Private geo-engineers are just winging it to shade the planet

A startup offering climate cooling services should be a wake-up call

- FAYE FLAM

There is no law or treaty to prevent a private company from tinkering with geo-engineering-say, releasing sulphur dioxide high in the stratosphere to alter the climate. And so there will be no fines or arrests following recent news that a startup quietly pulled off such a release last year by launching two balloons over Mexico. This sort of manipulation can alter the energy balance between the sun and Earth. In the upper atmosphere, sulphur dioxide forms suspended particles of sulphuric acid that act to scatter sunlight and cool the planet. The US Clean Air Act isn't set up to deal with this sort of thing-it's focused on power plants, cars and regional air-quality standards, said UCLA environmental law professor Edward Parson.

The startup is Make Sunsets, and their plan, as per MIT Technology Review, was to counter global warming. They'd make money by selling carbon credits, so firms could pay them to release cooling particles that would allegedly nullify their emissions. Each gram of sulphur would cost $10 and offset 1 tonne of CO2.

The main problem is that it would not work. Sulphuric acid particles can only mask global warming for a year or so. Then they settle out of the atmosphere, while the carbon stays up there for thousands of years. And there are likely side effects from doing this at any useful scale. Parson has called it a case of "a rogue pseudo-scientist claiming to help the environment."