Research on the area of agricultural land needed to produce our food reveals that technological improvements alone will not be sufficient to compensate for increasing population pressure and richer diets. Sanderine Nonhebel, Associate Professor of Environmental Sciences at the University of Groningen, has charted the global effects of changing dietary habits over the past 46 years. The results of the research were published on 16 April in the leading journal Proceedings of the National Academy of Sciences (PNAS).
The production of food has the largest impact on the environment of all human activities. The availability of food mainly depends on the availability of productive agricultural land. Sanderine Nonhebel and her students analysed data on land use, food production and diet provided by the Food and Agriculture Organization of the United Nations (FAO).
Nonhebel’s research resulted in a detailed overview of changes in the agricultural land area in relation to the demand for food in each continent during the past 46 years. The researchers then linked this data to forecasts of population growth, agricultural technology improvements and dietary trends.
The demand for agricultural land will continue to grow during the coming decades thanks to the increasing numbers of people in Asia, South America and Africa who can afford a richer diet. Lower birth rates as a result of increasing prosperity will not compensate for this, because this impact will be felt much later, says Nonhebel. ‘We estimate that, around the year 2050, we will need 70-100% more agricultural land to feed a world population of nine billion people with Western dietary habits and using Western agricultural production methods.’
At first sight, the global situation looks hopeful. ‘Thanks to technological improvements, such as fertilizers and pesticides, the average area of land needed to feed a person has fallen,’ explains Nonhebel. Although the average person now consumes 500kcal more than 46 years ago and the available calories have increased from 2250 to 2750kcal per person per day, the area of farmland needed to produce such a portion of food has decreased from 2650 to about 1700m2 per year.
Nevertheless, it appears that the technological improvements will not be sufficient to compensate for population growth. The total area of agricultural land increased by 267 million hectares during the last 46 years. There are major differences between the continents: ‘In East Asia, the area of agricultural land needed per person actually increased during the past decade. A billion people live in this region, so any change there is going to have a huge impact.’
The Western diet is dominated by high meat and vegetable fat consumption, which together account for some three quarters of all agricultural land use. Asia only uses half this amount, but the ratio of these richer foods in Asian diets is increasing fast. The Netherlands will suffer the effects of this, predicts Nonhebel: 'China will have to import more food, while our livestock industry relies on imported feed. Once China enters the international food market, the price of food - and so animal feed - will rise. Dutch stock farmers will feel the effects immediately.’
Sanderine Nonhebel (1960) studied plant pathology at Wageningen University and then became a researcher with the department of physical geography and soil science at the University of Groningen. She conducted PhD research on the consequences of climate change for food production in Wageningen. After gaining her PhD in 1993, she conducted research on the potential of biomass crops as an energy source. Since 1995 she has been working with the University of Groningen’s Center for Energy and Environmental Studies (IVEM), part of the Energy and Sustainability Research Institute Groningen (ESRIG). She was appointed Associate Professor of Environmental Sciences in 2009.
- More information: Dr Sanderine Nonhebel, Associate Professor of Environmental Sciences, IVEM, University of Groningen, tel. +31 (0)50-363 4611, s.nonhebel rug.nl
- Article: Global changes in diets and the consequences for land requirements for food. Authors: Thomas Kastner, Maria Jose Ibarrola Rivas, Wolfgang Koch and Sanderine Nonhebel. PNAS, 16 April 2012.
Prof. Roelfes receives NWO ENW-KLEIN grant of EUR 304.000
for his project ‘Time-resolved dynamics of glutamate transporters'
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