One evening in the small village of Ashton Hayes in Cheshire, England, someone started a conversation about climate change and energy at the local pub. It was 2005. Two years later, residents had cut their carbon dioxide emissions and energy costs by 20 percent.
Wholemeal rye bread, lettuce and chard are some of the products on offer from the El Caminito urban vegetable garden at the small organic produce market in this southern Spanish city, with prices set in "comunes", one of more than 30 social currencies circulating in the country.