Dive Brief:

• Twenty-seven of the largest global cities report they are no longer increasing their greenhouse gas (GHG) emissions, according to an analysis by climate group C40 Cities. The U.S. cities included on the list are Boston, Chicago, Los Angeles, New Orleans, New York, Philadelphia, San Francisco, Washington, DC, and Portland, OR.
• The cities have reduced their greenhouse gas emissions by at least 10% since their respective peaks. To qualify as having reached peak emissions, the high point must have occurred at least five years ago to confirm a long-term trend instead of an anomaly.
• Some of the actions the cities took to reduce emissions include improvements to the electric grid and energy consumption, promoting cleaner transportation options and improving waste management. 

Dive Insight:

All of the 27 global cities named as having reached peak emissions are part of the C40 climate action group, which aims to uphold the principles in the Paris Agreement. C40 has 73 member cities that have committed to being carbon neutral by 2050.

One requirement cities must meet to make the peak emissions list is a publicly stated commitment to further reducing emissions. In addition to the 27 listed cities that reached their peak by 2012, C40 indicates quite a few others will reach peak emissions by 2020. The group notes that is an important milestone because a number of scientists believe emissions must peak by 2020 and then decline sharply to mitigate further climate change impacts.

The group points out the cities listed are some of the largest in the world and achieved reductions in emissions even as populations and economic development increased.

"To prevent the worst impacts of climate change, we have to cut greenhouse gas emissions even as the population grows. Cities are showing that it can be done — and that the same steps they're taking to reduce their carbon footprint are also strengthening their local economies, creating jobs, and improving public health," Michael Bloomberg, UN Secretary-General’s Special Envoy for Climate Action and President of the C40 Board, said in a statement. 

C40 cities have committed to their own climate action plans beyond what their countries have done. This is especially true for cities in the United States, which President Trump pulled from the Paris Agreement.

"As the federal administration rolls back critical environmental protections, San Francisco continues to lead in the fight against climate change," San Francisco Mayor London Breed said in a statement. "San Francisco is committing to reducing landfill disposal by 50% by 2030 and ensuring all of our buildings are net-zero emissions by 2050.'