Gas emissions calculator launched

The United Nations launched yesterday the first common system of calculating the amount of greenhouse gases produced in a given city and by specific sector or time, allowing cities to compare their performances and analyse differences.

The UN Environment (UNEP), UN Human Settlements Programme (UN-HABITAT) and the World Bank jointly launched the Global Greenhouse Gas Standard for cities at the World Urban Forum in Rio de Janeiro.

The Greenhouse Gas Standard calculates emissions on a per capita basis. For example, greenhouse gas emissions are 4.20 tons of carbon dioxide per capita in Barcelona, Spain, 10.6 in Bangkok, Thailand, and 17.8 in Calgary, Canada.

The new common standard also takes into account cities' primary energy sources, climate, means of transportation and urban form.

As a result, a high-density city like New York produces 10.4 tons per capita, while another United States city, Denver, emits 21.3 tons per capita.

The new common standard also allows cities to compare their emissions over time, across cities and in specific sectors such as energy, transportation or waste.

At yesterday's launch, the organizers stressed that city mayors and other urban leaders, business and civil society recognize the need to act to reduce climate change in cities.

"In reducing greenhouse gas emissions, cities are part of the solution: city officials are discovering new ways to get people out of cars and into rapid transit buses."