We drive too much, and a new report says that unless we start to reduce urban and suburban sprawl the increasing emissions from our expanding vehicle use will negate other technology-based efforts to combat global warming.

The report by the Urban Land Institute, Smart Growth America and other national and state organizations warns that, if sprawling development continues, the total miles driven will increase 59 percent by 2030, and the carbon emissions that increase produces will overwhelm expected gains from vehicle efficiency and low-carbon fuels.

The report released today in Washington, D.C., recommends that metropolitan growth strategies are needed to curb automobile emissions, including an increased focus on "compact development" areas. Such developments are close to the urban core, denser than sprawling suburban development, and provide a mix of uses that give residents an option of walking or biking or shorter drives to business, commercial and recreational destinations.

"The impact of smart growth is profound, not only because of the increased miles driven by so many people but also because most of those people are also spending a lot more time stuck in traffic, moving slowly if at all, while the gas keeps burning," said Brian Hill, president of the Pennsylvania Environmental Council.

"Being able to spend less time behind the wheel will benefit our health, our pocketbooks and the environment. We urge Gov. Rendell and our state legislators to make smart growth a key strategy to mitigating global warming in Pennsylvania."

Pennsylvania residents are driving more than ever before -- up 50 percent since 1980 -- causing increases in vehicle emissions which account for roughly one-third of all emissions of carbon dioxide, a greenhouse gas that fuels global warming. Only part of that increase is the result of population growth.