“There are substantial environmental, technical, and cost challenges in using carbon dioxide removal (CDR) at the scale needed to significantly reduce global warming…. [that make it] unlikely that CDR could be implemented rapidly enough or at sufficient scale to entirely avoid dangerous levels of climate warming in the near term.” (Pro, public letter, February 27, 2023)
“The speculative possibility of future solar geoengineering risks becoming a powerful argument for industry lobbyists, climate denialists, and some governments to delay decarbonization policies.” (Con, open letter: January 17, 2022)
It is hard, contradictory, and hypocritical to be “green” as conventionally defined. I am reminded of a comment in the 1970s that noted “a general frustration generated by the energy crisis: every solution to the problem seems to create tremendous problems of its own.”
Unintended consequences of government intervention is a category unto itself. Today’s climate/energy policy has created many eco-sins from just about anyone’s viewpoint.
Wind and solar mar the landscape with heavy infrastructure that produces energy at a fraction of rated capacity. There are well-documented rare-earth mining issues. There is corporate cronyism and programs such as carbon capture and storage that is greenwashing with taxpayer green. There is a climate elite jetting around to global climate conferences. And most recently, wind turbines built in sensitive (homesteaded?) areas attracted the civil disobedience of none other than Greta Thunberg.
There are the biomass and biofuels industries that could well manufacture energy that is carbon positive. Closed nuclear plants promise more fossil fuel usage, not less. And finally, the policies of less abundant, more expensive, and and less reliable energy have turned millions to wood and dung burning for their daily bread.
One has to wonder, as James Hansen once did, whether the whole anti-CO2 movement is net positive, not net negative, with overall emissions.
Geoengineering, a last gasp of the (growing) climate industrial complex, premised on a climate crisis that is not, is a growing area of eco-tension. And it got a big boost yesterday. An open letter “from more than 60 physical and biological scientists studying climate and climate impacts about the role of physical sciences research, including the central role it plays in effective governance,” is introduced as follows:
Given the severity of climate change, scientists and scientific bodies have recommended research on potential approaches to increasing the reflection of sunlight (or release of long wave radiation) from the atmosphere, referred to as “solar radiation modification” (SRM), to slow climate warming and reduce climate impacts. In particular, this research is important for understanding their potential for responding to climate change rapidly, in order to reduce the dangers to people and ecosystems of the climate warming that is projected to occur over the next few decades while society reduces greenhouse gas emissions and concentrations in the atmosphere.
Continuing, the letter
… affirms the importance of proceeding with responsible research to objectively evaluate the potential for SRM to reduce climate risks and impacts, to understand and minimize the risks of SRM approaches, and to identify the information required for governance. While not addressed in this letter, any decisions to actively use SRM would also need to be preceded by work to address the complex legal, ethical, and political aspects of making such a decision.
Of course! Go slow at first. But, as per Milton Friedman, beware of “the tyranny of the status quo” where the introduction of a new program (a qualitative change) results in future debates over how much to increase its budget (quantitative change). The climate industrial complex is after a new perch.
Just Say No!
Expect a big backlash. Last year, Solar Geoengineering Non-Use Agreement (SGNUA) went all-out against geoengineering. So-called solar radiation management or modification (SRM) technologies intended to lower global temperatures are “artificially intervening in the climate systems of our planet,” SGNUA stated. 
And, as bad:
The speculative possibility of future solar geoengineering risks becoming a powerful argument for industry lobbyists, climate denialists, and some governments to delay decarbonization policies.
It is hard being green.
 This is the ‘deep ecology’ view that led John Holdren and Paul Ehrlich to write in the mid-1970s:
[T]here can be scant consolation in the idea that a man-made warming trend might cancel out a natural cooling trend. Since the different factors producing the two trends do so by influencing different parts of Earth’s complicated climatic machinery, it is most unlikely that the associated effects on circulation patterns would cancel each other.
Source: Ecoscience: Population, Resources, Environment (W. H. Freeman: 1977 [third edition]), p. 686.