CH mitigation potentials from China landfills and related environmental co-benefits.

China's CH emissions from 1955 existing (old) and 495 planned (new) landfills are estimated and projected by adopting a bottom-up method, targeting a 2012 baseline year and a 2030 projected target year. Nine key CH mitigation measures are proposed for the CH mitigation assessment from landfills. Approximately 0.66 million metric tons (Mt) of CH and 1.14 Mt of CH will be released, respectively, from new and existing landfills under a 2030 business-as-usual (BAU) scenario, which is 23.5% lower than a U.S. Environmental Protection Agency estimation. It is estimated that 0.60 and 0.97 Mt of CH can be reduced under new policies (NP) and low-carbon (LC) policy scenarios, respectively. The combined biocover and landfill gas collection and flaring system is the most promising mitigation measure, while mechanical biological treatment and mineral landfill also contribute substantially to CH reduction. The odor-affected population under NP and LC scenarios will decrease by 39.5 and 64.2%, respectively, when compared to the 2030 BAU scenario. The LC scenario is a recommended policy for meeting China's nationally determined contribution targets and reducing the not-in-my-backyard impact due to this policy's significant reduction of CH emissions.