Is a hotter world necessarily a hungrier one?
THE FUTURIAN #3
We often assume that a hotter world will be a hungrier one. As the climate warms, the margins of cultivation will head towards the respective poles, taking out of cultivation vast areas that are currently productive. We tend to focus on this loss of arable land with very little consideration for land that cannot be cultivated currently, which may come into cultivation in the future. It is worth standing back to take stock of these cross currents.
The increase in global population seen in recent decades is the result of greater agricultural production. The area under cultivation has increased, but fails to account for much of the increases in food supply. Instead, agricultural productivity has increased by a disproportionate amount to meet the rising demands for food. Much of this increased productivity has been achieved through greater use of irrigation, pesticides, and machinery. In recent decades, the focus has shifted to improving crop yields through the use of data management and various forms of biotechnology.
These productivity enhancements have been partially offset through increased environmental degradation and biodiversity loss. Many now take the view that a changing climate will add to this offset by pushing temperatures beyond the cultivation ceiling and by altering rainfall patterns in a detrimental way. The main food growing areas we see today may not be the main food growing areas of tomorrow.
There is considerable uncertainty over how rising temperatures will affect the global supply of food. In warm areas, such as the tropics, the rise in temperature is likely to slow the increase in agricultural productivity more than in more temperate regions. This will ensure a loss to the global food supply. In the boreal regions, land that is currently outside of the agricultural cultivation zone is likely to come into it. This is likely to result in a gain to the global food supply. The net effect of these gains and losses is hard to gauge at present. We fear a net loss of global food supply and we hope for a net gain instead.
To enjoy a net gain to the global food supply, a number of factors need to come into play. It may be that the higher latitudes may only become cultivable with extensive irrigation. This presumes a degree of investment in irrigation and the ready availability of potable water. Both of these are big assumptions. It is also assumed that crop pathogens, as they migrate polewards, retain broadly the same form as they currently possess. Any degree of mutation or genetic variation could have a considerably adverse effect on crop production. Finally, there is an implicit assumption that the soil of the newly cleared boreal forests will be as productive as the soil in lower latitudes. This may not be the case if the underlying boreal soil proves to be too thin and too acidic. It may take some time to build the soil to a point where it could be put to productive use.
There is also a geopolitical dimension of which we should account. Much of the benefit of a northwards shift in the margin of cultivation will accrue to Canada and Russia. Already, since 2015, Russia has become the largest producer of wheat in the world due to rising temperatures. If we consider a future balance of power to be based around food production, then it is easy to imagine Canadian wheat as a rival to Russian wheat. Exactly where China fits into this picture is an interesting point of conjecture. However, I think that the point is made that the production of food, in a potentially hungry world, is likely to assume a degree of importance geopolitically and has the potential to be a source of future conflict.
This brings us back to the balance of advantage. In the study of the future, we like to think of most things as being possible. In the warmer areas, it could be that some form of technology would be deployed to maintain current levels of crop yields and to support the current growth in agricultural productivity. For example, bio-technologists could develop heat and drought resistant strains of crops. The loss to the global food supply might not be as acute as we currently fear.
Equally, it may be the case that the gains from the extension of the area under cultivation may be greater than currently envisaged. It could be that a number of crop strains are more productive in the boreal soils, that they respond better to the use of fertilisers, and that concerns about irrigation have been misplaced. Crop yields are the result of a complicated sequence of inputs and it may be the case that the actual outcome is far better than expected. Again, in these circumstances, the loss to the global food supply may not be as acute.
We also need to be mindful of future demand for food. So far, we have taken this to be relatively static. We know that there will be more mouths to feed until the middle of the century. However, there may not be as many people as we currently forecast. It may be that the lower forecast is what actually happens, in which case the global food situation is not as tight as we currently expect it to be.
It also may be the case that our tastes for food change. At present, our tastes are that, as we become more affluent, we switch away from a plant based diet towards a meat based diet. This is particularly the case in the newly enriched East Asian economies. However, it may also be the case that tastes will shift from a meat based diet towards a plant based diet. The rise of vegetarianism and veganism in western societies is a case in point. If there is an appreciable change in this direction, more plant based food would be released to feed humans as opposed to feeding farm animals. It is likely that there would be a net increase in the food available, once again easing the supply of food.
It is not necessarily the case that a hotter word will end up being a hungrier one. If the loss of food production in the tropics is not as much as feared, if the gain in food production in the boreal regions is better than we could hope for, and if the demand for food doesn’t quite grow by as much as expected — either through lower than anticipated birth rates or a change in food tastes away from meat — then we can envisage a world in which the supply of food is not so tight. However, this view of the future relies upon a number of heroic assumptions. It might not be prudent to rely upon these alone.
© Stephen Aguilar-Millan 2021
