资源限制 2
GMO 季度信函 2011 年 7 月
资源局限性之二:区分危险与仅属严重
杰里米·格兰瑟姆
“你、我和我们的政府,必须避免那种只为今天而活、为了自身的安逸与便利而掠夺明天宝贵资源的冲动。”
德怀特·D·艾森豪威尔,1961 年 1
“他们想让我们相信,大可不必忧虑,石油储量能延续数千年,而且在耗尽之前,科学早已创造出奇迹。我们的历史与安逸让我们多愁善感地相信,我们所恐惧的事情永远不会真的发生——一切最终都会好起来。但谨慎之人会拒绝这些安慰剂,更愿意直面事实,以便能够明智地规划……”
海曼·里科弗上将,1957 年 2
“毁灭自己土壤的国家,就是在毁灭自己。”
富兰克林·德拉诺·罗斯福,1937 年 3
引言
上一季度,我试图论证一个观点:在经历了多次虚惊之后,有限资源与指数级人口增长之间那不可避免的错配,终于露出了真面目。这通过原材料价格一场极其泡沫式的暴涨变得显而易见。重要的是,价格在四年内两次飙升,这在我们的历史记录中是最不像泡沫的现象。数据向我们暗示了一种极为罕见的物种:一个新范式。而且是一个相当令人不安的范式。(不过,总体而言,我在这里尽量不重复上一季度用过的论点或数据。)
本季度,我想聚焦于即将到来的短缺中最危险的部分。我将尝试区分两类情况:对于富裕国家而言,哪些仅仅是因价格上涨而拖慢我们财富增长速度的;哪些不仅会做到这一点,而且当人口达到 100 亿时,还会真正对我们这个物种的长期存续构成威胁。在所有情况下,贫穷国家受到威胁最大。那些会让我们一些人因价格上涨而烦恼的情况,将导致另一些人忍饥挨饿。那些会让我们一些人挨饿的情况,对另一些人来说则将是真正的灾难,而且我相信,不幸的是,这并非发生在遥远模糊的未来。
显然,专家们对一些子话题写过不少书,而我把它们压缩成了一句话。我或许还应该补充一点,这些书以及这些拥有数十年经验的专家们所写的无数文章,彼此之间绝对意见不合。事实上,其分歧之大,可能与任何科学话题不相上下,往往差一个数量级,并且常常充满火药味。与许多科学分歧不同,那些关乎我们长远的资源问题,有些可能确实是生死攸关之事。我试图从一个加权平均的立场出发,然后留出安全边际,倾向保护我们的长期福祉。按定义来说,会有大量专家不同意这里的每个论断。我的希望是,“我们”的专家是那些更严谨、更聪明、更具保护意识的人。
资本主义并不能轻松或良好地解决这些非常长期的问题。在我看来,资本主义的有效性沿着时间跨度的光谱移动:在短期一端极为出色,但在极长期的一端却迷失方向、无关紧要,甚至相当危险。
GMO QUARTERLY LETTER July 2011 Resource Limitations 2: Separating the Dangerous from the Merely Serious Jeremy Grantham “You and I, and our government must avoid the impulse to live only for today, plundering, for our own ease and convenience, the precious resources of tomorrow.” Dwight D. Eisenhower, 19611 “[They] would have us believe that there is no cause for anxiety, that reserves [of oil] will last thousands of years, and that before they run out science will have produced miracles. Our past history and security have given us the sentimental belief that the things we fear will never really happen – that everything turns out right in the end. But prudent men will reject these tranquilizers and prefer to face the facts so that they can plan intelligently…” Admiral Hyman Rickover, 19572 “The nation that destroys its soil destroys itself.” Franklin Delano Roosevelt, 1937 3 Introduction Last quarter I tried to make the case that the inevitable mismatch between finite resources and exponential population growth had finally shown its true face after many false alarms. This was made manifest through a remarkably bubble-like explosion of prices for raw materials. Importantly, prices surged twice in four years, which is a most unbubble-like event in our history book. The data suggested to us that rarest of rare birds; a new paradigm. And a very uncomfortable one at that. (In general, though, I have tried here not to repeat arguments or data used last quarter.) This quarter, I would like to focus on the most dangerous parts of the coming shortages. I will try to separate those that, for us rich countries, are merely going to slow down the growth rate of our wealth through rising prices, and those that will do not only that, but will actually be a threat to the long-term viability of our species when we reach a population level of 10 billion. In all cases, poorer countries will be the most threatened. Situations that will irritate some of us with higher prices will cause others to starve. Situations that will cause some of us to go hungry will be for others a real disaster, and I believe this, unfortunately, will not be in the dim and distant future. Obviously, experts have written books on subtopics that I reduce to one sentence. I might add that these books and a myriad of articles by these experts – who have decades of experience – absolutely do not agree with each other. In fact, they differ probably as widely as any scientific topic around, often by a literal order of magnitude and often with heat. Unlike many scientific differences, some of those concerning our resources in the long run may actually be a matter of life and death. I have tried to start from a weighted-average position and then have allowed for a safety margin tilted in favor of protecting our long-term well-being. By definition, plenty of experts will disagree with each statement made here. My hope is that “our” experts are those that are more rigorous, intelligent, and protective. Capitalism does not address these very long-term issues easily or well. It seems to me that capitalism’s effectiveness moves along the spectrum of time horizons, brilliant at the short end but lost, irrelevant, and even plain dangerous at the very long end.
1 德怀特·D·艾森豪威尔,告别演说,1961 年 1 月 17 日。(另见:杰里米·格兰瑟姆的《我喜欢艾克:一个被忽视的强力警告》,2011 年 1 月 14 日;位于 GMO 网站的资料库,需注册。)
1 Dwight D. Eisenhower, Farewell Address, January 17, 1961. (Also see, Jeremy Grantham’s “I Like Ike: A Powerful Warning Ignored,” January 14, 2011; located in the Library of GMO’s website, registration required.)
海曼·里科弗上将,《能源资源与我们的未来》,1957 年演讲。
2 Admiral Hyman Rickover, "Energy Resources and our Future," remarks delivered in 1957.
3 富兰克林·德拉诺·罗斯福,1937 年 2 月 26 日,致全体州长关于统一水土保持法的信函。
3 Franklin Delano Roosevelt, Letter to all State Governors on a Uniform Soil Conservation Law, February 26, 1937.
概要 — 我们人类拥有足够的智力和手段来实现真正的全球可持续性。问题出在我们自身,以及我们对短期增长和利润的过度关注,这很可能会引发大规模的苦难。凭借远见和周密的规划,这种苦难完全可以避免。— 尽管我们会因石油峰值而面临能源问题,但这很可能是一个人类创造力最终将取得胜利的领域,50 年后,尽管一路走来会有价格问题,我们也能勉强应付过去。— 金属和淡水的短缺将各自引发严重问题,但最终我们会调整自身行为,使其仅带来困扰而非威胁,尽管就金属而言,来自短缺和价格上涨的压力将永远缓慢加剧。— 完全耗尽钾(钾碱)和磷(磷酸盐)以及土壤侵蚀,才是我们面临的真正长期问题。这些资源的完全或近乎完全枯竭,将使养活预计 50 年后将达 100 亿的人口成为不可能。— 钾和磷是所有生命所必需的;它们无法人工制造,也无法被替代。我们依赖于全球分布极不均匀的有限矿产资源。— 全球范围内,土壤侵蚀的速度是自然再生速度的数倍。尽管尚不确定,但美国很可能仍在流失土壤。全球整体上肯定如此。— 唯一一条明确的好消息来自免耕农业的增长。在免耕法中,上一季作物的残留物被留在地表,新种子在无需犁地的情况下直接播种。这项技术可将侵蚀减少约 80%,减少化肥径流,保持水分,改善土壤(并且很可能提高食物质量),同时减少温室气体排放。— 免耕农业在南美洲增长非常迅速,在美国也增长迅速(目前已达 35%),并在许多其他发达国家实现温和增长。但在全球范围内,仅有约 5% 的农场采用此技术。— 总体而言,最好的农场将没有侵蚀问题,但平均而言,全球土壤将持续流失。加之极端天气增多和投入品价格走高(可能大幅走高),养活全球不断增长的人口将面临越来越大的困难。— 特别是,大量主要分布在非洲和亚洲的贫穷国家,几乎必将遭受日益加剧的营养不良和饥荒。按照所需规模提供外国援助的可能性似乎很渺茫。— 气温升高将至少略微加剧农业面临的诸多压力,而日益不稳定的天气,尤其是更频繁、更严重的干旱和洪水,将严重加剧这些压力。— 这类在我们面前数十年间悄然逼近、且缺乏科学精确性的慢燃问题,正击中我们资本主义体系和人类天性的痛处。— 资本主义,尽管在短期内拥有诸多卓越美德——尤其是其适应不断变化条件的能力——却在影响这一问题上存在几个弱点。○ 它无法应对公地悲剧,例如过度捕捞、集体性土壤侵蚀和空气污染。○ 自然资源的有限性被完全忽略,定价完全基于短期供需。○ 更普遍地说,由于使用极高的贴现率,现代资本主义对发生在遥远未来的损害不计入实质性成本。我们的子孙后代以及他们将因全球变暖、天气日益不稳定、特别是资源短缺而面临的问题,按照标准的资本主义方法,都没有实质性的现值。关于资本主义缺陷的更详细讨论将在下一季度的信中发表。此外,关于当前市场(包括本文的任何投资启示)的讨论将在两周后发布。
Summary We humans have the brains and the means to reach real planetary sustainability. The problem is with us and our focus on short-term growth and profits, which is likely to cause suffering on a vast scale. With foresight and thoughtful planning, this suffering is completely avoidable. Although we will have energy problems with peak oil, this is probably an area where human ingenuity will indeed eventually triumph and in 50 years we will have muddled through well enough, despite price problems along the way. Shortages of metals and fresh water will each cause severe problems, but in the end we will adjust our behavior enough to be merely irritated rather than threatened, although in the case of metals, the pressure from shortages and higher prices will slowly increase forever. Running out completely of potassium (potash) and phosphorus (phosphates) and eroding our soils are the real long-term problems we face. Their total or nearly total depletion would make it impossible to feed the 10 billion people expected 50 years from now. Potassium and phosphorus are necessary for all life; they cannot be manufactured and cannot be substituted for. We depend on finite mined resources that are very unevenly scattered around the world. Globally, soil is eroding at a rate that is several times that of the natural replacement rate. It is probable, although not certain, that the U.S. is still losing ground. The world as a whole certainly is. The one piece of unequivocal good news can be found in the growth of no-till farming. In no-till, the residue of the previous crop is left on the ground and new seeds are planted without plowing. This technique reduces erosion by around 80%, reduces fertilizer run-off, preserves moisture, improves the soil (and, quite possibly, the quality of the food), and reduces the emissions of heat trapping gasses. The growth of no-till has been very rapid in South America, rapid in the U.S. (which is now at 35%), and moderate in many other developed countries. But it is used on only about 5% of farms globally. Overall, the best farms will have no erosion problems but, on average, soil will continue to be lost across the globe. Together with increased weather extremes and higher input prices (perhaps much higher), there will be increasing problems in feeding the world’s growing population. In particular, a significant number of poor countries found mostly in Africa and Asia will almost certainly suffer from increasing malnutrition and starvation. The possibility of foreign assistance on the scale required seems remote. The many stresses on agriculture will be exacerbated at least slightly by increasing temperatures, and severely by increased weather instability, especially more frequent and severe droughts and floods. These types of slow-burning problems that creep up on us over decades and are surrounded by a lack of scientific precision hit both our capitalist system and our human nature where it hurts. Capitalism, despite its magnificent virtues in the short term – above all, its ability to adjust to changing conditions – has several weaknesses that affect this issue. o It cannot deal with the tragedy of the commons, e.g., overfishing, collective soil erosion, and air contamination. o The finiteness of natural resources is simply ignored, and pricing is based entirely on short-term supply and demand. o More generally, because of the use of very high discount rates, modern capitalism attributes no material cost to damage that occurs far into the future. Our grandchildren and the problems they will face because of a warming planet with increasing weather instability and, particularly, with resource shortages, have, to the standard capitalist approach, no material present value. 4 4 An expanded discussion on the failings of capitalism will be in next quarter’s letter. In addition, a discussion on the current market, including any invest-ment implications from this piece, will be posted in two weeks.
GMO 2 季度信函——资源限制 2——2011 年 7 月观点 事后看来,关于上一季度的资源问题信函,我想做一些补充和修正。我先从人类集体福祉的前景谈起:资源限制问题中没有什么是我们无法解决的。我们拥有智慧,尤其是创造力。我们拥有一些近乎无限的资源:太阳的能量和海洋中的水。我们拥有一些至关重要的有限资源,但可以通过明智、有远见的行为进行配给和延展,以填补从今天(我们生活水平远超可持续水平)到大约 200 年后(我们可能已实现真正的长期可持续性)之间的空白。这种可持续性需要改进能源和农业技术,并且很可能需要大幅减少人口。通过明智的规划,这一切都可以合理预期。人口减少可以通过缓慢而自愿的下降来实现(或许通过加大教育等方式鼓励小家庭规模)。这样的减少可能使世界人口落在 15 亿到 50 亿之间的某个数值,具体取决于许多复杂变量的细微差别和相互作用。届时,我们将与资源达到长期平衡,包括到那时仍存留的现有生物多样性——但愿能达到今天的二分之一到四分之三。
GMO 2 Quarterly Letter – Resource Limitations 2 – July 2011 Perspective With hindsight, there are a few additions and qualifications I would like to make regarding my letter on resources of last quarter. I will start with an overview of the prospects for our collective well-being: there is nothing about the resource limitation problem that we cannot resolve. We have the brain power and, especially, the inventiveness. We have some nearly infinite resources: the sun’s energy and the water in the oceans. We have some critically finite resources, but they can be rationed and stretched by sensible, far-sighted behavior to fill the gap between today, when we live far beyond a sustainable level, and, say, 200 years from now, when we may have achieved true long-term sustainability. Such sustainability would require improved energy and agricultural technologies and, probably, a substantially reduced population. With intelligent planning, all of this could be reasonably expected. A population reduction could be arrived at by a slow and voluntary decline (perhaps with some encouragement of smaller family size achieved, for example, through greater education). Such a reduction might leave us with a world population of anywhere from 1.5 billion to 5 billion, depending on the subtleties and interactions of many complicated variables. We would then be in long-term balance with our resources, including what will remain by then of our current biodiversity, which will hopefully be as much as one-half to three-quarters of what we have today.
问题不在于我们能做到什么,而在于我们实际上会怎么做。浪费现状在当今的企业和政治体系中有着强大的盟友。我们不太容易接受坏消息,也不太擅长处理长期问题。正如上个季度提到的,我们并不特别擅长处理数字,尤其是在概率、复利增长和贴现率方面。我们拥有的资本主义体系反映了我们的弱点——一个只为当下和近期而精心调整的体系。由于这些因素,我们很可能会等到迹象强烈而明确、表明我们必须改变时,才去处理那些入不敷出的明显问题——换句话说,等到基本上为时已晚。所谓为时已晚,是指无法保护我们今天所享有和珍视的许多东西;是指无法避免掠夺子孙后代的资源。这很遗憾,但一个从另一个星球观察的信息充分的赌徒,大概会下这个赌注。这也就是为什么,在环境问题(与资源管理有许多相同问题)这个领域,可以诚实地说,有年长的环保主义者和乐观的环保主义者,但没有既年长又乐观的环保主义者。我大概就是你能找到的最接近的了。下面的论述将以乐观程度递减的顺序来审视我们面临的资源问题。我认为接下来的内容合理而非末日论调。而且,还有一个非常利好的消息——免耕农业的稳步兴起。在这方面,发达国家似乎至少是交了好运!然而,在短期利润最大化的压力下,我们未必能利用好这份好运。
The problem is not what we are capable of, but how we will actually behave. The wasteful status quo has powerful allies in the present corporate and political system. We do not easily accept bad news, nor do we easily deal with long-horizon problems. As mentioned last quarter, we are not particularly good with numbers, especially when it comes to probabilities, compound growth, and discount rates. We have a capitalist system that reflects our weaknesses; one that is fine-tuned only for the present and immediate future. Because of these factors, we will probably wait to deal with the obvious problems of living well beyond our means until the signs are powerful and clear that we must change; until, that is, it is basically too late. Too late in the sense of failing to protect much of what we enjoy and value today. Too late to have avoided plundering our grandchildren’s resources. It’s a shame, but it’s the bet a well-informed gambler, observing from another planet, would probably make. It’s why, in the environmental business, which shares many of the same problems with resource management, it can be honestly said that there are old environmentalists and optimistic environmentalists, but no old, optimistic environmentalists. I’m probably as close as you’re going to get. The following argument looks at the resource problems we face in order of declining optimism. I think what follows is reasonable rather than apocalyptic. And, there is one remarkable piece of good news – the steady rise of no-till farming. In this, the developed world at least seems to have truly lucked out! However, with the pressures of short-term profit maximizing, there is some chance that we will not capitalize on our good luck.
潜在问题排序 1. 能源 从石油转型将给我们带来严重且持续的问题。我们很久以前就已经过了人均石油峰值,并且距离石油绝对峰值还有 30 年,甚至可能只有 10 年。价格波动将超乎我们最疯狂的想象(或噩梦),而价格趋势将上涨,尽管有时这种趋势难以从波动中辨别出来。交通运输总体上会变得困难,航空运输尤其如此。但在石油背后,有相对充足的天然气和煤炭,它们可以替代石油,尽管需要成本和难度。然而,即使有煤炭和天然气,我们面对的也仅仅是几十年的供应,而非几个世纪。但在碳氢化合物之外,确实有好消息。我认为,大约 50 年内,我们在太阳能、风能、潮汐能及其他能源(包括储能)的科学与工程方面将取得惊人进展。举个近期的简单储能管理思路:每辆电动汽车配备两个易于更换的电池组,一个在车库里,在你开车上班时储存来自屋顶的太阳能。只要可能,所有这些电池都应连接到智能电网上,该电网既能从电池中取电,也能向电池充电,按今天标准看这将带来极大的灵活性。也有可能(尽管我可惜地认为可能性不大),我们会迎来核裂变的大规模新热潮,也许受到某些技术进步的刺激。更长远来看,完全新型的商业能源可能出现,可能来自某种核聚变,也可能来自我们当前雷达屏幕之外的全新事物。这正是我乐观的来源,因为我相信,在大约 50 年内,经历了许多严重的经济问题(可能还有社会问题)之后,我们将拥有充足且价格合理的能源,让每个人都能过上体面的生活(如果我们暂时排除其他非能源问题的话)。换句话说,当前资本主义对更高价格的反应应该能够解决问题。不过,我们应该认识到,“价格合理”并不意味着战后时期石油那种近乎白送的价格,那恰恰证明了标准自由市场实践的失败——未能认识到一种重要资源是有限的,从长远来看会改变一切。“价格合理”的燃料,其价格上涨速度会稳定地高于 CPI,而不是毁灭性的上涨。
A Possible Hierarchy of Problems 1. Energy The transition from oil will give us serious and sustained problems. We passed peak oil per capita long ago and we are within 30 years, possibly within 10, of peak oil itself. The price will be volatile beyond our wildest dreams (or nightmares), and the price trend will rise, although at times this will be difficult to discern through the volatility. Transportation will be difficult in general and air transportation in particular. But behind oil, there is a relative plenty of natural gas and coal, which can, although with cost and difficulty, be substituted for oil. Even with coal and gas, however, we are dealing with only many decades of supply, not centuries. But beyond hydrocarbons there really is good news. Within 50 years or so, I believe we will have made spectacular progress in the science and engineering of solar, wind, tidal, and other energy sources, together with storage. One simple storage management idea for the nearer term, for example, is that every electric car would have two easily-exchangeable battery packs, with one in the garage, storing solar from your roof while you drive to work. Whenever possible, all such batteries would be attached to an intelligent grid that would be able to raid batteries or deposit into them, giving massive flexibility by today’s standards. It is also possible (although, unfortunately, I believe improbable) that we will have a new, large-scale burst of activity in nuclear fission, perhaps stimulated by some technological improvements. Further out, completely new forms of commercial energy are likely, perhaps from nuclear fusion of some kind, or perhaps from something completely off of our current radar screen. This is where my optimism comes in, for I believe that in 50 or so years Quarterly Letter – Resource Limitations 2 – July 2011 3 GMO – after many and severe economic and, possibly, social problems – we will emerge with sufficient, reasonably-priced energy for everyone to live a decent life (if we assume other non-energy problems away for a moment) even if we don’t radically improve our behavior and make true sustainability our number one goal. In other words, current capitalist responses to higher prices should get the job done. We should realize, though, that reasonably-priced does not mean the nearly give-away prices of oil in the post war period, which serves as a real testimonial to the failure of standard free-market practices to recognize that a vital resource being finite changes everything in the long run. “Reasonably-priced” fuel would be where prices rise steadily faster than the CPI rather than ruinously so.
2. 金属 金属当然比能源更是一个长期的难题。它们是熵在起作用……从优质的金属矿石到分散的废弃物。即使是最好的回收利用也会产生损耗。熵的力量令人惊叹;一切确实都在走下坡路,铁确实会生锈。因此,我们的未来无疑将越来越受制约,特别是如果人口及其财富都稳定增长的话。最终,人口和财富的增长都将受到限制,甚至可能因金属短缺而停滞,但幸运的是,这应该还有很长一段时间。如果我们像我相信的那样,通过更加注重质量和规模小巧,配合日益明智且不浪费的生活方式来应对不断上涨的价格压力,那么我们就能将这些严峻的制约因素再推后一百多年。这再次假设,除了由更高价格引发的变化之外,人们的态度和行为没有发生根本性的转变。
2. Metals Metals are, of course, a bigger long-term problem than energy. They are entropy at work ... from wonderful metal ores to scattered waste. Even the best recycling will have slippage. Entropy is impressive; everything really does run downhill, iron really does rust. So our future will undoubtedly be increasingly constrained, particularly if our population and its wealth both grow steadily. Eventually, the growth of both population and wealth will be limited and possibly even stopped by a lack of metals, but that should, with luck, be a long time away. If we respond to increasing price pressures, as I’m sure we will, with a greater emphasis on quality and small scale along with an increasingly sensible and non-wasteful lifestyle, then we can push these serious constraints out for well over a hundred years. This is assuming, once again, no radical shift in attitudes and behavior other than those elicited by higher prices.
3. 农业 农业才是麻烦的真正起点。这个因素让我几乎确信,我们最终会迎来一个 15 亿到 50 亿的世界人口。我唯一的疑问是,我们究竟是通过温和、有计划的渐进式约束优雅地抵达这个数字,还是埋头猛冲、以相当快的速度一头撞上南墙。农业中有三个最让人头疼的具体方面:水、化肥和土壤。所有这三点都必须放在人口快速增长的大背景下来看。先交代一下背景:图 1 展示了人均耕地面积。与我们不同,自大约 1 万年前农耕开始以来,适宜农业的土地并没有增加。事实上,在我们的帮助下,它反而大幅减少了,可能减少了一半甚至更多!
3. Agriculture The trouble really begins with agriculture. This is the factor that I believe almost guarantees that we end up with a world population between 1.5 and 5 billion. The only question for me is whether we get there in a genteel, planned manner with mild, phased-in restraints, or whether we run head down and at considerable speed into a brick wall. There are three particular aspects of agriculture where the shoe pinches the most: water, fertilizer, and soil. All three must be seen in the context of a rapidly growing population. To set the scene, Exhibit 1 shows arable land per person. Unlike us, suitable land for agriculture has not increased since farming started some 10,000 years ago. In fact, with our help it has declined considerably, perhaps by as much as half or more!
表 1 全球人均耕地面积(公顷)
0.5
0.4
人均公顷数
0.3
0.2
0.1
0.0
1961 1966 1971 1976 1981 1986 1991 1996 2001 2006
资料来源:联合国粮食及农业组织、美国人口普查局
截至 2010 年 12 月 31 日
GMO 第 4 季报 – 资源限制 2 – 2011 年 7 月
A. 水
毫无疑问,水资源短缺将永远成为经济和社会麻烦的源头。各国会为了争夺河流水权而挥舞刀剑,甚至发动战争。这一点是确定的。但若将其视为美国或整个地球的问题,它似乎并非无法克服的障碍。毕竟,我们星球的表面大部分是水。我们直接使用和灌溉作物所需的水量,仅占地球水资源总量的微不足道的一小部分。目前全球浪费性使用的全部淡水量,只相当于亚马逊河流量的 80%。而且,我们以极其低效、浪费的方式使用现有的可再生淡水资源。随着价格上涨,我们不仅能节省几个百分点,而是能通过在对的地点种植对的作物、理性地共享和循环利用水资源,节约绝大部分用水。从更长远看,借助可获得的相对廉价的能源,我们可以通过海水淡化为沿海人口补充供水。除了调整作物种植外,对农业的主要影响将是水成本的稳步上升——因为我们会逐渐认识到向农业供水的真实成本。不过,我相信,再过 50 年或 100 年,我们会被水问题持续困扰,但作为物种从未受到严重威胁。
Exhibit 1 World Hectares of Arable Land per Capita 0.5 0.4 Hectares per Capita 0.3 0.2 0.1 0.0 1961 1966 1971 1976 1981 1986 1991 1996 2001 2006 Source: United Nations Food and Agriculture Organization, U.S. Census Bureau As of 12/31/10 GMO 4 Quarterly Letter – Resource Limitations 2 – July 2011 A. Water There is no doubt that water shortages will be a source of economic and social trouble forever. Countries will rattle sabers or, worse, go to war over access to river waters. That is certain. But viewed as a problem for the U.S. or for the planet as a whole, it does not seem to be a game stopper. The surface of our planet is, after all, mostly water. For our direct use and for our crops, we need a derisorily small fraction of Earth’s supply of water. The entire planet’s current wasteful use of fresh water is equal to only 80% of the flow of the Amazon. We also use our existing supplies of renewable fresh water with desperate inefficiency and wastefulness. As prices rise, we can save not just a few percent but a great majority of our water by growing the right things in the right places and by sensibly sharing and recycling the resource. Further out, with likely sources of reasonably cheap energy, we could supplement our supply with desalinated ocean water for coastal populations. Other than shifting crops, the main effect on agriculture will be a steady increase in the cost of water as we move slowly to recognizing the real costs of supplying water to farming. However, come back in 50 or 100 years and we will, I believe, have been persistently irritated by water problems but never seriously threatened as a species.
在农业生产力方面,未来 50 年最大的困扰之一将是化石水源的枯竭——那些几乎得不到降雨补给的大型地下淡水湖泊。不幸的是,这些巨大的地下储水层恰好分布在世界上几个最重要的粮仓之下,包括美国大平原的部分地区、印度次大陆西北部部分地区,以及中国东北部分地区,正是这些水源支撑着这些地区的农业生产。如果这些大片区域要继续维持生产(而且它们确实不可或缺),那么就必须建设大型调水系统——长度在 500 到 2000 英里之间的运河——从其他地方引水。不过,尽管这会在投资和环境方面带来巨大的麻烦,听起来终究还是有办法做到的,无非是付出代价而已。(这类问题中最棘手、最紧迫的当属也门,那里几乎完全依赖地下化石水源,而就在我写这篇文章时,这些水源已经开始枯竭!)
For farming productivity, one of the greatest irritants for the next 50 years will be the depletion of fossil water: the great underground lakes of fresh water that receive little or no replenishment by rainfall. By bad luck, such vast deposits underlie and make possible some of the planet’s great bread baskets, including parts of the U.S. plains, parts of the Northwest of the Indian subcontinent, and parts of Northeastern China. If these very large areas are to stay in production, and they will certainly be needed, then major water transfer systems – canals of 500 to 2,000 miles in length – will have to be developed and the water taken from elsewhere. But even this, although it spells investment and environmental troubles in a big way, sounds ultimately doable, at a price. (The nastiest near-term problem of this kind will be in Yemen, where there is almost total dependence on underground fossil water, which is beginning to run out as I write!)
B. 化肥
我认为,化肥问题没有那么容易解决。草坪肥料中著名的 N-P-K 三大宏量营养元素肥料,分别是氮、磷、钾。氮是三者中每年需求最迫切的元素,但它在空气中含量最丰富,因此也是最不成问题的一个。许多作物,比如大豆和苜蓿,能够为我们主要的谷类生产供应或“固定”氮元素。生物工程很可能会增强这种能力,并扩大能够这样做的植物范围。雷暴天气本身就能从空气中提供大量氮肥。(这约占所有固氮量的 5%,而现代农业约占 50%。)更可靠的人造——准确说是人工处理——氮肥,是用天然气高效生产的,而幸运的是,世界上许多地区正发现越来越多的天然气储备。其中几个地区——尤其是美国和中国——是主要的粮食生产国。因此,只要我们不刻意把天然气浪费在不太重要的产品上,至少在本世纪内我们应该不会有问题。氮是空气中含量最多的成分,只需要能量就能转化成肥料。所以,长期来看,氮基肥料的可得性问题,和水一样,关乎成本,而非供应短缺。但是,从今天天然气低得离谱的价格(按 BTU 热值当量仅为石油的 20%——几乎是历史最低水平)出发,农民应该预见到,未来 10 到 15 年内,氮肥价格将上涨数倍。
B. Fertilizers Fertilizers are, I believe, less tractable. The three major macro nutrient fertilizers are the well-known N-P-K of lawn fertilizer: nitrogen, phosphorus, and potassium. Nitrogen, the most urgently needed of the three every year, is found in the greatest quantity so is happily the least problematical. Many crops, such as soya and alfalfa, supply or “fix” nitrogen for our main cereal production. Bioengineering is likely to increase this ability as well as broaden the range of plants that are able to do this. Electrical storms provide large quantities of nitrogen fertilizer out of the very air itself. (This provides about 5% of all nitrogen fixation, while modern agriculture accounts for about 50%). More dependable man-made, or rather man-processed, nitrogen fertilizer is very efficiently made with natural gas, which is being found, fortunately, in increased quantities in many different regions of the world. Several of these regions – notably the U.S. and China – are major grain producers. Therefore, if we don’t go out of our way to waste our natural gas on less important products, we should be fine at least through this century. Nitrogen is the largest component of air and just needs energy to be converted into fertilizer. So, longer-term availability of nitrogen-based fertilizer is, as with water, about cost, not availability. But, starting with today’s almost ridiculously low prices for natural gas (20% BTU equivalency of oil – just about the lowest in history), farmers should count on seeing increasing multiples of the price for nitrogen fertilizer in the next 10 to 15 years.
钾(碳酸钾)的处境不太乐观。当今已知的资源分布如附表 2 所示。尽管钾广泛存在,但规模极大、品位极高(即成本低廉)的矿床却相当集中地分布在两个区域:一块在俄罗斯与白俄罗斯,另一块——如果各国保持友善关系,这对北美洲而言倒是幸事——在加拿大。除非出现相当程度的卡特尔式行为(这在当今某些大宗商品领域并不鲜见),否则我们有充足的时间来研究长期短缺的问题。对我们来说幸运的是,钾是地壳中储量丰富的元素。
Potassium (potash) Potassium is in a less favorable situation. Today’s known resources are shown in Exhibit 2. Although it is found widely, very large and high grade (i.e., cheap) deposits are concentrated to quite a remarkable degree in two areas: one in Russia and Belarus and the other, happily for North America if we all stay friendly, in Canada. Unless there is considerable cartel-like behavior, which is certainly not unheard of these days with some commodities, then we have plenty of time to study the very long-term shortage problem. Luckily for us, potassium is a generously supplied element in the Earth’s crust.
季度信函——资源限制之二——2011 年 7 月 GMO 图表 2 世界钾肥产量与储量(千公吨) 产量 储量 美国 900 130,000 白俄罗斯 5,000 750,000 巴西 400 300,000 加拿大 9,500 4,400,000 智利 700 70,000 中国 3,000 210,000 德国 3,000 150,000 以色列 2,100 40,000 约旦 1,200 40,000 俄罗斯 6,800 3,300,000 西班牙 400 20,000 乌克兰 12 25,000 英国 400 22,000 其他国家 - 50,000 全球合计(四舍五入) 33,000 9,500,000 数据来源:美国地质调查局(截至 2010 年 12 月 31 日)尽管如此,值得指出的是,钾和磷(磷酸盐)具有一些我们在整洁且短期导向的投资世界里不常打交道的特性。这些特性会使得能源问题显得微不足道,因为能源可以通过多种不同方式获取。钾和磷无法被制造,它们是基本元素。没有替代品能奏效。钾和磷对一切有生命物质(动物和植物)都是必需的。最值得注意的是,对我们人类而言。例如,按体重计算,人类大约含有 1% 的磷。现代高产、单一作物的农业如今非常依赖有限的矿物资源,这些资源如果被浪费性地使用,可能在 50 年内轻易引发严重问题;如果被明智且节约地使用,则可能维持大约 200 年。然后呢?你必须像依赖生命一样,对资源进行回收和超级智能化的耕作。而事实也将如此。
Quarterly Letter – Resource Limitations 2 – July 2011 5 GMO Exhibit 2 World Potash Production and Reserves (thousands of metric tons) Production Reserves United States 900 130,000 Belarus 5,000 750,000 Brazil 400 300,000 Canada 9,500 4,400,000 Chile 700 70,000 China 3,000 210,000 Germany 3,000 150,000 Israel 2,100 40,000 Jordan 1,200 40,000 Russia 6,800 3,300,000 Spain 400 20,000 Ukraine 12 25,000 United Kingdom 400 22,000 Other Countries - 50,000 World Total (rounded) 33,000 9,500,000 Source: U.S. Geological Survey As of 12/31/10 Nevertheless, it is worth pointing out that both potassium and phosphorus (phosphates) have some characteristics that we are not accustomed to dealing with in our neat and short-term-oriented investment world. They are characteristics that make energy problems seem trivial because energy can be extracted in so many different ways. Potassium and phosphorus cannot be made. They are basic elements. No substitutes will do. Both potassium and phosphorus are required for all living matter, animal and vegetable. Most notably, us. We humans are, for example, approximately 1% phosphorus by body weight. Modern high-production, single-crop agriculture today is very dependent on finite mined resources, which, if used wastefully, could easily cause a severe problem within 50 years and, if used sensibility and sparsely, could last for perhaps 200 years. And then what? You must recycle and farm super intelligently, as if your life depended on it. And it will.
磷(磷酸盐)的储量情况见附录 3。无可否认,关于钾肥和磷酸盐的储量存在巨大争议,因为这两者的勘探都不如石油储量那样全面。在这方面我们也很幸运,因为储量的可开采年限给了我们足够的时间来为余生(作为人类这个物种而言)做出合理的规划。但同样,这些储量的分布也不均衡,而且这一次的倾斜程度,可以说,更具戏剧性。据估计,50% 到 75% 的储量位于摩洛哥及其“关联的”西撒哈拉地区。摩洛哥所拥有的磷酸盐份额,让沙特阿拉伯的石油份额看起来都像是小巫见大巫——说到底,取暖和吃饭相比,哪个更重要?
Phosphorus (phosphates) The reserve situation for phosphorus is shown in Exhibit 3. Admittedly, there are big arguments over reserves of both potash and phosphates because neither has been explored as comprehensively as have oil reserves. Here, too, we are quite lucky because the reserve life gives us time to plan sensibly for the rest of our lives (as a species, that is). But here again, the reserves are not evenly distributed and this time the skew is more, shall we say, interesting. It is thought that between 50% and 75% of the reserves are in Morocco and “associated” Western Sahara. Morocco’s share of phosphates makes Saudi Arabia’s share of oil look like small potatoes and, in the end, who values heating more than eating?
图表 3 所示的高品位现有储量,表面上看非常令人满意。现有储量相当于当前产量水平的 369 年。即使考虑每年 2% 的增长以维持产能,这些储量也能维持约 200 年。但如果不算摩洛哥、同时保持 2% 的增长,总储量将在 50 年内彻底耗尽。因此,无论是否能发现新储量,几十年内都必然会引发相当重大的博弈性行为。或者换个说法:如果这些磷酸盐矿在我的王国里,我会想办法趁机大捞一把。
The existing high quality reserves shown in Exhibit 3 look, superficially, very satisfactory. There are reserves equal to 369 years of current production. Even allowing for 2% growth to help maintain productivity, these reserves would not run out for about 200 years. But, without Morocco and at 2% growth, reserves would be totally depleted in under 50 years. So with or without new reserves being located, some substantial gamesmanship should be expected within a few decades. Or, put it this way: if the phosphates were in my kingdom, I would try to make some hay.
GMO 第 6 期季报——资源限制 2——2011 年 7 月
表 3 世界磷矿产量与储量(千公吨)
| 国家/地区 | 产量 | 储量 |
|---|---|---|
| 美国 | 26,100 | 1,400,000 |
| 阿尔及利亚 | 2,000 | 2,200,000 |
| 澳大利亚 | 2,800 | 82,000 |
| 巴西 | 5,500 | 340,000 |
| 加拿大 | 700 | 5,000 |
| 中国 | 65,000 | 3,700,000 |
| 埃及 | 5,000 | 100,000 |
| 以色列 | 3,000 | 180,000 |
| 约旦 | 6,000 | 1,500,000 |
| 摩洛哥和西撒哈拉 | 26,000 | 50,000,000 |
| 俄罗斯 | 10,000 | 1,300,000 |
| 塞内加尔 | 650 | 180,000 |
| 南非 | 2,300 | 1,500,000 |
| 叙利亚 | 2,800 | 1,800,000 |
| 多哥 | 800 | 60,000 |
| 突尼斯 | 7,600 | 100,000 |
| 其他国家 | 9,500 | 620,000 |
| 全球 | 176,000 | 65,000,000 |
| 全球(不含摩洛哥) | 150,000 | 15,000,000 |
数据来源:美国地质调查局,截至 2010 年 12 月 31 日
磷的长期供给很可能是迄今最棘手、也最具威胁性的问题。也许存在大量低品位储量的磷矿,它们尚未被列入清单,甚至未被勘探。(既然还有几十年的低成本、高品质储量可用,谁会花钱去做那种事呢?)但也许并不存在。我们目前正在尽可能多地搜集那些有限的现有数据。(关于这个问题以及本信讨论的多个议题中提到的其他许多难题,我们一旦有所发现,会时不时地陆续提供相关数据。)眼下,认真的科学专家们大多“假设”——就像许多其他资源的情况一样——还有更多、通常多得多的未记录低品质储量,超过了已知的高品质储量。但这并不总是事实。例如,英国曾拥有大量高品质的无烟煤和烟煤储量,这推动它们进入了工业革命,但如今它的无烟煤已耗尽,烟煤也所剩无几,而且没有像德国等国那样大规模的褐煤或柴煤储量。
GMO 6 Quarterly Letter – Resource Limitations 2 – July 2011 Exhibit 3 World Phosphorus Production and Reserves (thousands of metric tons) Production Reserves United States 26,100 1,400,000 Algeria 2,000 2,200,000 Australia 2,800 82,000 Brazil 5,500 340,000 Canada 700 5,000 China 65,000 3,700,000 Egypt 5,000 100,000 Israel 3,000 180,000 Jordan 6,000 1,500,000 Morocco and Western Sahara 26,000 50,000,000 Russia 10,000 1,300,000 Senegal 650 180,000 South Africa 2,300 1,500,000 Syria 2,800 1,800,000 Togo 800 60,000 Tunisia 7,600 100,000 Other Countries 9,500 620,000 World 176,000 65,000,000 World excluding Morocco 150,000 15,000,000 Source: U.S. Geological Survey As of 12/31/10 The long-term phosphorus supply is probably the trickiest and most threatening issue to date. There may be a lot of lower-grade reserves that have not been listed or even looked for. (Why pay money to do that when there are decades’ worth of low-cost, very high-quality reserves?) But there may not be. We are currently ferreting out as much of the limited data there is available. (Data on this and the many other conundrums raised in several of the topics discussed in this letter will be relayed from time to time as we can dig them out.) Serious scientific experts at this point are mostly “supposing” that, as is the case with many other resources, there are more, often much more, lower-quality reserves that are currently unrecorded than there are known high-quality reserves. But this is not always the case. The U.K., for example, had a lot of high-quality anthracite and bituminous coal reserves, which propelled them into the Industrial Revolution, but today all of its anthracite is gone, most of its bituminous is gone, and there are no very large reserves of brown coal or lignite as there are, for example, in Germany.
大多数钾盐和磷酸盐矿床都与曾经的海洋或盐海有关联——至少很多人这么认为。好吧,如果你想要悲观一点,你可以争辩说,要么你拥有的是一片因亿万年地壳隆起而干涸的古海洋,要么你没有。也许你并没有大量通常不含盐分的、更小规模的干涸水体。无论如何,在这一点上我们都在推测。尽管这个问题潜在的重要性很高,但可靠的数据就是无从获取。
Most, if not all, of the potash and phosphate deposits are associated with former oceans or salty seas, or that is believed by many to be the case. Well, if you wanted to be pessimistic, you could argue that you either have a dried up former ocean due to the ground rising over aeons, or you don’t. Perhaps you don’t have masses of smaller dried up bodies of water, which normally would be salt-free. In any case, we are all speculating at this point. Despite its potential importance, reliable data is just not available.
让我们想象一下,50 年或 150 年后会发生什么——当最后一批价格可承受的磷肥被交付,而摩洛哥相当明智地对其最后三分之一资源收取每吨数千美元时。我们也许正着手从大陆架进行近海开采,价格略低于摩洛哥的报价,但仍然高得令人咋舌,贫穷国家根本负担不起。但更多时候,我们会在回收利用上下功夫——这个词会让我们的孙辈感到无比厌倦。在商业肥料出现之前的农耕时代,农作物就是这么种植的,至少在有条件不搞刀耕火种和轮作迁移的农民那里是如此。尤其是中国农民,几乎以宗教般的虔诚坚持回收利用,成功保持了土地数千年的生产力:挑着两桶豆子去镇上集市,再挑着两桶“夜香”回来。人类和动物的排泄物,以及蔬菜废弃物,都被一丝不苟地重新利用。那些拼命提高产量或在回收利用上不够仔细的国家,土壤纷纷枯竭。东欧尤其如此,直到 19 世纪 80 年代,农作物还屡屡歉收,饥荒频发。而现在,我们可以做得比旧时代的中国人更好,因为科学已经进步了。过去 50 年里,我们在大幅减少养分流失方面学到了很多。我们还能做更多,而且最好赶紧行动起来:上一次世界主要依赖回收利用时,全球人口仅有 10 亿。下一次,人口可能达到 100 亿——祈祷它不是更多吧。一个以养分回收为基础的世界,即使有开采肥料资源中价格极高的剩余部分作为补充,真的能养活 100 亿人吗?或者 50 亿?我认为,如果在未来几十年里不能尽快行动起来,答案肯定是不能。即便如此,真正的可持续人口规模也很有可能远低于 100 亿。
Let us imagine for a minute what might happen in 50 or 150 years when the last affordable phosphorus is delivered and Morocco is, quite sensibly, charging thousands of dollars a ton for the last one-third of its resources. We might be developing offshore recovery from the continental shelf at a little less than Morocco’s price, but still a gaspingly high price that would not be even remotely affordable by poorer countries. But mostly we would be recycling, a word with which our grandchildren will get awfully bored. It’s how crops were grown in the pre-commercial fertilizer age, at least wherever farmers could not engage in slash and burn and move on. Chinese farmers in particular successfully maintained the productivity of their fields for thousands of years by almost religiously recycling: off to the town market with two buckets of beans and back with two buckets of “night soil.” Human and animal waste, as well as Quarterly Letter – Resource Limitations 2 – July 2011 7 GMO vegetable waste, was scrupulously reused. Countries that pushed their production or were not so careful in recycling depleted their soils. Eastern Europe in particular had recurrent crop failures and starvation as late as the 1880s. And, we could do it better now than the Chinese did in the old days, for science has marched on. We have learned to reduce nutrient loss considerably in the last 50 years. There is also much more that we could do, and we had better get moving: the last time the world depended mainly on recycling, the global population was a mere one billion. The next time it may be 10 billion – cross your fingers it’s not more. Could a world based on recycling nutrients, even one supplemented by very high-priced remnants of our mined fertilizer resources, really feed 10 billion? Or even 5 billion? I think the answer is certainly no if we do not get our act together in the next very few decades. Even then, it is more likely that true sustainability will be a much lower number than 10 billion.
C. 土壤侵蚀
最后,是真正的难题:土壤侵蚀。地球是一个奇妙的地方,它慷慨地利用风雨侵蚀加上细菌和微生物作用,从基岩中制造出新的土壤。更了不起的是,这些新土壤还带着充足的磷和钾一同到来。这颗星球如此慷慨,待我们不薄。在人类出现之前,雨水溶解并冲走土壤及其携带的养分,速度与新土壤生成的速度相当,不会更快。这同样堪称精妙的平衡把戏。我们可以从古代湖床中记录下稳定而缓慢的侵蚀速率。可惜,人类出于对树木的渴求——最初是为了取暖和栖身,后来是为了耕地和肥料(焚林会释放森林储存的肥料和其他养分)——开始以极快的速度砍伐森林,使得侵蚀速率随之加快。没有什么比毁林更快加剧侵蚀和养分净流失了。(而且,具有讽刺意味的是,也没有什么比侵蚀更快推动毁林,因为侵蚀降低了土地生产力,从而加剧了开垦新土地来填补缺口的压力,形成一个相当恶性的反馈循环。)随着人口增长,森林面积因此缩减,耕地面积则扩大了。即便是在几乎从未长树的稀树草原上开垦,也会让侵蚀速率成倍增加。有时这些因素累积起来,就会产生可以预见的后果。例如在巴拿马,常见的情形是:那些曾经完全被森林覆盖的陡峭山地,如今被用来放牧。牛群踩出的小径形成了沟壑,汇聚起热带雨水,而这雨水又在几十年内将整片山坡冲刷殆尽。
C. Soil Erosion Finally, there is the real bugbear: soil erosion. The Earth is a wonderful place that obligingly creates new soil from bedrock, using the wear and tear of weather plus bacterial and microbial action. Perhaps even more remarkably, this new soil arrives with a good complement of phosphorus and potassium. This is pretty good treatment from a very generous planet. Before humans appeared, the rains would dissolve and wash away the soil and its associated nutrients just as fast as it was produced, but no faster. That’s a pretty neat balancing trick too. We can record the steady, modest rate of erosion in ancient lake beds. Humans, alas, with their tree lust, initially for heat and shelter and later for arable space and fertilizer (burning the forest sheds its store of fertilizer and other nutrients), began to cut forests down so fast that the erosion rate increased. Nothing increases erosion and net nutrient loss faster than deforestation. (And, ironically, nothing encourages deforestation like erosion, because erosion decreases productivity and, hence, increases the pressure to bring on new land to fill the gap in a rather vicious feedback loop.) As our population grew, the forests were thus diminished in size, and the arable land increased. Even plowing savannahs, where trees had seldom or never grown, increased erosion by a large multiple. Sometimes these factors would accumulate with predictable results. In Panama, for example, it is common to see very hilly land that was once totally forested being used for cattle grazing. The cattle create paths that form gullies that funnel the tropical rains, which in turn denude whole hillsides in a few decades.
今天的具体情况很难说清:第一,土壤流失在不同地区因土壤类型和耕作方式的差异而差别巨大。第二,其测量也必然困难重重,因为科学家们对最佳方法存在截然不同的看法。在某个极端上,报告几乎令人恐惧。康奈尔大学的一群科学家在《科学》杂志上撰文,将其研究结果总结如下:“土壤侵蚀是对农业可持续性和生产能力的主要环境威胁。在过去 40 年里,世界上近三分之一的耕地因侵蚀而流失,并且正以每年超过 1000 万公顷的速度持续流失……在美国,估计每年流失 400 亿吨土壤。” 不幸的是,康奈尔大学的农学院在该领域享有盛誉——读到他们的总结,人的本能反应是:“好吧,就这样了。一百年后,所有人都得饿死。” 幸运的是,另一个极端也有一些人认为我们最终能安然度过,至少在美国是这样。而且,正如我们即将看到的,免耕农业的兴起有潜力带来巨大帮助。关于土壤流失与补充的简要实情是:自然补充一英寸(25 毫米)表土需要 50 到 1000 年,具体取决于当地条件和研究者的判断。不同土壤重量各异,但平均每英亩每毫米约 5 吨,即每英亩每英寸约 125 吨。因此,自然补充率相当于每年每英亩 2.5 至 0.125 吨,而非美国农业部一直用作可接受侵蚀率的每年每英亩 5 吨。非常保守地说,目前美国的土壤流失很可能高于自然补充速度,甚至可能高出很多。在澳大利亚,那里的记录可追溯到 19 世纪,同样明显的是,超过 70% 的耕地已受到相当程度的退化。就整个地球而言,土壤流失肯定超过补充速度,而在一些地区,特别是非洲,其超出程度是灾难性的。
What the precise situation is today is hard to tell: First, erosion varies widely from region to region by type of soil and agricultural practice. Second, its measurement must also be difficult, for scientists have widely different views as to the best methodology. At one extreme, the reports are almost terrifying. A group of scientists from Cornell University writing in Science magazine5 summarized their findings as follows: “Soil erosion is a major environmental threat to the sustainability and productive capacity of agriculture. During the last 40 years, nearly one-third of the world's arable land has been lost by erosion and continues to be lost at a rate of more than 10 million hectares per year ... In the U.S. an estimated 40 billion tons of soil ... are lost each year.” Unfortunately, Cornell’s Agricultural School has high standing in its field – reading their summary, one’s instinct is to say, “Well that’s it then. In a hundred years, everyone starves.” Fortunately, there are also those at the other extreme who think we’ll muddle through just fine, at least in the U.S. And, as we will see, the rise of no-till farming has the potential to help a lot. The brief nitty-gritty on erosion and replacement is that somewhere between 50 and 1,000 years is needed to naturally replace one inch (25mm) of subsoil, depending on local conditions and who is doing the research. Different soil has different weights, but averages about 5 tons per acre per millimeter or 125 tons per acre per inch. Therefore, the natural replacement rate is equal to 2.5 to 0.125 tons per acre per year, rather than the 5 tons per acre per year that the U.S.D.A. has been using as an acceptable erosion rate. To state this very conservatively, current U.S. soil losses are very probably higher than natural replacement and possibly considerably higher. In Australia too, where records go back into the nineteenth century, it is also clear that more than 70% of arable land has been degraded to some considerable degree. For the planet as a whole, soil losses are certainly higher than replacement, and for some areas, notably in Africa, they are disastrously higher.
5 David Pimentel 等人在《科学》杂志新系列第 267 期发表文章“土壤侵蚀的环境与经济成本及保护效益”,刊于《GMO 季度通讯第八期——资源限制之二——2011 年 7 月》。美国方面,任何更有利的数据,都被爱荷华州立大学最近的一份报告进一步抵消了。6 该报告声称达到了新的精度水平,指出问题不在于典型的侵蚀,而在于罕见的极端暴风雨——一次夜晚就能造成相当于一年到数年的侵蚀,因为新形成的冲沟与普通降雨期间形成的冲沟截然不同。不幸的是,近年来在全球范围内,这些极端暴风雨事件已变得相当普遍,原本罕见的天气事件因气候变暖而变得更加频繁。
5 David Pimentel, et al., “Environment and Economic Costs of Soil Erosion and Conservation Benefits,” Science, New Series, Volume 267 GMO 8 Quarterly Letter – Resource Limitations 2 – July 2011 Further offsetting any of the more favorable data in the U.S. is a recent report from Iowa State University.6 The report, which claims new accuracy levels, holds that typical erosion is not the issue, but that the rare extreme storm can cause one to several years’ erosion in a single night as new gullies form in a way totally unlike those that form during regular rain storms. These outlier storms have unfortunately become much more common globally in recent years, with formerly rare weather events having become more frequent as a consequence of a warming climate.
侵蚀的历史 我们现在知道,新月沃地及其他早期文明中心的土壤——主要因耕作而流失——往往导致人口密度急剧下降。当这些文明最终被入侵者取代时,它们往往只剩下昔日强盛的躯壳,人口仅剩原来的零头。北非曾是迦太基等帝国的家园,这些帝国强大到足以挑战罗马,另一些地区——如古利比亚和突尼斯——则肥沃得足以供养罗马。如今这片土地上的大部分地区已失去其过去绝大部分的农业生产力。古希腊、罗马统治下的意大利中部、叙利亚、伊拉克以及许多其他地区,都曾遭受到底土侵蚀长达千年以上的影响,从而限制了人口规模,削弱了经济与军事力量。到了罗马帝国晚期,曾处于肥沃平原中心的罗马,到处是废弃的农田,完全依赖从埃及和叙利亚进口粮食。叙利亚的历史中,一些整座城市连同其周边数十个村庄,后来因不可持续的农业实践导致土壤消失,而被彻底遗弃在沙漠之中。一千五百年前的美洲,玛雅等文明过度消耗土壤,有证据表明他们流失的土壤之多,已无法可靠地养活其峰值时期的人口。(夏季可读的两本详述此话题的书是:戴维·R·蒙哥马利的《土壤:文明的侵蚀》和贾雷德·戴蒙德的《崩溃:社会如何选择成败兴亡》。)此前引用的学术研究声称,全球土壤在短短几十年内就损失了三分之一。不难相信,自人类历史开端以来,这个数字可能已达二分之一,甚至更多。土壤侵蚀导致古代帝国覆灭的历史本应是一个强有力的警告,但它似乎并未起到作用。自殖民地时代以来,美国被认为已损失了三分之一到一半的表层土,而今天流失速度仍快于形成速度,尽管近年已大幅减慢。然而,就在 20 世纪 20 年代、著名的“沙尘暴”30 年代及 40 年代,尽管历史早有警示,美国农场的侵蚀速率仍达到灾难性的水平——远超形成速度的 10 倍。
History of Erosion We now know that population density in the Fertile Crescent and some of the other centers of early civilization often dropped precipitously as their soils, due mainly to plowing, eroded. By the time they were finally disposed of by invaders, they were often shells of their former might with tiny fractions of their original populations left. North Africa was home to empires such as Carthage, which were powerful enough to challenge Rome and, in other cases, fertile enough to help feed Rome, which was the case of ancient Libya and Tunisia. Most of this territory has lost the great majority of its former agricultural capacity. Ancient Greece, Central Italy under the Romans, Syria, Iraq, and many others all suffered from the effects of subsoil erosion over a period of one thousand or more years, thus limiting their populations and reducing their economic and military power. In its later years, Rome, once at the center of fertile plains, abandoned farms everywhere and was totally dependent on imports from Egypt and Syria. Syria’s history is one in which whole cities, with their dozens of surrounding villages, were later completely abandoned to the desert as their soil disappeared due to unsustainable agricultural practices. Fifteen hundred years ago in the Americas, civilizations such as the Mayans overtaxed their soils and provably lost enough soil to make it impossible to reliably feed their peak populations. (Two readable books for the summer that cover this topic in detail are: Dirt: The Erosion of Civilizations, by David R. Montgomery and Collapse: How Societies Choose to Fail or Succeed by Jared Diamond.) The academic study previously cited,7 claims the loss of one-third of our soil globally in just a few decades. It is easy to believe that since the beginning of human history it might be fully one-half, or even more. The history of soil erosion bringing ancient empires down might have served as a powerful warning, but it does not seem to have done so. Since Colonial times, the U.S. is thought to have lost one-third to one-half of its topsoil, and today is still losing at a rate faster than replacement, although at a recently much-reduced rate. Yet, as recently as the 1920s, the 1930s of Dust Bowl fame, and the 1940s, U.S. farms were eroding at disastrous rates – well over 10 times replacement, despite the historical warnings.
全球范围内,情况一直——并且现在依然——比美国严重得多。我们很难想清楚,要怎样才能让人们明白:土壤侵蚀或许是对我们长期福祉最大的单一威胁。它肯定是其中之一。但侵蚀的阴险之处在于,它在古今文明中都始终极其缓慢地悄然逼近。公元 100 年的叙利亚农民,关心的是在粮价高涨之年向罗马供应粮食。可以肯定的是,与他们眼前的问题相比,缓慢(即便持续)的生产力损失在他们看来像是书本上的抽象概念。如今,所谓贴现率的暴政保证了同样的行为模式。遥远的损害几乎不值一提,而对全体人类造成的损害也没有任何调整系数。电子表格里只体现个人或企业的收益。这是传统自由市场资本主义的一个严重缺陷,甚至可能是致命缺陷。与这个一般性话题相关的还有另一些问题:资本主义没能轻松应对我们资源的有限性。这个主题——资本主义的缺陷——是个大话题,我将在下个季度尽力讲清楚。眼下,为了将本季度的侵蚀话题与下季度资本主义的话题联系起来,我来讲一个魔鬼和农夫的小故事。
Globally, the situation has been, and remains, much worse than in the U.S. It is not clear what it will take to drive home the message that erosion is perhaps the single largest threat to our long-term well-being. It is certainly one of them. But erosion is insidious in that it has always crept up very slowly on both ancient and modern civilizations alike. Syrian farmers in 100 A.D. were concerned with supplying Rome in a year when prices were high. We can be sure that slow (even if steady) losses of productivity seemed to them to be academic abstractions in contrast. Today, what we might call the tyranny of the discount rate guarantees the same behavior. Damage far out has little value, and there is no adjustment factor for damage to all of us collectively. Only the gain of the individual or the corporation appears in the spreadsheet. This is a severe, perhaps even fatal, flaw in traditional free-market capitalism, and there are others that relate to this general topic: capitalism has not easily handled the finiteness of our resources. This topic – deficiencies in capitalism – is a big one and I will try to do it justice next quarter. For now, to link the current topic of erosion with that of next quarter’s on capitalism, I offer a brief story of the Devil and the Farmer.
魔鬼与农夫
魔鬼化身为一家大型农业公司的无辜代理人,来到一座典型的中西部农场。他建议农夫更激进地耕作,并像往常一样,带来了一份合同。合同规定,若农夫签署,就必须承诺采用激进耕作方式,而魔鬼则保证农夫的利润将增长四倍。但老规矩,这里面藏着陷阱:第 23 条附则告诉农夫,6 Craig Cox, Andrew Hug, and Nils Bruzelius, “Losing Ground,” April 2011; http://static.ewg.org/reports/2010/losingground/pdf/losingground_report.pdf 7 Ibid.
The Devil and the Farmer The Devil, disguised as an innocent agent of a large agricultural company, arrives at a typical Midwestern farm. He has come to suggest to the farmer that he engage in more aggressive farming, and he comes, as usual, with a contract. The contract, if signed, pledges the farmer to farm aggressively and pledges the Devil to guarantee that the farmer’s profits will be multiplied five-fold. But, as always, there is a catch: Footnote 23 is a clause that informs the farmer 6 Craig Cox, Andrew Hug, and Nils Bruzelius, “Losing Ground,” April 2011; http://static.ewg.org/reports/2010/losingground/pdf/losingground_report.pdf 7 Ibid.
季度信函 – 资源局限性 2 – 2011 年 7 月 GMO 认为,强行榨取短期最大产出,每年只会损失 1% 的土壤肥力。魔鬼的这笔交易危险却合理,因此我猜测,90% 的农夫会觉得自己家人的福祉必须接受这个条件。魔鬼还附上了一张电子表格,清晰列出利润,也如实列出土壤生产力逐年下降的趋势——而且,恶毒的是,它做得相当诚实。到 40 年合同结束时,农场的生产力只下降了不到 5%,而农夫获得的净财务收益却极为可观。
Quarterly Letter – Resource Limitations 2 – July 2011 9 GMO that squeezing out maximum short-term output will result in the loss of just 1% per year of his soil. The Devil’s deal is dangerously reasonable, and therefore I would guess that 90% of farmers would feel that their families’ well-being requires that they accept it. The Devil has included a spreadsheet that accurately lays out the profits and also lays out the steady decline in the soil’s productivity and, fiendishly, does it honestly. By the end of the 40-year contract, the farm’s productivity is down by barely 5%, and the farmer’s net financial gains are enormous.
这个时期如此成功,以至于农夫又续租了 40 年。魔鬼依然没有使诈。到第 80 年时,经过部分自然恢复后的土壤深度几乎正好是第一年水平的一半(而且别忘了,在耕作的头 150 年里,土壤平均已经流失了三分之一到一半),但农场已经极其兴旺。而且,即便经历了土壤流失,它仍然算不上特别差,因为结果发现,当地所有农夫都做了同样的交易。他们的产量全都下降了 20% 到 25%,但由于全球粮食价格的压力,这笔交易看起来依然有吸引力。那些过去从不说谎的电子表格,仍然准确而诚实地显示着,重孙子和他的所有邻居再次续租会多么有利可图。就这样,通过始终采用最优现值方案并遵循严格的资本主义原则,中西部乃至整个地球一步步走向悬崖边缘——农夫们几乎一直富足到最后,最终却被成群结队、饥饿的城里人淹没!
So successful has this period been that the farmer re-ups for another 40 years. Once again, the Devil does not cheat. By the 80-year mark, the soil depth after some natural replacement is almost precisely half of its year 1 level (and, remember, it also lost one-third to one-half of its soil on average in the first 150 years of farming), but the farm has prospered enormously. And, even after the soil loss, it is still by no means particularly sub-average because it turns out that all of the local farmers have made the same deal. All of their productivities have dropped by 20% to 25% but, because of global pressures on grain prices, the deal still looks attractive. The spreadsheets, which have not lied in the past, still accurately and honestly show how profitable it will be for great-grandson and all of his neighbors to re-up yet again. In this way, by always adopting the plan with the optimal present value and by following strict capitalist principles, the Midwest and the planet marches off the edge of the cliff, as farmers, prosperous almost to the very end, are finally overwhelmed by armies of starving city dwellers!
(注:附录 2 展示了相关支撑材料。结果根本不在一个量级。普通农民用任何一种合理的贴现率来算,都会反复签署,直到土地肥力和产出归零!)
(Note: Appendix 2 shows the back-up material. It is not even close. Normal farmers, using any reasonable discount, would sign and re-sign until soil and productivity go to zero!)
最后讲讲好消息。为了避免以过于灰暗的基调收尾,我把最好的消息留到了最后;这消息好到让“丰裕派”可以欢呼雀跃,让悲观的“马尔萨斯派”只能暗想:“这运气也太不该有了吧!”绝大多数事物的巨大改进,都需要同样巨大的时间、精力和资本投入。但这一项改进——把水土流失率从远高于可持续水平降到可接受水平——几乎不需要什么投入,只需要愿意改变自己的做法,而这一特质在任何群体中(包括农民)都不总是那么充裕。近几十年发展起来的免耕农业,虽然起步缓慢,但在南美洲已经极速推广开来。目前那里超过 50% 的可耕地都采用了这项技术,考虑到该地区大部分地方降雨量大,这再好不过了。在美国,免耕农业的采用率最近急剧加速,根据美国农业部的数据,目前已占农田面积的 35% 以上。总体来看,这项技术在世界其他地方也有所推广,尽管速度缓慢,而在非洲几乎毫无进展。坏消息是,在全球范围内,尽管免耕优势明显,但它仅占谷物种植面积的 5%。顾名思义,免耕就是把上一季的作物残茬留在田里,第二年不是翻耕土地,而是用一个旋转轮每隔几英寸刺入地下,种下一粒种子,有时还同时施入精确计量的肥料。几年之后,地表覆盖的草垫层就能大幅减少暴雨造成的水土流失:一般学术研究报告指出,流失量减少超过 80%,最高可达 98%,最低也有 50%。如此一来,水土流失问题便可一举有效解决。
Finally, the Good News So as not to end too gloomily, I have saved the best news for the end; news so good that Cornucopians can jump for joy and gloomy Malthusians can think “What undeserved luck!” Most huge improvements in anything take equally huge investments of time, energy, and capital. This one, which reduces erosion rates from way over sustainability to acceptable levels, requires very little except a willingness to change one’s ways, a characteristic not always in great supply in any group, including farmers. No-till farming, developed in recent decades has, after a slow start, been spreading very rapidly in South America. It is now used in more than 50% of all arable land there, which, given the heavy rains in much of the area, is just as well. In the U.S., the adoption of no-till has very recently accelerated and it now accounts for more than 35% of farmland according to the U.S.D.A. In general, it is growing elsewhere, albeit slowly, and hardly at all in Africa. The bad news is that globally, despite its advantages, it makes up only a 5% share of grain production. Just as it sounds, no-till leaves the crop residue on the field and the following year, instead of plowing up the ground, a rotating wheel pierces the ground every few inches and plants a seed, sometimes together with a precisely measured dose of fertilizer. After a few years, the mat of ground cover massively reduces the erosion caused by heavy rains: the average academic study reports more than an 80% reduction, with the highest being 98% and the lowest 50%. In one fell swoop, the erosion problem can be effectively resolved.
保护土壤可能是免耕法最大的一项好处,但还有其他几项重要优势。当土壤被水冲走或被风吹走时,流失的是最表层的土壤,而正是这层土壤承载着相当一部分养分——这些养分是以高昂成本施入的。大约三分之一的肥料被浪费。五年前钾肥价格为每吨 175 美元时,这还算是个让人恼火的问题;在最近每吨 420 美元的价格下,这已是一笔不菲的节省——足以引起农民的重视。采用免耕法,累积的残茬中会提供增量养分,这进一步降低了成本,而且更关键的是,减轻了对本就紧缺的有限肥料资源的压力。
Protecting the soil may be the biggest single advantage of no-till, but there are several other important ones. When soil is washed or blown away, it is the very top soil that goes, and this is the soil that carries much of the nutrients that have been added at no small cost. About one-third of the fertilizer is wasted. This was an irritant when potash was $175 a ton five years ago. At the more recent price of $420 a ton, it is a serious saving – enough to get farmers’ attention. With no-till, there are incremental nutrients in the accumulated stubble, which further reduces costs and, more importantly, reduces the load on critical limited fertilizer resources.
土壤中的保水能力也大幅提升,因为大规模翻耕会使湿润土壤暴露在阳光下,而免耕法则能减轻这种影响。当雨水充沛且分布均匀时,这两种耕作方式在这方面差异不大;但若雨水稀少或遭遇全面干旱,地表覆盖物保护下的额外水分就能对产量产生显著影响。因此,无论是洪水还是干旱,土壤都变得更容易应对——在如今天气愈发不稳定的时代,这一点尤其具有说服力。
Water retention in the soil also greatly increases because the effects from full-scale plowing, which exposes the moist soil to the sun, are mitigated by no-till. When rain is plentiful and evenly spaced, there is little difference between the two systems in this respect, but when rains are scarce or there is full-scale drought, the extra moisture protected by the ground cover can make a big difference to productivity. So life is easier for the soil, whether it is a flood or a drought; a particularly compelling case in these days of increased weather instability.
最后,相对未被扰动的土壤质量会逐步改善,因为微生物、细菌、真菌及其他生物的数量在持续增加。这反过来又可能提高土壤的碳密度,而且无疑会提升土壤的持水能力以及微量营养素含量——在全面翻耕的条件下,这些营养素基本会降为零。人们普遍认为微量营养素能让食物更健康,而现代食物中长期缺乏这些营养素,对我们来说并不健康,因为数万年来我们一直食用成分更复杂的食物。总而言之,免耕法就像是农业女神刻瑞斯赐予的礼物,仅凭这一方法就能消除或长期推迟我们面临的大部分长期生产力问题。采用免耕法,最初几年产量通常会略有下降,但之后会缓慢上升。相反,采用高侵蚀率的翻耕法,产量会缓慢下降,在极长期内可能产生严重后果。免耕法的另一个缺点是,尤其是在最初几年,需要更多杀虫剂,这会带来环境和财务成本。不过,研究人员越来越相信,通过精细调整作物轮作、覆盖作物及其他“工程”技巧,这种增加大部分是可以消除的。归根结底,如果我们能在全球范围内对绝大多数粮食作物采用免耕法,那么对农业生产力的唯一严重威胁将来自非常长期的矿产肥料短缺,而即便这一威胁也能被大幅推迟。在土壤改良和全面有机农业方面投入更多努力,可以进一步提高土壤肥力,降低对“外部”肥料的需求,但这涉及一个过于复杂和争议性大的话题,不在此处讨论。
Finally, the quality of the relatively undisturbed soil improves as the number of microbes, bacteria, fungi, and other living critters steadily multiplies. This in turn arguably increases the carbon density of the soil and definitely further GMO 10 Quarterly Letter – Resource Limitations 2 – July 2011 increases the water retention capacity and the amount of micronutrients, which, under full plowing, basically fall to zero. It is widely believed that micronutrients make food healthier and that their chronic absence in modern food has not been healthy for us, molded as we are by tens of thousands of years of eating more complicated foods. All in all, no-till is like a gift from Ceres and single-handedly would remove or long postpone most of our long-term productivity problems. With no-till, productivity typically drops slightly in the first few years, but then slowly increases. Conversely, with high-erosion plowing, it slowly decreases, with potentially severe consequences over very long periods. Another disadvantage of no-till is that it requires more insecticide, especially in the first few years, which has environmental and financial costs. Researchers, though, increasingly believe that most of this increase can be removed by fine-tuning crop rotation, cover crops, and other “engineering” tricks. The bottom line seems to be that if we adopted no-till globally for a great majority of our grain crops, the only serious threat to agricultural productivity would be from the very long-term shortage of mined fertilizers, with even that threat much postponed. Additional efforts with soil enhancement and full-scale organic farming could further improve fertility and lower the need for “outside” fertilizer, but that is a topic too complicated and controversial to be covered here.
结论 这些都改变不了一个根本等式:我们有一个有限的承载能力。随着人口持续增长,我们将因碳氢化合物、金属、水资源、尤其是化肥的反复短缺而承压。不过,全球农业无疑将承受最大的压力——它可能要为额外 20 亿到 30 亿张嘴巴提供食物,这在短短 40 年内增长了 30% 到 40%。最优质土地的供应量几乎肯定会持续缓慢减少,而全球典型可耕土壤的质量也将因侵蚀而持续缓慢下降,尽管各方防止侵蚀的努力在加大。这给提高生产率带来了巨大负担。这样的生产率提升不仅需要应对越来越贫瘠的土壤,还要应对日益加剧的气候不稳定、所有投入品成本的上升,以及化肥长期可用性的限制。过去一两百年不曾适用、但确曾在许多古代文明中发生的情况是:如果我们不打算步那些文明的后尘堕入沙砾与岩石、走向人口凋零,我们就必须保护和滋养我们的资源——尤其是我们的农田。在高价格的激励下,我们会变得更节俭、更理性,拉长资源的可使用年限,从而为人口的自然减少——最终让我们重新达到平衡——赢得更多时间。(举例来说,实现粮食消费更大节俭的首要候选方案是减少肉类消费,以及禁止使用优质农田来生产汽油替代品。从全球层面看,美国的乙醇计划是一种冷酷的取舍:一边是不必要地帮助美国农民,另一边则是加剧一些最贫困国家的营养不良乃至赤裸裸的饥饿。)
Conclusion None of this changes the ultimate equation that we have a finite carrying capacity. As the population continues to grow, we will be stressed by recurrent shortages of hydrocarbons, metals, water, and, especially, fertilizer. Our global agriculture, though, will clearly bear the greatest stresses. It may have the responsibility for feeding an extra two to three billion mouths, an increase of 30% to 40% in just 40 years. The availability of the highest quality land will almost certainly continue to shrink slowly, and the quality of typical arable soil will continue to slowly decline globally due to erosion despite increased efforts to prevent it. This puts a huge burden on increasing productivity. Such increases have to contend not only with thinner soils, but also with increasing climate instability, rising costs of all inputs, and long-term availability limitations of fertilizer. In a way that has not applied to the last one or two hundred years but certainly did to many ancient civilizations, we will need to protect and nurture our resources – particularly our farms – if we do not intend to follow them into sand and rocks and depopulation. Encouraged by higher prices, we will become more frugal and more sensible and stretch out our resources, buying us more time for a natural decline in population to eventually bring us into balance. (Leading candidates for greater frugality in grain consumption, for example, would be reduced meat consumption and the banning of the use of quality farmland to produce gasoline substitutes. The U.S. ethanol program is, on a global level, a callous trade-off between unnecessary help to U.S. farmers on the one hand and increasing malnutrition and outright starvation in some of the poorest countries on the other hand.)
这里谈论的是,在通往长期可持续性的道路上所经历的痛苦和时间,以及如何分辨那些只是令人烦恼的问题,与那些真正、往往隐秘地威胁着我们当前富裕但鲁莽社会长期存续的风险。但其中的道理是清楚的。正如吉姆·罗杰斯喜欢说的那样:做个农民,而不是银行家——这个世界需要好农民!我想补充一句:或者成为一名资源效率专家,帮助这个世界为我们的子孙后代保留一些资源。如果全球范围内,我们能够应对长期的农业挑战,那么农业将是一份令人满足且充实的经历。而如果那该死的短期利润最大化继续像曾经发生在叙利亚、希腊和罗马农民身上那样,那么至少今天的农场主们会与船同沉,不过他们坐的是头等舱。
Here, the discussion is about the pain and time involved in getting to long-term sustainability as well as trying to separate the merely irritating from the real, often surreptitious, threats to the long-term viability of our current affluent but reckless society. The moral however, is clear. As Jim Rogers likes to say: be a farmer not a banker – the world needs good farmers! I might add: or become a resource efficiency expert and help the world save some of them for our grandchildren. Farming will be a satisfying and enriching experience if, on a global basis, we rise to the long-term agricultural challenges. And, if good old short-term profit maximizing continues as it did for the Syrian, Greek, and Roman farmers before us, then at least today’s farm owners will go down with the ship, travelling in first class.
季度致函——资源限制 2——2011 年 7 月 GMO 附录 1:马尔萨斯主义者与丰饶论者:埃利希-西蒙赌局
既然还在讨论资源话题,我想就 1980 年保罗·埃利希与朱利安·西蒙之间的那场著名赌局再多说几句——这个赌局常被那些反对资源限制观点的人拿来引用。这些人被称为“丰饶论者”,我觉得这个称呼非常贴切。埃利希认为我们正开始耗尽资源;我们或许可以称他为马尔萨斯主义者。他代表了罗马俱乐部的思想,以及那本著名的《增长的极限》。8 而西蒙,他曾在卡托研究所工作多年,是一位典型的超级丰饶论者:一切总会好起来,因为人类拥有无限的创造力;人口增长值得欢迎,因为它推动增长,而增长又刺激发明创造,资源永远充足。卡托研究所通常支持任何能减少政府干预、削弱企业约束的理论。(他们由科赫家族资助——这个家族拥有碳氢化合物帝国——毫不意外,他们深受这些信念的认同。)人类可能因浪费性过度消费或不必要的大量二氧化碳排放,而严重危及地球的长期生产力——这种论点对于自由意志主义者和丰饶论者来说是一个危险的“观念”(我认为,我们完全可以称其为“事实”),它可能会为监管打开大门。因此,这些事实必须受到质疑。而这条路上的每一个论点,无论大小,都必须被顽强捍卫,尤其是无限增长这个理想。
Quarterly Letter – Resource Limitations 2 – July 2011 11 GMO Appendix 1: Malthusians and Cornucopians: the Ehrlich-Simon Bet While still on the topic of resources, there are a few points I’d like to make on the subject of the famous bet made between Paul Ehrlich and Julian Simon in 1980, which is so often mentioned by opponents of any ideas regarding resource limits. They have been called Cornucopians, which I think is a great term for them. Ehrlich believed that we were beginning to run out of resources; we might call him a Malthusian. He reflected the Club of Rome’s thinking and the famous book entitled The Limits to Growth.8 Simon on the other hand, who worked at the Cato Institute for many years, was a classic super-Cornucopian: everything will always be fine because of our species’ boundless resourcefulness; population increases are to be welcomed because they cause growth, which in turn stimulates invention so that there will always be plenty. The Cato Institute generally supports any theory that will result in less government and fewer restraints on corporations. (They were grubstaked by the Koch family, they of the hydrocarbon empire, who, not surprisingly, profoundly agree with those beliefs.) The argument that mankind might seriously endanger the long-term productivity of the planet by wasteful overconsumption or by unnecessarily large emissions of carbon dioxide is a dangerous “idea” for libertarians and Cornucopians (we might, I think, reasonably call such things “facts”) that might open the door to regulation. Ergo, the facts must be disputed. And every argument along the way, large or small, must be grimly defended, especially the ideal of limitless growth.
而西蒙先生确实捍卫了它,而且非常有效。他围绕这个主题与埃利希打了一个赌,并由此闻名天下,丰裕论者此后从未让任何人在这个领域忘记这件事。这个赌的核心在于,埃利希认为,在资源有限的世界里,复合增长无法持续,因此原材料的实际价格会上涨。西蒙则认为,无论增长速度如何,实际价格都会下跌。当然,这个赌的精神没有时间限制——40 年优于 10 年,100 年优于 40 年。但这样一场赌局发生在中年人之间,双方都希望能在有生之年看到结果。于是,赌局定为 10 年,双方共同选择了 5 种商品。同样,所有商品都能比 5 种更好地体现这个赌的精神,但 5 种更容易监控。在 10 年的时间节点上,西蒙光明正大地赢得了所有 5 个独立的赌局。但我们必须承认,对于我们这些真正关注这场思想竞赛的人来说,这个时间段非常令人不满。因此,让我们选择一个同样随意但更令人满意的赌局:从那时(1980 年)到现在,涵盖所有最重要的商品。西蒙会在死后以惨败告终!(即使在最初的 5 种商品中,他也只赢了 1 种,即最不重要的锡。)所以,请“丰裕论者”们,不要再提埃利希-西蒙赌局了,因为这场赌局实际上既证明了人终有一死、必须下短期赌注,更重要的是,它证明了埃利希的观点(到目前为止)是正确的。
And defend it Mr. Simon did, and very effectively. He engaged Ehrlich in a bet on this topic, which he famously won, and the Cornucopians have never let anyone in this field forget it. The essence of the bet was that Ehrlich believed that compound growth could not be sustained in a world of finite resources, and therefore the real price of raw materials would rise. Simon argued that, regardless of the rate of growth, real prices would fall. Of course, the spirit of this bet has no time limit – 40 years is better than 10, and 100 is better than 40. But a bet like this between humans of middle age is one that both would like to collect on. So, the bet was set at 10 years and five commodities9 were chosen by mutual agreement. Here again, all commodities would have represented the spirit of the bet better than five, but five was easier to monitor. Simon won all five separate bets fair and square at the 10-year horizon. But let’s admit that this is a very unsatisfactory time period for the rest of us who are really interested in this contest of ideas. So, let’s take an equally arbitrary but much more satisfactory bet: from then, 1980, until now, and include all of the most important commodities. Simon would have lost posthumously, and by a lot! (Even of the original five, he is only one for five, having won the least significant of the five: tin.) So, please “Cornucopians,” let’s not hear any more of the Ehrlich-Simon bet, which proves, in fact, both that man is mortal and must make short-term bets, and, more importantly, that Ehrlich’s argument was right (so far).
8 唐妮拉·H·梅多斯、丹尼斯·L·梅多斯、约尔根·兰德斯、威廉·W·贝伦斯三世,《增长的极限》,宇宙图书公司,纽约,1972 年。9 铜、铬、镍、锡、钨。
8 Donella H. Meadows, Dennis L. Meadows, Jørgen Randers, and William W. Behrens, III, The Limits to Growth, Universe Books, New York, 1972. 9 Copper, chromium, nickel, tin, and tungsten.
GMO 季度信函 —— 资源限制(二)—— 2011 年 7 月
附录二:魔鬼与农夫
魔鬼的交易:土壤与生产力累计损失
100 100%
90 90%
农场生产力(占原始水平的百分比)
80 80%
农场生产力
70 70%
土壤深度(英寸)
60 60%
50 50%
40 40%
土壤深度
30 30%
20 20%
10 10%
0 0%
2011 2031 2051 2071 2091 2111 2131 2151 2171 2191 2211
来源:GMO 季度信函 —— 资源限制(二)—— 2011 年 7 月 13 日
附录二:魔鬼与农夫
我们中西部地区的农夫起初拥有 16 英寸*的土壤深度,每年产出价值 100 美元的作物。他的作物利润率是 3%——美国农场平均经营利润率是 11%(2010 年《家庭农场报告》,美国农业部经济研究局)——但我们的农夫完全实现了可持续经营,比清洁还干净,土壤没发生任何侵蚀,也没有任何污染。
GMO 12 Quarterly Letter – Resource Limitations 2 – July 2011 Appendix 2: The Devil and the Farmer The Devil's Deal: Cumulative Soil and Productivity Loss 100 100% 90 90% Farm Productivity (% of Original Level) 80 80% Farm Productivity 70 70% Soil Depth (Inches) 60 60% 50 50% 40 40% Soil Depth 30 30% 20 20% 10 10% 0 0% 2011 2031 2051 2071 2091 2111 2131 2151 2171 2191 2211 Source: GMO Quarterly Letter – Resource Limitations 2 – July 2011 13 GMO Appendix 2: The Devil and the Farmer Our Midwestern farmer starts with a soil depth of 16 inches*, producing $100 of crops. He has a profit margin of 3% on his crops - the average operating profit margin for U.S. farms is 11% (2010 Family Farm Report, USDA Economic Research Service), but our farmer is completely sustainable and cleaner than clean, incurring no erosion or pollution.
魔鬼找到他,问是否愿意以每年不到 0.16 英寸的速度——也就是他土壤的 1%——让土壤贫瘠,持续四十年。作为交换,魔鬼会把农民的利润率提高 5 倍,从 3% 变成 15%。我们假设,魔鬼也这样告诉农民,他的土壤生产力——进而他的作物产量——会以与土壤深度的四次方根成比例的方式下降(这大致符合关于土壤深度与生产力的实证研究)。
The Devil approaches him and asks if he will allow his soil to deplete at just under 0.16 inches per year - 1% of his soil** - for forty years. In return the Devil will multiply the farmer’s profit margin by 5 times, from 3% to 15%. We assume, and the farmer is told by the Devil, that the productivity of his soil and therefore the size of his crop, will fall proportionally to the fourth root of the soil depth (this is approximately in line with empirical studies of soil depth and productivity).
第一次魔鬼来找农夫的交易,会让未来四十年的利润现值变为原来的 4.83 倍(以 6% 的折现率计算)。他接受了交易。四十年后,他只剩下 64% 的土壤…… 第一个四十年过去了,第二个四十年开始了。魔鬼再次找到农夫。这一次,签约会让他的利润现值变为原来的 4.78 倍。他接受了交易。四十年后,他只剩下 36% 的土壤……
| 第一个四十年 | 与魔鬼交易 | 不交易 | 第二个四十年 | 与魔鬼交易 | 不交易 | ||||
|---|---|---|---|---|---|---|---|---|---|
| 土壤深度 | 利润 | 土壤深度 | 利润 | 土壤深度 | 利润 | 土壤深度 | 利润 | ||
| 第一年 | 15.8 | $14.96 | 16.0 | $3.00 | 第一年 | 10.1 | $13.37 | 10.2 | $2.68 |
| 第十年 | 14.4 | $14.62 | 16.0 | $3.00 | 第十年 | 9.0 | $12.99 | 10.2 | $2.68 |
| 第二十年 | 13.0 | $14.23 | 16.0 | $3.00 | 第二十年 | 7.8 | $12.55 | 10.2 | $2.68 |
| 第三十年 | 11.6 | $13.83 | 16.0 | $3.00 | 第三十年 | 6.8 | $12.09 | 10.2 | $2.68 |
| 第四十年 | 10.2 | $13.42 | 16.0 | $3.00 | 第四十年 | 5.8 | $11.62 | 10.2 | $2.68 |
| 利润现值 (6% 折现率) | $217.94 | $45.14 | 利润现值 (6% 折现率) | $193.14 | $40.37 |
魔鬼再次找到农夫。这一次,签约会让他的利润现值变为原来的 4.71 倍。他接受了交易。四十年后,他只剩下 16% 的土壤…… 魔鬼再次找到农夫。这一次,签约会让他的利润现值变为原来的 4.55 倍。他接受了交易。四十年后,他只剩下 4% 的土壤……
| 第三个四十年 | 与魔鬼交易 | 不交易 | 第四个四十年 | 与魔鬼交易 | 不交易 | ||||
|---|---|---|---|---|---|---|---|---|---|
| 土壤深度 | 利润 | 土壤深度 | 利润 | 土壤深度 | 利润 | 土壤深度 | 利润 | ||
| 第一年 | 5.7 | $11.57 | 5.8 | $2.32 | 第一年 | 2.5 | $9.43 | 2.6 | $1.90 |
| 第十年 | 4.8 | $11.12 | 5.8 | $2.32 | 第十年 | 2.0 | $8.87 | 2.6 | $1.90 |
| 第二十年 | 4.0 | $10.61 | 5.8 | $2.32 | 第二十年 | 1.4 | $8.22 | 2.6 | $1.90 |
| 第三十年 | 3.2 | $10.06 | 5.8 | $2.32 | 第三十年 | 1.0 | $7.50 | 2.6 | $1.90 |
| 第四十年 | 2.6 | $9.49 | 5.8 | $2.32 | 第四十年 | 0.6 | $6.71 | 2.6 | $1.90 |
| 利润现值 (6% 折现率) | $164.61 | $34.96 | 利润现值 (6% 折现率) | $129.87 | $28.55 |
*这里指的是表土或“农学家所称的土壤”,特指 A 层和 B 层土壤
魔鬼再次找到农夫。这一次,签约只让他的利润现值变为原来的 3.97 倍。他接受了交易。即使到了第五次,尽管一开始只有 4% 的土壤,他通过签约获得的这段时期内的利润仍然比完全不签约高出 77%。
在经历了 200 年、五次与魔鬼签约之后,土壤已经彻底消失殆尽。农夫未来的所有利润都归为零——而对我们其他人来说更令人担忧的是,农场未来的粮食产量也归为零。
The first time the farmer is approached, taking the Devil’s deal will multiply the The Devil approaches the farmer again after the first forty years. This time present value of the next forty years’ profits by 4.83 times (at a 6% discount signing the deal will multiply the present value of his profits by 4.78 times. rate). He takes the deal. Forty years later he only has 64% of his soil left… He takes the deal. Forty years later he only has 36% of his soil left… FirstFortyYears SecondFortyYears Devil'sDeal NoDeal Devil'sDeal NoDeal SoilDepth Profits SoilDepth Profits SoilDepth Profits SoilDepth Profits FirstYear 15.8 $14.96 16.0 $3.00 FirstYear 10.1 $13.37 10.2 $2.68 TenthYear 14.4 $14.62 16.0 $3.00 TenthYear 9.0 $12.99 10.2 $2.68 TwentiethYear 13.0 $14.23 16.0 $3.00 TwentiethYear 7.8 $12.55 10.2 $2.68 ThirtiethYear 11.6 $13.83 16.0 $3.00 ThirtiethYear 6.8 $12.09 10.2 $2.68 FortiethYear 10.2 $13.42 16.0 $3.00 FortiethYear 5.8 $11.62 10.2 $2.68 NPVofProfits NPVofProfits (6%discountrate) $217.94 $45.14 (6%discountrate) $193.14 $40.37 The Devil approaches the farmer again. This time signing the deal will multiply The Devil approaches the farmer again. This time signing the deal will the present value of his profits by 4.71 times. He takes the deal. Forty years multiply the present value of his profits by 4.55 times. He takes the deal. later he only has 16% of his soil left… Forty years later he only has 4% of his soil left… ThirdFortyYears FourthFortyYears Devil'sDeal NoDeal Devil'sDeal NoDeal SoilDepth Profits SoilDepth Profits SoilDepth Profits SoilDepth Profits FirstYear 5.7 $11.57 5.8 $2.32 FirstYear 2.5 $9.43 2.6 $1.90 TenthYear 4.8 $11.12 5.8 $2.32 TenthYear 2.0 $8.87 2.6 $1.90 TwentiethYear 4.0 $10.61 5.8 $2.32 TwentiethYear 1.4 $8.22 2.6 $1.90 ThirtiethYear 3.2 $10.06 5.8 $2.32 ThirtiethYear 1.0 $7.50 2.6 $1.90 FortiethYear 2.6 $9.49 5.8 $2.32 FortiethYear 0.6 $6.71 2.6 $1.90 NPVofProfits NPVofProfits (6%discountrate) $164.61 $34.96 (6%discountrate) $129.87 $28.55 * This refers to topsoil or “agriculturalist’s soil ” specifically the A and B soil horizons The Devil approaches the farmer again. This time signing the deal will multiply After After 200 200 years years andand five five signings signings of of the the Devil’s Devil’s deal, deal, there there is is no no the present value of his profits by only 3.97 times. He takes the deal. Even this fifth time, starting with only 4% of the soil, he will still make 77% more profits in soil soil left left at at all. all. All All of of the the farmer’s farmer’s future future profits profits are are zero zero -- and and what what this period by signing than if he had never signed at all. is is more more concerning concerning toto the the rest rest of of us, us, the the farm’s farm’s future future food food production production is is zero. zero.
第五四十年的魔鬼交易不交易土壤深度利润土壤深度利润但但是,魔鬼的交易直到那一刻之前都利润丰厚。它直到魔鬼交易的第一年 0.6 6.62 美元 0.6 1.34 美元第 193 年才让与魔鬼签约的利润总额降至低于从不与魔鬼签约的利润。第十年 0.4 5.81 美元 0.6 1.34 美元事实上,如果让农场主在第一年就做出选择,是永远与魔鬼签约还是永远不签,第二十年 0.2 4.74 美元 0.6 1.34 美元他的折现率必须低于 0.17%,不签约才是净现值上的理性选择。第三十年 0.04 3.35 美元 0.6 1.34 美元第四十年 0.000 0.00 美元 0.6 1.34 美元利润净现值(折现率 6%) 80.07 美元 20.19 美元
FifthFortyYears Devil'sDeal NoDeal SoilDepth Profits SoilDepth Profits But But the the Devil’s Devil’s deal deal isis profitable profitable right right up up until until that that point. point. ItIt is is not not FirstYear 0.6 $6.62 0.6 $1.34 until until year year 193 193 ofof the the Devil’s Devil’s deal deal that that the the profits profits from from signing signing with with TenthYear 0.4 $5.81 0.6 $1.34 the the Devil Devil all all along along fall fall below below the the profits profits from from never never signing signing with with TwentiethYear 0.2 $4.74 0.6 $1.34 the the Devil Devil at at all. all. In In fact, fact, ifif the the farmer farmer were were made made to to choose choose inin year year ThirtiethYear 0.04 $3.35 0.6 $1.34 FortiethYear 0.000 $0.00 0.6 $1.34 11 between between signing signing with with the the Devil Devil permanently permanently or or never never signing signing at at NPVofProfits all, all, his his discount discount rate rate would would need need to to be be 0.17% 0.17% or or lower lower for for not not (6%discountrate) $80.07 $20.19 signing signing to to be be the the rational rational choice choice in in NPV NPV terms. terms.
- 这里指的是表土层,或称“农夫土壤”,具体来说就是 A 层和 B 层土壤。** 实际上,魔鬼的土壤流失量会随时间递减,从第一年的 0.16 英寸下降到第四十年的 0.13 英寸。此后,它会继续线性下降,到第一百年降至 0.08 英寸,到第二百年降至 0 英寸——因为魔鬼的交易条件是,农夫的土地将在第二百年彻底耗尽。
- This refers to topsoil or “agriculturalist’s soil,” specifically, the A and B soil horizons. ** In fact the Devil’s soil depletion will fall over time, from 0.16 inches in the first year to 0.13 inches in the fortieth year. It will continue to fall linearly to 0.08 inches in the one-hundredth year, and 0 inches in the two-hundredth year - because the Devil’s deal is that the farmer’s soil runs out in the two-hundredth year.
来源:GMO GMO 第 14 期季度信函——资源局限 2——2011 年 7 月 附录 2:魔鬼与农夫
魔鬼提出的 5 倍利润的提议,对我们的农夫来说显然好到无法拒绝。但如果农夫一开始的盈利能力就高得多呢?假如他拥有 7.5% 的利润率——更接近美国 11% 的平均水平——而魔鬼只能提出将他的利润翻倍至 15%,作为交换,他要接受同样的土壤耗尽时间表。这对农夫来说仍然是一笔好交易吗?
Source: GMO GMO 14 Quarterly Letter – Resource Limitations 2 – July 2011 Appendix 2: The Devil and the Farmer The Devil’s offer of 5x profits is quite clearly too good for our farmer to pass up. But what if the farmer were much more profitable to start with? What if he had 7.5% profit margins - closer to the U.S. average of 11% - and the Devil could only offer to double his profits to 15%, in exchange for the same soil depletion schedule? Would this still be a good deal for the farmer?
我们那位(利润更高的)农夫第一次被找上门时,接受了魔鬼的交易。第一个四十年过后,魔鬼再次找上农夫。这次签署协议能使未来四十年利润的现值乘以 1.93 倍(签约时能使利润现值乘以 1.91 倍,贴现率为 6%)。他接受了交易。四十年后,他只剩下 64% 的土壤……他接受了交易。四十年后,他只剩下 36% 的土壤……
| 第一个四十年 | 魔鬼交易 | 无交易 | 第二个四十年 | 魔鬼交易 | 无交易 | ||||
|---|---|---|---|---|---|---|---|---|---|
| 土壤深度 | 利润 | 土壤深度 | 利润 | 土壤深度 | 利润 | 土壤深度 | 利润 | ||
| 第一年 | 15.8 | $14.96 | 16.0 | $7.50 | 第一年 | 10.1 | $13.37 | 10.2 | $6.71 |
| 第十年 | 14.4 | $14.62 | 16.0 | $7.50 | 第十年 | 9.0 | $12.99 | 10.2 | $6.71 |
| 第二十年 | 13.0 | $14.23 | 16.0 | $7.50 | 第二十年 | 7.8 | $12.55 | 10.2 | $6.71 |
| 第三十年 | 11.6 | $13.83 | 16.0 | $7.50 | 第三十年 | 6.8 | $12.09 | 10.2 | $6.71 |
| 第四十年 | 10.2 | $13.42 | 16.0 | $7.50 | 第四十年 | 5.8 | $11.62 | 10.2 | $6.71 |
| 利润现值(6% 贴现率) | $217.94 | $112.85 | 利润现值(6% 贴现率) | $193.14 | $100.93 |
魔鬼再次找上农夫。这次签署协议能使利润现值乘以 1.88 倍。他接受了交易。四十年后,他只剩下 16% 的土壤…… 签署协议能使利润现值乘以 1.82 倍。他接受了交易。四十年后,他只剩下 4% 的土壤……
| 第三个四十年 | 魔鬼交易 | 无交易 | 第四个四十年 | 魔鬼交易 | 无交易 | ||||
|---|---|---|---|---|---|---|---|---|---|
| 土壤深度 | 利润 | 土壤深度 | 利润 | 土壤深度 | 利润 | 土壤深度 | 利润 | ||
| 第一年 | 5.7 | $11.57 | 5.8 | $5.81 | 第一年 | 2.5 | $9.43 | 2.6 | $4.74 |
| 第十年 | 4.8 | $11.12 | 5.8 | $5.81 | 第十年 | 2.0 | $8.87 | 2.6 | $4.74 |
| 第二十年 | 4.0 | $10.61 | 5.8 | $5.81 | 第二十年 | 1.4 | $8.22 | 2.6 | $4.74 |
| 第三十年 | 3.2 | $10.06 | 5.8 | $5.81 | 第三十年 | 1.0 | $7.50 | 2.6 | $4.74 |
| 第四十年 | 2.6 | $9.49 | 5.8 | $5.81 | 第四十年 | 0.6 | $6.71 | 2.6 | $4.74 |
| 利润现值(6% 贴现率) | $164.61 | $87.41 | 利润现值(6% 贴现率) | $129.87 | $71.37 |
魔鬼再次找上农夫。这次签署协议只能使利润现值乘以 1.59 倍。他接受了交易。但土壤消耗开始造成损失:在这个时期内,他赚到的利润只有他从未和魔鬼签约时的 71%。即使魔鬼只提出把利润翻倍,这个交易还是好得难以拒绝。事实上,即使只是让农夫利润翻倍,也远比魔鬼需要提供的条件好得多。魔鬼需要 200 年才能夺走农夫的全部土壤——而 200 年是一个太漫长的时间,贴现起来会非常遥远。
The first time our (more profitable) farmer is approached, taking the Devil’s deal The Devil approaches the farmer again after the first forty years. This time will multiply the present value of the next forty years’ profits by 1.93 times (at a signing the deal will multiply the present value of his profits by 1.91 times. 6% discount rate). He takes the deal. Forty years later he only has 64% of his He takes the deal. Forty years later he only has 36% of his soil left… soil left… FirstFortyYears SecondFortyYears Devil'sDeal NoDeal Devil'sDeal NoDeal SoilDepth Profits SoilDepth Profits SoilDepth Profits SoilDepth Profits FirstYear 15.8 $14.96 16.0 $7.50 FirstYear 10.1 $13.37 10.2 $6.71 TenthYear 14.4 $14.62 16.0 $7.50 TenthYear 9.0 $12.99 10.2 $6.71 TwentiethYear 13.0 $14.23 16.0 $7.50 TwentiethYear 7.8 $12.55 10.2 $6.71 ThirtiethYear 11.6 $13.83 16.0 $7.50 ThirtiethYear 6.8 $12.09 10.2 $6.71 FortiethYear 10.2 $13.42 16.0 $7.50 FortiethYear 5.8 $11.62 10.2 $6.71 NPVofProfits NPVofProfits (6%discountrate) $217.94 $112.85 (6%discountrate) $193.14 $100.93 The Devil approaches the farmer again. This time signing the deal will multiply The Devil approaches the farmer again. This time signing the deal will the present value of his profits by 1.88 times. He takes the deal. Forty years multiply the present value of his profits by 1.82 times. He takes the deal. later he only has 16% of his soil left… Forty years later he only has 4% of his soil left… ThirdFortyYears FourthFortyYears Devil'sDeal NoDeal Devil'sDeal NoDeal SoilDepth Profits SoilDepth Profits SoilDepth Profits SoilDepth Profits FirstYear 5.7 $11.57 5.8 $5.81 FirstYear 2.5 $9.43 2.6 $4.74 TenthYear 4.8 $11.12 5.8 $5.81 TenthYear 2.0 $8.87 2.6 $4.74 TwentiethYear 4.0 $10.61 5.8 $5.81 TwentiethYear 1.4 $8.22 2.6 $4.74 ThirtiethYear 3.2 $10.06 5.8 $5.81 ThirtiethYear 1.0 $7.50 2.6 $4.74 FortiethYear 2.6 $9.49 5.8 $5.81 FortiethYear 0.6 $6.71 2.6 $4.74 NPVofProfits NPVofProfits (6%discountrate) $164.61 $87.41 (6%discountrate) $129.87 $71.37 The Devil approaches the farmer again. This time signing the deal will multiply the present value of his profits by only 1.59 times. He takes the deal. But the soil depletion has taken its toll: he will make only 71% of the profits over this The The deal deal is is still still too too good good toto pass pass up up ifif the the Devil Devil only only offers offers to to period that he would have made had he never signed with the Devil. double double his his profits. profits. Truth Truth is, is, even even doubling doubling the the farmer’s farmer’s profits profits is is FifthFortyYears still still aa far far better better deal deal than than the the Devil Devil needs needs to to offer. offer. ItIt takes takes 200 Devil'sDeal NoDeal years years for for the the Devil Devil to to take take all all of of the the farmer's farmer's soil soil -- and and 200200 years years SoilDepth Profits SoilDepth Profits is is aa very very long long time time to to discount discount over. over.
原件此处是表格,PDF 抽取时列结构已丢失,下面只剩按列读出的数字,行列对应关系无法还原。核对数据请打开来源正文。
第一年 0.6 $6.62 0.6 $3.35 事实上,如果农民使用的折现率是 6%,魔鬼只需要在第一年将农民的利润提升 4.3%——即从 7.50 美元增至 7.82 美元——就能让农民理性地接受这笔交易。第十年 0.4 $5.81 0.6 $3.35 第二十年 0.2 $4.74 0.6 $3.35 第三十年 0.04 $3.35 0.6 $3.35 第四十年 0.000 $0.00 0.6 $3.35
FirstYear 0.6 $6.62 0.6 $3.35 TenthYear 0.4 $5.81 0.6 $3.35 TwentiethYear 0.2 $4.74 0.6 $3.35 In In fact, fact, ifif the the farmer farmer has has aa 6% 6% discount discount rate, rate, thethe Devil Devil only only needs needs ThirtiethYear 0.04 $3.35 0.6 $3.35 to to offer offer to to boost boost his his profits profits by by 4.3% 4.3% -- that that is, is, from from $7.50 $7.50 to to $7.82 $7.82 FortiethYear 0.000 $0.00 0.6 $3.35 in in the the first first year year -- in in order order for for the the farmer farmer to to rationally rationally take take the the deal. deal.
利润净现值(6% 折现率)
80.07 美元
50.47 美元
来源:GMO
免责声明:本文所表达的观点仅为杰里米·格兰瑟姆截至 2011 年 7 月 22 日的观点,并可能随市场及其他条件的改变而随时发生变化。本文不构成任何证券的买卖要约或招揽,也不应被理解为上述行为。文中提及特定证券及发行方仅用于说明目的,不应被视为购买或出售此类证券的建议。
NPVofProfits (6%discountrate) $80.07 $50.47 Source: GMO Disclaimer: The views expressed are the views of Jeremy Grantham through the period ending July 22, 2011, and are subject to change at any time based on market and other conditions. This is not an offer or solicitation for the purchase or sale of any security and should not be construed as such. References to specific securities and issuers are for illustrative purposes only and are not intended to be, and should not be interpreted as, recommendations to purchase or sell such securities.
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