Crop Yields: Could Go Down when They Need to Go Up


August 22, 2014

Paul McMahon, author of “Feeding Frenzy: The New Politics of Food,” asserts, “Science shows that our planet has the biophysical resources to feed 10bn people. We already produce enough to feed that many, but much food is wasted or diverted towards the rich.” [“Opinion: Food market is increasingly volatile,” Financial Times, 11 April 2014] McMahon may be correct; but, the fact of the matter is, changing people’s eating habits or trying to dissuade farmers from making a profit or getting food from where it’s grown to where it is needed all contribute to the fact that food security for much of the world’s population is anything but guaranteed. If those weren’t serious enough concerns about the future of food security, you can add a couple of more — climate change and air pollution. Anthony Wood (@AKGWood) reports, “A new study has examined the potentially disastrous implications that a combination of global warming and air pollution could have on crop yields by the year 2050. The research is one of the first projects to take into account a combination of the two dangers, and highlights the humanitarian crisis that could arise should the threat not be tackled head-on.” [“New study indicates dramatic fall-off in global crop yields by the year 2050,” Gizmag, 31 July 2014] McMahon adds, “If you plot population growth against land availability and climate change, it is clear that the places where more food can be grown will not be where it is most needed.”

Crops studied in the research, which was conducted by scientists from MIT, the University of Hong Kong, and Colorado State University, included rice, wheat, corn, and soy. These crops “represent over half the calories consumed by the global population.” The study concluded “that global crop yields will drop by around 10 percent by the year 2050 due to global warming, however the damaging effects of air pollution may be harder to quantify due to the difficulty in differentiating it from other damaging phenomenon.” These conclusions support a UN study, Intergovernmental Panel on Climate Change, released earlier this year that “found global warming was already having a detrimental effect on food security.” [“Climate change raises risk to food supplies,” by Scheherazade Daneshkhu, Financial Times, 11 April 2014] Researchers around the globe are working feverishly on new ways to increase crop yields; but, their efforts could be for naught if something isn’t done to reduce air pollution and curb climate change. Estimates are that crop yields need to increase by 14% by mid-century in order to keep up with demand. A 10% percent drop in crop yields could prove disastrous. McMahon reports, “Innovation is most urgently needed at the production end, on the farm. Much attention has been given to closing the ‘yield gap’ – helping less productive parts of the world attain the sorts of yields that are achieved in the US, Europe or Australia.”

Daneshkhu reports that Agco, “the US farm equipment manufacturer best known for its bright red Massey Ferguson tractors,” is one company that is trying to help farmers around the world increase crop yields. She continues:

“The [Agco] project is one of an escalating number of partnerships stemming from the WEF’s New Vision for Agriculture initiative. Multinational agriculture groups, including Syngenta, Monsanto and Cargill, in partnership with governments, international organisations and farmers’ organisations aim to develop sustainable methods and improve farming practices for Africa’s 80m smallholders. For the companies involved, the benefits are obvious – better yields mean richer farmers and more customers for their products. For the rest of the world, higher yields mean more food for a global population expected to peak at about 10bn mid-century, from 7bn today.”

Another group that is working on the crop yield challenge is the Agricultural Research Service (ARS) of the United States Department of Agriculture (USDA). The USDA-ARS has created a tool called the Geospatial Agricultural Management and Crop Assessment Framework (GAMCAF), that “brings together crop models that estimate plant growth and crop yield at scales as fine as 30 meters (90 feet), with spatial sources of information on soils, water, land use, and other factors.” [“Food security increased by new scientific model in agricultural production,” by the American Society of Agronomy, Science Codex, 5 May 2014] The GAMCAF tool is designed to integrate crop models with spatial data, something that had been previously unavailable. The article notes, “The platform now includes climate data, enabling predictions of how future temperature and precipitation scenarios will affect crop yields. It can also examine the effects of land use changes such as farmland loss — or, conversely — of bringing abandoned farmland in places like Maine back into production. Eventually, it might even be used to make similar forecasts for other U.S. regions or the entire country, the scientists say.” If the results in the U.S. prove successful, I’m sure the tool would be made available to organizations around the world.

Creating models that can ingest data from a number of different sources will be essential in the effort to increase crop yields enough that they can counteract the detrimental effects of climate change and pollution. As an example, the MIT/UHK/CSU study, which the authors described in Nature Climate Change, discovered that damage to soy crops once attributed solely to global warming was found to have been caused by air pollution. Wood reports:

“Whilst the two phenomenon damage the crops in their own right, they are also inextricably linked. The rising temperatures caused by global warming is itself the catalyst that leads to an increase in the creation of plant-damaging ozone. Furthermore, the study highlights that while individually air pollution or global warming would be damaging to global food production capabilities, together they pose a much greater threat, working in concert to detrimentally affect a much wider range of crops than either one could harm on its own. For example, corn crops are very susceptible to damage from heat created as a result of global warming, but less affected by ozone. Wheat on the other hand suffers in completely the opposite manner, and is easily damaged via interaction with polluted air.”

Wood also noted that the study stressed the geospatial aspect of crop production. He reports, “According to the study, the effects of the damage will differ significantly by region.” He concludes:

“Whilst scientific advances are being made focusing on improving crop yield and quality, the fact remains that food production and distribution is still inefficient in dealing with undernourishment in less developed countries. The food shortage in Africa will only be exacerbated under current trends, with the study predicting an increase in undernourishment on the continent from 18 to 27 percent. The end message is that world leaders must take the potential reduction in food production seriously, as they consider national air pollution and food security policy. A ten percent drop in crop yields, compounded by the unquantifiable damage caused by air pollution by the year 2050, is untenable at a time when we are predicted to need to produce 50 percent more food simply to sustain our planet’s burgeoning global population.”

Although his estimates of how much more food will need to be produced may be high, his bottom line is on the mark.