An estimated 40 percent of carbon dioxide pollution in the United States comes from energy used in homes. In Portland, Oregon, the Bureau of Planning and Sustainability wanted to reduce greenhouse gas emissions in the city while bettering the economic and social development of local residents and businesses. In 2009, stakeholders came together to draft a plan designed to provide energy upgrades to 500 Portland homes and cut energy consumption by 10 to 30 percent using an innovating financing model to eliminate the upfront costs that deterred homeowners from pursuing environmentally-friendly energy retrofits. Led by Derek Smith, a sustainability expert with a record of working in the private, public, and non-profit sectors, collaborators came together to create Clean Energy Works Portland (CEWP), an innovative program that used a revolving loan to finance upgrades, working with local contractors to add high-quality jobs to the economy which resulted in a reduction of twenty percent or greater energy consumption in most participating homes.