Recently evidence shows that the global concentration of CH<sub>4</sub> is increasing by about 1% per year. The average worldwide tropospheric mixing ratio of CH<sub>4</sub> has increased from ...Recently evidence shows that the global concentration of CH<sub>4</sub> is increasing by about 1% per year. The average worldwide tropospheric mixing ratio of CH<sub>4</sub> has increased from 1.52 parts per million by volume （ppmv）in January 1978 to 1. 684 ppmv in September 1988.展开更多
文摘Recently evidence shows that the global concentration of CH<sub>4</sub> is increasing by about 1% per year. The average worldwide tropospheric mixing ratio of CH<sub>4</sub> has increased from 1.52 parts per million by volume （ppmv）in January 1978 to 1. 684 ppmv in September 1988.
