In Silicon Valley, a Rogue Plan to Alter the Climate

SARATOGA, Calif. — A silver Winnebago pulled up to a self storage warehouse on the outskirts of a Silicon Valley suburb and three renegade climate entrepreneurs piled out, all mohawks, mustaches and camouflage shorts.

Working swiftly, the men unlocked a storage unit crammed with drones and canisters of pressurized gas. Using a dolly, they wheeled out four tanks containing sulfur dioxide and helium, and stacked them on the floor of the camper van. Then, almost as quickly as they arrived, they were on the road, headed for the golden hills near the Pacific Ocean.

With their jury-rigged equipment and the confidence that comes with having raised more than $1 million in venture capital, they were executing a plan to release pollutants into the sky, all in the name of combating global warming.

“We’re stealth,” said Luke Iseman, one of the co-founders of Make Sunsets, delighting in their anonymity as he rode in the back. “This looks like just another R.V.”

Make Sunsets is one of the most unusual start-ups in a region brimming with wild ideas. Iseman, 41, and his co-founder, Andrew Song, 38, claim that by releasing sulfur dioxide into the stratosphere, they can reflect some of the sun’s energy back into space, thereby cooling the planet.

It’s a gutsy undertaking, yet it has at least a partial grounding in science. For 50 years, climate scientists have suggested that releasing aerosols into the stratosphere could act as a buffer and reduce the heat from the sun. Volcanic eruptions have temporarily cooled the planet this way in the past, but no one has attempted to intentionally replicate the effect at scale.