Cities urged to take strong actions in protecting world's remaining "carbon budget"

It's vital for cities to take strong actions in ensuring the world not to emit exceeding the remaining global "carbon budget," the amount of carbon dioxide (C02) that can still be emitted without causing dangerous climate change, a new report said Thursday.

Urban policy decisions before 2020 could determine up to a third of the remaining global "carbon budget" that is not "locked-in" by past decisions, said the report released by the C40 Cities Climate Leadership Group (C40), a global city alliance focusing on climate change.

Scientists have previously calculated that the world can emit a "carbon budget" of just 1,000 gigatonne (Gt) C02 to avoid a rise of 2 degrees Celsius in global average temperatures above the pre-industrial levels, and that 80 percent of this budget has been locked-in by investments or policy decisions that have already been made to build infrastructure such as fossil fuel power stations, highways and energy-hungry buildings.

The new report focused on the remaining carbon budget of 200 Gt C02 in the next 15 years and found urban infrastructure development could account for 31 percent of that budget.

It also showed that investing in modern and efficient infrastructure in the next five years will be four times less expensive than continuing to expand traditional high-carbon infrastructure now, and then having to replace it in the future.

"This report provides hope for the future because it shows that we don't just have to rely on the outcome of the critical COP21 Treaty negotiations (in Paris in December), but that mayors and city leaders in office right now have the opportunity to protect a large share of the world's carbon budget," C40 chair and mayor of Brazilian city Rio de Janeiro Eduardo Paes said in a statement.

As for what measures cities should be taken before 2020, Seth Schultz, C40 director of Research, Measurement & Planning, told Xinhua that reducing emissions from buildings and transport is vital in staying on a climate safe path.

Climate action in transport, for instance, ensuring condensed urban form, combined with more efficient vehicles and effective widespread public transport such as buses and bike sharing, could save up to 15 Gt CO2 by 2030, Schultz said.

More efficient building codes are also "a vital way" for city governments to reduce the emissions of buildings, he said.

"Together, action in cities could avoid locking in 45 Gt CO2 in cities by 2030. This is equivalent of eight times the current annual emissions of the United States," Schultz said. "Without strong action by cities, efforts to stay within the globally agreed carbon budget would be very difficult."

The report was launched at an event honoring international and U.S. mayors, including those from many C40 cities, which was held Thursday at the U.S. State Department. The event served as the culmination of the "Our Cities, Our Climate" initiative, a partnership between the U.S. State Department and Bloomberg Philanthropies. Endit