First, evidence of climate change has begun to convince almost all climatologists and many other informed observers that our current approach to producing and using energy is very dangerous to the biosphere. Because changes in carbon dioxide emissions, unlike pollutants such as sulfur dioxide and nitrogen dioxide, cannot be easily detected, and because of the multi-century persistence of CO2 in the atmosphere, the problem of reducing its level in the atmosphere is much harder to solve than are other environmental problems.
首先，气候变化的证据已经说服几乎所有的气候学家和许多了解内情的观察人士，让他们相信我们目前沿用的能源制造和使用方法会给生物圈的安全带来威胁。因为二氧化碳排放量的变化与二氧化硫和二氧化氮等污染物不同，很难被人们所轻易察觉，还因为二氧化碳成份已经在大气中存在了几个世纪之久，所以降低二氧化碳 水平 的难度远高于解决其他环境问题。