New research indicates that as much as one third of the World's food production could be threatened by global warming with the globe's poorest hit the hardest.
Whilst it is well-understood that climate change represents a major threat to our way of life in a multitude of ways, what is less certain is the areas of human activity that will be most impacted and to what extent.
Researchers have been aware that climate change could have a negative impact on the raising and keeping of livestock and agriculture in general. Still, thus far, they have been uncertain which areas and practices will be the worst hit.
New research from a team of scientists, led by Aalto University, Finland, looks at the effect of climate change on global food production if greenhouse gases continue to be emitted at current rates. The researchers discovered the net result would be a knock-on effect on food supply, with some of the World's poorest regions hit the hardest.
Our research shows that rapid, out-of-control growth of greenhouse gas emissions may, by the end of the century, lead to more than a third of current global food production falling into conditions in which no food is produced today — that is, out of safe climatic space.
Matti Kummu, Professor of global water and food issues, Aalto University
The team's findings indicate that the forecasted temperature rise of 3.7 ⁰C predicted if greenhouse emissions are not mitigated, this will result in increased rainfall and further temperature rises. These conditions will impact some of the World's major food production areas, resulting in major effects felt in Africa's Sudano-Sahelian zone and South and South-East Asia.
Alongside Doctoral Candidate Matias Heino, Kummu is a co-main author of a paper that documents the team's findings, published in the latest edition of the journal One Earth¹.
A Climatic Safe-Space
In the team's paper, they define a concept they call a 'safe climatic space' (SCS), an area in which food production systems are accustomed to current climate conditions. They say that currently, 95% of crop production is centered in these areas.
The researchers defined these conditions by three major parameters — rainfall, temperature and aridity — which gives the study an advantage over other similar studies that only consider one parameter.
"The good news is that only a fraction of food production would face as-of-yet unseen conditions if we collectively reduce emissions so that warming would be limited to 1.5 to 2 degrees Celsius," says Kummu.
It is changes in the aforementioned parameters, particularly rainfall and aridity, that could pose a significant threat to food production in South and Southeast Asia as well as the Sahel region of Africa. To compound this problem, these are also the regions that seem to be the least capable of adapting to changing conditions.
Much of the problem is because food production arose and is thus tailored to stable Holocene climate conditions, which have persisted over several millennia.
Food production as we know it developed under a fairly stable climate, during a period of slow warming that followed the last ice age. The continuous growth of greenhouse gas emissions may create new conditions, and food crop and livestock production just won't have enough time to adapt.
Matias Heino, Doctoral Candidate
Assessing Future Climate Scenarios
In conducting the study, the researchers used two possible future climate change models.
In the less extreme of these models, emissions of carbon dioxide — one of the greenhouse gases that is the major contributor to climate change — is cut radically. This results in a global temperature rise of between 1.5 and 2 ⁰C. In the other model, greenhouse emissions are projected as continuing at current rates.
This allowed the team to predict how climate change could affect over 25 important food crops and seven different breeds of livestock. They also factored in different societies' capability to adapt to changes.
What emerged was a clear picture of current threats affecting different regions of the globe in very different ways, with 52 of the 177 examined countries able to keep food production in their remaining SCS areas.
This revealed something much more concerning, however. It was the countries that are already vulnerable which were hit hardest — especially in the 'no change' climate scenario.
So, whilst more affluent western countries can adapt to the threat, more impoverished regions will struggle to meet this challenge. This includes countries like Benin, Cambodia, Ghana, Guinea-Bissau, Guyana, and Suriname, where 95% of current food production occurs in areas that will no longer be SCSs.
The team's result revealed worrying trends beyond food supply too. The less extreme scenario of reduced carbon emissions suggested that by 2100 the boreal forest, which stretches across North America, Russia, and Europe — would shrink from its current 18.0 to 14.8 million square kilometers. If emissions can not be cut this could result in these forests being reduced to as little as 8 million square kilometers.
The team's models also suggested that in this latter scenario the Arctic tundra — a treeless polar desert found in the high latitudes in the polar regions, such as Alaska, Canada, Russia, Greenland, Iceland, and Scandinavia — could cease to exist altogether. Meanwhile, tropical desert and dry forest zones will grow.
"If we let emissions grow, the increase in desert areas is especially troubling because in these conditions barely anything can grow without irrigation," Kummu says. "By the end of this century, we could see more than 4 million square kilometers of new desert around the globe."
The study may differ from other similar research by taking a more holistic approach to the climate change model, but the message is the same; the climate crisis requires us to take immediate action.
"We need to mitigate climate change and, at the same time, boost the resilience of our food systems and societies — we cannot leave the vulnerable behind," concludes Heino. "Food production must be sustainable."
1. Kummu. M., Heino. M., Taka. M., et al, , 'Climate change risks pushing one-third of global food production outside the safe climatic space,' OneEarth, [DOI:https://doi.org/10.1016/j.oneear.2021.04.017]