Policy Documents

Reducing Greenhouse Gases from Personal Mobility: Opportunities and Possibilities

November 29, 2011

Federal, state and local governments are considering or have implemented policies that seek to reduce human emissions of greenhouse gases (GHGs). This study seeks to assess the relative merits of specific policies intended to reduce GHGs from automobiles. (It does not consider whether or not reductions in GHGs are actually desirable.)

Current policies and proposals for reducing GHGs from autos would require implementation of strong land use restrictions (compact development). Technological alternatives for reducing GHG emissions have received considerably less attention. 

We estimated the costs of a range of such policies, beginning with government documents and reports prepared in cooperation with organizations advocating behavioral policies. Behavioral strategy costs and the costs of technological strategies were evaluated against the upper limit on acceptable costs for GHG emissions reductions as estimated by the Intergovernmental Panel on Climate Change. (This upper limit, $50/ton of carbon dioxide equivalent in 2020–2030, is used because of its source, not because we endorse that value).

GHG emission reduction goals cannot be realistically achieved by applying “fair share” quotas to economic sectors. Depending on the availability of strategies requiring expenditures less than $50 per ton, a sector might account for more or less of the eventual reduction in GHG emissions than its share of total emissions. A “fair share” approach would require some unnecessarily expensive strategies, while neglecting some less costly strategies. As an example, IPCC research indicates that transportation represents 23% of global emissions, yet estimates the economic potential for GHG reduction in transport to be less than one-half that figure (10% or less). 

Research by McKinsey & Company and The Conference Board found that substantial GHG emission reductions can be accomplished cost-effectively while “maintaining comparable levels of consumer utility” (an economic term denoting quality of life). This means “no change in thermostat settings or appliance use, no downsizing of vehicles, home or commercial space and traveling the same mileage” and “no shift to denser urban housing.”

Sustainability is often narrowly defined as pertaining to the environment, such as GHG reduction. However, environmental sustainability also depends upon achieving other dimensions of sustainability, including financial, economic and political.