From mimicking a volcanic eruption to mirrors in space, some geoengineering schemes are pretty far out there.
从模拟火山爆发到在天空中安放反射镜，一些地球工程方案真是非常“离谱”。
World’s Craziest Geoengineering Scheme
A manmade volcano erupting continuously to shade the Earth until greenhouse gas levels in the atmosphere are brought down. Thousands of mirrors boosted into geosynchronous orbit to block sunlight. Crewless ships wander the oceans spewing saltwater into the air to increase cloud cover.
These are just a few of the proposals from scientists to manipulate, or geoengineer, the planet to stave off global warming.
The U.K.’s Royal Society has spent the last year identifying which schemes are just plain crazy and which just might be needed if the world doesn’t start reducing greenhouse gas emissions right away.
Covering the world’s deserts in reflective material is the most dangerous, expensive and ineffective geoengineering scheme, not least because it would likely change weather patterns. Fertilizing the ocean with iron to promote plankton blooms also gets high marks for danger because of the potential for unintended ecosystem impacts.
On the safer side? Artificial trees to suck CO2 out of the air are safe… but they don’t come cheap. Painting roofs white is also safe… but not likely to make much impact. In the sweet spot of safe, immediately available as well as relatively effective and inexpensive sits—capturing excess CO2 where it largely comes from: power plants.
And the simplest and cheapest way to slow global warming on a planetary scale, it turns out, is simply to stop cutting down the forests helping control today’s climate. It won’t solve the whole problem but a few trees go a long way.
Of course, the craziest geoengineering scheme to date is the one we’re already doing: changing the climate with an excess of greenhouse gas emissions. If we don’t stop that experiment, we might have to start an even crazier one.
世界上最疯狂的地球工程方案
利用人造火山不断地喷发，以便使地球处于阴凉之下直到大气中温室气体的水平下降；把成千上万的反射镜安放于地球同步轨道上，以期拦住太阳光；让游弋于海洋中的无人轮船向空气中喷洒盐水，以便增加云层的覆盖……
为了控制全球变暖，科学家们提出了不少方案来控制地球，或者说是进行地球工程。上述这些仅仅是其中的几个方案而已。
英国的皇家学会去年花了一年的时间来确认哪些计划纯粹是疯狂的想法，哪些计划可能用得上，如果全球不立即开始减少温室气体的排放的话。
在地球上的沙漠里覆盖上反射材料是最危险、最昂贵同时也是最没有实际效果的地球工程方案，这不仅仅因为这个方案可能会改变气候类型。在海洋中加入铁来增加浮游生物的数量也有很大的危险，因为这可能会带来潜在的意想不到的生态影响。
哪些方案是安全的呢？用人工树林来吸收空气中的二氧化碳是安全的，但是实施起来也不便宜。把房顶涂成白色也很安全，但是这对减少全球变暖可能不会有多大效果。最安全的方法，而且又是立即可用的，同时也相对有效和便宜的方案——“俘获”由发电厂排出的大量二氧化碳。
结果发现，在全球规模上减缓气候变暖最简单而且最便宜的方法是停止砍伐森林，这些森林有助于控制目前的气候。这虽然不能解决所有的问题，但是多一些树能起到长久的作用。
当然，到目前为止最疯狂的地球工程正是我们正在实施的行为：通过排放过量的温室气体来改变气候。如果我们不停止这个实验，我们可能不得不开始实行更加疯狂的解决方案。
Vocabulary: Mimic：滑稽地模仿
Geoengineering：地球工程
Boost：使增长；提高
Geosynchronous：与地球同步的
Crewless：没有船员的
Wander：漫步
Spew：喷射
Stave off：暂时拦住；延缓
Reflective：反射的
Plankton：浮游生物
Ecosystem：生态系统
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