TEMPO.CO, Jakarta - A post on Instagram [archive] on January 23, 2026, claimed that weather modification operations leave "chemtrails," or the dispersal of chemical substances by airplanes. This narrative emerged amidst local government efforts to implement Weather Modification Technology (TMC) to mitigate flood risks.
The video attached in the post featured a collage of weather modification measures undertaken by the Jakarta Provincial Government, alongside several screenshots of articles about chemtrail conspiracy theories. “Chemtrails will be spread from Sabang to Merauke in 2026. Protect your immunity,” read the caption on the post.
However, is it true that weather modification is tantamount to chemtrails, as claimed in the video?
FACT CHECK
Tempo verified the content by conducting an interview and citing several other credible references. The results showed that the technology used for weather modification differs from chemtrails.
How does weather modification technology work?
I Putu Santikayasa, Secretary of the Center for Climate Risk and Opportunity Management in Southeast Asia Pacific at Institut Pertanian Bogor (IPB University), explained that weather modification technology alters cloud and rain formation processes. This technology aims to regulate the intensity of rainfall in a region, either to reduce or increase it.
According to Putu, if the goal is to increase rainfall, the team will swiftly lower rainfall potential in the target area. In contrast, to reduce the risk of flooding, the rain will be transferred to drop over another region. “This technology cannot create rain but rather utilizes clouds or rainfall potential and specific atmospheric conditions,” Putu told Tempo on Monday, January 26, 2026.
Weather modification operations begin with the analysis of meteorological data obtained from field observations, such as data from the Meteorology, Climatology, and Geophysics Agency (BMKG). In addition, teams of experts use weather satellite and radar data to monitor weather parameters such as wind, humidity, temperature, and air pressure. “The atmosphere is a constantly moving fluid, so analysis on atmospheric dynamics is crucial,” said Putu.
History of the Chemtrail Conspiracy Theory
A BBC report revealed that the roots of the chemtrail conspiracy theory—white smoke trails from aircraft claimed to contain harmful chemicals—began with a series of events in the 1950s and 1960s. Long before this theory was popularized, authorities in most parts of the UK did spray chemicals in a series of secret germ warfare tests. In 1950, a ship also sprayed chemicals in San Francisco to gauge the impact of bioweapons attacks on the population.
To this day, conspiracy theorists exploit data from these past secret experiments to legitimize their claims. They spread the misleading narrative that contrails (condensation trails) from modern aircraft are identical to the 1950s secret operations.
According to the BBC, chemtrail buzzers are highly active on platforms such as Facebook and Telegram, discussing alleged “spraying” and tracking aircraft. These groups often promote anti-vaccine movements and promote climate change denialism. This conspiratorial mindset has grown stronger during the height of the Covid-19 pandemic and is intertwined with the emergence of the QAnon conspiracy theory in the United States.
In Indonesia, chemtrail conspiracy theories were widespread during the Covid-19 pandemic. To this day, disinformation spreaders continue to link this phenomenon to various health issues, including the tuberculosis epidemic.
Are Contrails Different from Chemtrails?
The white trails left behind airplanes are not chemtrails, but contrails—trails of condensed water vapor produced by jet engines. Etymologically, "contrails" is an acronym for "condensation" and "trail."
According to data from the United States' National Weather Service website, contrails are formed through two basic processes. The first method relies on hot and humid engine exhaust mixing with cold, low-vapor-pressure air in the atmosphere. When added moisture and particles from the exhaust mix with the cold air, condensation occurs and forms a streamer. This phenomenon is often referred to as an exhaust trail (see Figure 1).
The second formation method occurs when the aircraft flies through clear air with relative humidity close to 100 percent. The airflow over the wing tip triggers a pressure change that causes a drastic drop in temperature, creating complete air saturation.
Turbulent vortex at the wing tip then completes the process, creating contrails directly behind the wing tips (Figure 2). Unlike engine exhaust trails, this phenomenon, often referred to as aerodynamic trails, is less prominent and relatively rare in the atmosphere.
Under the right conditions, contrails can persist for prolonged periods of time and sometimes develop into a complete layer of cirrus clouds.
Contrails most often form at cruising altitudes, between approximately 32,000 and 42,000 feet (10,000 to 13,000 meters) in the upper troposphere, according to the Rocky Mountain Institute (RMI), because that is where these conditions are found. Because the atmosphere is constantly changing, conditions may not be right for contrail formation at these altitudes, which is why not all aircraft produce contrails on every flight, according to the Space website.
CONCLUSION
Tempo's verification concludes that the narrative claiming that toxins will be spread from Sabang to Merauke in 2026 through chemtrails and weather modification operations is false.
TEMPO FACT-CHECK TEAM
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