英国城市垃圾回收的问题与经验

今天《卫报》发表文章，题为[《垃圾回收的真相》](http://www.guardian.co.uk/environment/2009/feb/26/recycling-waste-environment)（The truth about recycling），讨论了生活垃圾的大量产生，“可回收垃圾”的复杂定义，以及具体实施过程中在搜集、处理和再利用环节当中的问题。虽然讨论的范围局限在英国，但垃圾分类处理和回收利用在中国这样一个无论是[填埋](http://news.xinhuanet.com/environment/2009-02/06/content_10772832.htm)还是[焚烧](http://www.sei.gov.cn/ShowArticle2008.asp?ArticleID=167998)都受到诸多限制的国家应该是一个可能性最大的发展趋势，因此这篇文章中谈到的问题对中国以及处于类似阶段的国家都有引以为鉴的意义。

英国目前使用的“双桶”系统建立在原有的以户为单位的垃圾收集制度基础上，除了原有的黑色盖子的垃圾桶，英国不少城市的居民现在都可以把常见的可回收垃圾如纸张、金属等投入绿色盖子的垃圾桶。市政部门一周收集黑色盖子的垃圾桶，下一周收集绿色盖子的垃圾桶，如此循环。市政部门专门印制了宣传材料通过邮政部门发放到各家各户，告诉居民哪些垃圾可以被回收，以及在什么日期派人收集可回收和不可回收垃圾。在网站上也有类似的信息，例如我所在的区的政府[网站](http://www.broxtowe.gov.uk/index.aspx?articleid=1352)。我猜测，由于对可回收和不可回收垃圾的回收周期都由过去的一周变成了两周，而生活垃圾的产生总量和垃圾桶的总容积短时间内不变，居民就自然而然地产生了将垃圾分类处理的动机——否则一个垃圾桶放不下，而把不可回收垃圾放入可回收垃圾桶是会被市政部门拒收的。从我对住处附近垃圾处理设施的观察看，这套系统的效果还是不错的。

但是《卫报》的文章暴露了这套系统的问题，并向读者展示了ta们看不到的层面。对我来说，有切身感受的就是这套系统由于某种原因被复杂化了。比如，玻璃瓶是可回收的，但如果我将其放入绿色盖子的垃圾桶，也会导致被拒收。我们必须将其放入一个专用的绿色大袋子等待专人来收取，或者自己把瓶子带到超市停车场的玻璃回收箱。同样是塑料袋，超市购物使用的聚乙烯塑料袋也不鼓励放进绿色垃圾桶，只能通过超市渠道回收。仍然是我的猜测，玻璃分开处理大概是为了分拣工人的安全和健康考虑，怕玻璃碴子划伤工人，但这无法解释为什么不把聚乙烯塑料袋也纳入同一个回收体系。这套系统对于熟悉它的人尚且很混乱，对于初来乍到的人就更难搞清楚了。

不难想象，这种混乱会带来效率的降低和成本的提高。而更严重的问题，据《卫报》说，是垃圾被回收后的去向问题。英国自身对这部分垃圾的利用程度有限，虽然在造纸和塑料行业有成功的例子，但据说不少垃圾实际上在本国由于企业缺乏经济动机而没有市场，都被来自中国这样对资源需求较大的国家的买主以相对低廉的价格收购。但也有人声称，并不是所有可回收垃圾都被回收利用了，有些可回收垃圾可能最终还是在尼日利亚等国家的填埋场埋掉了。这些问题使得有人提出应该用焚烧替代回收，因为它成本更低，更简单，也许更环保。

但我的担心是如果“双桶”系统被焚烧取代，很可能会导致垃圾产生量的增加。再没有什么比想到所有的垃圾都只会化作一缕青烟和可以用来发电的热能更能让人放心地产生垃圾的想法了。现有的回收系统虽然问题不少，但它至少有效地控制了垃圾的源头产生量。垃圾税系统也可能成为有效的控制源头的手段，但它其实并没有给居民提供一个有效的替代选择。在现有的生活方式和商业行为没有改变的情况下，很可能住户该扔多少垃圾还是会扔多少垃圾。

如果中国要推行垃圾分类回收制度的话，可以从英国经验学到什么呢？“双桶”模式对于单元楼为主的大部分中国社区不好复制，但也许可以通过收集渠道的多元化和结合回收补贴与垃圾费（读作：胡萝卜加大棒）的方式促进回收率的提高。最值得学习的正面经验应该是英国市政部门系统化的投入和对居民有效的信息支持。而对于回收垃圾的消化，可能需要一个比现在更好的经济气候，还需要一个更透明的定价系统和适当的政策激励。将回收垃圾转移到国外似乎并不可行，考虑到英国在有这条渠道的情况下仍然面临着垃圾无处可去的困境，当中国也开始进行垃圾回收后这条渠道的容量就更小了。无论在中国还是英国，源头的控制都是垃圾问题根本的解决之道，但中国的现代化进程和促进消费的政策无疑都会给这种控制带来挑战。

Mind Map：小组教学和研讨课

links for 2009-02-18

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  桌面城市DeskCity.com(经典桌面资源站) ｜ 壁纸、素材、桌面、设计
  
  
  
  (tags: 素材 design art wallpaper)
  
  

links for 2009-02-17

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  Academic Earth - Video lectures from the world's top scholars
  
  
  内容丰富的大学课程视频网站，涵盖天文学、生物学、历史、数学等众多学科，与 iTunes U 类似，但视频质量都很高。可惜只能在线观看。
  
  
  (tags: science university teaching education)
  
  

Are mustangs merely horses?

Image via Wikipedia

I just finished this month's issue of National Geographic Magazine and find, among other interesting or informative articles, a [story](http://ngm.nationalgeographic.com/2009/02/wild-horses/fuller-text/1) about mustangs in America's Old West especially thought-provoking. The article mourns about the shrinking habitat for mustangs ("wild horses" or feral horses) and possible loss of a valuable animal (I would reserve in saying it unique) and the spirit behind it.

The preservation of mustangs in my opinion has a larger symbolic purpose rather than a biological or ecological one. As pointed out in the NG article, the mustangs may very likely be the descendant of horses brought by Spanish *conquista* c. 1519. Genetically they may have little or none difference from the original Iberian species or other domestic species produced in the U.S. later. Preserve mustangs therefore is saving meme instead of saving gene, which is rare practice in animal conservation. Considering the huge investment in the conservation of mustangs, I think I have the right to ask as a by-stander: why don't the U.S. put the money to some better conservation use?

The difficulty in conservation lies in mustang's impressive ability to reproduce and extremely limited "wild" habitats nowadays. The authorization did what they can to control the total number of mustangs in the wild so as to make sure they do not graze the grassland into deserts and themselves to death. But this is criticized by people for reducing viability of the wild population. Some other people say that the population should be taken care of by Nature, to live the way they are supposed to be. However, such romantic imagination of Nature may not work in reality, as the habitat is so small and fragmented. All these creates a typical dilemma if you insist that mustangs are indeed a distinctive species that needs protection. Defeatist as it may sound like, I think feral horses should be left by themselves like feral dogs, and [euthanized](http://abcnews.go.com/Technology/AmazingAnimals/wireStory?id=6261967) in a controlled manner if necessary.

Image via Wikipedia

All this talk because mustangs are not genetically distinctive to be called as a species. On the other hand, it may sound tyrannical, even unethical, to judge an animal's conservation value merely by their genes. As a population, mustangs do have their culture values that cannot be replaced by purely domestic horses, despite their identical genes. This is just like the value of most human populations is not their genetic uniqueness, but their culture. But to extend the analogy a bit further, we can easily find that the unsuccessful strategy used to conserve mustangs is deemed to be a failure just like such a strategy used to protect a culture. You cannot protect a human population by taking samples from them regularly and put them in a so-called reserved area. The only way for a mustang or human population to be viable is to guarantee them the way of life they are used to and deserve. Different from protecting a human population, it is ethical and necessary to cull existing mustang population and re-introduce their predators into the wildness of the west. As it was mankind who broke the coyote/wolf-horse equilibrium out of balance, now mankind also have the duty to re-introduce the equilibrium, or at least create a human-horse equilibrium, i.e. artificially control mustang population. Failing to do that, all efforts to preserve mustang population and culture would be self-defeating.

To make the equilibrium happen, and to serve other many important ends, it is of paramount importance to conserve a valid wildness. It may not be free from human interference, but should be able to support a viable wild horse population and the ecosystem they are in. Indeed, the need to preserve mustang culture can be itself an emotionally powerful driver for advocating conservation of habitats. But if local stakeholders finds the idea of saving mustangs not so appealing, maybe the authorization can a) find another proxy wildlife to achieve the same goal, or b) persuade local people to accept mustangs as a healthy symbol and a worthy backup gene bank that can be used to strengthen their own livestock. Option (b) seems to be an easier way, and the NG article no doubt does it good.

Now I can't help thinking, if we Chinese linked Chinese sturgeon *Acipenser sinensis* with something more meaningful rather than saying in our dictionaries that it is edible, perhaps Yangtze River as an important habitat would be better protected.

links for 2009-02-16

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  Flu: It's the Humidity. Absolutely -- Enserink 2009 (209): 3 -- ScienceNOW
  
  
  流感病毒在较低的绝对湿度下更易传播，缺乏褪黑激素和维生素D则会削弱免疫系统。躲在暖气充足的房间里也许不是好主意。
  
  
  (tags: health research)
  
  

中美能源合作的新契机

英国《卫报》[报道](http://www.guardian.co.uk/environment/2009/feb/11/network-us-china-climate-change)，中美两国50多名专家日前起草了一份报告，旨在为奥巴马政府提供一份与中国在能源和减排技术领域进行合作的路线图。这份报告是由亚洲协会美中关系中心和 Pew 全球气候变化中心发布的，全文可以在 Pew 中心的网站[下载](http://www.pewclimate.org/US-China)。

报告指出了两国可以开展合作的五大方向，包括发展低排放煤炭能源技术，提高能源效率和改善节能措施，开发先进电网技术，推广可再生能源，以及投入资金发展低碳技术。报告指出，虽然目前的经济形势对大规模的环境投资造成了压力，但高额的基础设施建设投资和经济刺激方案也能带来改变现有能源体系的难得契机，同时造就大量的[“绿领”](http://www.guardian.co.uk/environment/2009/feb/12/green-collar-jobs-environment)工作岗位，可谓一举多得。报告认为，中国和美国作为世界上最大的发展中国家和发达国家，以及最大的能源消费国和温室气体排放国，如果能够在气候变化问题上展开合作，将对哥本哈根会议之后的气候问题格局乃至更广泛意义上的世界格局都产生积极的影响。

这一合作能否实现，取决于双方是否愿意参与，以及投入到什么程度。从美国的角度推测，对中国进行适当的技术出口将有利于形成积极面对气候问题的国际形象，在未来的气候谈判中获得有利地位。但在有限的资金和高昂的外债负担条件下，在经济不景气的时期美国能够投入多少资金到低碳项目和风险巨大的新技术验证项目的建设当中还是未知数。而中国能够通过合作获得的技术看起来相当有吸引力，但美国对于知识产权的顾虑也可能对技术的转移产生不利影响。更重要的是，中国是否能将发展可持续能源与发展欠发达地区的目标统一起来。

从政治经济的角度说，合作如果能够实现，将是中国在未来国际上进一步提升影响力的契机，同时可能对西方的经济复苏产生积极影响，甚至使[世界经济重心向东方迁移](http://davidharvey.org/2009/02/why-the-us-stimulus-package-is-bound-to-fail/)。