Climate patterns like the El Niño-Southern Oscillation (ENSO) have been responsible for widespread, simultaneous crop failures in recent history, according to a recent paper published on 3 July in the journal Science Advances (1). For example, in 1983, ENSO was responsible for the largest synchronous crop failure in modern recorded history.
Globally synchronous crop failures refer to the simultaneous failure of a single crop in multiple as distant as the United States, China, and Argentina. And many researchers predict these events will become much more frequent owing to climate change. So how important is the risk of potential global-scale failures to food security?
Current models of the global agriculture system assume crop failures in geographically distant regions are unrelated. However, the new findings suggest that to make global food systems more robust, we need to know more about the most damaging consequences of so-called multiple ‘breadbasket’ failures. Especially since around two-thirds of the world’s staple foods are produced by about 25 per cent of the Earth’s croplands. And fewer people than ever before have inadequate access to a sufficient quantity of food, the authors write. Moreover, an increasing number of people are dependent on imported food to meet daily minimum caloric needs.
The researchers at Columbia University’s International Research Institute for Climate and Society in collaboration with the International Food Policy Research Institute (IFPRI) assessed how different modes of climate variability cause volatility in the global and regional crop yields. The study is the first to estimate to what different modes of climate variability influence the volatility in global and regional crop production.
In particular, they examined the impact of the ENSO, the Indian Ocean Dipole, and other well-understood climate patterns on the global production of corn, soybeans, and wheat. More specifically, they analyzed how these modes of climate variability influenced drought and heat in major growing regions.
On a global level, corn is the most susceptible to climate variability, which causes around 18 per cent of the year-to-year variation in corn production. Whereas, only 7 per cent and 6 per cent of the variation in soybean and wheat yields are related to changes in global productivity, and are therefore at lower risk of simultaneous failures.
The researchers also found the risks are greatest for poor farmers in developing countries who do not have adequate coping mechanisms and lack the infrastructure and resources to manage large fluctuation in crop yields.
Furthermore, certain geographical regions, such as Africa and Brazil, are more exposed to the perils of climate variability. For instance, ENSO and other recurring climate phenomena account for 40–65 per cent of the variation in food production in Africa and NorthEast Brazil, the authors report. While other regions experience fluctuations closer to 10 per cent.
Despite these large differences, the findings expose a definite link between climate patterns in multiple regions. Moreover, the authors suggest these results can be scaled up to monitor and perhaps, even predict the influence on global production and potential global crop failures.
(1) Anderson, W.B. et al. Synchronous crop failures and climate-forced production variability. Science Advances (2019). DOI: 10.1126/sciadv.aaw1976