【英语生活】低碳生活？没那么简单

Those of us resolving to lead a lower-carbon life in 2010 could do worse than acquire a copy of Prashant Vaze's new book, The Economical Environmentalist, in which the author picks over the fine details of his life. He works out how much CO2 he could save by driving more slowly, installing loft insulation or becoming a vegetarian. The result will be a little dense for some, but it is delightfully geeky and has the virtue of being right more often than not.

This virtue is underrated. Environmentalists have been slow to realise that the fashionable eco-lifestyle is riddled with contradictions. The one that particularly exasperates me is the “food miles” obsession, whereby we eschew tomatoes from Spain and roses flown in from Kenya, in favour of local products grown in a heated greenhouse with a far greater carbon footprint.

Other less-than-obvious truths are: that pork and chicken have substantially lower carbon footprints than beef and lamb (yes, even organic beef and lamb); that milk and cheese also have a substantial footprint; that dishwashers are typically more efficient than washing dishes by hand; and that eco-friendly washing powders may be distinctly eco-unfriendly because they tend to tempt people to use hotter washes.

My conclusion is that a well-meaning environmentalist will make counterproductive decisions several times a day. I don't blame the environmentalists: the problem is intrinsically complicated. Over a vegetarian curry in London recently, Vaze ruefully described to me the “six bloody months” he spent trying to research an eco-renovation of his home.

Even the experts can tie themselves in knots. Duncan Clark, author of The Rough Guide to Green Living, unveiled “10 eco-myths” in a Guardian podcast in November. Many of them were well chosen, but unfortunately his number one “myth” was not a myth at all: that switching off lights will reduce CO2 emissions. Clark's logic is seductive: some European carbon emissions, including those generated by electricity, are subject to a cap. Clark is right to say that conserving electricity will allow other sectors to take up the resulting slack, because they will be able to buy permits to emit more cheaply than if we left our lights blazing.

Where Clark goes wrong is in assuming the cap will remain fixed forever. If we all turn out our lights, the price of permits will fall and politicians will find it politically easier to tighten the cap. So, keep installing those energy-efficient light bulbs. (Another less-than-obvious truth is that it's not worth waiting for your old bulbs to burn out before you fit the new ones.)

After picking through the ideas of Vaze, Clark, David MacKay (a Cambridge physicist) and others, my view is that it is hopeless to expect that volunteers will navigate this maze of decisions.

That is why a broad-based, credible carbon price will be the foundation of any successful policy on climate change. The price would affect the cost of every decision we make; it would take away the guesswork. Current carbon pricing schemes, such as the European emissions trading scheme, are a good start, but they leave out too many sectors, and permits are too cheap.

And a final admission: not every feature of the low-carbon lifestyle is impossibly obscure. I felt rather smug when I realised I could stop drinking cappuccino in favour of espresso, saving 90kg of CO2 a year. Then I totted up my carbon footprint from air travel in 2009. It is the equivalent of almost 50 tonnes of CO2 – or more than the entire footprint of a typical British family of three. It doesn't take a genius to figure out how to shrink that particular footprint. This year I shall do better.

对于我们中间那些决意在2010年过一种低碳生活的人而言，买一本普拉尚特•瓦兹(Prashant Vaze)的新书《节约的环保主义者》(The Economical Environmentalist)并不是最糟糕的选择。作者在书中仔细检查了自己生活的点滴细节，计算出了如果自己开车速度更慢、在阁楼安装绝缘材料、或是改吃素食，分别能减少多少二氧化碳排放。其结果对于一些人来说会有点晦涩难懂，但其专业性古怪得讨人喜欢，而且优点是往往是正确的。

这个优点被低估了。环保主义者一直迟钝，没有意识到时髦的环保生活方式充满着矛盾。尤其让我恼怒的一点，是对于“食物英里数”(food miles)的执迷：我们杜绝来自西班牙的西红柿和来自肯尼亚的玫瑰，而偏爱本地温室里生长、碳足迹高得多的作物。

另一些不那么显而易见的事实包括：猪肉和鸡肉的碳足迹明显低于牛肉和羊肉（没错，哪怕是有机牛肉和羊肉）；牛奶和奶酪同样拥有相当高的碳足迹；用洗碗机通常比用手洗碗更高效；而环保型洗衣粉可能明显对环境不利，因为它们往往会诱使人们使用热水。

我的结论是：好心的环保主义者每天会做出很多事与愿违的决定。这不能怪他们：这个问题本身就十分复杂。最近在伦敦，瓦茨愁苦地向我讲述，他是如何花了“该死的6个月”试图研究出对自己家进行环保改造的方式，他面前放着一盘咖喱什蔬。

就连专家也会把自己弄糊涂。去年11月，《绿色生活简明指南》(The Rough Guide to Green Living)一书的作者邓肯•克拉克(Duncan Clark)在卫报(Guardian)的播客 (podcast)中揭露了“环保的十大误区”。其中许多条都选得不错，但遗憾的是，他所说的第一个“误区”根本不是误区：随手关灯将减少碳排放。克拉克的逻辑很具诱惑性：欧洲某些部门的碳排放，包括电产生的那些排放，都受到上限约束。因此，克拉克有关节约用电不过会让其它部门得以利用由此省下的那部分限额的说法是对的，因为与任凭灯火通明相比，省电让这些部门能够买到碳排放许可，从而以更低廉的成本排放二氧化碳。

但克拉克的错误在于假定那个上限会永远保持不变。如果我们大家都把灯关掉，碳排放许可的价格就会下降，政治家们会发现收紧上限所面临的政治阻力降低。因此，让我们继续安装那些节能灯泡吧。（另一个不那么显而易见的事实是，等到你的旧灯泡烧坏再换新灯泡是不合算的。）

仔细了解过瓦兹、克拉克和戴维•麦凯(David MacKay)——剑桥大学的一名物理学家——等人的观点之后，我的看法是，不要指望志愿者们能够理清这一团谜宫般的决定。

这正是一个基础广泛、公平可靠的碳价格体系之所以将成为气候变化政策成功基石的原因。碳价格会影响我们每一个决定的成本，能够排除一切臆测。目前的碳定价机制（例如欧洲的碳排放交易机制）是一个良好的开端，但它们遗漏了太多的行业，而且排放许可的价格过低。

最后我得承认：并不是低碳生活方式的所有特征都晦涩得让人无法想象。当我意识到，用意式浓咖啡取代卡布其诺后，我可以每年减少90千克的二氧化碳排放量时，感到颇为自得。接着我合计了自己2009年乘飞机出行产生的碳足迹，结果相当于近50吨二氧化碳——比一个英国典型的三口之家一年的碳足迹总量还要多。不需要什么天赋，你就能知道该如何缩减这部分碳足迹。今年我会做得更好。

译者/管婧