Scientists Weigh Risk of Experimenting with Sunlight Reflection to Combat Climate Change
A team of researchers has proposed experimenting with a method that could potentially reduce the effects of global warming by reflecting sunlight away from the Earth. The idea, which dates back to 1965 when Lyndon B Johnson's science advisers suggested it as the only way to cool the planet, has garnered renewed attention in light of the growing concern over climate change.
Currently, about 30% of incoming sunlight is reflected by the Earth, and increasing this fraction could strengthen the planet's natural heat shield. However, researchers are hesitant to deploy a large-scale experiment due to concerns about its safety and efficacy.
A study published recently has suggested that stratospheric aerosol injection (SAI), which involves injecting particles into the stratosphere to reflect sunlight, could offset 1 degree Celsius of warming with around 12 million tonnes of sulfur dioxide per year. This idea is not without risks, however, as a poorly designed experiment could have catastrophic consequences.
To mitigate these concerns, researchers are advocating for a phased approach to studying SAI, similar to clinical trials in medicine. The goal is to develop robust models and gather evidence through small-scale experiments before scaling up the process.
Phase one of such an experiment would involve releasing tiny amounts of sulfur dioxide into the stratosphere, carefully measuring its evolution using various instruments. This amount would be far too small to affect the climate but would allow researchers to study how aerosols form and behave.
If successful, phase two could involve larger-scale experiments, potentially involving tens or even hundreds of times more particles than in phase one. These experiments would aim to determine key factors such as how aerosols mix and distribute in the stratosphere.
The proposed research framework includes a post-licensure trial, where small deliberate cooling occurs under constant observation and strict oversight. This slow and reversible deployment could provide the evidence policymakers require if governments decide to move forward with SAI.
Critics of the idea point out that we don't need to reinvent the wheel. Medicine has solved the "too risky to test" dilemma 60 years ago by codifying phased clinical trials. A similar structured program for SAI would help build confidence in its predictions and identify areas where current projections are robust – or require refinement.
Outdoor research is not a slippery slope to deployment, but rather how we make sure that any future decision – whether to move forward, reject the idea entirely or refine it – is based on facts, not fear or wishful thinking. The real danger isn't asking the question; it's waiting too long to learn the answer.
Experts Dakota Gruener and Daniele Visioni believe that carefully designed experiments can reduce both scientific uncertainties and political risks. By accelerating the pace of sunlight reflection research, they hope to provide policymakers with the evidence needed to make informed decisions about this potentially game-changing technology.
A team of researchers has proposed experimenting with a method that could potentially reduce the effects of global warming by reflecting sunlight away from the Earth. The idea, which dates back to 1965 when Lyndon B Johnson's science advisers suggested it as the only way to cool the planet, has garnered renewed attention in light of the growing concern over climate change.
Currently, about 30% of incoming sunlight is reflected by the Earth, and increasing this fraction could strengthen the planet's natural heat shield. However, researchers are hesitant to deploy a large-scale experiment due to concerns about its safety and efficacy.
A study published recently has suggested that stratospheric aerosol injection (SAI), which involves injecting particles into the stratosphere to reflect sunlight, could offset 1 degree Celsius of warming with around 12 million tonnes of sulfur dioxide per year. This idea is not without risks, however, as a poorly designed experiment could have catastrophic consequences.
To mitigate these concerns, researchers are advocating for a phased approach to studying SAI, similar to clinical trials in medicine. The goal is to develop robust models and gather evidence through small-scale experiments before scaling up the process.
Phase one of such an experiment would involve releasing tiny amounts of sulfur dioxide into the stratosphere, carefully measuring its evolution using various instruments. This amount would be far too small to affect the climate but would allow researchers to study how aerosols form and behave.
If successful, phase two could involve larger-scale experiments, potentially involving tens or even hundreds of times more particles than in phase one. These experiments would aim to determine key factors such as how aerosols mix and distribute in the stratosphere.
The proposed research framework includes a post-licensure trial, where small deliberate cooling occurs under constant observation and strict oversight. This slow and reversible deployment could provide the evidence policymakers require if governments decide to move forward with SAI.
Critics of the idea point out that we don't need to reinvent the wheel. Medicine has solved the "too risky to test" dilemma 60 years ago by codifying phased clinical trials. A similar structured program for SAI would help build confidence in its predictions and identify areas where current projections are robust – or require refinement.
Outdoor research is not a slippery slope to deployment, but rather how we make sure that any future decision – whether to move forward, reject the idea entirely or refine it – is based on facts, not fear or wishful thinking. The real danger isn't asking the question; it's waiting too long to learn the answer.
Experts Dakota Gruener and Daniele Visioni believe that carefully designed experiments can reduce both scientific uncertainties and political risks. By accelerating the pace of sunlight reflection research, they hope to provide policymakers with the evidence needed to make informed decisions about this potentially game-changing technology.