Marginal abatement cost estimates for non-CO₂greenhouse gases: lessons from RECLAIM

Recognizing the potential for over- as well as under-estimating the mitigation costs of non-CO2 greenhouse gases in an offset programme, this article examines the accuracy of cost estimates prepared by government agencies for the control of other types of emissions from small/medium sources via an offset programme. Specifically, analogy is made to the control of SOx and NOx controlled by California's Regional Clean Air Incentives Market (RECLAIM) Program. Even allowing for the energy crisis in 2000–2001 that drove up NOx emissions and control costs, it appears that the engineering cost methods used turned out to be generally accurate, defined as ±25%. Although such a finding does not ensure that the same results will apply to the case of non-CO2 GHGs, it certainly reinforces the growing literature on ex ante—ex post cost comparisons of environmental controls.