黃天福特聘研究員兼副主任(環境變遷研究中心)
While there have been fluctuations in the concentration of atmospheric CO2 through out geologic time, its rate of increase since the advent of the industrial revolution in about 1750 has been much accelerated. Thus, in the pre-industrial time between 1000 and 1750, the concentration of atmospheric CO2 varied only within a narrow range of 275 to 285 ppm, and without a definitive systematic increasing trend. In the next 200 years, it increased steadily by some 50 ppm, or at a rate of about 0.25 ppm/year. In the recent years, between 1995 and 2005, that rate of increase has accelerated dramatically to 1.9 ppm/year, or about eight fold of that in those previous 200 years (Forster et al., 2007).