According to a study released Wednesday evening in the medical journal Lancet, climate change could result in the deaths of half a million adults due to malnutrition per year by 2050. The modelling study, conducted by the University of Oxford’s Marco Springmann, was the first to estimate this number and to analyze how climate change will impact diet composition and body weight.
The answers are not good for many people who will still be eating food 34 years from now — even those who are currently food-secure.
On current greenhouse gas emissions trajectories, the projected increases in food availability will be a third less than they otherwise would be. The average person will have access to 3.2 percent less food, consume four percent less fruits and vegetables, and a smaller reduction in red meat.
“Health researchers have known for quite some time that most deaths are attributable to simple dietary risk factors — which really says something about the imbalance of diets,” Springmann told ThinkProgress in a phone interview. “Those include things such as diets low in fruits, diets low in vegetables, diets high in red and processed meat.”
“Yet so far, people have been mostly concerned with classical questions of food security — that is if people have enough food in general,” he continued. “From a health perspective it’s actually very natural to look at changes in diet quality and not just changes in diet quantity of food.” The researchers’ idea was to go beyond those questions of food security and try to answer questions of “nutrition security.”
The hardest-hit countries, the researchers found, were likely to be middle- and low-income nations in the Western Pacific and Southeast Asia, but also some in Europe and the Americas. But it’s not just the world’s poorest that have to be most concerned about the impacts of climate change, which is not only a key point for U.N. negotiators, but has also been suggested by other studies.
The world’s wealthiest (and well-fed, and overweight) people also risk fundamental changes to their diets as crop productivity falls for fruits and vegetables, which are critical planks in the food pyramid.
“It is notable I think that the Springmann analysis showed the effects of climate change on the quality of diets were more important than the impacts on quantity (i.e. calorie supply),” Professor John Porter from the University of Copenhagen in Denmark told ThinkProgress. “High income countries can buy protection from many of the immediate consequences of climate change, but can’t avoid them.”
“We showed with the impact that climate change has on different levels, for example, it’s not even a problem that climate change would reduce the quantity of food,” Springmann explained. “Sometimes it leads in highly overweight and obese countries to a mild reduction in obesity. That by itself would actually be a good thing. But what would be a bad thing is if fruits and vegetables would be decreased, because that always has positive impacts, in contrast to just the pure quantity of food.”
In some communities, it is actually beneficial to take a climate change-charged break from overconsumption. Yet these groups will face lower fruit and vegetable consumption, which increases their risk factors.
Last year, a Harvard study also published in the Lancet found that higher carbon emissions could dramatically worsen the impacts of zinc deficiency, threatening the health of 138 million people by 2050.
“Our studies are really complementary,” Silbermann said. “Those micronutrients are a totally different thing in a sense — things like iron deficiencies are really important for both mother and child. These dietary changes often result in communicable diseases such as diarrhea, while we focus on more dietary and weight-related health impacts the result in chronic diseases like stroke, heart disease, and cancer.”
Global population has a large impact on potential future global carbon emissions, so it could follow that higher population could mean worse health results. Yet the researchers found that the impact of a low population growth trajectory versus a high one was far less important than the emissions trajectory. Silbermann said that lowering carbon emissions was a much more important predictor of nutrition levels than population growth rates.
Critics often greet studies and predictions like these by saying that the world has faced food crises before, and used technological innovation to expand crop yields to feed billions more people than anyone thought possible. The researchers say, however, that the model has already predicted for that.
“In a sense those increases in yields are taken into account in the baseline scenario,” Silbermann said. “It is expected that agriculture will innovate to higher food production levels. I do hope they can find ways to produce more, but climate change represents an additional shock to the system. While it would be great if they could immediately react to that, it’s not clear if they could.”
Porter agreed, saying that the coming agricultural changes due to climate change will be more abrupt. “It changes faster, the extremes are more severe, and more variable than what has been seen. For those reasons it is unwise, I suggest, to rely on adaptation to solve the problem.”
Other research has concluded that increasing clean energy production to cut carbon emissions will save lives — something that the analysis’ model also finds.
The world is already beginning to change cultivation practices to adapt.
“There are adaptation strategies one could think about, that would be employed to, for example, safeguard food fruit and vegetable cultivation,” Springmann said. “Irrigation technology could be one, for example. Added drought tolerance would be another one. There are some foods that are better adapted to warmer climates.” He noted that parts of Russia are switching from wheat to corn cultivation as their region warms.
But what can an average person do in their own lives to consume a climate-friendly diet?
Eating more fruits and vegetables, the researcher said, may be the logical response to hearing research like this. However, “with climate change you can expect there will be increases in prices and maybe also temporary unavailability of some products,” he said. Fruits and vegetables are even more important as people around the world cope with heat stress. Due to their higher water content, fruits and vegetables are necessary to compensate for heat stress.
Silbermann said he would soon publish research looking at environmental health, which finds that the more fruit and vegetables and the less animal-based products, the better for environmental health.