How Does the World Feed 10 Billion People by 2050 While Reducing Agricultural GHG Emissions by Two-Thirds? A Critique of World Resource Institute Recommendations

2020-04-15 12_11_16-Window

As we approach mid-2020, the world is focused almost exclusively on the COVID-19 pandemic, and rightfully so. Eventually global challenges that were dominant only weeks ago will return to prominence – and that includes climate change and greenhouse gas (GHG) emissions. Agriculture and food production are important sources of GHG emissions.  The task of substantially reducing GHG net emissions in agriculture while simultaneously increasing world food supply will be especially difficult.

Some agricultural groups are using the present COVID-induced hiatus – and the paucity of meetings, conferences and associated travel – to consider strategies for meeting the GHG/food-supply challenge. For those who doing so, a 2019 report called Creating a Sustainable Food Future published in 2019 by the World Resources Institute (WRI) is a highly valuable resource.

At 556 pages, the report is very long, something that precluded my own reading of it until COVID-seclusion provided the needed time. I have not read it all, but I’ve read most. It’s a comprehensive, well-written and – for the most part in my view – credible analysis and presentation of a strategy for feeding nearly 10 billion people in 2050. That’s an increase of 56% in global food calories needed above the WRI-chosen base year of 2010. The report also includes a strategy for a two-thirds reduction by 2050 in GHG emissions associated with agriculture – to meet a target that they define as 4 Gt/year of CO2 equivalent in net emissions.

The report has a three-page executive summary and a 40-page overview that provides an overview for readers (i.e., almost everyone) not wanting to read it all. I see little value in my repeating that summary in any detail here. It’s easily accessible by clicking this link. But I will note that WRI strategy consists of five parts (or “courses” as the authors refer to them); they are:

  1. Reduce Growth in Demand for Food and Other Agricultural Products, including less wastage/loss, fewer livestock, no biofuels and fewer human births;
  2. Increase Food Production without Expanding Agricultural Land, including improved livestock, crop and land productivity, and water-use efficiency;
  3. Protect and Restore Natural Ecosystems and Limit Agricultural Land-Shifting, including different usages for marginal agricultural land;
  4. Increase Fish Supply, including both wild fisheries and fish farms; and
  5. Reduce Greenhouse Gas Emissions from Agricultural Production, including less methane and nitrous oxide from ruminants, manure, fertilizer application and rice farms; use of non-fossil-fuel energy and consideration of soil C sequestrations.

The authors conclude that meeting a 4Gt CO2 equivalent target for net GHG emissions will be more difficult than that of producing more food. That makes sense to me.

If you or your organization are considering options/strategies for increasing food production while reducing GHG emissions, the WRI report is one good place to start.

At the same time, there are some notable weaknesses in Creating a Sustainable Food Future, at least in my opinion, and readers/planners should be aware of them. Since I’ve not seen these discussed elsewhere, I’ll do so below.

  1. WRI projections are essentially all based on the output of a multi-component model called the “GlobAgri-WRR” model. A brief overview of the model is provided in an appendix, and reference is made to various model assumptions throughout the text. However, many of the calculations remain obscure and the sensitivity of model output to these assumptions is largely undefined. The authors present one table comparing their projections of future agricultural land-use needs to those of other investigators using other models (Table 10-1). Differences of several hundred million hectares exist among these models in calculated land requirement for global food production. This does not mean the WRI model projections are meaningless. It just means interpret with caution.
  2. The authors generally provide no indication of their relative confidence in their various projections and analysis of options. I prefer the approach used in most IPCC (International Panel on Climate Change) documents where relative confidence in most statements/conclusions is stated. Even better would be statistical confidence ranges for various projections though I realize that this is virtually impossible with the modelling approach used.
  3. The authors assume that agri-food import/export balances will remain unchanged on a percent basis until the year 2050. And with rare exceptions, they have avoided economic considerations in their analyses. Indeed, the authors argue that economic input would weaken their analysis and projections. I find this curious in that economics is generally about how finite resources are allocated among competing demands. Given that the increase in food demand will be largely concentrated in some regions/continents/countries (eg. Sub-Saharan Africa) much more than others (eg., Europe), it’s puzzling that corresponding shifts in import/export patterns are largely rejected in the modelling approach.
  4. The authors also avoid discussion of the effects of their recommendations on the economic and social viability of farm families and associated rural communities – especially in developed countries. It seems deficient to recommend, for example, that the United States abandon production of fuel ethanol from corn (more discussion below) without considering the effect on the rural economy of the US Midwest. The report does discuss effects of some of their recommendations on rural communities in parts of the developing world.
  5. While the authors consider regional differences in model inputs, the output is generally one set of numbers for the entire world. The implication is that the solutions offered are largely global – with a few notable exceptions (example, limiting birth rates in Africa). I found this limitation to be frustrating as it implies that, for example, that North America should curtail grain processing for non-food uses because more food will needed in Africa. The flaws in meeting world food needs by increased shipment of food ingredients from ‘have’ countries to ‘have nots’ like Canada have been demonstrated on numerous occasions over the past century – and as recently as the ‘food crisis’ and the associated panic buying, hoarding and export prohibitions of 2007/08. We are seeing signs of the same in early stages of the COVID-19 crisis. Most countries want some degree of food self-sufficiency, regardless of the ease of importation during so-called ‘normal’ times. For more discussion on this, see The 2007/08 Agricultural Price Spikes: Causes and Policy Implications, issued by the Department of Environment, Food and Rural Affairs, Government of the UK.
  6. The authors emphasize comparisons with the years 1960 to 2010 – and sometimes 1980-2010 – in computing the potential for annual incremental increases in average agricultural/food production. But they don’t acknowledge that the years from about 1981 to 2007 were mostly years of global surplus production for many agricultural commodities. Indeed, that quarter century was an era when the focus of many (most?) international agricultural negotiations was on managing surplus production. Several countries introduced programs to discourage farm production for food during those years. One of the stated goals of the ill-fated Doha Round of World Trade Organization negotiations was to reduce subsidies that encouraged over-production and exports of cheap food ingredients to less-developed, less-wealthy countries. Many countries – both developed and under-developed – reduced expenditures on agriculture after about 1981. To base estimates of future productivity on production during decades when increased production was often discouraged seems misguided.
  7. One must agree with the authors’ assertion that reduction in food losses and wastage represents good opportunity to increase food supply. However, I don’t believe enough attention was given by WRI to the issue of year-to-year variations in weather and crop productivity. Food processors and farmers supplying those companies usually plan for some over-production in seasonal plantings to allow for those unpredictable years when inclement weather or pests mean below-average production. The same applies to the need to have reasonable reserves (including commodities with relatively short warehousing lifetimes) for disruptions in transportation, labour supply, government interjections and irrational hoarding. Wastage – while it does affect supply needs directly is often a less critical sin than the spectre of food shortages.
  8. The authors are harsh on livestock, especially ruminant agriculture, though avoided the too-simplistic approach of total elimination sometimes recommended by others. That’s not likely to happen, for reasons that the authors discuss. That said I believe that the authors have over-looked three considerations in their call for large reductions in ruminant agriculture.
    • While authors discuss at some length the implications of grazing, or not, of grassland and potentially grazable grasslands like savannah and thin forests, they largely overlook the benefits of perennial forage crop species in arable crop rotations. A further shift away usage of perennial forage usage in favour of more annual crops like grains, oilseeds and pulse crops would be negative for soil quality with long-term effects on crop-soil productivity. With some types of agriculture (notable organic), the cessation of ruminant agriculture would mean drastic effects on production and productivity.
    • Methane emissions are the main reason why ruminant agriculture is considered worse for GHG emissions compared to other classes of livestock and plant-based alternatives. However, missing is recognition that methane, because of its relatively short atmospheric existence (half-life ~10 years) is different from CO2 and N2O that last much longer. There is growing recognition that this must be considered in future analyses of ruminant contribution to climate change, even if the scientific community does not yet agree on how to so this in calculations. Note that it is different with N2O from livestock manure. Manure is an important source of N2O, but its elimination would mean a correspondingly larger supply of N2O from other sources of nitrogen fertilizer.
    • Thirdly, though I may have missed this, I don’t think the authors address the fate of grasslands if marked reductions occur in grazing by ruminant agriculture. My guess is that one result would be more grazing by wild animals – including ruminants like deer.
  9. The authors devote one chapter to plant breeding with a quick overview of technologies available and a projection of future achievements based on extensions of the past. I am disappointed in their discussion of genetic engineering (transgenics, CRISPR, etc.). The authors note, correctly in my view, that the most significant achievements of plant biotechnology are likely to come from other applications, but then focus virtually all of the subsequent discussion on two current technologies – herbicide tolerance and Bt usage in major commercial crops. There are several pages of discussion about the use and safety of glyphosate (with excessive attention paid, in my view, to a comparatively minute number of studies that report negative effects). Unfortunately, there is essentially nothing in this report about biotech-enhanced drought tolerance, improved nutritional composition (‘Golden Rice’ is not mentioned), disease resistance or tolerance to difficult soils, nitrogen fixation in non-legume species, or enhancements in photosynthetic ability, to list but a few of the opportunities now under intensive current investigation. The authors state that biotech usage to date is dominated by large companies but fail to note that this is almost entirely the result of lobbying by NGOs and their allies in European governments. It is not because of inherent difficulties in using/exploiting these technologies per se, or their relative risks to health and environment as compared to other widely used technologies such as genetic mutation created by exposure to radiation or mutagenic chemicals. In a later chapter in the report, the authors highlight “breakthough technologies” but with only the scantiest reference to use of biotechnology in plant breeding. Very strange, in my view.  If I’d been writing a report on how to produce more food in 2050 while producing fewer GHG emissions, I’d likely have devoted half the report to improvements through genetics and plant breeding. But we all have our biases, World Resources Institute writers included.
  10. The report is very negative on biofuels, recommending a complete elimination of their usage. Their argument is based on calculations of effects of biofuels on total food supply and on the assumption that biofuels means increased losses of organic carbon from soils and forests. If one assumes a fixed amount of photosynthetic production by global agriculture, the usage of some of this for biofuels means less for food. That’s inarguable. But this neglects how biofuel development occurred, at least in the case of ethanol from corn in North America. Steady increases in corn yields over recent decades, thanks to plant breeding and other technologies, has meant major increases in grain corn production per hectare or nation relative to more traditional usage needs, such as food and feed usage and exports. Ethanol production/usage has helped to use that increased supply. Increases in corn acreage increase, to the extent that they have occurred, have come at the expense of other lower-yielding arable annual crops such as wheat, and not from the cultivation of former rangeland or forests. WRI argues that the increased supply provided by biofuel elimination should be used to produce food for consumption in other countries or through a reversion of former Midwest cornfields to forests and grasslands. The WRI analyses ignores effects on farm family and rural community viability. Note that my analysis does not apply to biofuel production everywhere. What’s right for Iowa or Southern Ontario is not necessarily right for other continents – and vice versa.

I want to close this critique on the positive. I was especially impressed with the depth of the discussion in the WRI report on the potential (likely limited) for sequestering carbon in agricultural soils. The discussion on nitrous oxide from synthetic fertilizer and manure usage, and methane from manure, is detailed and very informative, even if oriented mainly to developed countries like the United States. (India, as an example, has three times more cattle than the USA.)

The report provides a very useful resource for organizations and governments developing strategies to produce much more food by 2050 while reducing GHG emissions substantially. This applies even if readers/users do not follow the specific recommendations provided. Congratulations to the authors.




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