With gas prices topping $4 a gallon, Americans are changing how they get around. People in small towns are increasingly using the bus to get to work, go grocery shopping and visit friends.

According to APTA, bus ridership in communities with fewer than 100,000 residents rose a whopping 6.7 percent in 2007. In cities, commuters are choosing to take public transit instead of drive: subway use in Atlanta, for example, rose more than 10 percent this past year. In cities like Santa Fe, N.M., or Nashville, Tenn., commuter rail use doubled or even tripled. The story is the same across the country. But while Americans’ increasing use of transit is newsworthy, there is a part of the story that’s not getting told. Public transit does more than just save money for commuters; it plays a key role in the fight against climate change.

Shrinking footprints
By taking cars off the road, public transit has a direct effect on the greenhouse gas emissions that cause global warming: according to APTA, a single commuter taking public transit to work instead of driving can reduce carbon dioxide emissions by 4,800 pounds a year. People who are choosing to leave their cars in the driveway may not be aware of the broader impact of their choice, but it turns out that by taking public transit they are shrinking their personal carbon footprint. For people in a two-car household, the impact of leaving one car idle means the household is emitting 25 percent to 30 percent less carbon. Other ways to reduce carbon, such as switching to compact fluorescent light bulbs, while good to do, don’t even come close in terms of impact.

This is an important story in itself, because climate change has become more prominent in the news. The latest reports from scientists indicate that the consequences of global warming are happening faster than anyone expected. To take one example: according to the U.S. National Academy of Sciences, the growth rate of carbon emissions has tripled since 2000. This is faster than the most pessimistic scenario predicted by the Intergovernmental Panel on Climate Change (IPCC), the Nobel prize-winning, international climate science body. Another example: the National Oceanic and Atmospheric Administration has found that the tropical belt is expanding faster than the IPCC’s extreme scenario. Another: a third U.S. body predicts that the Arctic will be ice-free by 2040, not 2080.

Drastic consequences
The consequences predicted in the IPCC’s current models are drastic enough: they indicate that climate change could result in up to 250 million people facing water shortages by 2020; a decrease in crop yields of up to 30 percent; increasing severity of droughts, cyclones and heat waves; sea level rise, sea ice shrinkage and glacier loss; and huge species losses. Yet, scientists are now telling us that the consequences of global warming are potentially more severe and immediate than we had thought.

For the transit community, this means that there is a significant opportunity to tell the transit story in a new way. Local transportation planning must begin to incorporate transit’s climate benefits, and transit agencies should communicate these benefits to their customers.

At the national level, climate legislation will be one of the major items on the agenda for the new President and Congress as they take office in January. Thanks to transit and efficient land use patterns, which have resulted in the reduction of 37 million metric tons of carbon dioxide annually, increased funding for transit can and should be an integral part of that legislation. And, given the need to reduce our greenhouse gas emissions significantly, there is an equally important opportunity in making sure that the upcoming transportation authorization bill is consistent with larger climate goals.

Of course, the story doesn’t end with new legislation. The next step — designing smart, livable communities with transit at the center — is the real work, and it’s not easy. But transit’s contribution to the fight against global warming means that the transit community has the opportunity to help reshape American communities, while becoming part of the solution to one of the most difficult challenges facing the world today. That’s a story worth being a part of.