Climate may undermine food security efforts
Donna Lu/ The New Scientist 30-01-2021
Warming temperatures and changing rainfall patterns may reduce diet diversity among children around the world– and may even undermine efforts to improve food security.
Meredith Niles at the University of Vermont and her colleagues analysed the results of health surveys from more than 107,000 children in 19 countries – in Asia; North, South-east and West Africa; and Central and South America. The surveys were conducted between 2005 and 2009.
In the surveys, the diversity of a child’s diet was quantified with a score based on their intake of foods from different food groups, including cereal grains, dairy products and meat. The data included details of each child's diet the day before they were surveyed.
On average, the children– aged 5 and under – ate food from 3.2 food groups out of a possible 10. But there was variation from country to country. Children in Colombia ate from 4.8 food groups on average, while that in Lesotho ate from just 1.8.
To study whether climate affected the diversity of the children diets, the researchers linked the results from each country to 30 years of rainfall and temperature data in the surveyed regions. They found that higher long-term temperatures were associated with lower overall diet diversity for children everywhere except Central America.
19 countries included in the study, in Asia, Africa and the Americas
There were shorter-term trends too. In North Africa and South America, there was typically a reduction in diet diversity in countries that experienced higher-than-average temperatures in the year prior to the survey. In Central America and West Africa, diets typically became more diverse in countries that experienced above-average rainfall in the previous year.
The researchers controlled for geographic and socio-economic factors that could affect diet diversity, such as household wealth, and population and livestock density.
In some countries, the researchers say that the negative effect of climate change on diet diversity was so great that it outweighed the beneficial impact of development efforts focused on education, improved toilet facilities and poverty reduction. These negative impacts may even undermine efforts to improve food security, the researchers suggest (Environmental Research Letters, doi.org/frkx).
Diet diversity is a useful metric for regions with high rates of child malnutrition, says Daniel Mason-D’Croz at the Commonwealth Scientific and Industrial Research Organisation in Australia.
“That they’re getting a fruit or a vegetable or animal product in addition to the rice or the maize [staple] – that’s an important thing to know,” he says. Mason-D’Croz points out that the years the health surveys were done coincided with the 2007 to 2008 world food price crisis, during which food became much more expensive. The crisis was caused by many factors and not just climate change, and may have affected diets across the world. “There were food riots in some of the countries that were in the study,” saysMasonD’Croz. A follow-up study with more recent data could confirm more authoritatively the effect of climate in reducing diet diversity, he says.