a one-page form with the Commerce Department 10 days before they do so, thanks to a law from the 1970s that requires reporting of efforts to modify the weather.

That’s not enough, say academics and researchers who are urging the government to expand their rules governing private firms’ solar radiation modification efforts. It’s part of a broader push to regulate small-scale geoengineering experiments that are already happening.

“There’s no governance on the international level, national governance, there’s no state governance, there’s nothing,” said Bookbinder.

Bookbinder represented environmental groups during his tenure at Sierra Club in the landmark climate case Massachusetts v. EPA, which confirmed the agency’s authority to regulate greenhouse gases as pollutants under the Clean Air Act. He went on to work for the Niskanen Center, a libertarian think tank. He’s now self-employed.

Bookbinder is agnostic on whether geoengineering technologies should be deployed, he said, but he’s worried it could be done without proper oversight and that the United States and international governments aren’t prepared to keep it in check.

It’s been on his mind for a few years, Bookbinder said, since he started wondering about “the next big problem that we’re not thinking about yet.”

“I said, ‘Holy shit, it’s not the climate change.’ We know what that is. We know how it’s proceeding,” Bookbinder said. “It’s going to be the solutions that people start offering up.”

Fodder for science fiction

Scientists know that aerosol particles can cool the Earth’s surface because they temporarily reflect sunlight. The 1991 eruption of Mount Pinatubo in the Philippines, for example, lowered the average global temperature by about 1 degree Fahrenheit for roughly a year.

But widespread questions remain about the scientific and geopolitical implications of injecting aerosols into the upper atmosphere to modify the climate. Potential risks could include damage to the ozone or changes to weather patterns — possibly impacting other countries. Geoengineering also doesn’t address other harms associated with producing and burning fossil fuels, such as local pollution and ocean acidification.

And if a country or company were to implement a major geoengineering scheme, it would have to continue until carbon concentrations in the atmosphere fell to a safe level or risk triggering a catastrophic spike in global warming — a risk known as termination shock.

A proposal to study solar geoengineering was withdrawn from consideration at a U.N. Environment Assembly earlier this year after nations failed to reach agreement over how to approach the contentious issue.

Bookbinder pointed to a scenario laid out in the 2020 climate fiction novel “Ministry for the Future” by Kim Stanley Robinson. Geoengineering is central in the novel, which depicts India suffering from a deadly heat wave and spraying aerosols into the stratosphere.

If something like that were to happen in the real world, “suppose then the monsoon fails over India and China has a disastrous drought or heat wave,” Bookbinder said. “Who do you think they’re gonna blame? The geopolitical problems that can come if people start doing this on a national scale are beyond imagining.”

‘Gaps’ in government rules?

International doomsday scenarios are Bookbinder’s biggest worry, he said.

On a smaller scale, he’s hoping to get the regulatory ball rolling by prodding the U.S. government to update 1970s-era rules that track efforts to modify the weather.

“As climate change accelerates and its damages mount, the investigation and testing of some forms of climate intervention technologies” including solar radiation modification, “appear imminent and inevitable,” Bookbinder and others wrote in a March petition filed with NOAA.

“While some of these activities will likely take place with federal oversight and funding, the field overall lacks transparency and oversight,” the petition says.

Signatories include Bookbinder; Tracy Hester of the Environment, Energy, and Natural Resource Center at the University of Houston Law Center; Shuchi Talati, founder of the Alliance for Just Deliberation on Solar Geoengineering; and other professors.

Current NOAA rules, which stem from a 1970s law, require reporting of all nonfederal efforts to modify weather. The most common form of weather modification is cloud seeding to boost rain or snowfall, according to NOAA.

The petitioners are asking the government to update its reporting act regulations to “expand and clarify their application” to private solar radiation modification activities. NOAA’s current regulations, the petitioners wrote, fail to require all the information needed to “assess the potential impacts and risks” of geoengineering activities.

NOAA is currently leading a congressionally mandated research effort investigating “natural and human activities that might alter the reflectivity and radiative balance of the atmosphere” and the potential impact of those activities, according to the agency’s website.

Under current regulations, “any activity designed to modify Earth’s energy budget is considered weather modification,” NOAA spokesperson Theo Stein said in an email.

“Companies that intend to engage in weather modification activities within the United States are required by the Weather Modification Act of 1976 … to provide a report to the Administrator of NOAA at least 10 days prior to undertaking the activity,” Stein said.

Bookbinder and other petitioners want the reporting rules to explicitly address solar radiation modification activities and to address what they call “several important gaps” in the agency’s rules.

That “would help the federal government prevent harm and track activities until or unless Congress chooses to take legislative action or all or any appropriate federal agencies undertake full notice-and-comment rulemaking,” they wrote.

“Solar radiation modification has the potential to be a much, much bigger thing than weather modification ever was,” said Tyler Felgenhauer, a senior research scientist at Duke University who studies the risks and benefits of potential solar radiation modification.

“We need some sort of regulation,” said Felgenhauer, who wasn’t involved in the petition. “If this is the way that it gets in the door, maybe that’s how it’s going to be.”

Geoengineering is happening

Solar geoengineering isn’t just theoretical.

Make Sunsets sells “cooling credits” to launch weather balloons that aim to deposit the sunlight-reflecting sulfate particles into the upper atmosphere.

The company ignited controversy after launching balloons in Baja California, Mexico. The Mexican government said it hadn’t been notified and that it would “prohibit and, where appropriate, stop experimentation with solar geoengineering in the country.”

Make Sunsets announced in January 2023 that it would cease operations in Mexico. The following month, the firm launched additional balloons carrying sulfur dioxide near Reno, Nevada.

NOAA told Reuters in March 2023 that Make Sunsets hadn’t reported its launches in Nevada. Luke Iseman, Make Sunsets CEO and co-founder, told the news outlet at the time that he did seek clearance from the Federal Aviation Administration.

“As far as I can tell, there isn’t any rule that would require us to do so — or even anyone who it would be relevant to notify,” Iseman told Reuters.

Make Sunsets later submitted the required form after NOAA communicated with the company, Stein told E&E News Friday in an email. Anyone who knowingly and willfully violates the rule may be subject to a fine. Outside of the reporting requirements, NOAA has no role in approving such activities, Stein said.

released a report last June laying out a research plan for solar radiation modification. The Biden administration stressed that the report came in response to a directive from Congress and that the administration “remains focused on reducing emissions, increasing resilience, advancing environmental justice, and achieving true energy security.”

There are “no plans underway to establish a comprehensive research program focused on solar radiation modification,” the White House wrote last year.

Reporter Corbin Hiar contributed.