1975年，科学家和研究人员齐聚加州蒙特雷半岛的阿西洛玛。这些人来自当时足以改变世界的前沿科学领域——基因工程。这条新辟的科学蹊径所触及的道德底线，以及它的技术安全性，是与会人士共同探讨的话题。就在会议的前一年，多数基因科学家自愿停止了在物种间进行基因转换的实验，因为这项试验引发了广泛担忧。人们担心“转基因”生物可能会危及人类健康，对环境构成威胁。停止实验的决定增强了外界的信心：作为生化领域的新学科，基因工程的发展是审慎的，认真考虑到后果的。阿西洛玛会议的召开正是为了探讨安全性的范围，从而在此前提下能继续进行转基因实验。同时，也为不久后分子生物学和生物技术的振兴扫清了障碍。

Another bunch of researchers, accompanied by policy experts, social scientists and journalists, gathered in Asilomar between March 22nd and 26th, hoped for a similar outcome to their deliberations. This time the topic under discussion was not genetic engineering but geoengineering—deliberately rather than accidentally changing the world’s environment.

今年3月22日至26日期间，另一批科学人员，决策专家，社会学家及记者也在阿西洛玛会面，此次会议与1975年的会议有异曲同工之妙。只是这次的讨论主题从基因工程换成了地球工程——没有随意性，而是有目的地改变地球环境。

Geoengineering is an umbrella term for large-scale actions intended to combat the climate-changing effects of greenhouse-gas emissions without actually curbing those emissions. Like genetic engineering was in the 1970s, the very idea of geoengineering is controversial. Most of those who fear climate change would prefer to stop it by reducing greenhouse-gas emissions. Geoengineers argue that this may prove insufficient and that ways of tinkering directly with the atmosphere and the oceans need to be studied. Some would like to carry out preliminary experiments, and wish to do so in a clear regulatory framework so that they know what is allowed and what is not.

地球工程只是一个范畴性概念，它涵盖了各种科学上的尝试，目的是为了抑制温室气体排放对环境变化的影响，前提是尽量保证必要的排放。地球工程的提出重演了上世纪70年代基因工程的一幕，仍是争议不断。担心气候变化的绝大多数人认为，只要减少温室气体排放，就能遏制变化趋势。地球工程学家的反驳理由是这样做根本不够，对大气和海洋治标的方法尚待研究。一些人希望着手初步实验，但前提是制定出明确的规范体系，这样他们才知道许可和限制。

Ruled in or ruled out?纳入还是排除？

Like the biotechnology of the 1970s, geoengineering cannot be treated just as science-as-usual. There are, however, important differences between the subjects. One is that in the 1970s it was clear that the ability to move genes between creatures was going to bring about a huge change in the practice of science itself, and biologists were eager for that to happen. Modern climate scientists, by contrast, usually see geoengineering research as niche, if not fringe, stuff. Many wish it would go away completely. Another difference is that in the 1970s there was a worry that DNA experiments could in themselves present dangers. With geoengineering the dangers are more likely to be caused by large-scale deployment than by any individual scientific experiment.

地球工程和基因工程一样，不能同一般意义上的科学混淆。然而，这两者之间也有本质的不同。20世纪70年代的科学家很清楚，生物体之间的基因移植一旦实现技术上的应用，会带来怎样巨大的变革，即使如此，生物学家仍然跃跃欲试。 相反，在现代气候科学家看来，地球工程学研究即使不被边缘化，也是稀有人涉足的专业性领域。很多人甚至希望这项研究销声匿迹。对于70年代的DNA实验，科学家只是担心某个实验本身具有危险。现在，地球工程学牵涉的不是独立的科学试验，而是广泛的研究探索，人们担心会有大范围的危险。

There are two broad approaches to geoengineering. One is to reduce the amount of incoming sunlight that the planet absorbs. The other is to suck carbon dioxide out of the atmosphere and put it somewhere else. The second of these approaches is not particularly in need of new regulation. Whether the carbon dioxide is captured by real trees, as some would like, or by artificial devices, environmental problems caused by the process would be local ones at the site of the sucking. Underground storage of the captured carbon would be regulated in the same way that carbon dioxide sequestered from power stations might be—again, for the most part, a local matter. Even the most potentially disturbing suggestion, which involves fertilising the oceans with iron in order to promote the growth of planktonic algae (in the hope that they would sink to the seabed, taking their carbon with them), can be covered by the London Convention on marine pollution, which regulates dumping at sea, and has already addressed itself to research in the area.

目前，地球工程学主要有两个研究方向。其一是减少地球吸收的太阳辐射量。其二是提取大气中的二氧化碳，将其储存在另外的地方。第二项研究尚不需要新的规定管理。一些人希望靠树木捕获碳，而另一种途径是靠人工设备捕获，不论实行哪种办法，引发的环境问题也只造成碳捕获地区的小范围影响。发电厂处理吸取的二氧化碳的方法，对于捕获碳的地下储存也适用。储存碳同样也是碳捕获地区可自行管理的项目。

Reducing incoming sunlight, by contrast, is fraught with danger. While it is possible to imagine doing so in a way that cancels out the change in average temperature caused by an increase in carbon dioxide, such a reduction would not simply restore the status quo. Local temperatures would still change in some places, as would ocean currents, rainfall patterns, soil moisture and photosynthesis. Sunshine reduction, then, clearly needs to be regulated. (It also needs to be renamed: these techniques are currently referred to as “Solar Radiation Management”, a term invented half in jest that has somehow stuck.)

比起第二种方法，减少太阳辐射有很大风险。二氧化碳浓度过高引起的平均温度变化，可能会因为实施第一种办法有所缓和，单纯减少太阳辐射量却并不能让气温恢复到以前的状况。当地的温度仍旧会发生变化，比如受洋流，降雨量，土壤湿度和光合作用的影响。因此，减少日照必然需要规范。（相关技术也需要重命名：现行统称是日照管理。这个命名本来有半开玩笑的性质，但听起来有些死板）

One set of small-scale sunshine-reduction experiments discussed in Asilomar would send plumes of various sulphurous fluids in the stratosphere to find out which would best produce a haze of small particles similar to those that cool the planet after a large volcanic eruption. Another would attempt to whiten clouds over the oceans by wafting tiny salt particles up into them. Thus enriched, the clouds would, in theory, tend to have more, smaller droplets in them. More droplets mean more reflection and less sunshine down below. A team of scientists and engineers that calls itself Silver Lining is working on this idea, with some of its research paid for with money from Bill Gates.

阿西洛玛会议正在研讨一系列小规模的减少日射实验。其中一个是将不同的含硫气流送入平流层，观察哪种气流最适于形成有冷却效果的粒子尘，这种粒子类似于火山爆发后冷却地球表面的微粒。另一种实验是准备将含盐微粒吹送入海洋上空的云层中，理论上，这样做会使云层变白，云中形成更多更微小的云滴，反射阳光的能力也大大增强。代号为银边的一组科学家和研究人员正着手进行实验，比尔·盖茨将赞助一部分实验经费。

In both cases, the experiments would be tiny compared with what people are already doing. In the week of the Asilomar meeting Science published evidence that more pollutants than previously appreciated, including oxides of sulphur, are getting into the lower stratosphere. Exhaust gases from shipping already brighten clouds over various bits of the ocean, and in so doing are thought to cool the Earth appreciably. As new regulations clean up shipping fuels in order to improve air quality in coastal regions, that brightening effect will be reduced, adding to the world’s warming in a sort of inadvertent reverse geoengineering.

相比人类已经造成的破坏，即使两种途径的试验都得以实施，仍然积重难返。在持续一周的会议期间，科学家证实现在的污染比早先预计的更严重，含硫氧化物进入平流层底部。另外，海运船只排气让周边的每一寸云团变白，据说这样有利于降低地球表面温度。地球工程的新办法规定船只必须清除运输燃料，以此提高沿海地区的空气质量。然而，云层反射能力也因此变弱，加剧地球变暖。地球工程的反作用是实施者始料未及的。

Researchers in the field fear, though, that despite being much smaller than existing, inadvertent changes, their experiments will nevertheless become a focus for strident opposition unless there is a clear and respectable system of regulation. Without that, each experiment, however harmless, would be forced to serve as a proxy for the whole approach—a recipe for strangulation by protest and bureaucracy.

地球工程学研究者开始担心出现这样的反作用，尽管这些疏忽比起现在的错误要小得多，仍然会成为众矢之的，试验也无法进行。只有出台明晰可靠的管理体系才是出路。如若不然，即使是不造成危害的试验，也会成为反对者阻挠地球工程的借口。欲加之罪何患无辞是抗议者和政客惯用的伎俩。

In retrospect, the Asilomar meeting may come to be seen as a step towards that respectable system, but probably only a small one. The participants did not produce clear recommendations, but they generally endorsed a set of five overarching principles for the regulation of the field that were presented recently to the British Parliament by Steve Rayner, a professor at the Saïd Business School, in Oxford.

重新审视阿西洛玛会议，可以说它为建立可信的管理体系奠定了一些基础，但是做的远远不够。与会者没提出具体的建议，只对五条总体方针表示了赞同。这些总体方针是由牛津赛德商学院的史蒂夫·雷纳拟写的。最近他将其提交给英国议会，旨在管理环境保护进程。

The “Oxford principles”, as they are known, hold that geoengineering should be regulated as a public good, in that, since people cannot opt out, the whole proceeding has to be in a well-defined public interest; that decisions defining the extent of that interest should be made with public participation; that all attempts at geoengineering research should be made publicand their results disseminated openly; that there should be an independent assessment of the impacts of any geoengineering research proposal; and that governing arrangements be made clear prior to any actual use of the technologies.

这套“牛津方针”认为地球工程应该比照公益事业来管理。既然公众是必不可少的因素，工程实施必须维护公众利益；关乎利益的决策制定必须包含公众的参与；任何地球工程方面的试验计划应该公之于众；试验的提议会有何影响应得到独立评估；如果进行任何实际的技术应用，必须事前规划好监管进程。

The conference’s organising committee is now working on a further statement of principles, to be released later. Meanwhile Britain’s main scientific academy, the Royal Society, and the Academy of Sciences for the Developing World, which has members from around 90 countries, are planning further discussions that will culminate at a meeting to be held this November.

会议组委会正忙于进一步完善方针的内容，不久后就会公布于众。同时，英国主要科学团体英国皇家学会，连同包含90个国家成员的发展中国家科学院，正筹划进一步的讨论，下一次讨论将在11月举行的会议上进行。

Producing plausible policies and ways for the public to have a say on them will be hard—harder, perhaps, than the practical problem of coming up with ways to suck up a bit of carbon or reduce incoming sunshine. As Andrew Mathews, an anthropologist at the University of California, Santa Cruz, puts it, it is not just a matter of constructing a switch, it is a matter of constructing a hand you trust to flip it.