Why land and water are ‘planetary boundaries’ – not population

When it comes to food production, humanity is on a collision course with the planet. Agriculture is one of the biggest drivers of global ecological degradation: farming displaces natural ecosystems, uses valuable freshwater, pollutes rivers and estuaries, and releases potent greenhouse gases. And yet we undeniably need more of it – 1 billion people are still starving or malnourished in today’s world, surely one of the greatest moral outrages of our time. Looking to the future, we must feed more than 9 billion people by 2050, an increasing fraction of them on meat and dairy-heavy First World diets. To do that, agricultural production must be doubled, whilst the damaging environmental impacts of farming must be more than halved.

The challenge sounds like Mission Impossible. But it can be tackled effectively, according to a world-leading group of experts who have just published what may turn out to be one of the most important scientific papers this year. Entitled ‘Solutions for a Cultivated Planet’ (free PDF here), the article – by the University of Minnesota’s Jonathan Foley and colleagues – demonstrates that land use ranks with climate change as a planet-scale problem – and may be much more difficult to solve. Whilst there is no fundamental shortage of energy – thanks to renewables, nuclear fission and other low-carbon options – land is absolutely limited, and ranks as a top-level ‘planetary boundary’ because of its importance in maintaining the resilience of the Earth system.

In my new book ‘The God Species’ I outline all nine proposed ‘planetary boundaries’ – which include biodiversity loss, climate change, land use, water use, nitrogen loading and various other global ecological threats – and conclude that all must be considered simultaneously if we are to avoid simply replacing one critical problem with another. There is no place for simplistic linear thinking in a complicated and globally-interdependent human society and environment.

The proposed ‘planetary boundary’ for land use is for cropland to be limited to 15% of the Earth’s ice-free terrestrial surface. About 12% of this is already committed, so expansion alone cannot provide the needed increase in food. Moreover, agriculture has already destroyed 70% of grasslands, 50% of savannas, 45% of deciduous forests and more than a quarter of tropical forests. Agricultural expansion in the tropics emits more than a billion tonnes of carbon per year, and threatens biodiversity treasure troves in rainforests. What is needed instead is more efficient agricultural production elsewhere – getting more from less in land areas that are already used in cultivation. But doing this successfully will mean reassessing some of our most cherished notions about farming and the environment.

First off, organic farming is no silver-bullet solution. Whilst the organic movement has delivered valuable lessons about how to conserve soils and produce food in more wildlife-friendly ways, it is in general only half as productive as conventional farming and thereby – directly or indirectly – uses twice as much land for the same amount of food. Moreover, improving yields in highly unproductive agricultural areas in parts of Africa and Asia will mean using more not fewer artificial chemical fertilisers. The scientists estimate that closing ‘yield gaps’ could increase food production by a billion tonnes, or nearly 30% worldwide.

The organic movement has also erred by ruling out genetic modification as a critically-important technology to improve yields. Because of ill-considered public opposition, mainly in well-fed rich countries, very little genetic engineering effort has so far gone into key food crops like wheat, potato and rice, meaning big opportunities still exist to make these staples produce much more food for less water, nitrogen and land inputs. With both freshwater use and nitrogen capture ranked as ‘planetary boundaries’ in their own right, achieving much greater production efficiencies is a globally-important environmental goal.

In addition, my judgement is that very little can – or should – be done about global population growth. Populations are growing in developing countries largely because fewer people are dying, rather than because more children are being born, and this improvement in life expectancies can only be a good thing. Whilst I personally think access to family planning services is a human right in any civilised society, I do not think it is necessary to try to control population increase for the sake of the environment. In any case, the majority of people who will be alive in 2050 have either already been born or will be within the next decade, and they all have to be fed.

So what can we as consumers do? Whilst few people will be persuaded to embrace full vegetarianism, pressure on the land can be reduced by shifting away from grain-fed beef to grass-fed beef, as well as pork and poultry, which use land more efficiently. Subsidies which encourage food crops to be turned into biofuel must also be eliminated. We must also waste less: according to some analyses, as much as half of world food production is simply thrown away. Above all, solutions must be practical and pragmatic – there is no room for ideological narrow-mindedness in an age of ecological scarcity. We can certainly feed ourselves and reduce the ecological burden of agriculture simultaneously – but to do so we need to do things very differently, starting now.


  1. Rob Yorke

    I’ve just launched my debate paper ‘New demands; old countryside’ (endorsed by Minister for the Natural Environment) which delves into many of the issues touched on by Mark.
    Share your ideas and shelve your ideals – we need a national conversation not a polarised debate! @blackgull

  2. Mark Brown

    But your view that we are nothing like yeast in the petri dish is still valid? Is there a conclusion to be reached about the potential limits to growth? I am still reading “The God Species” so will reserve judgement. However I will contest the statement where you suggest Organic Farming yields half that of “conventional” farming. By Lconventional” I assume you mean “high fossil fuel input”. The debate will rage as to whether high chemical versus organic is best but the figure of a half is very pessimistic. It depends how you measure the efficiency of such farms in turning fossil fuels into food. One may have a future. One may not. We may well one day have a happy organic/GM hybrid farming industry. I support that. Whatever works. But it has to work sustainabley. And dare I say it. Cheaply.

    1. Mark Lynas (Post author)

      Hi Mark – there are references to support the organic land use productivity statement in TGS book… which I hope are helpful. I completely agree that energy/fossil fuel efficiency is also critical – that’s the climate planetary boundary, and we have to consider them all. I don’t know whether organic is significantly less fossil fuel intensive than conventional – certainly the absence of fertiliser means a saving on natural gas expended via the Haber-Bosch process, but on the other hand more extensive farming with lower productivity over larger areas might push the other way. Organic farmers tend to be similarly mechanised, except on the very small scale where labour is basically ignored as a cost.

      Anyway, as you say, there is a lot to consider here, and many more questions than answers! I’m pleased to hear you think GM-organic hybrid is a possibility – try telling that to the Soil Association…


    2. Rob Yorke

      Mark. The Soil Association will have to buy into a GM/organic status one day. Mainly because so many farmers are moving out of organic status due to the low returns and lack of consumer interest (down to cost). Organic farmers are highly mechanised as they have to cultivate to keep weeds down (rather than use pesticides) and of course rely on manure, the noxious methane producer, as fertiliser. And don’t mention having to use copper sulphate for to contain potato blight…..
      As I said in the launch of my rural debate paper, we must “share our ideas & shelve our ideals”.

  3. Gidon Gerber

    Alternatives to meat from farm animals should also be researched, such as articifially grown meat, or protein from insects. I hope it will be as delicious as “real” meat.

    Agriculture in cities could be another alternative, using rooftops or other unused spaces. Remember that space-saving vegetables such as Brussels sprouts and Belgian endives were cultivated in previous centuries to grow food on very limited space for a rapidly growing urban population.

    1. Michael Porter

      I quite agree with your comment about the scale of operations. Small area intensive production using aquaponic methods (a mixture of aquaculture and hydroponics) may become a preferred solution in urban environments. They also have the advantage of being virtually weed-free systems, and can be combined with other animal production as the wastes can be fed to fish in ponds or to worms for fish food. There are many alternative foods, and the conversion of food to fish meat is very efficient (can be 1.5:1 or less), unlike beef conversion rate of approximately 14: 1

  4. Rouget

    In both energy and food sectors you see the same patterns: scarcity of ressources, growing numbers of consumers.

    But instead of thinking of new fancy technologies to produce more, we can firstly consider that we have a very inefficient system where production represents twice the real final consumption (both in food and energy). Wastes along those chains demands an increasing efficiency.

    And efficiency means a better organisation. Technological advances in history only represents a small part of what we call innovation. The way people organise themselves represents a much better way of transformation than simply imagining humanity as a learning curve driven by technological progress. Remember than now obesity and diabetes is much important than starvation. GMO crops are sure a good thing (hard to say that when you are an European!) but it’s definively only a part of the solution.

    So thinking less of silver bullets coming from nowhere and having more interests into how changing organisation. A lot of work has to be done on this subject at an international scale. Who’s going to promote that? I hope Europe will lead the way.

    For inspiring books and authors about those subjects, I recommand several ones:
    – Vaclav Smil (all his books about energy and agricultural espacially the one on the history of Haber-Bosch process and the Green Revolution of the 70’s)
    – Jeremy Rifkin “The European Dream” on the creation of a society focused on the quality of life in contrario to the failed American Dream of being “an island”, independantly of the others. The kind of project China is aiming for with absolutely no different point of viw. They’re catching up, that’s all.
    – and of course Stewart Brand, the last one is a must-read.

    Finally it’s good to see that writers like Mark are using basic reality and science to try to think at solutions instead of using old fashioned green ideology that put everyone in the mud looking at our feet instead of thinking differently. Way to go.

    A summary of what I just said, way better expressed: http://classiclit.about.com/library/bl-etexts/eapoe/bl-eapoe-descent.htm

  5. Miles

    Heard your interview on Quirks and Quarks. I must say I am shocked by your technocratic naivete. Modernism is over, man. To think that we can manage a complex planet with our – although impressive – limited knowledge is just plain wrong-headed. History is full of examples of unpredicted, unintended consequences to “scientifically-informed” management decisions. Enjoy life in the 80s…

  6. Nata


    Though I agree that we need to keep an open mind as to the diversity of solutions that may be needed in the future, be they technological, behavioral or other, I would like to stress the need for prudence and simplicity.

    The element that makes organic agriculture most interesting, and is too often forgotten in the debate, relates to its accessibility. An integrated, local, small scale garden can supply a family or community with much more resources that can an equivalent area of monocultured crops. While subsistence agriculture may be hard pressed in northern countries where people have lost their habit of cultivating soil, it is still a fundamental element of the billions of people living in developping and emerging countries. Defending the right of people to grow their own food reduces the impacts on the environment and on resources, diversifies land-use and reduces poverty. It is plain to see how this is true from the example of Cuba, where this sorte of production assumes over 80% of the food needs of most city dwellers, and 100% of the food needs of rural communities. It allows to adapt the means of production to the actual needs of the end-users and minimizes waste.

    GM crops are, yes, a tempting solution to our food shortage problems, and may indeed be needed if the climate should rapidly mutate. However, we have grown food throughout the world under the toughest conditions throughout our history.This was possible because of the inherent diversity of life. A standardized means of production, assumed to be adapted to known conditions, is exactly the opposite of what should be developped under present circumstances. We should be favoring the multiplication of adaptative strategies, not favoring the emergence of centralized food production systems. And though an argument can be made that this is exactly what BT tries do do, it is naive to think that BT is not the toy of a strongly centralized oligarchy which aims to submit food production to the laws of free markets (and I say this sarcastically, as our markets are far from free)… As such, it is not a tool of empowerment, but a short-sighted attempt at maximizing corporate benefits. See the case for the sugare-beet grab in the US by Monsanto, in 2009-2010…

    All this to say that overcoming the physical limits to growth (or survival) needindeed to be adressed in an integrated way. But mostly, that the solutions to our problems often lie in overcoming our deeply entrenched beliefs that in order to be viable, projects need to be large scale. We need to adapt our production to our real, shared needs so as to truly respect the carrying capacity of our living environments.


  7. Scott

    “First off, organic farming is no silver-bullet solution. Whilst the organic movement has delivered valuable lessons about how to conserve soils and produce food in more wildlife-friendly ways, it is in general only half as productive as conventional farming and thereby – directly or indirectly – uses twice as much land for the same amount of food”

    Wrong. You are confusing organic with Traditional. Huge difference.


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