Friday, October 31, 2014
12

人类文明的粮食威胁

帕罗奥图—人类面临着日益严峻、错综复杂的环境问题,既包括气候变化等讨论激烈的挑战,也包括同样甚至更加严峻的微生物生存威胁。微生物提供着诸如作物授粉、农业病虫害控制等关键生态系统功能,支持着我们的生命。我们还面临着其他各种威胁:有毒有机化合物在全世界的传播、流行病爆发,以及矿场资源、水和土壤质量大幅下降和获得难度大幅上升。

资源战争已经来临;如果(比如)印度和巴基斯坦之间爆发“小型”核战争,那么我们知道,这很可能已足以使文明终结。

但我们认为,未来数十年中对全球可持续性最严重的威胁将是一个已经获得了广泛一致的问题:阻止大饥荒变得越来越困难。《2013年世界经济论坛报告》(2013 World Economic Forum Report)指出:“全球粮食和营养安全是重大全球问题,世界必须用越来越少的资源基础养活越来越多的人口,同时必须面临日益波动和不确定的时代。”事实上,该报告指出,超过“如今超过8.7亿的人口吃不饱饭,还有更多人需要面临气候事件和价格飙升风险。”因此,“改善粮食安全”的措施“的需要从未如此紧迫”。

事实上,在我们看来,几乎所有此类警告都低估了粮食问题。比如,微量元素的缺乏可能已经影响到20亿人。更有许多其他脆弱性被低估:农业和渔业气候恶化的潜在影响、不再使用化石燃料会如何影响粮食产量;农业本身作为温室气体主要排放者如何加速气候变化;以及过度开采地下水和土壤逐步恶化的后果。事实上,农业已经成为生物多样性损失——从而供应耕种和其他人类活动的生态系统功能亦然——的主要原因,也是全球毒化的主要罪魁。

也许最重要的是,几乎所有分析都假设2050年人口总数将增加25亿,而没有寻找减少这一数字的方法。许多分析师对我们养活新增的几十亿人口的能力表示乐观,这相当令人担忧,因为如今每年死于营养不良的人数已达数百万,更有多得多的人因营养不良而生活在痛苦之中。既然人口增加35%,要养活也易如反掌,为何无法在今天做到人人营养充沛?

解决粮食问题的解决之道通常有五个步骤:停止增加农业用地(以保护自然生态系统功能);尽可能提高产量;增加肥料、水和能源使用效率;增加素食;以及减少粮食浪费。除此之外,你还可以加上几条:停止海洋污染、大量增加农业研发投资、将人人获得合理营养置于全球政策日程最优先的位置。

所有这些步骤都要求人类行为发生建议已久的变化。许多人没有认识到适应变化的紧迫性,这是因为他们不明白农业体系及其与导致环境恶化的机制之间的复杂的非线性(非比例性)悬系。平均而言,养活每位新增人口的所有必要投入都来自更紧缺、更劣质和更不相干的资源,需要多得多的能源、放出多得多的温室气体。

一千多年来的温度和积淀模式——对作物产量至关重要——让地球走上了大风暴、大旱灾和大洪水越来越多的道路。因此,维持——更不用说扩大了——粮食产量将越来越困难。

我们需要一场大众运动,让文化意识转向提供市场不能提供的“远见智慧”和农业、环境和人口规划。惟其如此,我们才能够开始纠正严重的人口灾难——考虑一下在人口达到90亿然后开始逐渐减少之前人道地结束人口增长所带来的营养/卫生好处吧。

在我们看来,要达到人口下降的目标,最好的方法莫过于给予女性完全的权利和机会,并让性生活丰富的人获得现代避孕方法和后备堕胎措施。这些步骤会造成总生育率多大程度的下降还有待争议,但它们可以让大量新鲜脑力加入解决问题事业中,同时通过减少不安全避孕拯救数十万生命,这会带来巨大的社会和经济好处。

人类能避免因饥饿导致的崩溃吗?是的——尽管我们认为目前的可能性只有10%。前景如此凄凉,因此我们认为,为了子孙后代,竭尽所能把机会提高到11%是值得的。

我们最杰出的同事之一、生物地理学家和能源专家、新墨西哥州立大学的詹姆斯·布朗(James Brown)有不同意见。他认为人类文明持续下去的可能性只有1%,但也认为将它提高到1.1%是值得的。

发展远见智慧、动员文明社会为可持续性而奋斗是斯坦福大学人类和生物圈前年同盟(Millennium Alliance for Humanity and the Biosphere,MAHB)的核心目标。加入了MAHB,就是加入了为避免文明终结而奋斗的最优秀全球文明社会。

Hide Comments Hide Comments Read Comments (12)

Please login or register to post a comment

  1. CommentedNelson Pitter

    Nowadays It is very difficult to produce sufficient farm food without any use of fertilizers.
    Further the use of pesticides is not optional.
    How we can expect pure harmless food quality.
    I think we should accept the change.
    http://pinnaclepest.com

  2. CommentedGunnar Rundgren

    I do agree that population growth is an issue, but I don't agree fully with the arguments here. People were starving when we were 1 billion, 3 billion and now also when we are 7 billion. It is still mainly poverty and inequality that make people starve, and not biological limits. It is technically possible to feed even more people - yields can increase a lot in many places. The problem with production is that it is not done in a sustainable way, and that we occupy a too big share of the total biosphere for human civilization. In that sense, a smaller population would be beneficial.

  3. CommentedC. Jayant Praharaj

    The authors should address the question of the encroachment of non-agricultural activities on natural ecosystems. Today's earthlings and future earthlings will have to determine the most optimum and equitable use of land for agriculture, ecosystem sustenance ( keeping in mind environmental stability ) and nonagricultural activities.

  4. CommentedJon Jermey

    Nice to see Professor Ehrlich working so hard to maintain his status as the Man Who Is Never Right.

  5. CommentedAvraam Dectis

    .
    We are only one discovery away from solving all food problems.

    When we discover a way to produce virtually free environmentally nonpolluting energy, food problems will disappear.

    Free energy means we can generate as much pure water as we want, which we could use to irrigate the deserts and produce an abundance of food for everyone.

    Free energy means we can create nonpolluting virtually free hydrogen fuel from water.

    All of the concerns stated in this article are valid and hunger and malnutrition are completely unnecessary, even today. Hopefully we will, in a relatively short matter of time, produce the discoveries to take care of all these problems.

    There is no compelling reason for energy to remain expensive. The entire universe is effectively energy.

    Avraam J. Dectis

  6. CommentedMichael Lee

    Shouldn't Mr. Ehrlich first explain why his similar predictions from the late 1960s failed so spectacularly?

    If markets are failing, what is his proposed approach to managing the global economy, population control and resource allocation?

    Should we outsource all of this to the Chinese politburo? If not, then who does he believe can safe humanity from itself?

  7. CommentedNicolas Alexandratos

    Ehrlich’s question: “If it will be so easy to feed a population 35% larger, why isn’t everyone well nourished today?” fails to focus on the real problem. Firstly, nobody says it will be easy; and, secondly, really no need to comment on why so many people go hungry. Traditionally hunger has existed and persisted in times of global food gluts as well as in those of global scarcity. The problem of food production, or rather availability (production plus net imports), is not global but local. The food vs. population problem (in the sense of food scarcity as the explanatory factor in the persistence of hunger) is principally relevant to countries/localities with high population growth, poor agricultural resources/technology and limited access to imported food. You may have global overproduction of food but if these people have no access to it, the global glut can be irrelevant to them, except in the form of lower world prices if they could afford to import, or more plentiful food aid. For latest assessment to 2050, see World agriculture towards 2030/2050: The 2012 Revision - http://www.fao.org/economic/esa/esag/en/)

  8. CommentedZsolt Hermann

    All the problems mentioned in the article, the whole spectrum of the global crisis originates from one root problem: the human attitude towards the natural system we exist in.
    We base all our activity on the belief that humans are above nature and the general, absolute laws governing nature do not apply to us, evolution stopped with us and we can apply our present static "human laws" to the constantly changing, evolving natural system.
    Based on this attitude we explore, get to know nature in order to exploit it for our own use, regardless of any consequences (which most of the time we have no idea about), and we behave the same within human society with each other.
    But our fundamental belief is wrong, we are part of the natural system, our biological body, our human psyche, every desire, our whole being is based on the same principles, laws as the most simple living cells, bacteria, and the ongoing evolutionary process with its changing conditions also apply to us as to any other species.
    Humanity with all its technological, mental development, breakthroughs (which were and are basically nothing else but copying, emulating natural processes, templates) is simply a speck in the vast and infinitely more powerful system we exist in.
    If we want to continue our evolution, development, no partial, superficial solution will succeed, only a fundamental change in how we see ourselves within the system, how we adapt to the system instead of wanting to change the system to our liking.
    Humanity's superiority above other lifeforms is coming from our ability of critical self assessment, and active self change. Humans are the only creatures capable of becoming active partners with the system not in an instinctive manner, but being fully aware, understanding it and maximizing its potential.
    In this way we could benefit much more than ever before, but not in a way we want it, how we think it should be done based on our own delusions, "inventions", but by following nature's lead, flowing with it.
    The true hero is not the one always charging ahead, destroying killing to the point of self extermination, the true hero bows his head, rises above himself like a rodeo rider over the bull, and blends into the natural, interconnected living system around him.

  9. CommentedNicolas Bollion

    A few basic facts: since 1970 the percentage of people in third world countries who suffer malnutrition has dropped from 38% to a little less than 15% today in spite of population growth of 3 billion people and in spite of the fact that population grew and still grows faster in Africa, where the malnutrition problem is worse than in other developing countries. In fact this population growth is to a large extent the result of the fact that ever less people starve, in addition to other advances.

    More people doesn't necessarely mean more hunger, at least not in relative terms, because more people means more food producers. I agree with the autors on one thing, albeit for a different reason: fertility rate in Africa should drop, as is today taking place in other developing countries, not necessarely because there is overpopulation but in order to reduce the dependency ratio. That would mean relatively more food producers.

  10. CommentedFrank O'Callaghan

    Malthusian warnings all through history have one thing in common; they have all proved to be wrong. But you only have to be right once! Maybe it will be this time?

    The good question about how we feed a 35% increase when we have starving people now deserves a serious answer. But first it might be reasonable to note who and where and why people starve. They starve because of POVERTY and inequality and powerlessness. It has very little to do with food. Famine countries are often food exporters and those taking the decisions are often profitably obese in the presence of others starving.

    It is misleading nonsense to display concern for food production while noting the existence of both starvation and great wastage.

      CommentedAndrew N Mason

      You know that one in five people in the USA is food insecure no? Food insecurity will soon hit everyone, and inequality is doing no good to that. Not here (in the US) not anywhere.

      Its ironic though. over 20% of food waste in the us is postharvest CONSUMER WASTE. Yes, people throw away the food in a manner that is simply appalling. Over 30% of food is wasted globally and in third world countries most of this is due to supply chain inefficiencies.

      I think we can survive this one... But we all need to get our acts together, and rich countries must lead the way and moderate consumption (and waste) there is a lot of low hanging fruit to address this issue.

  11. Commentedchad bircher

    The entire premise of this is absolutely ridiculous. The amount of food grown in the US has increased over the last few decades while the number of acres has decreased. Food production is massively more efficient in nations like Brazil where clear cutting forests for temporary grazing land has basically ended. Desalination techniques are improving to where it is nearly cheaper to build desalination plants in Los Angelos than to bring in water through an Aquifer. With a slightly greater improvement in desalination techniques drought will effectively end in lowland areas (that is, most of our farmland). Finally, food production has historically been greater during warm periods than cold periods. If the planet warms by a couple degrees large areas that are inhospitable to farming will become hospitable.

    Are people hungry? Yes, but almost half the food in underdeveloped countries goes to rot, and food is held by the powerful. Hunger may be an issue, but famine is not. An improvement in food storage and delivery in countries like China and India would go a long way to providing enough food for an additional 2.5 Billion people. Where you get that number from I don't know, since the UN predicts global population maxing around 9 billion (less than 2 billion more than currently alive). Not using our corn for ethanol would go pretty far as well.

    Malnutrition is another issue, but things like golden rice may have the ability to reduce many types of malnutrition.

Featured