Biogas from trash is helping to drive Rio de Janeiro towards its C40 Cities initiative goals. That means the city has pledged to slash emissions by 20 percent of its 2004 volume by 2020. But that won’t be the end of the matter. C40 Cities say they aim to be carbon neutral by 2050 and that will mean producing no more greenhouse gas than they are able to offset.
Emissions Nearly to Zero by 2050
Early on, Rio de Janeiro pinpointed a little-recognized but major source of greenhouse gas as an area where it could get significant results quickly – trash.
Organic Waste an Important Source of Greenhouse Gas
Cities produce a great deal of organic waste, and in landfills, this waste decomposes under anaerobic conditions, producing methane gas. As a greenhouse gas, methane is 28 times more harmful than carbon dioxide, making it an important source of city emissions and a major contributor to climate change.
Rio de Janeiro transports its domestic and industrial organic waste to a treatment plant 60 kilometers outside the city where organic waste’s potential to produce methane is put to good use. The plant receives 10,000 tons of waste daily, collects biogas from the waste, purifies it and sells it to the state gas company or to industries.
However, the plant is not the only waste management initiative to reduce city greenhouse gas production. The city reports two thirds of its reduced emissions as being attributable to good waste management practices.