emission factor

例句：

1. 1. The emission factor of carbon dioxide is a key indicator of climate change.
   二氧化碳的排放系数是衡量气候变化的关键指标。
2. 2. The government has set a target toreduce the emission factor of greenhouse gasesby 20%.
   政府已设定目标，到2020年将温室气体排放系数降低20%。
3. 3.To achieve this goal, we need toimprove our energy efficiency and reduce the emissionfactor of pollutants.
   为了实现这一目标，我们需要提高能源效率并减少污染物的排放系数。