FACT CHECK: Do planes leave trails in the sky to manipulate weather? 

An Instagram post has claimed that trails are intentionally put in the skies.

“To those who are unsure what happens when the trails are put in to the skies,” reads the caption of an Instagram post shared on December 17, 2022, with over 10, 150 likes. 

The post was shared with a collage of four pictures of the sky with thin white lines running across it, suggesting to be the state of the sky, photographed at 7:30 am, 10:23 am, 10:30 am, and 11:30 am respectively.

The picture collage, captioned chemtrails, seeks to explain to social media users what happens when trails are put into the sky.

The post also claims that trails are formed in the sky when it is very cold, yet they are more seen in the summer months. 

“The UK 🇬🇧 has been clear, cold for weeks. Not one trail in the sky but lots of flights. I thought these “trails” are formed when the air temperature is very cold? Yes we see a lot more in the Spring and Summer months? Interesting to say the least,” reads the concluding caption of the post. 

The history of weather modification dates back to 1932 when the Leningrad Institute of Rainmaking was established in the Soviet Union. Also, during the 2008 Olympics, the Chinese government used cloud seeding to create a downpour elsewhere, so as to keep the stadium dry, ahead of the opening ceremony of the global sporting event.

But how true are the claims by conspiracy theorists that chemtrails are deliberately put in the skies by planes?

WHAT CONSPIRACY THEORISTS SAY ABOUT CHEMTRAILS

The Instagram page that shared the post goes by the name, Chemtrailsworldwide. 

According to the page description, the handle is dedicated to sharing “images, videos and other evidence of geoengineering (chemtrails)/climate engineering and weather modification in our skies today”.

Without adequate evidence, conspiracy theories have postulated that the white lines of condensed water vapour that jets leave in the sky are toxic substances the government deliberately spray on the unsuspecting populace.

Conspiracy amplifiers refer to the white lines planes leave behind as chemtrails. 

While some say the sprays are put on the skies by the government to slow global warming, others say they are sprayed to weed out the old and sick. In some instances, it has been said that the white lines show up in the sky as a result of poisons used to control the weather, by spraying chemicals from the aircraft.

WHAT ARE CONTRAILS

The white lines in the Instagram images are scientifically called contrails. They are formed when water vapour and fine soot particles from burning jet fuels freeze into ice crystals at high altitudes. 

Depending on the humidity of the air, the frozen vapour could either change from solid to gas in low humidity or remain as water droplets or ice crystals in high humidity, hence creating the white lines often seen in the sky.

The difference in humidity actually explains why some planes produce vapour trails while others do not. Humidity is also the reason contrails may be less visible in winter, as the atmosphere is less humid compared to the warm period of summer.

Contrails disappear quickly in clear air with no cloud, such that the ice particles sublimate, which means they pass from solid to gas. However, if the atmosphere is humid, the ice particles can’t transform from solid to gas, they remain visible as trails for much longer after the passage of the aircraft.

WHAT DO EXPERTS HAVE TO SAY?

Experts have established that there is no evidence to support the claim that the white lines seen in the sky are chemicals or weather-altering tools dispersed from aeroplanes. 

In fact, scientists say that contrails are not large enough to cause any weather on the ground. 

In a 2022 report by the BBC, Aidan McGivern, Met Office meteorologist, established that cirrus clouds are short, detached and hair-like, therefore, it is very unlikely that any of the purported chemicals sprayed in the clouds would even reach ground level because they are at high altitudes.

In a report by NASA, scientists said the cloud-forming contrails conspiracy theorists make issues of, are “perfectly natural”. In the same report, another expert who studied contrails discarded the social media claim, saying that the white lines seen in the sky are nothing except water vapour and ice crystals, adding that the line patterns in the sky can be explained as contrails blown together by the wind.

Kenneth Sassen, an atmospheric scientist at the University of Utah, was quoted by NASA as saying: ”These things are at 30,000 to 40,000 feet in the atmosphere. They’re tiny particles. They’re not going to affect anyone.”

VERDICT

There is no adequate scientific evidence to buttress the claim that trails are deliberately put into the sky by planes to disrupt weather or control population growth. 

This fact check was produced by TheCable with support from Code for Africa’s PesaCheck, International Fact-Checking Network, and African Fact Checking Alliance network.