"Intensity" targets: pathway or roadblock to preventing climate change while enhancing economic growth?

After establishing the operative definitions of greenhouse gas emissions "intensity" targets and "absolute" targets for greenhouse gas emissions limits, we identify examples of these approaches in current laws and policies. We focus in particular on the US experience with the sulfur dioxide emissions "cap and trade" program as an example of the use of an "absolute" target approach. We compare and contrast this example with "performance standard" programs under the US Clean Air Act and the Corporate Average Fuel Economy standards for motor vehicles, which embody the emissions rate or "intensity" concept. These case studies give us insights into the pros and cons of the intensity versus absolute approaches.Moving from retrospective to prospective, we consider the possible application of alternative absolute and intensity targets (IT) to global, national and firm-level emissions. We then identify criteria for evaluating the use of "intensity" targets as a tool for achieving both environmental and economic goals. These include success in limiting climate change, achieving cost certainty and manageability, providing flexibility for public and private sector decision-makers in responding to new information, stimulating technological progress and sustaining a global climate regime.© 2003 Elsevier Ltd. All rights reserved.