As global warming starts lowering food production around the world, many more people will die in densely populated and vulnerable countries such as India

Food production is expected to decline as our planet heats up. (Photo by Michael Foley)

Food production is expected to decline as our planet heats up. (Photo by Michael Foley)

As many as 160,000 people will die every year in India by 2050 due to decreased food production because of climate change, an Oxford University study has predicted. India ranks second in the mortality forecast after China, where as many as 248,000 are expected to die for this reason. Surprisingly, the US ranks fifth, after Vietnam and Bangladesh.

Asked whether China wouldn’t face fewer deaths than India, considering that India will have overtaken its population by around 2030, and China has a higher standard of living, Marco Springmann, lead author of the study by the Oxford Martin Future of Food programme in the university, told, “It also depends on mortality rates and the magnitude of climate and yield shocks. The US comes in fifth because of its high population and its vulnerability to climate shocks.”

Worldwide, there would be 529,000 more deaths due to climate-related factors midway this century. The study, which was published in the UK health journal Lancet in March, used models to estimate the health impacts due to shortages of food crops caused by changes in climate. It assessed the risk to human health caused by reduced consumption of fruits and vegetables, red meat consumption and changes in body weight. This could lead to deaths due to heart disease, stroke, cancer and other ailments.

“In our study, we accounted for the feedbacks between grain as feedstock and grain for human consumption, and we took into account standard population projections,” Springmann said. It calculated the change in the number of deaths attributed to climate-related factors to lowering of body weight and reduction in diet in different emissions scenarios – ranging from high to medium to low.

Lower food availability

By 2050, in the 155 countries analysed, climate change will lower people’s availability of food by 3.2%, fruits and vegetables by 4% and red meat by 0.7%. “Twice as many climate-related deaths were associated with reductions in fruit and vegetable consumption than with climate-related increases in the prevalence of underweight, and most climate-related deaths were projected to occur in south and East Asia,” the study says.

Diarmid Campbell-Lendrum, who leads a team on climate change and health at the World Health Organisation (WHO), told, “WHO has been saying for almost a decade that climate change is perhaps the greatest threat to public health of the current century, and we have been highlighting that one of the main risks of climate change is through impacts on food and nutrition security, for even longer.”

“However, while it is clear that agricultural production is sensitive to weather and climate and therefore must be affected by climate change, there are few studies that quantify how this may eventually impact health – so the current work is an important addition to our knowledge.”

Sowing paddy in Tamil Nadu. (Photo by Michael Foley)

Sowing paddy in Tamil Nadu. (Photo by Michael Foley)

The Oxford study confirms that the impact on food supply and food security “could be one of the most important consequences of climate change in view of the large number of individuals that might be affected”. The changes could reduce the food harvested, leading to higher prices and reduced consumption, and to an increase in the number of malnourished people. Agricultural and regional food availability also affects the composition of diets.

In 2010, the WHO’s Global Burden of Disease study reported that most deaths throughout the world were attributable to dietary risk factors associated with imbalanced diets. In developing countries these were diets low in fruits and vegetables, while in affluent countries, these were related to red and processed meat consumption.

As the Oxford study points out, “The increasing importance of dietary risk factors represents a general trend away from communicable diseases associated with undernutrition and poor sanitation to non-communicable diseases associated with high bodyweight and unbalanced diets.”

Quantitative risk assessment

In 2014, the WHO published a quantitative risk assessment of the impact of climate change on selected causes of deaths in 2030 and 2050. It quantified climate-related mortality according to heat, coastal flooding, diarrhoeal disease, malaria, dengue and undernutrition. It estimated that due to climate change, an additional 38,000 elderly people would die due to exposure to heat, 48,000 people to diarrhoea, 60,000 to malaria and 95,000 children due to malnutrition in 2030.

By the middle of this century, it attributed the biggest toll to heat, which would claim an additional 95,000 deaths annually, while undernutrition would come a close second with 85,000 deaths. “By 2050,” the study points out, “impacts of climate change on mortality are projected to be the greatest in south Asia.”

Since India is by far the biggest country in this region, it will suffer the most on this account. The excess number of deaths annually due to heat in south Asia would be 21,648 in 2030 and 62,821 in 2050. However, with proper adaptation measures to cope with climate change, these numbers could fall sharply.

At the same time, the WHO notes that global predictions of deaths due to heat in the decades to come indicate “there is a significant burden on mortality. Hot weather is also known to affect mortality and morbidity in other age groups, and this may indicate that the results [of its study] are an underestimate of the total burden on health.” The WHO estimates that by 2030, there would be 241,000 additional deaths due to climate change, going up marginally to 245,000 in 2050.

“Our overall estimate is higher than that of the WHO because we looked at different risk factors that were not covered by the WHO assessment, but that impact a broad spectrum of the population. The impacts of climate change on food affect everybody, because everybody eats. In contrast, some of the vector-borne diseases analysed by the WHO are constrained to certain regions,” Springmann told

“We have also pointed out that our own previous estimates are conservative (low), precisely because they do not cover the full range of ways in which we expect climate change to impact on health – as we have lacked quantitative studies of many of the likely mechanisms,” said Campbell-Lendrum. “The current work (by Oxford University) is therefore also welcome in that it broadens the range of evidence beyond simply calories, to include the type and quality of the food that we will have available.”

Climate change will lead to yield shocks. (Photo by Rajarshi Mitra)

Climate change will lead to yield shocks. (Photo by Rajarshi Mitra)

“Although the numbers are not directly comparable, the scale of the difference between the new estimates and those which we published a couple of years ago are quite surprising. The largest differences appear to be because of the impacts on consumption of fruits and vegetables,” Campbell-Lendrum said. “This is plausible as we know that low levels of consumption of these types of foods are now a major killer – but it is important to point out that there has been much less research on the effect of climate change on the production, and then the availability, of fruits and vegetables, than there has been on staple crops.”

Wanted: stronger public health programmes

The Oxford study points to how adaptation to climate change can mitigate the impact on mortality. It points to the need for stronger public health programmes – in India, for instance, the employment of anganwadi workers who measure the weight of infants every month to monitor their progress. This can prevent and treat diet and weight-related ailments.

Vandana Prasad, a paediatrician who works with the Jan Swasthya Abhiyan and is part of the right to food campaign, told, “The study adds a welcome fresh angle to the growing body of evidence suggesting dangerous trends of food insecurity currently and in the near future.”

“It is of course an issue that is likely to lead to both increases in undernutrition and overnutrition, and increased deaths from both infections as well as non-communicable diseases in the same countries, since they happen to be in transition with different socio economic groups affected differentially by the same pathways. The use of large global databases is also likely to hide even graver consequences for certain groups such as tribal communities and the poorest of the poor,” Prasad said.

“However, without an analysis of the political economy of climate change and factors affecting food security and diversity, it is highly unlikely that this evidence will provoke any fundamental alterations in the policy environment that could avert or mitigate the current grave inequity in food security and diversity in India.”

The Oxford study identifies areas where further research is required. One is the impact of climate change on crops that policymakers consider less important than staples like rice and wheat — like fruits and vegetables, which play a greater role in people’s health. Impacts on crops like groundnuts, maize, potatoes, sorghum and soybeans are also well known while those on other crops have to be analysed after taking their biophysical similarities into account.

High uncertainty

Secondly, agricultural commodity markets are already highly volatile in economic terms and this is accentuated with climatic shocks, making them subject to high uncertainty. “It is also important to point out that the eventual impacts of climate change on agricultural practices, then on food trade, availability and price and then, dietary choices, are not set in stone. They will depend at least as much on our policy and individual choices, including what we do in response to climate change, as to the effects of climate change itself,” Campbell-Lendrum told

“In practical terms, the (Oxford) study reinforces the need for adaptation to climate change, and a greater focus on equity and sustainability in food and nutrition policy, in order to protect health. It also underlines the need to promote stronger mitigation policies, to limit the damage that climate change will do to environmental determinants of health such as food and nutrition security, but also water and sanitation, among others. We also know that there are large opportunities to promote agricultural practices and diets that will reduce emissions of greenhouse gases, and promote health.”


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