White streaks left behind aircraft, known as contrails, are simply water vapour condensing into ice crystals. However, a growing number of people online claim these trails are evidence of a secret government conspiracy to control the weather or poison the environment. These so-called 'chemtrail' theories persist on social media despite scientific explanations.
Suzanne Maher, founder of the group Bye Bye Blue Sky, believes the trails are part of a massive covert operation. 'Twenty to thirty years ago we never saw these trails. We had a beautiful blue sky,' she says. Maher claims the term 'chemtrail' was invented by the CIA to discredit those questioning the government. Her closed Facebook group has around 5,000 members who share this belief.
Conspiracy theorists vary in their claims, but common themes include governments controlling the weather, scientists using geo-engineering to secretly poison the public, or powerful groups spraying chemicals to make people pliant. However, contrails have been documented since the Second World War, as seen in images from the Battle of Britain.
Weather modification has a long history, such as Soviet rainmaking efforts in the 1930s and Chinese cloud seeding for the 2008 Olympics. Geo-engineering, a newer field, has seen limited field testing. Professor David Keith of Harvard University told the New York Times that solar geo-engineering, which involves injecting reflective particles into the atmosphere, has only been tested twice.
Despite the lack of evidence, an international survey suggested nearly 17% of respondents find chemtrail theories true or partly true. Maher says her awakening began six years ago after reading a post by a young girl who claimed the skies were no longer blue due to spraying. 'Why would such a young child be sharing this information if it wasn't truthful?' she asks.
