As thermometers across Europe hit record highs once again, social media platforms have seen a resurgence of claims that a US military program is deliberately manipulating the weather to cause the continent's heatwaves. These assertions, however, are not supported by available evidence.
Several accounts have shared clips of journalists, scientists, and public figures discussing geoengineering—large-scale interventions in Earth's climate system—presenting them as proof that weather events are being artificially controlled. One widely circulated video features French TV presenter Anne-Claire Coudray discussing geoengineering on a news program.
"In response to climate change, more and more countries are exploring what's known as geoengineering," she said in the clip. "The idea is to intervene directly in the climate system to artificially cool the planet."
The clip, originally published in late August 2025 as part of a report on theoretical methods to mitigate climate change, does not suggest that such technologies are currently being deployed to create or intensify heatwaves. The original context was an exploration of potential future solutions, not a confirmation of active manipulation.
The HAARP Conspiracy Theory
Many of the posts also reference HAARP—the High-frequency Active Auroral Research Program—a US research facility in Alaska that has long been a magnet for conspiracy theories. Launched in the 1990s, HAARP was built to study the ionosphere, a layer of Earth's upper atmosphere, by transmitting high-frequency radio waves and measuring how electrically charged particles respond.
According to the program's stated mission, the research aims to improve understanding of the ionosphere and help develop communication and surveillance technologies. Since 2015, HAARP has been operated by the University of Alaska, which publicly documents its research activities.
The theory that HAARP can control weather relies on a fundamental misunderstanding of atmospheric science. Weather systems, including heatwaves, develop in the troposphere and, to some extent, the stratosphere—the lowest layers of the atmosphere. HAARP's experiments take place in the ionosphere, hundreds of kilometres above the Earth's surface. The radio waves used by the facility do not interact with the lower layers where weather forms.
Scientists have repeatedly stated that there is no known mechanism through which HAARP could create or intensify weather events. The recent heat across Europe, according to climate scientists, was driven by a persistent high-pressure system that trapped hot air over western parts of the continent.
As heatwaves become more frequent and intense across Europe, the need for accurate information is critical. For those seeking practical advice on coping with extreme heat, our guide on how to turn your European garden into a wildlife haven during heatwaves offers useful tips. Meanwhile, the human toll is stark: June heatwaves linked to over 10,000 excess deaths across Europe underscores the urgency of addressing climate impacts.
In response to these challenges, some European countries are taking action. Portuguese environmentalists demand climate shelters as heatwaves intensify, highlighting grassroots calls for adaptation measures. And infrastructure is being upgraded: Eurostar upgrades Celestia trains to withstand 55°C as heatwaves intensify shows how rail operators are preparing for a hotter future.
In short, the claim that a US military program is behind Europe's heatwaves is a conspiracy theory without scientific basis. The real driver is climate change, which is making extreme weather events more common across the continent.
