300 miles. Starting September 26, about 200 cyclists, including myself, will embark on a 300 mile, 5-day ride from New York City to the steps of the Capitol in Washington, DC to promote awareness for climate change and to raise money for rails-to-trails conservancies and clean energy NGOs (http://www.climateride.org/ ). If I were to drive the same distance, using my beloved '93 Ford Probe (Ford Mustang Lite), my gas consumption would produce about 100 kilograms of carbon dioxide. Energy bars and a 9.5 kg bike can indeed take one very far and lower one's carbon footprint.
I hope to raise awareness for the exigent development challenge that is climate change. In the United States, with all the focus on domestic legislation and emission levels of OECD countries vis-a-vis the growing emitters in the developing world, such as China and India, we tend to lose sight of the fact that developing countries - especially ones that have contributed very little historically to the problem - will disproportionately suffer with climate change: 75-80 of the potential cost. More about this in our new World Development Report: Development and Climate Change [www.worldbank.org/wdr2010]
The salient charge for the development community remains: how do we decouple economic growth from greenhouse gas-intensive development when 1.6 billion people in the developing world currently lack access to modern energy? The World Bank has a burgeoning work program on climate change, which you can read about on the Bank's climate change website [www.worldbank.org/climatechange]
Last summer, I rode 300 miles in the Sierra Nevada Mountains of California, where the evidence of climate change is conspicuous: glaciers have lost over 50% of their surface area this past century. Colleagues of mine have determined that 48 of 53 bird species studies have shifted their range in response to climate change.
So, while I am on my bike ("Burning Embers") over the next several days, dodging cabbies in NYC, wetlands and the Soprano Family in New Jersey and errant horse-drawn buggies in Lancaster County, Pennsylvania, you can follow me at: www.twitter.com/WorldBankBiker 
Much more has to be done. But every journey begins with a single pedal.