Animated by the “move fast and break things” credo that permeates Silicon Valley, the founders of Make Sunsets have no such concerns. They are selling “cooling credits” to customers who want to offset their personal carbon emissions. And a few times each month, after selling enough credits, they head for the hills and release balloons full of sulfur dioxide into the California sky.

“This is the one tool realistically that can cool Earth in our lifetime,” said Mr. Iseman. “Every day we’re not doing this leads to needless harm.”

Sikina Jinnah, a professor of environmental studies at the University of California Santa Cruz who has studied geoengineering, is also concerned about harm. “They are a couple of tech bros who have no expertise in doing what they’re claiming to do,” she said. “They’re not scientists and they’re making claims about cooling credits that nobody has validated.”

Yeah…Gotta admit I didn’t have a lot of confidence in the idea when I first started reading the article. Then I read this part and my confidence went from low to zero.