emission
noun
ENVIRONMENT uk/ɪˈmɪʃən/ us [ C, usually plural ]
an amount of something, especially a gas that harms the environment, that is sent out into the air:
emissions of sth The bill is intended to lower emissions of greenhouse gases.
cut/reduce/limit emissions Many countries are reluctant to cut emissions if it means sacrificing economic growth.
emission cuts/reductions/control
California's emissions standards would cut global warming emissions nearly 30% by year 2016.
[ U ]
the act of sending gas, heat, light, etc. out into the air:
Hybrid vehicles reduce the emission of pollutants by about 20%.