As people from all corners of the world are living off an increasingly similar diet, decreasing crop diversity is making the global food system more vulnerable to the impacts of climate change, a new study has warned.
The study, which is published in the journal Proceedings of the National Academy of Sciences of the United States of America, claims to be the first to quantify the effects of a trend towards a unified international diet over the last 50 years.
“Over the past 50 years, we are seeing that diets around the world are changing and they are becoming more similar – what we call the ‘globalised diet’,” Colin Khoury of the International Center for Tropical Agriculture, a co-author of the study, told the BBC.
“This diet is composed of big, major cops such as wheat, rice, potatoes and sugar.
“It also includes crops that were not important 50 years ago but have become very important now, particularly oil crops like soybean,” he explained.
Khoury and his colleagues also found that, for example, Pacific islanders are eating fewer coconuts while many people in Southeast Asia are becoming less dependent on rice.
Overall, diets from around the world have become 36% more similar over the past 50 years, the study found. This dependence on the same kinds of major crops leaves populations more exposed to harvest failures.
A leaked draft of an Intergovernmental Panel on Climate Change report, seen by some news outlets in November, suggests that climate change could cause a 2% drop in agricultural output each decade this century.
“A more homogeneous global food basket […] makes agriculture more vulnerable to major threats like drought, insect pests and diseases, which are likely to become worse in many parts of the world as a result of climate change,” adds co-author Luigi Guarino.
“As the global population rises and the pressure increases on our global food system, so does our dependence on the global crops and production system that feeds us.
“The price of failure of any of these crops will become very high,” he told the BBC.
As more people are also becoming dependent on meat and dairy products, the authors also warn that populations are shifting towards diets linked to risks of heart disease, cancers, obesity and diabetes.
The study authors say there is now an urgent need for diversification of global diets, which means the use of crops that are currently out of fashion, such as rye, yams or cassava, should be actively encouraged.
Despite this, they warn that there is no sign yet of the trend of unification reversing. In a report published earlier this year, the European Parliament suggested that another third of the crop diversity that exists today could disappear by 2050.
One project seeking to protect populations from crop failures is the Global Crop Diversity Trust, which recently made headlines.
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