Boston composting initiative aims to help reduce city’s greenhouse gas emissions

The city could convert about 638,000 tons of its annual churn of about 1.2 million tons of waste to compost or to recyclable material under a new plan from Mayor Marty Walsh.

The move is part of a larger effort to render Boston carbon-neutral by midcentury. Approximately 6 percent of Boston’s greenhouse gas emissions come from the city’s discarded materials, according to a release from the Walsh administration about what it’s calling its Zero Waste Plan.

Overall, the administration wants to increase the share of compostable or recyclable waste—that would otherwise end up in a landfill—to 80 percent by 2035 from around 25 percent today, and then to nearly 100 percent by 2050.

Part of that would be through curbside composting of food waste. Boston would charge residents for the service through subscriptions—though the Walsh administration says the city would try to subsidize some of the cost. That subscription cost has not been determined, though the service could roll out this fall. The administration says it will seek “a local partner or partners” to provide the service through an imminent request for proposals.

A subscription model would be in contrast to neighboring Cambridge, which has provided free citywide curbside composting pickup since April 2018 for buildings with fewer than 13 units (it’s expanding to larger buildings beginning this year).

Cambridge’s goal in composting is similar to Boston’s, and it appears to be working. The city wanted to reduce residential trash disposal 30 percent by 2020 and 80 percent by 2050. So far, the city’s trash tonnage has dropped 8 percent.

But Boston is about six times the population of Cambridge—thus the subscription model, which other cities nationwide also use. Boston is also planning a free pickup service for surplus textiles, such as linen and clothes—that too is supposed to roll out in the fall through a partnerhip—and plans to expand its recycling efforts in general.

That includes through a $250,000 pilot program grant from the Coca-Cola Foundation, which the city will use in part to add recycling bins, signage for recycling, and collection services to parks. Boston was one of seven U.S. cities the foundation picked this year for the pilot.

The city is confident the composting push will work, and that it in particular is necessary. It estimated that around 36 percent of what Bostonians throw away is, in fact, compostable material, including yard waste such as grass clippings as well as leftover food.

“Preparing Boston for climate change means ensuring our city is sustainable, both now and in the future,” Mayor Marty Walsh said in a statement. “We need to lead, and design city policies that work for our residents, and for the environment and world we depend upon. These initiatives will lead Boston towards becoming a zero waste city, and invest in the future of residents and generations to come.”