A number of readers have sent in links to articles suggesting that climate engineering may be feasible. For example, T.M.L. Wigley writes,
Future climate change may be reduced through mitigation (reductions in greenhouse gas emissions) or through geoengineering. Most geoengineering approaches, however, do not address the problem of increasing ocean acidity. A combined mitigation/geoengineering strategy could remove this deficiency. Here we consider the deliberate injection of sulfate aerosol precursors into the stratosphere. This action could substantially offset future warming and provide additional time to reduce human dependence on fossil fuels and stabilize CO2 concentrations cost-effectively at an acceptable level.
An article in National Geographic notes that Paul Crutzen proposed sulfate seeding as a solution. Prior to that, John Latham proposed "a plan to whisk up seawater to encourage cloud formation in the lower atmosphere, thereby reflecting radiation back into space."
I am not saying we should go full speed ahead with climate engineering. However, given the costs of achieving a significant reduction in atmospheric CO2 by altering fuel consumption, I think that the case for studying the climate engineering approach is pretty easy to make.