans to "prohibit and, where appropriate, stop experimentation practices with solar geoengineering in the country."
  • The startup Make Sunsets, which had been experimenting in Baja with releasing sulfur dioxide into the atmosphere to reflect sunlight back out to space and cool the earth, said on Wednesday it would cease operations until it gets more regulatory clarity.
  • Make Sunsets was planning to launch three latex weather balloons that would release anywhere between 10 and 500 grams of sulfur dioxide in January, but the plans came under widespread criticism from industry watchers for being hasty and lacking sophistication.
The sun sets behind power lines near homes during a heat wave in Los Angeles, Sept. 6, 2022.

The tiny startup Make Sunsets, which had been experimenting with releasing sulfur dioxide into the atmosphere to reflect sunlight in order to cool the earth, said Wednesday it would cease operations for the time being and review its approach after the Mexican government cracked down on solar geoengineering.

The idea of releasing aerosols into the atmosphere to cool the earth has been around since the 1960's, but it had largely been relegated to science fiction until recently, as the urgency of climate change has become more apparent. The White House is currently coordinatingfive-year research plan to study the idea, which is colloquially known as "solar geoengineering," and the quadrennial U.N.-backed Montreal Protocol assessment report for the first time included an entire chapter it.