NASA scientists have revealed an ambitious strategy to combat climate change: seeding the atmosphere with ice.
The method would involve sending high-altitude planes flying 58,000 feet above the surface, more than 20,000 feet higher than commercial airliners, and spraying ice particles into the upper atmosphere.
According to the proposal, this would freeze water and remove water vapor before it is converted into greenhouse gas emissions, which prevent heat from escaping into space, ultimately raising temperatures on Earth.
The ice particles would freeze the water, which would then fall back to Earth, removing excess water vapor and dehydrating the stratosphere where the water turns into heat-trapping gas.
Scientists would use high-altitude aircraft to inject two tons of ice particles 11 miles into the air each week, freezing water that would fall back to Earth.
The plan is a collaboration between NASA and the NNational Oceanic and Atmospheric Administration (NOAA).
The idea of drying out the upper atmosphere is the latest addition to what some scientists call a last-ditch toolbox for tackling climate change by manipulating the world’s atmosphere or oceans.
Known as geoengineering, it is It is often rejected due to its potential side effects, and is typically mentioned not as an alternative to reducing carbon pollution, but in addition to emissions cuts.
Joshua Schwarz, a NOAA physicist and lead author, said, “This is not something we can implement at this time.”
“It’s about exploring what might be possible in the future and identifying research directions.”
Schwarz noted that the efforts would not counteract the effects of carbon dioxide (CO2) and would only cool the atmosphere by 1/70, which is equivalent to the amount of heat provided by CO2.
If temperatures continue to rise, there could be devastating effects here on Earth, including a dramatic loss of marine life, an ice-free Arctic, and more regular “extreme” weather. But the NASA and NOAA plan aims to mitigate the effects.
It will only be “a very small change in the other direction,” he said.
The NASA and NOAA plan would seed the region just below the stratosphere with ice particles.
This region is where the air rises slowly, bringing water vapor with it.
According to NASA, water vapor is the most abundant greenhouse gas on Earth: it is responsible for half of the planet’s greenhouse effect.
As temperatures on our planet increase, the amount of evaporation from water and land areas also increases.
“The water vapor then absorbs the heat radiated from the Earth and prevents it from escaping into space,” NASA reported.
“This further warms the atmosphere, which creates even more water vapor in the atmosphere.”
The team believes the ice’s target would be the Western Pacific Cold Spot (WCP), a region of the atmosphere the size of Australia.
The area was chosen because water vapor normally enters the stratosphere via upward transport across the tropopause (the boundary separating the troposphere from the stratosphere) in the tropics.
“The tropopause over the western tropical Pacific, particularly in the WCP, is known to be the critical gateway in determining the amount of water vapor transported to the stratosphere,” NOAA shared.
“The WCP is cold enough to naturally freeze moist air, forming and raining down ice crystals.”
The team theorizes that releasing two tons of ice particles each week could remove enough water to reduce warming by a small amount.
In their study, the researchers used a computer model to simulate WCP conditions, driven by observations of temperature and movements of tropical air near the stratosphere.
The strategy’s models showed a 10 percent decrease in temperatures.
Schwarz acknowledged that the efforts would not reduce heating as much and should not be used as an alternative to reducing pollution.
However, other scientists aren’t quite sure what side effects might occur, and that’s the problem.
Intentionally modifying Earth’s atmosphere to address climate change is likely to create cascading new problems, said University of Victoria climate scientist Andrew Weaver, who was not part of the study.
He said the engineering aspect of this makes sense, but he compared the concept to a children’s story where a king who loves cheese is invaded by mice, gets cats to deal with the mice, then dogs to scare away the cats, lions to get rid of them. from the dogs and elephants to eliminate the lions and then back to the mice to scare away the elephants.
It makes more sense to address the initial problem: cheese or carbon dioxide, Weaver said.
Lynn Russell, an atmospheric chemist at the Scripps Institution of Oceanography, who was not part of the research, said the idea is worth examining, but the study “doesn’t have many answers given all the uncertainties.”