2004
Aspen plays host to the first AREDay (Aspen Renewable Energy Day, later changed to American Renewable Energy Day.)
2005
City Council unanimously passed an city ordinance that mandated that businesses separate their trash and use one of the three local commercial trash haulers at their own expense.
The City of Aspen’s Canary Initiative was created to address the climate challenge and provide leadership in reducing greenhouse gas emissions locally. The City of Aspen’s Climate Action Plan calls for Aspen to reduce greenhouse gas emissions 30 percent by 2020 and 80 percent by 2050, below 2004 levels.
2006
The Aspen City Council approved plans for a $737,000 recycling center between Obermeyer Place and Rio Grande Park.
2008
Telluride edges out Aspen in a three-month challenge to see which town could use thee most reusable bags in groceries stores. Telluride used 29,351, which Aspen used 26,793.
2010
The first Aspen Eco Fest is launched. The event is a cultural, education, and environmental festival.
On Oct. 10, 2010 (10/10/10) the city of Aspen hosted the first-ever Climate Action Party. Participants were able to choose among several carbon emission-reducing events, including: tree planting, forest restoration, DIY solar ovens, build a garden at City Hall, energy efficiency canvassing and political action.
2011
The city of Aspen began drilling for a geothermal test well project next to Prockter Open Space to see if there is potential to utilize geothermal energy.
The city of Aspen introduces its Aspen Tap program, strategically installing filling stations around town that provide filtered tap water to the public. The program is designed to discourage the use of bottled water.
2012
In March, Aspen’s Car To Go, a membership-based car-sharing program, became the first such municipal car-sharing program in the U.S. to have a completely hybrid fleet of vehicles.
On May 1, the city of Aspen and the town of Carbondale will institute a single-use plastic bag ban at grocery stores, and a 20-cent fee for paper bags. Basalt recently overturned an ordinance that would have also seen a bag been there.