The US Army is currently taking steps to reduce its carbon emissions in order to make its operations more environmentally sustainable. This initiative aims to decrease the Army's climate-warming carbon dioxide emissions by 30 percent by 2015. Deputy assistant secretary for environment, safety, and occupational health, Tad Davis, is leading the effort to track and reduce the Army's carbon 'bootprint' in locations such as Iraq, Afghanistan, and training ranges in the United States. "We aim to reduce emissions and decrease energy usage from fossil fuels while promoting environmental sustainability across all Army bases," stated Davis. The initiative began at Fort Bragg in North Carolina in 2001, where changes were made to the setup of training ranges. Previously, mock towns and villages for combat training at Fort Bragg cost up to $400,000 each to build. Davis stated that now shipping containers, which cost approximately $25,000 each, are being made from recycled truck-sized containers to avoid adding to solid waste. During the early years of the Iraq war, convoys were at risk from IEDs due to the long supply chain from Kuwait to the battlefield, with much of the cargo being fuel. Davis emphasized the importance of reducing fuel consumption on the front line to minimize the risk to soldiers, suggesting the use of renewable energy sources such as wind or solar power instead of diesel generators to decrease the number of supply convoys targeted by IED attacks. A recent survey of U.S. forward bases in Djibouti, Kuwait, Iraq, and Afghanistan revealed that a significant amount of power, at least 85 percent, was being used for air conditioning. This was necessary for providing comfort for sleeping and keeping communications equipment cool. The typical poorly insulated tents and temporary buildings in these areas made it difficult to keep them cool. To address this issue, foam insulation sprayed directly on tents was found to reduce energy loss by 45 percent. However, reducing greenhouse emissions from Army vehicles poses a different challenge, as making vehicles lighter to save fuel could compromise troop protection. Davis said that there is new technology developing which allows for lighter armor, suggesting that there may be an increase in hybrid vehicles in the military fleet in the future. He also expressed doubts about the US military being one of the largest greenhouse gas emitters in the world. The Army has begun tracking carbon emissions at Fort Carson, revealing that the base emits approximately 205,000 tons of carbon dioxide per year, similar to a town of 25,000 people. The system created by Enviance, a company based in California, will eventually be implemented in all Army bases. It is currently being used by corporations and utilities in 45 countries to monitor adherence to environmental and safety regulations, according to Enviance's president Lawrence Goldenhersh.