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Climate Change

Science Supporting Policy in California and Beyond

Photo: Tractor kicking up dust in a field

Professor Susan Handy develops strategies for addressing automobile dependence in the United States. (Sylvia Wright/UC Davis)

Solutions and Human Adaptation


How can changes in travel, or the way communities develop, reduce climate change?

Deb Niemeier, Director, John Muir Institute of the Environment and the UC Davis-Caltrans Air Quality Project, develops models that help policymakers understand how built roads and public travel preferences can help to reduce vehicle emissions. As a professor in civil and environmental engineering, she has studied roadside emissions, examined automobile dependence and its relationship to socio-economic characteristics, and evaluated the effectiveness of transportation control measures that help to reduce traffic delay--thereby improving air quality. Her classes often highlight contemporary policy issues and their relationship to theoretical models, allowing students to conduct real world policy evaluations. Recent classes have included "The Governor's Plan for Investing in California Infrastructure" and "AB32: Transportation and Air Quality". As associate vice chancellor for research, Niemeier nurtures new broad campus projects in interdisciplinary policy and environmental law, environmental justice, road ecology, "green" entrepreneurs, and climate change.

Can land use policies reduce automobile dependence and thus greenhouse gas emissions?

Susan Handy, environmental science and policy, studies the connections between transportation, land use, and travel behavior. Automobile dependence is an important contributor to greenhouse gas emissions, and evidence shows that automobile use is associated with land use patterns. Evidence shows that residents of communities with higher densities, greater land use mix, and better pedestrian infrastructure drive less than residents of more conventional suburban communities. Handy has examined the impact of neighborhood design on driving and walking in studies in Northern California and in Austin, TX. She has prepared reports on automobile dependence for the European Conference of Ministers of Transport and written on the issue for the American Planning Association. Her publications can be downloaded from the Institute of Transportation Studies web site.

What can governments and citizens do to reduce greenhouse gas emissions?

Stephen Wheeler, landscape architecture, studies theory and practice of sustainable development at various levels of planning, including local government, with emphasis on land use, transportation, and urban design. He studies regional government with emphasis on urban growth management, and state government with an emphasis on climate change planning frameworks. He is currently preparing a comparative study of the approaches taken by the 29 states that have developed climate change plans.

Why do people travel so much, and how can we reduce travel and greenhouse gas emissions?

Patricia Mokhtarian, civil and environmental engineering, studies travel attitudes and behavior from a variety of perspectives. One key theme has been the impacts of telecommuting, internet shopping and other communication technologies on transportation. Through a number of different studies, she has determined that the net impact of such technologies will be to generate more travel rather than to reduce it. Another theme of her work has been the impact of residential location on travel behavior. For example, do people who live in denser and mixed-use neighborhoods drive less and walk more because the built environment itself prompts them to do so, or is it because the kinds of people who want to travel that way are more likely to choose to live in such neighborhoods? If it's the latter, then policies attracting "auto-dependent" people to live in such areas (e.g. because of financial incentives) may not have the desired effect on travel. Finally, a third theme focuses on attitudes toward travel itself. Mokhtarian has identified a number of compelling reasons why people travel more than they must (curiosity, variety-seeking, control, independence, escape, health), and is analyzing the circumstances under which those motivations are strongest.

What should be the optimal timing of investment in climate change control policies and what are the economic costs of no action or delayed action?

Y. Hossein Farzin, economics, has examined the optimal timing of investment in climate change policies and the economic costs of delaying action. He has addressed the economic aspects of climate change and the use of economic disincentives such as carbon taxes and carbon permits. His publications have described the economic obstacles and prospects of the Kyoto treaty. Farzin has expertise in environmental regulations and market structure, environmental regulation and uncertainty, and linkages between environmental and economic development.

How is climate change related to environmental justice?

Julie Sze, Director, Environmental Justice Project, John Muir Institute of the Environment, examines the relationship between environmental justice and climate change. Climate change poses additional threats to public health that may be expected to have more severe impacts in communities which are disinfranchised due to race, gender and economic inequities. Her graduate student monitors the California Air Resources Board Global Warming Environmental Justice Advisory Committee that "seeks to provide helpful, workable recommendations on how best to ensure and encourage public engagement in the implementation of the (AB32) Act and how best to reduce greenhouse gas emissions while maximizing the overall societal benefits, including reductions in other air pollutants, diversification of energy sources, and other benefits to the economy, environment, and public health."