温室效应(2/7)

Without it, scientists estimate that the average temperature on Earth would be colder by approximately 30 degrees Celsius, far too cold to sustain our current ecosystem. Second, we need to clarify the way humans contribute to the greenhouse effect. While the greenhouse effect is an essential environmental prerequisite for life on Earth, there really can be too much of a good thing. The problems begin when human activities distort and accelerate the natural process by creating more greenhouse gases in the atmosphere than are necessary to warm the planet to an ideal temperature, for example, burning natural gas, coal and oil, including gasoline for automobile engines, raises the level of carbon dioxide in the atmosphere. Some farming practices and land-use changes increase the levels of methane and nitrous oxide. Many factories produce long-lasting industrial gases that do not occur naturally, yet contribute significantly to the enhanced greenhouse effect and global warming that is currently under way.

按科学家估计,如果没有温室效应，地球上的平均气温会降低大约30摄氏度,温度过低无法维持我们目前的生态系统。第二,我们需要弄清楚人类是如何造成温室效应。尽管温室效应是地球上的生命的一个重要的环境前提,但是太多却会造成伤害。当人类活动在大气中制造更多的温室气体，从而扭曲和加速自然过程，地球变暖的理想的温度,例如,燃烧天然气,煤和石油——包括汽油汽车发动机——增加了大气中二氧化碳的浓度,此时问题便开始产生了。一些农业实践和土地利用变化增加了甲烷和一氧化二氮的浓度;许多工厂排放非正常产生的工业气体,很难散去,然而，目前这些气体明显加强了温室效应和促进全球变暖。