To the Editor:

Re “The Risks of Climate Engineering” (Op-Ed, Feb. 12):

Contrary to Clive Hamilton, a recent National Research Council study isn’t a “Plan B” that sits ready to be deployed as a substitute for deep cuts in emissions. Instead, at best geoengineering — defined in the article as “technologies aimed at deliberate, large-scale intervention in the climate system to counter global warming” — is a possible tourniquet that might crudely blunt, in an emergency, some of the most horrible effects of climate change.

When policy makers realize the severe flaws of this option, yet its possible need, they won’t lose the nerve to make essential cuts in emissions. Rather, they will probably redouble their efforts. Without research, however, this emergency option isn’t really available, nor are the badly needed mechanisms for governing geoengineering that will emerge only if countries do research and testing.

Contrary to Mr. Hamilton’s suggestion, moves by Russia to insert pro-geoengineering language in a recent United Nations assessment of climate science are not an ominous sign that governments are trying to deploy the technology. As one of the main authors of that report, I found much more worrisome the successful efforts by many other governments and NGOs to strip away all mentions of geoengineering.

DAVID G. VICTOR

La Jolla, Calif.

The writer, convening lead author for the United Nations Intergovernmental Panel on Climate Change, is a professor of international relations at the University of California, San Diego.