The UN has finalized rules on a single global greenhouse-gas standard for cities that will allow mayors to calculate with some precision how much CO2 their cities are releasing.
The World Bank, the UN Environment Program (UNEP) and UN-HABITAT launched the "Global Greenhouse Gas Standard" this week at the World Urban Forum in Rio de Janeiro, Brazil.
"The common standard is a critical first step for cities to better understand their greenhouse gas emissions," said Zoubida Allaoua, World Bank director for finance, economics, and urban development.
"With this knowledge, cities can better target policies and inform their citizens."
Cities are responsible for two-thirds of global energy use and more than 70 percent of heat-trapping emissions, according to most estimates.
"With the majority of the world’s population now urbanized, cities will be at the forefront of efforts to reduce greenhouse gas (GHG) emissions," the 11-page draft of the new rules states.
Jennifer Ewing Thiel, the U.S. tools and technical innovation director at ICLEI-Local Governments for Sustainability, an international group of local and regional governments, called the UN-World Bank announcement a positive step. ICLEI developed the first high-level emissions protocol for cities, called the International Emissions Analysis Protocol, and each of its offices worldwide is now developing nation-specific systems. In the U.S., "hundreds of local governments" are using the ICLEI standard, Thiel said.
Still, before this week, there was no internationally accepted form for reporting carbon footprints of urban places. The idea of a common metric is to give cities a nudge to keep cutting carbon and allow them to compare efforts.
"These standards and protocols are really useful for measuring our emissions and managing our emissions and then also measuring our emissions reductions, which is really the main goal," Thiel said.
Once a city nails down its total greenhouse gas emissions, the next step is to create a comprehensive plan to reduce fossil fuel consumption. They will then, presumably, move to implementing energy- and money-saving measures, such as greener building design, cleaner energy sources and more efficient heating and cooling equipment.
Many cities and states have already come to understand that cutting back on carbon is an agent for saving money.
In Michigan, for example, a recent study by the Center for Climate Strategies found that a plan to curb statewide emissions would create a $25 billion net gain in the state’s gross product and create 129,000 jobs over 15 years. For its part, the city of Denver has already saved more than $800,000 a year from installing 48,000 energy-efficient LED traffic signals. Boston is predicted to save up to $4 billion a year from 48 planned green-building projects that are currently under review.
The new standard works by calculating emissions on a per capita basis. Viewed this way, New York, an extremely high-density city, produces 10.4 tons of CO2 per capita, while Denver, with a much lower density, produces more than double that at over 21 tons.
The standard has already been applied to 40 cities. The goal, according to UNEP, "is to eventually have all cities around the world represented."
The system builds on ICLEI’s protocol and is modeled after internationally approved guidelines of the UN Intergovernmental Panel of Climate Change (IPCC), which is used by the U.S. Environmental Protection Agency and many countries to report their greenhouse gas inventories to the UN climate body.
Emissions will be counted from a city’s energy sources, industrial production, transportation, farming, forestry and waste, among other sectors. It will count CO2 plus the five other Kyoto Protocol gases, including methane and HFCs.
But cities, like nations, have an extra complication — how to cover the emissions of goods and services that get used up by their residents but are located beyond their borders.
"It is impractical to quantify all of the emissions associated with the myriad of goods and materials consumed in cities," the rules state.
The new standard at least claims to try. For instance, cities must detail emissions from electricity generation that is located outside urban confines but is used to power local homes and business. Emissions from planes and ships that carry passengers or goods away from cities are also inventoried.
The "out-of-boundary" emissions accounting practice comes from the Greenhouse Gas Protocol, the carbon inventory gold standard, especally for corporate accounting. The system was developed in 2004 by the World Resources Institute (WRI) and the World Business Council for Sustainable Development (WBCSD) for the U.S. voluntary carbon market.
According to WRI, some two-thirds of Fortune 500 firms use the Greenhouse Gas Protocol to account for global warming emissions in their corporate social responsibility reports.
With cities getting on board with emissions counting and cutting, advocates say the world has a shot at meaningful greenhouse gas reductions by 2020.
"The Copenhagen Accord, for which 110 countries representing over 80 percent of global emissions have expressed support, remains a work in progress," said UNEP Executive Director Achim Steiner. "There remains an ambition gap between where we are and where we need to be in 2020 — bigger cuts by cities may be one route toward bridging this divide."