The Science is Settled if you Halt All Research

This diagram depicts the key aerosol, cloud, dynamics, and radiation processes in the marine boundary
layer (left) and the MCB approach using ship-based generators to produce fine sea-salt aerosol droplets
(right). The droplets are lofted into clouds by updrafts, where they increase droplet concentrations, extending
the reflectivity coverage and lifetime of the clouds. Credit: After Sorooshian et al. 2019. (NOAA)

If global warming is an "existential threat" to mankind, why aren't all solutions being investigated? Your humble blogger can't help but ask this question when the City of Alameda killed a small cloud-brightening research project. [bold added]

The project, led by the University of Washington, involved scientists using specialized machines to spray sea salt particles into the air above the USS Hornet. The research was part of a larger push toward someday using salt particles to brighten low-lying clouds, thereby reflecting enough sunlight away from the Earth to decrease the warming effects of climate change.

Last month, Alameda ordered researchers to stop the project on the basis that it violated the city’s lease with the USS Hornet. The city then hired biological and hazardous material consultants to evaluate the experiment. The consultants concluded that it presented no measurable risk to the health of the surrounding community or environment.

The City of Alameda was pressured by environmental groups who not only insist on the righteousness of their goals but also that the only method to halt global warming is through the elimination of fossil fuels. Per the Center for International Environmental Law:

“We cannot geoengineer our way out of the climate crisis, what we need is to focus on real and proven solutions, starting with a phase out of all fossil fuels,” Mary Church, the center’s campaign manager, said in the statement. The center added, “Deployed at scale, Marine Cloud Brightening would not reverse the climate crisis but create a different climate change potentially exacerbating droughts, hurricanes, and flooding far from the deployment site.”

According to the National Oceanic and Atmospheric Administration Marine Cloud Brightening holds promise as a way to "buy us enough time to reduce greenhouse gas emissions" but more studies are needed. There is currently no evidence that MCB will succeed or that it will be harmful either.

Anti-fossil-fuel advocates like to say that their prescriptions are "based on science", but they stop research that might further our understanding of the science. What are they afraid of?