Contrails are not evidence of plan to block out the sun

25 August 2022
What was claimed

White lines in the sky are what’s being called chemtrails, or geoengineering designed to block out the sun.

Our verdict

The lines in the sky are contrails, not chemtrails, which do not exist. It is true that some scientists have suggested spraying particles in the atmosphere to reduce solar radiation, but contrails are not evidence of this.

A YouTube video shared on Facebook shows clips of contrails left by aeroplanes and claims that “global elites” are trying to “block out the sun”.

The video claims that “Bill Gates has many times talked about spraying particles to block out the sun”, and that evidence of this can be seen in the Netherlands, UK and Italy.

While it’s true that some scientists have proposed releasing particles into the atmosphere to reduce heat from the sun, this has not been carried out on a wide scale, and videos of vapour trails in the sky are not evidence of this.

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Vapour trails are contrails, not chemtrails

The video claims that the plans are known as “chemtrails or geoengineering”. Chemtrails are not real. The white vapour lines in the sky which are often described as “chemtrails” are in fact contrails—long thin lines of cloud which are formed when water vapour produced at high altitudes by aeroplane engines freezes as it is released into cold air.

The frozen vapour leaves a trail of tiny ice crystals behind the aeroplane which, depending on the humidity of the air, either become invisible after a few minutes, or remain as water droplets or ice crystals, creating the lines seen in the sky.

The chemtrails conspiracy theory claims, falsely, that these lines are evidence of chemicals being sprayed either as poison or to control the weather. We’ve written a number of articles recently on this issue as part of our work checking online misinformation.

Solar geoengineering has been suggested as way to combat global warming

According to the Met Office, geoengineering is the “deliberate large-scale manipulation of climate”. Two key aspects of this are Greenhouse Gas Removal—using natural and artificial means to remove greenhouses gases from the atmosphere, ranging from planting more trees to chemically removing carbon dioxide from the atmosphere—and Solar Radiation Modification, which involves using technology to reflect some of the Sun’s energy back into space, thereby reducing the amount of heat it transfers to the Earth. 

Solar geoengineering proposes using various techniques, including deploying non-toxic particles into the atmosphere, in order to reduce the amount of solar radiation that reaches Earth.

As we have written before, in 2021 it was confirmed that Bill Gates had offered financial support to a Harvard University research programme which aimed to test the idea in Sweden. The small-scale experiment planned to spray aerosols into the atmosphere to reflect some sunlight back into space in order to understand the risks and efficacy of undergoing large scale solar geoengineering. 

Solar geoengineering is controversial, and has been heavily criticised by some scientists who argue that there are too many unknown risks. The Harvard experiment’s planned test was ultimately cancelled following opposition from local indigenous and environmental groups.

Whether more artificial means should be used to counteract climate change remains a matter of debate. In an open letter published in January 2022, a group of academics called for the establishment of an International Non-Use Agreement on Solar Geoengineering, writing: “So far, the risks and efficacy of solar geoengineering are poorly understood. Impacts are likely to vary across regions, as artificial cooling will affect some regions more than others. There are also uncertainties about the effects on regional weather patterns, agriculture, and the provision of basic needs of food and water.”

The video shared on Facebook claims that attempts to “block out the sun” are already taking place in Europe, using videos apparently taken of contrails seen in the Netherlands, southern England and Italy as evidence of this.

But solar geoengineering is not taking place in any of these countries, and the clips seen in the video are of ordinary aeroplane contrails.

Image courtesy of Gabriella Natiello

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