A recent modeling study led by researchers from the University College London (UCL) revealed that stratospheric aerosol injection to cool the planet could be carried out without the need to develop specialized aircraft.
The work, published in the journal Earth’s Future, concluded that the technique could be performed at 13 km altitude in polar regions, using commercial aircraft such as the Boeing 777F.
A method with advantages and challenges
Traditionally, this intervention has been considered to be carried out in the tropics, at altitudes above 20 km, which would require aircraft specifically designed for the task.
However, the researchers found that:
- At lower altitudes, effectiveness is one-third lower, requiring more aerosol quantity.
- Side effects would be generated, such as increased risk of acid rain.
- The impact in the tropics would be lower, where vulnerability to warming is higher.
Despite these limitations, this alternative could accelerate the implementation of solar geoengineering.
How stratospheric aerosol injection works
The method consists of introducing sulfur dioxide into the atmosphere, where it transforms into reflective particles that reduce solar radiation.
For it to be effective, the injection must be done in the stratosphere, an atmospheric layer free of clouds, where particles can persist for months or years.
This process is similar to the effect observed after the eruption of Mount Pinatubo in 1991, which caused a global temperature decrease.
Implications for climate policy
The study suggests that, instead of waiting for the development of high-altitude aircraft, the injection could start earlier with modifications to existing commercial aircraft.
Researcher Wake Smith from Yale University indicated, according to EuropaPress agency, that designing and certifying new high-flying aircraft could take a decade and cost billions of dollars.
Not a definitive solution
Co-author Dr. Matthew Henry from the University of Exeter emphasized that solar geoengineering does not replace the need to reduce greenhouse gas emissions.
“We will only achieve long-term climate stability with net zero emissions”, he stated, highlighting that any intervention should be gradual to avoid catastrophic impacts.
This study provides new insights into the technical and political feasibility of solar geoengineering to cool the planet, fueling the debate on its potential implementation and global consequences.
