Food news (new series): How to feed the world

Start: 95.4 Last week: 88.4 This week: 89.3

There’s nothing to say I can get serious here from time to time, or that I can’t cross-post to anywhere that'll have me.

There’s a fascinating paper in last week's Science Express¹ from a heavyweight bunch of scientists and advisers in the UK, on “the challenge of feeding 9 billion people”. It makes some seriously interesting points, raising lots of questions (and far fewer answers, natch). And being as it is behind a paywall (I think), I’m just going to quote from it at length. And comment.

After reviewing the main challenges -- land, water, mouths, climate -- the authors set out their stall.

So how can more food be produced sustainably? In the past, the primary solution to food shortages has been to bring more land into agriculture and to exploit new fish stocks. Yet over the last five decades, while grain production has more than doubled, the amount of land devoted to arable agriculture globally has increased by only about 9% (14). Some new land could be brought into cultivation but the competition for land from other human activities makes this an increasingly unlikely or costly solution, particularly if protecting biodiversity and the public goods provided by natural ecosystems (for example carbon storage in rainforest) are given higher priority (15). Formerly productive agricultural land has in recent decades been lost to urbanization and other human uses, as well as to desertification, salinization, soil erosion and other consequences of unsustainable land management (16). Further losses, which may be exacerbated by climate change, are likely (7).

They consider five sets of options: Closing the yield gap, increasing production limits, reducing waste, changing diets and expanding agriculture. Most important first ...

The yield gap is the difference between what farmers achieve with the best genetic material, inputs and management and the average under particular circumstances, and it has become common to claim that bringing all farmers up to snuff would solve the world’s food security woes. Godfray et al. avoid that pitfall, and have a neat way of illustrating the yield gap, with changes in per capita food production over the past 50 years.

In Asia this has increased approximately twofold (in China by a factor of nearly 3.5), in Latin America by 1.6-fold, while in Africa per capita production fell back from the mid-1970s and has only just reached the same level as in 1961 (2, 20). Substantially more food -- as well as the income to purchase food -- could be produced with current crops and livestock if ways were found to close the yield gaps.

Completely ignoring the truly great idea that instead of improving food production everywhere, we just produce everything where it does best, the heavies concentrate on practical ideas. For example ...

Farmers ... may not have access to the technical knowledge and skills required to increase production.

Sounds like another call for increased investment in extension services. Here’s another nice counter-intuitive notion.

In some situations such as low-income food-importing countries investing purely in generating widespread income growth to allow food purchases from regions and countries with better production capabilities may be the best choice.

Pointing out that “the yield gap is not static,” it's nice to see a multitude of suggestions for moving with the challenges.

Innovation involves both traditional and advanced crop and livestock breeding, as well as the continuing development of better chemical, agronomic and agro-ecological control measures. The maximum attainable yield in different regions will also shift as the effects of climate change are felt. ... Models that couple the physics of climate change with the biology of crop growth will be important to help policy makers anticipate these changes, as well as to evaluate the role of “agricultural biodiversity” in helping mitigate their effects (25).

Traditional and advanced breeding; hot damn! But guys, what’s with the scare quotes around agricultural biodiversity? Is that because you don’t know what it is? Or because you don't know how it might help mitigate the effects of climate change? Then we move on to the whole issue of sustainability, which Godfray et al. consider part of plugging the yield gap. Again, lots of questions.

• Over what spatial scale should food production be sustainable?
• Though simple definitions of sustainability are
  independent of time scale, in practice how fast should we seek to move from the status quo to a sustainable food system?
• [A] major problem when evaluating alternative strategies and negotiating trade-offs. ... [A]n over-emphasis on what can be measured relatively simply -- carbon for example -- may lead to dimensions of sustainability that are harder to quantify -- such as biodiversity -- being ignored.

Other elements in closing the yield gap relate to areas that are even less amenable to the old ways of doing things, for example working with women, ensuring that farmers have secure land rights, and social protection programmes for those who can neither buy nor grow an adequate diet.

Making ”Closing the yield gap” the most important factor bucks a lot of the trends in prescriptions for greater food security. Hard on its heels, though, is “Increasing production limits,” but here too the authors show a great deal of good sense. Of course genetic manipulation is in there, with the fond hope that by mid-century the genetic engineers will have delivered some more radical options. With this fond hope, however, comes some rather refreshing awareness.

Domestication inevitably means that only a subset of the genes available in the wild-species progenitor gene pool is represented among crop varieties and livestock breeds. Novel genetic material from land races, rare breeds and wild relatives will be important in allowing breeders to respond to new challenges. International collections and genebanks provide valuable repositories for such genetic variation but it is nevertheless necessary to ensure that locally adapted crop and livestock germplasm is not lost in the process of their displacement by modern, improved varieties and breeds.

There’s more about ensuring access to the fruits of GM and asking farmers what they want, but frankly I found it hard to focus through tears of joy. Wild relatives! International collections! Yikes!

“Reducing waste” follows, pointing out the crucial difference between developing countries, where waste is a matter of post-harvest losses, and developed countries, where the end user generates most of the waste.² Then comes a section on "Changing diets" which I think I might have ranked above waste. No matter; that too raises interesting points.

• [T]he argument that all meat consumption is bad is overly simplistic.
• [I]n developing countries meat represents the most concentrated source of some vitamins and minerals, which is important for individuals such as young children.
• Well-balanced diets rich in grain and other vegetable products are considered healthier than those containing a high proportion of meat (especially red meat) and dairy products.
• As developing countries consume more meat in combination with high sugar and fat foods they may find themselves having to deal with obesity before they have overcome under-nutrition, leading to an increase in spending on health that could otherwise be used to alleviate poverty.

That last one is already happening; the “diseases of affluence” are not diseases of affluence at all but diseases of an over-simplified diet. Developing countries are also increasingly facing the spectre of the so-called double burden of obese and under-nourished members in a single family. The trick for policy-makers will be to get Treasury, Agriculture, Health and Environment to sit around a single table and figure out how to scoop the four-way-win that awaits their closer cooperation.

The paper ends with “Expanding aquaculture,” as I suppose it must, and concludes by appropriating what is fast becoming the world’s favourite Big Crisis Metaphor.

Together these challenges amount to a perfect storm.

Navigating the storm will require a revolution in the social and natural sciences concerned with food production as well as a breaking down of barriers between fields. The goal is no longer just to maximise productivity, but to optimise across a far more complex landscape of production, environmental and social justice outcomes.

Can I get a ramen?

Godfray and his colleagues have produced a great summary, one that I am sure will land on the desks of government ministers and other movers and shakers everywhere. Will they listen? Will they act? Will they even consider listening or acting? Stay tuned.