39 – Climate change and grain production: winners and losers

13 November, 2019

by Professor Ross Kingwell – AEGIC Chief Economist.

Climate change is projected to have a range of impacts on global crop production. Australian grain production faces the challenge of adverse climate change. Similarly, some parts of the USA, Canada, southern Europe and India also face the prospect of adverse climate change. Conversely, for some grain exporters like Argentina and Russia, they face the prospect of beneficial, rather than adverse, climate change.

The view widely held by scientists engaged in studying global climate is that we are entering a warming period in which the atmospheric concentration of CO2 will be higher and so rainfall and plant growth will alter. The exact ways that plant growth will alter are difficult questions to answer and so scientists use a range of global climate models coupled with crop simulation models to gauge the possible range of yield outcomes.

Many scientific institutions and collaborations have collected data and constructed models to deliver greater insight about the possible impacts of projected climate change on crop production. Drawing on those models is research by Liu et al (2013). These researchers used four different global circulation models and considered two contrasting scenarios for future CO2 emissions, to assess how future production of wheat, maize and rice might alter. So, these researchers examined eight different climate scenarios and contrasted their impact on the production of the world’s three main crop types in the 2030s relative to the 1990s.

Their main findings are shown in chart one as either decreases or increases in crop production, with the degree of confidence in the direction of change also being noted.

Chart One. Impact of projected climate change on crop production in the 2030s
Source: Liu J, Folberth C, Yang H, Röckström J, Abbaspour K, Zehnder, A. (2013) A global and spatially explicit assessment of climate change impacts on crop production and consumptive water use. PLoS ONE 8(2): e57750.

Note, their findings make no allowance for technology or plant breeding improvements over the next decade. Their results simply highlight how a change in global climate is liable to affect crop production across the globe. The 3 crops considered, wheat, maize and rice, provide more than 60% of human dietary calorie intake either via direct consumption or as feed grains to produce livestock products. It’s highly likely that these crops will continue to account for the bulk of the future human food supply because of the persistence of food customs, the high R&D investment in these grains, and the ease of growing, storing and transporting these grains.

Liu et al (2013) found that major grain exporting regions such as Canada’s southern prairies, the USA corn-belt, southern Brazil and southern Australia were likely to suffer from adverse climate change, with declines in crop production being likely (assuming no offsetting innovation from plant breeding or cropping technologies). However, some other grain export regions such as Argentina, central and northern Europe, western Russia and the northern parts of Canada’s prairies were forecast to be advantaged by climate change. India’s main grain producing region in its north was found also to be adversely affected, whilst China mostly was found to be advantaged by projected climate change.

These researchers found that climate change will result in an increase in cropland suitability in the higher latitudes of the northern hemisphere whilst the tropics will lose some land suitability, mostly for maize production. In Australia, apart from the higher rainfall southern or northern fringes, much of the current crop lands face a worsening in their climate for crop production over the next few decades. In many other important grain-growing regions, such as the USA corn-belt, southern Brazil and northern India, which face similar future climatic adversity, investment in crop breeding, cropping technology and agronomic research will be essential to underpin the prosperity of grain production. Innovations like heat tolerance of plants during grain-filling, soil moisture mapping, water-harvesting tillage and improved weed control are all examples of changes that assist crop production in the face of a changing climate.

Worth noting is Liu et al’s conclusion that despite the projected changes in climate, world agriculture should face no major constraints to produce the food it needs for its future population, provided that agricultural R&D, investment and appropriate policies facilitate a sustainable intensification of crop production. These technologies and investments make feeding the future global population possible.

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