House subcommittee hears sharply divided expert views on geoengineering, seeks oversight

WASHINGTON — On Sept. 11, 2025, the House Oversight and Reform Subcommittee on Delivering on Government Efficiency convened a hearing on weather modification and geoengineering, calling experts to testify about the scientific uncertainties, possible environmental harms and gaps in U.S. oversight.

The hearing drew testimony from three invited witnesses who offered contrasting views about risks and policy responses. Roger Pilkey Jr., a senior fellow at the American Enterprise Institute, urged Congress to order authoritative study and new laws to strengthen reporting and oversight. Christopher Martz, a meteorologist and policy analyst, emphasized uncertainties about efficacy and potential harms from large-scale solar radiation modification. Michael McCracken, chief scientist for climate change programs at the Climate Institute, said research is warranted and maintained there is no current global-scale geoengineering deployment.

Pilkey recommended that Congress request a National Academy of Sciences assessment “that precisely quantifies what is known and unknown” about weather modification, standardize federal law governing weather modification across states and lead diplomatic talks toward a “solar engineering nonuse agreement.” He told the subcommittee that geoengineering raises unique governance questions and “I have likened geoengineering to risky gain of function research on viruses with uncertain benefits and catastrophic risks.”

Martz told the panel that cloud seeding and contrails are distinct phenomena, and cautioned that solar radiation modification — stratospheric aerosol injection in particular — could reduce crop yields and create other environmental and public‑health risks. “Contrails are line shaped ice crystal clouds,” he said in his prepared remarks, distinguishing ordinary aircraft exhaust from deliberate weather‑alteration methods.

McCracken described the scientific consensus that recent warming is largely attributable to human activities and said that while research can help clarify options, “There is no geoengineering of any type going on at the global scale.” He said historical volcanic eruptions, which temporarily cooled the planet, provide a natural analogue for research questions but not a blueprint for deployment.

Members of the subcommittee debated scope and priorities. Ranking Member Rep. Melanie Stansbury (ranking member; opening statement) framed the hearing as an opportunity to focus on oversight and to weigh the Environmental Protection Agency’s role in regulating atmospheric hazards. The chair, identified in the record as Chairman Green, said Congress must protect the public from experiments that could create “adverse unintended consequences.” In her closing remarks the chair announced legislation, the Clear Skies Act, aimed at ending weather modification and geoengineering activities; the record shows the bill was offered for the subcommittee’s consideration but no formal votes occurred during the hearing.

Several members raised specific operational and legal questions: how effectiveness of cloud seeding would be measured, what reporting forms currently require, whether private companies have adequate disclosure, and the potential for interstate or international impacts that would require diplomatic agreements. Pilkey and others pointed to historical U.S. projects — Project Cirrus, Project Stormfury and Operation Popeye — to illustrate the long record of experimentation and to argue for clearer governance.

No formal committee action or votes were taken at the hearing. Witnesses and members repeatedly urged further, transparent study; Pilkey urged a National Academy review and McCracken urged continued peer‑reviewed research that links global models to regional impacts. Several members said they intend to pursue legislative or oversight steps to clarify reporting and liability for weather modification activities.

The hearing record contains written testimony from the witnesses and follow‑up materials submitted for the record. The transcript and oral testimony are entered into the subcommittee record as required by committee rules.