How Commercial Jets Could Soon Be Used To Cool Off Our Planet

LONDON — The same planes delivering online orders today could one day deliver cargo to fight global warming. New research from University College London reveals that ordinary commercial jets could be repurposed to inject particles into the atmosphere to fight climate change, potentially bringing geoengineering from science fiction into reality far sooner than experts predicted.

A new study published in Earth’s Future reveals that existing aircraft could effectively deliver sulfur dioxide into the stratosphere at high latitudes, where the atmospheric boundary layer is lower than at the equator. This suggests that geoengineering, deliberately manipulating Earth’s climate system to counteract global warming, might be technically feasible without creating specialized aircraft, which experts previously assumed would be necessary.

This is actually achievable. Their team discovered that while this method isn’t as efficient as purpose-built high-altitude jets, it could still deliver meaningful cooling effects and substantially reduce barriers to making this happen.

How Ordinary Jets Could Cool the Planet

For decades, scientists have discussed stratospheric aerosol injection (SAI) as a potential emergency brake on climate change. The concept mimics large volcanic eruptions by releasing sulfur particles high into the atmosphere, where they reflect sunlight back into space and temporarily cool the planet. Until now, most experts believed this would require new, specialized aircraft capable of flying at extremely high altitudes of around 20 kilometers (approximately 65,617 feet).

But by injecting sulfur dioxide at polar latitudes (around 60° North and South), where the stratosphere sits lower in the atmosphere, existing commercial aircraft could do the job at altitudes of just 13 kilometers (approximately 42,651 feet), well within their current operating ranges.

The researchers conducted 41 short stratospheric aerosol injection simulations using the UK Earth System Model, varying the altitude, latitude, and season of injection. Their models showed that seasonal high-latitude injection with a standard Boeing 777F could achieve roughly 35% of the cooling efficiency of the high-altitude approach using specialized aircraft.

This means more sulfur dioxide would need to be injected to achieve the same cooling effect, about 21 tons annually compared to 7.6 tons with the specialized aircraft approach. The increased injection amounts would multiply side effects like acid rain and stratospheric warming.

Yet the possibility of using existing aircraft dramatically alters the timeline and accessibility of potential geoengineering deployment. Rather than waiting a decade or more for specially designed high-altitude aircraft to be developed and certified, commercial jets could be modified within years.

However, the researchers warn that if this technology becomes easier to use, more groups could try to cool the planet on their own, raising the risk of rushed or poorly coordinated attempts to change the climate.

Using climate models, the research team estimated that injecting 12 tons of sulfur dioxide annually at an altitude of 13 kilometers at 60° North and South during local spring and summer could produce global cooling of about 0.6°C. This would be enough to significantly slow climate change if maintained over decades.

The team calculates that a fleet of 102 modified Boeing 777F jets would be needed to deliver enough sulfur dioxide to cool the planet by 1°C. By comparison, Boeing currently manufactures about 36 of these aircraft annually.

Restricting injections to spring and summer in each hemisphere increases cooling efficiency by 39% compared to year-round injection. Doing so seasonally takes advantage of higher sunlight levels during these periods, maximizing the cooling effect of the reflective particles.

While high-latitude injection would produce a more polar-focused cooling pattern, the effects would still be global. This pattern could provide stronger cooling in Arctic regions, potentially helping to preserve sea ice, but might be less effective at cooling tropical regions where many vulnerable populations live.

There are a few cons to this approach, though. The lower altitude injections are substantially less efficient than high-altitude injections. Using existing aircraft would require injecting nearly three times as much sulfur dioxide to achieve similar cooling, significantly increasing side effects.

Governance Challenges

This also raises serious questions about who would control climate-altering technology. If changing the climate no longer requires special equipment, many more countries—or even private groups—could gain the power to do it.

We can look at this as both an opportunity and a warning. The technical barriers to cooling Earth are lower than we thought, but this doesn’t mean we should rush toward geoengineering. Careful consideration about governance, permission, and unintended consequences is needed before modified cargo planes start releasing particles into our atmosphere.