Some wonder if we could geoengineer our way out of climate crisis

Debates about accelerating research into solar geoengineering put the cart before the horse. First, we must accelerate our commitments to transition from fossil fuels to clean energy. And we need to develop mechanisms and norms of international cooperation to govern solar geoengineering technologies.

Solar geoengineering is far too globally impactful and risky to be researched and potentially deployed by the United States or other powerful nations, especially without robust international rules and safeguards in place. Such governance structures should be established through an inclusive process with diverse publics and stakeholders that includes climate-vulnerable and historically marginalized communities.

Peter C. Frumhoff

Belmont

Shuchi Talati

Washington, D.C.

Frumhoff is the director of science and policy at the Union of Concerned Scientists. Talati is a scholar in residence at the Forum for Climate Engineering at American University.

It takes resolve, not quick fixes, to tackle greenhouse gases

Raymond Pierrehumbert warns us that solar geoengineering is “a misguided bid for a quick fix” to the climate crisis “that might hold off the symptoms of global warming without confronting the necessary task of kicking the world’s fossil fuel habit.”

If the spigot is on and the bathtub is overflowing, mopping up is necessary, but it won’t solve the problem. To consider geoengineering while the tap is flowing freely — with no real limits on carbon emissions — is absurd. Not only are technological mop-ups unproven, but they also won’t solve the ongoing buildup of greenhouse gases.

Our minds are good at developing new technologies and carrying out research, but what is needed is willpower. It’s critical that we immediately slow carbon emissions by ending fossil fuel subsidies, oil and gas exploration, and drilling and fracking, and instead invest in renewables and technology for energy efficiency.

Taking on fossil fuel interests is a daunting but critical task. It’s time to turn off the spigot.

Marjorie Lee

Wayland

Climate models are not true evidence

While the arguments put forward by Raymond Pierrehumbert and David Keith give readers a fairly good idea of the issues involved in the current debate as to whether increased funding should be approved for researching solar geoengineering technologies, there is one major omission in both op-eds: the acknowledgement that the only way to begin to estimate the impact of solar geoengineering on the climate in regions all over the world is to run existing climate change models, of which there are several dozen.

Thus, when Keith talks about “evidence” and scientific findings, he does not make clear that there is no direct evidence for these impacts, only evidence from these very complex climate change models. He also does not make clear that these models do not agree with each other on the likely regional impacts of climate change. Indeed, they do not even agree with each other as to the average global impact on the temperature of climate change assuming the same amount of CO2 emissions.

Given that climate scientists have been working on building better computer-based models to make these calculations for