Fifteen terawatts. That's 150 billion 100-watt light bulbs burning 24/7 for a year. Which is how muchenergy humanity now uses annually.
15太瓦。这足够1500亿盏100瓦的灯泡每周七天每天24小时的工作一整年，而这也就是人们现在每年消耗的能量。
Most of it is dirty. Burning coal sullies the atmosphere and leaves toxic ash mountains. Natural gas is better for CO2 but not enough to halt global warming. So the hope of man who combat climate change is that alternative energy—electricity from sunshine, wind orlow-carbon nuclear—can begin to replace fossil fuels.
这其中的多数都是肮脏的。燃烧煤污染大气并且产生一山一山的有毒煤渣。天然气产生的CO2少些，但是仍不足以中止全球变暖。因此人们对抗气候变化的希望就落在了替代性能源上——太阳能发电、风力发电，或者低碳的核能源已经开始替代化石燃料。
And renewables like wind and solar have been booming. There are now nearly 240,000 megawatts worth of wind turbines globally, and the U.S. added nearly 2,000 megawatts of solar in 2011.
像风能和太阳能这样的可再生能源的确在暴涨。现在全球有将近240 000兆瓦的风力机组，美国在2011年增加了将近2 000兆瓦的太阳能发电。
Unfortunately, the additional renewables are not helping cut back on fossil fuels much. That's according to an analysis published in the journal Nature Climate Change. In fact, over the last 50 years, adding a unit of alternative energy to the grid displaced a mere 1/10 of a unit of fossil fuel-fired power. And those alternative energy additions have been small.
不幸的是，这些额外的可再生能源并未减少多少化石燃料的使用。这是根据《自然气候变化》杂志的分析得到的结论。事实上，在过去的50年里，每增加1单位的替代性能源，只有0.1单位的化石燃料燃烧提供的能源被替代。那而且那些替代性能源的增加本身就很少。
In other words, to get away from fossil fuels requires not just expanding alternatives but also discouraging the use of coal, oil and natural gas. Carbon tax anyone?
换句话讲，想要摆脱化石燃料，不仅仅需要扩大替代性能源，还要降低煤、石油和天然气的使用。是不是该向某些人征收碳排放税呢？