Noted food historian Rachel Laudan was at the recent Borlaug Summit on Wheat for Food Security in Obregón, Mexico, organized by CIMMYT to celebrate 100 years of Norman Borlaug, and what an inspired decision it was to invite her. She spoke at the conference about the foundational role of wheat in the development of civilization, and I hope her slides and perhaps even a video of her presentation, along with those of the other distinguished speakers, will be made available. In the meantime, her blog post on the experience provides a refreshingly different perspective than is usually provided by participants at this sort of conference. 1 Too bad she didn’t get to see the CIMMYT genebank…
That IPCC report in 3 handy diagrams
Too busy to go through the latest IPCC report and extract the nuggets relevant to agriculture (including crop wild relatives)? Fear not, we’re not. Here’s three figures which pretty much tell the story, and the relevant bits of text from the report to go with them. There’s lots of commentary and opinion out there on the report. We thought you’d like to hear it straight.
Based on many studies covering a wide range of regions and crops, negative impacts of climate change on crop yields have been more common than positive impacts (high confidence). The smaller number of studies showing positive impacts relate mainly to high-latitude regions, though it is not yet clear whether the balance of impacts has been negative or positive in these regions (high confidence). Climate change has negatively affected wheat and maize yields for many regions and in the global aggregate (medium confidence). Effects on rice and soybean yield have been smaller in major production regions and globally, with a median change of zero across all available data, which are fewer for soy compared to the other crops. Observed impacts relate mainly to production aspects of food security rather than access or other components of food security. See Figure SPM.2C. Since AR4, several periods of rapid food and cereal price increases following climate extremes in key producing regions indicate a sensitivity of current markets to climate extremes among other factors (medium confidence).
For the major crops (wheat, rice, and maize) in tropical and temperate regions, climate change without adaptation is projected to negatively impact production for local temperature increases of 2°C or more above late-20th-century levels, although individual locations may benefit (medium confidence). Projected impacts vary across crops and regions and adaptation scenarios, with about 10% of projections for the period 2030-2049 showing yield gains of more than 10%, and about 10% of projections showing yield losses of more than 25%, compared to the late 20th century. After 2050 the risk of more severe yield impacts increases and depends on the level of warming. See Figure SPM.7. Climate change is projected to progressively increase inter-annual variability of crop yields in many regions. These projected impacts will occur in the context of rapidly rising crop demand.
All aspects of food security are potentially affected by climate change, including food access, utilization, and price stability (high confidence). Redistribution of marine fisheries catch potential towards higher latitudes poses risk of reduced supplies, income, and employment in tropical countries, with potential implications for food security (medium confidence). Global temperature increases of ~4°C or more above late-20th-century levels, combined with increasing food demand, would pose large risks to food security globally and regionally (high confidence). Risks to food security are generally greater in low-latitude areas.
Distribution of impacts: Risks are unevenly distributed and are generally greater for disadvantaged people and communities in countries at all levels of development. Risks are already moderate because of regionally differentiated climate-change impacts on crop production in particular (medium to high confidence). Based on projected decreases in regional crop yields and water availability, risks of unevenly distributed impacts are high for additional warming above 2°C (medium confidence).
Within this century, magnitudes and rates of climate change associated with medium- to high-emission scenarios (RCP4.5, 6.0, and 8.5) pose high risk of abrupt and irreversible regional-scale change in the composition, structure, and function of terrestrial and freshwater ecosystems, including wetlands (medium confidence). Examples that could lead to substantial impact on climate are the boreal-tundra Arctic system (medium confidence) and the Amazon forest (low confidence). Carbon stored in the terrestrial biosphere (e.g., in peatlands, permafrost, and forests) is susceptible to loss to the atmosphere as a result of climate change, deforestation, and ecosystem degradation (high confidence). Increased tree mortality and associated forest dieback is projected to occur in many regions over the 21st century, due to increased temperatures and drought (medium confidence). Forest dieback poses risks for carbon storage, biodiversity, wood production, water quality, amenity, and economic activity.
Agricultural biodiversity where you least expect it
Continuing our in-depth treatment of The Economist’s (unwitting?) coverage of agricultural biodiversity, two items in the most recent issue. First, consider this photo:
It’s from an article on the BBC World Service, and clearly shows the value of a radio in Africa. But what’s that the listener is holding? Could it be a cavy? I rather think it could, and of course one wouldn’t expect The Economist to mention its origins in the Andes. We, however, still want to know when they arrived, how they got there, and whether they are proving the “indispensable” option they were thought to be.
Then there’s this little table, from an article on price fixing and cartels.
See those innocuous little entries for F. Hoffman-La Roche, labelled Vitamins? Those reflect decisions more than a decade ago by the US and the EU to fine not just Hoffman but a bunch of other pharmaceutical companies for fixing the price of vitamin A supplements, proof enough of the economic value of treating vitamin A deficiency as a simple medical problem requiring a simple (and expensive) medical fix. And most of the time, synthetic supplements aren’t even that useful to the children who get them. How else might you improve vitamin A levels? Well, you could try promoting a more diverse diet. But where’s the profit in that?
p.s. I was slightly saddened to see that while Hoffman remains joint number 1 in the EU, it has slipped to a poor 5th in the US. So I ran the numbers through an inflation indexer, which brings the $500 million up to $705 million in today’s dollars, which at least bumps them up a place.
Brainfood: Sunflower genomics, Omani chickens, Ozark cowpea, Amerindian urban gardens, Thai homegardens, Global North homegardens, African pollination, Ugandan coffee pollination, Use of wild species, Wheat and climate change, Iranian wheat evaluation, Tunisian artichokes, Fig core, Onion diversity, Distillery yeasts
- Genomic variation in Helianthus: learning from the past and looking to the future. Paleopolyploid events, transposable elements, chromosomal rearrangements. Is there anything these plants don’t have? But then these guys would say that, wouldn’t they.
- Assessment of genetic diversity and conservation priority of Omani local chickens using microsatellite markers. Unsurprisingly, the Dhofar (far S) and Musadam (far N) populations are the most different. I collected crops in both places way back when, and I bet you it would be the same for things like alfalfa and sorghum. Or cowpea, which brings me to…
- Just Eat Peas and Dance: Field Peas (Vigna unguiculata) and Food Security in the Ozark Highlands, U.S. Still important after all these years. (I suspect Gary Nabhan would have predicted this, but I can’t even get an abstract of his paper Food Security, Biodiversity and Human Health: Ethnobiology as a Predictive Science.)
- Amerindian Agriculture in an Urbanising Amazonia (Rio Negro, Brazil). Traditional systems survive move to cities just fine.
- Human-Induced Movement of Wild Food Plant Biodiversity Across Farming Systems is Essential to Ensure Their Availability. Just like in Brazil, people move wild species to their homegardens in Thailand too.
- Urban home food gardens in the Global North: research traditions and future directions. Uhm, could maybe Brazilian and Thai homegarden studies guide similar work in the North… Yep, and here’s how.
- Priorities for Research and Development in the Management of Pollination Services for Agricultural Development in Africa. Old and traditional may not mean weak and out of date, but change gonna come anyway.
- Social and Ecological Drivers of the Economic Value of Pollination Services Delivered to Coffee in Central Uganda. No wait, change here already.
- Use it or lose it: measuring trends in wild species subject to substantial use. Wild species which are being used by people tend to be doing better than those that are not. Yeah, but settle down, the data are not that great.
- An assessment of wheat yield sensitivity and breeding gains in hot environments. The successes have been coming from the lower potential material, not the elite of the elite.
- Adaptation Patterns and Yield Stability of Durum Wheat Landraces to Highland Cold Rainfed Areas of Iran. It’s not always about heat. Anyway, in either case, thank goodness for diverse worldwide germaplasm collections.
- Karyological and genome size insights into cardoon (Cynara cardunculus L., Asteraceae) in Tunisia. The wild populations from Sicily and Tunisia are closest to the crop.
- Ex situ conservation of underutilised fruit tree species: establishment of a core collection for Ficus carica L. using microsatellite markers (SSRs). Fancy maths allows Spanish researchers to recover all microsats within a collection of 300 figs in only about 10% of the accessions. So who gives a fig for the rest, right?
- Assessing the genetic diversity of Spanish Allium cepa landraces for onion breeding using microsatellite markers. Alas, all the Spanish Allium cepa landraces fall in the same cluster, so a core could be tricky. These guys really know their onions.
- Biodiversity of non-Saccharomyces yeasts in distilleries of the La Mancha region (Spain). Gonna need some booze to wash down the figs and onions, right?
So how many crops feed the world anyway?
I am conscious of the fact that in my recent short post on the paper “Increasing homogeneity in global food supplies and the implications for food security” I did not actually provide the answer to the question that the lead author, Colin Khoury, asked four years back on this blog, when he began thinking about doing the study. And that is: How many plants feed the world?
Well, of course, almost 25 years ago Prescott-Allen and Prescott-Allen (1990) said that “85 species commodities and 28 general commodities contribute 90% of national per capita supplies of food plants.” Because of changes in the way agricultural statistics are recorded, it’s difficult to make exact comparisons, but here’s the money quote summarising the changes:
The total number of important crop species we identified remained relatively consistent in comparison with a previous point estimate based on national-level data from 1979 to 1981 (Prescott-Allen and Prescott-Allen, 1990), but the spread and abundance values of these crops have changed measurably. The rate of movement toward homogeneity in food supply compositions globally continues with no indication of slowing. This trend implies a likely deterioration in importance of unreported minor and geographically restricted food plants, along with the measured cereal, oil, starchy root, and other crops that displayed significant declines in abundance in national food supplies. Thus, even as the number of measured crops available to the consumer in a given country has increased over the past half-century as a global trend, the total diversity of crops contributing significantly worldwide has narrowed.
So, if you must know, it’s about 94 plant species that largely feed the world. To be more precise, according to the analysis of Colin and his colleagues, we can now say that 50 crops, or 94 species, contribute to 90% of food supplies at national level. If you want to know what they are, you’ll need Table S1 in the paper. Because FAOStat, which is the dataset which both Prescott-Allen and Prescott-Allen (1990) and this paper uses (and for which, therefore, despite all its faults, we should all be grateful) records only a particular set of (52) relatively big crops, it’s not easy to know what’s happening with consumption of other, more local crops. We do know from many local studies that a lot of them are declining in both cultivation and consumption. But also that something can be done about it. Look at quinoa. History is not destiny. So maybe 95 species feed you if you’re Bolivian or a hipster. And Henry Hargreaves and Caitlin Levin need to re-think their food maps.