By slashing food waste and improving waste management and recycling, 23 global cities and regions representing 150 million people pledged Tuesday to significantly cut the pollution-causing garbage they generate by 2030.
Places like New York, Tokyo, London, Paris and Sydney vowed to "cut the amount of waste generated by each citizen 15 percent by 2030," said a statement from C40 Cities, a global network dedicated to fighting climate change.
They will also "reduce the amount of waste sent to landfills and incineration by 50 percent and increase the diversion rate to 70 percent by 2030," according to the declaration.
The goal of the "Advancing Towards Zero Waste Declaration" is to avoid the disposal of at least 87 million tons of waste by 2030.
Waste is becoming one of the leading threats to the environment, increasing faster than any other pollutant.
Each year, 1.3 billion tons of wasted food is sent to landfills where rotting scraps send the potent heat-trapping greenhouse gas methane into the atmosphere.
Improving waste and material management around the world globally could reduce global emissions by 20 percent, and are "essential" to delivering on the goals of the 2015 Paris climate accords and keeping global temperature rise below 1.5 Celsius, said the C40 Cities statement.
The announcement was released ahead of the Global Climate Action Summit in San Francisco in mid-September.
Signatories include Auckland, Copenhagen, Dubai, London, Milan, Montreal, New York City, Newburyport, Paris, Philadelphia, Portland, Rotterdam, San Jose, San Francisco, Santa Monica, Sydney, Tel Aviv, Tokyo, Toronto, Vancouver Washington DC, and the regions of Navarra and Catalonia.
Specific steps include reducing food waste and facilitating safe food donation.
Participating areas may encourage separate collection of food scraps that could be used for compost, and supporting local policies like sustainable procurement and boosting awareness and use of recycling for construction and demolition materials.
Areas may also support reductions or bans on single-use and non-recyclable plastics.
The signatories pledged to publicly report their progress every two years.
"Dramatically reducing waste will help curb carbon emissions while helping us build a fairer, cleaner and more livable city for all New Yorkers," said New York Mayor Bill de Blasio.
"We're proud to stand alongside other leading cities worldwide in taking ambitious steps to cut down on waste."