What do you think should be the two or three highest priority political outcomes of the United Nations Conference on Sustainable Development (Rio+20), scheduled for Rio de Janeiro in June 2012?
It is clear that it will never be possible for everyone living in the cities of the South, especially in the rapidly growing mega-cities, to be connected to conventional water and sewerage mains. This technology allows homeowners to have hygienic and convenient on-site sanitation.
The reduction of CO2 emissions constitutes one of the largest challenges of the current era. Sustainable transportation, and especially cycling, can contribute to the mitigation of CO2 emissions since cycling possesses an intrinsic zero-emission value. Few studies have been conducted that appraise the CO2 reduction potential of cycling. Opportunity costs enable the estimation of avoided CO2 emissions resulting from bicycle trips. The methodology developed in this research allows the attribution of a climate value to cycling by substituting bicycle trips with their most likely alternative transportation modes and calculating the resulting additional CO2 emissions. The methodology uses data on the current modal shares of cycling mobility, the competition of cycling with other transportation modes, and CO2 emission factors to calculate the climate value of cycling. When it is assumed that the avoided CO2 emissions of cycling mobility could be traded on financial carbon markets, the climate value of cycling represents a monetary value. Application of the methodology to the case of Bogotá, Colombia — a city with a current bicycle modal share of 3.3% on a total of 10 million daily trips — results in a climate value of cycling of 55,115 tons of CO2 per year, corresponding to an economic value of between 1 and 7 million US dollars when traded on the carbon market.