Apr 28, 2025 03:51 PM
(This post was last modified: Apr 28, 2025 05:06 PM by C C.)
https://www.eurekalert.org/news-releases/1081781
INTRO: A technique to cool the planet, in which particles are added to the atmosphere to reflect sunlight, would not require developing special aircraft but could be achieved using existing large planes, according to a new modelling study led by UCL (University College London) researchers.
Previously, most research has assumed that the technique, known as stratospheric aerosol injection, would be deployed in the tropics and so would require specially designed aircraft capable of flying at altitudes of 20km or more to inject the particles.
For the new study, published in the journal Earth’s Future, scientists ran simulations of different aerosol injection strategies and concluded that adding particles 13km above the polar regions could meaningfully cool the planet, albeit much less effectively than at higher altitudes closer to the equator. Commercial jets such as the Boeing 777F could reach this altitude.
Lead author Alistair Duffey, a PhD student at UCL’s Department of Earth Sciences, said: “Solar geoengineering comes with serious risks and much more research is needed to understand its impacts. However, our study suggests that it is easier to cool the planet with this particular intervention than we thought. This has implications for how quickly stratospheric aerosol injection could be started and by who.
“There are downsides to this polar low-altitude strategy. At this lower altitude, stratospheric aerosol injection is about one third as effective. That means that we would need to use three times the amount of aerosol to have the same effect on global temperature, increasing side effects such as acid rain. The strategy would also be less effective at cooling the tropics, where the direct vulnerability to warming is highest.
“However, climate change is a serious problem and it is vital to understand all our options, so that policy-makers have the evidence they need to make informed decisions.”
The researchers ran simulations in the UK’s Earth System Model 1 (UKESM1), a computer model of the climate, to estimate the impact of stratospheric aerosol injection. By adding sulphur dioxide – which goes on to form tiny reflective particles – at different altitudes, latitudes and seasons, they were able to quantify the effectiveness of different deployment strategies... (MORE - details, no ads)
INTRO: A technique to cool the planet, in which particles are added to the atmosphere to reflect sunlight, would not require developing special aircraft but could be achieved using existing large planes, according to a new modelling study led by UCL (University College London) researchers.
Previously, most research has assumed that the technique, known as stratospheric aerosol injection, would be deployed in the tropics and so would require specially designed aircraft capable of flying at altitudes of 20km or more to inject the particles.
For the new study, published in the journal Earth’s Future, scientists ran simulations of different aerosol injection strategies and concluded that adding particles 13km above the polar regions could meaningfully cool the planet, albeit much less effectively than at higher altitudes closer to the equator. Commercial jets such as the Boeing 777F could reach this altitude.
Lead author Alistair Duffey, a PhD student at UCL’s Department of Earth Sciences, said: “Solar geoengineering comes with serious risks and much more research is needed to understand its impacts. However, our study suggests that it is easier to cool the planet with this particular intervention than we thought. This has implications for how quickly stratospheric aerosol injection could be started and by who.
“There are downsides to this polar low-altitude strategy. At this lower altitude, stratospheric aerosol injection is about one third as effective. That means that we would need to use three times the amount of aerosol to have the same effect on global temperature, increasing side effects such as acid rain. The strategy would also be less effective at cooling the tropics, where the direct vulnerability to warming is highest.
“However, climate change is a serious problem and it is vital to understand all our options, so that policy-makers have the evidence they need to make informed decisions.”
The researchers ran simulations in the UK’s Earth System Model 1 (UKESM1), a computer model of the climate, to estimate the impact of stratospheric aerosol injection. By adding sulphur dioxide – which goes on to form tiny reflective particles – at different altitudes, latitudes and seasons, they were able to quantify the effectiveness of different deployment strategies... (MORE - details, no ads)