Amid efforts to cool the planet, solar geoengineering draws heated debate

By Shannon Kelleher

Luke Iseman got tired of waiting for the world to stop climate change so he decided to try it himself. The founder of a controversial two-person startup called Make Sunsets has begun launching balloons filled with sulfur dioxide high into the sky with the intention of imitating the effects of volcanic eruptions. The molecules are meant to act like little clouds, cooling the planet by reflecting sunlight back into space before it reaches the Earth’s lower atmosphere.

Iseman’s venture into the relatively new arena known as solar geoengineering is drawing its own heat in the form of criticism from scientists amid an intensifying debate – should the world at least explore once-unthinkable measures that some say might buy time to address climate change?

The window to keep warming under 1.5 degrees Celsius (2.7 degrees Fahrenheit) in order to prevent dramatically more severe global impacts is closing fast. Earth is on track to hit that threshold “in the first half of the 2030s,” according to an Intergovernmental Panel on Climate Change (IPCC) report released last month.

Many scientists oppose geoengineering strategies, defined as interventions in the earth’s oceans, soils and atmosphere that reduce climate impacts such as extreme temperatures, variability in water availability, and the severity of storm systems. Solar engineering specifically focuses on masking the effects of climate change caused by greenhouse gases, although it isn’t a permanent fix since it doesn’t actually get rid of these gases.

Critics say further tinkering with Earth’s climate using new technologies could have dire unintended consequences such as acid rain and health problems, as well as rapid global temperature rises if such interventions were stopped without fixing the problem at its root. Some fear that investing research into such drastic avenues could create illusions of a cheap fix at a moment when there is no time to spare.

Even those in favor of studying solar geoengineering say they still have no idea if it should actually ever be used –the research is too early and the risks and effectiveness of such strategies are not well understood.

But Iseman, who has a history of launching startups and holds an economics degree from the Wharton Business School, says it’s past time to begin deploying and scaling up the untested technology.