Last week, China, the world's top greenhouse gas emitter, announced it was opening a national carbon market, a type of emissions trading system. Under the system, industrial units that cannot meet annual government-set greenhouse gas emissions targets will have to purchase surplus targets from units that met theirs.
A pilot emissions trading scheme (ETS) for particulate matter pollution implemented in Surat, Gujarat in September 2019--the world's first such programme--works similarly. Industries participating in the pilot scheme reduced their particulate matter pollution by 24% (with an 8% margin of error), compared to industries that continued to be under the business-as-usual regulation