When will we run out of land?

Between 1980 and 2000 over half of new agricultural land in the tropics was created through cutting down intact forest. Land clearing for crop production is a major issue for the maintenance of biodiversity and environmental stability but growing human demand for food is only one of several pressures on land, a resource that is rapidly shrinking.

Recently we at Agriculture for Impact came across a paper investigating global land scarcity, a topic much discussed in One Billion Hungry and on this blog. Published in 2011, the paper by Dr Lambin of Stanford University and Dr Meyfroidt of the University of Louvain, entitled Global land use change, economic globalization and the looming land scarcity, documents the processes that are driving global land use change and estimates when we might run out of land.

Of the total ice free land on the planet (13,300 million hectares), around 4,000Mha is suitable for rain-fed agriculture. The amount of land that is currently uncultivated, that isn’t forested, protected or populated by more than 25 people per km² is estimated at 445Mha and occurs mainly in the cerrados and grasslands of Latin America and the savannahs of Africa, which are important in themselves for biodiversity conservation and livestock grazing. The paper’s authors calculate low and high estimates of the amount of land needed to supply demand for different competing land uses:

Cropland for human food – an additional 2.7-4.9Mha each year depending on food waste, diets and efficiency.

Biofuels – 1.5-3.9Mha per year based on current biofuel mandates

Pasture – 0-5Mha per year based on the projected intensification of livestock systems

Urbanisation – 1.6-3.3Mha per year

Industrial forestry – 1.9-3.6Mha per year

Protected areas – 0.9-2.7Mha per year

Land degradation – 1-2.9Mha of land will be lost each year

Added together and balanced against current available land, and assuming that some deforestation will occur, means that current land reserves will run out by the late 2020s at the earliest and 2050 at the latest, and this is excluding the impacts of climate change.

Sustainable Food Systems

Food demand is expected to rise by 70% to 2050. Urbanisation and increasing incomes per capita are shifting diets to those more demanding of meat and other animal products, which has serious implications for the use of natural resources to produce food. Today around 1 in 8 people are malnourished and 870 million people chronically hungry, indicating our current food systems cannot meet present demand let alone future. Modifying the world’s food production systems to produce more food and perhaps distribute it more evenly, is made harder by a growing recognition of the negative impacts agriculture can have on the environment. Conversion of land to agriculture is the biggest threat to biodiversity. Agriculture places large demands on scarce natural resources, the overuse of which not only threatens the wider global environment and human wellbeing, but the very processes agriculture relies on e.g. pest control, pollination and rainfall.

A new report by the European Commission’s Science for Environment Policy, entitled Sustainable Food: A Recipe for Food Security and Environmental Protection, lays out the changes we need to make to our entire food system and the urgency with which we need to make them.

The report begins with a summary of the pressures on food production and the drivers of food demand namely: population growth; natural resource scarcity including land, biodiversity, water, climate change, and biofuels; changing dietary patterns and; rising food prices.

The report then turns to some of the solutions and pathways to making food systems more sustainable, advocating action around the following areas:

• Minimising food waste
• Rethinking land management and agricultural practices:
  • Using agroecological principles such as building soil organic matter, which the EU claim can reduce negative impacts and at the same time increase yields, although evidence of this potential win-win is scarce
  • Conservation agriculture and land sparing versus land sharing
  • Replenishing water supplies through, for example, no-till agriculture
  • Ensuring the long-term sustainability of fish stocks through expanding aquaculture
  • Reducing carbon emissions and mitigating climate change
  • Increasing the efficiency of agriculture through the application of science and technology
  • Understanding consumption patterns in a bid to contain the demand for the most resource-intensive types of food
  • Investing in smallholder farmers to help them increase their productivity and integration with global markets

Of course knowing that we need to undertake many of these actions is relatively easy. Understanding how to take action is hard and the report acknowledges that considerable policy and knowledge gaps exist, for example, what future per capita consumption levels will be, the benefits or impacts of different agricultural practices and ways of integrating multiple objectives in policy making.

Current increases in crop yields will not meet future food demand

Global food production must increase if we are to meet the rising demand for food, feed and fuel brought about by growing populations, incomes and western diets. It must increase in the face of severe natural resource constraints.  Current production growth, however, will not meet the world’s food needs, as a recent article by Ray et al, entitled Yield Trends Are Insufficient to Double Global Crop Production by 2050, attests.

To achieve food security we need to increase food production between 50 and 100% by 2050. Ray et al, however find that for four key global crops, maize, rice, wheat, and soybean, which currently produce nearly two-thirds of global agricultural calories, yield increases between 1961 and 2008 were only 1.6%, 1.0%, 0.9%, and 1.3% per year. To put this in perspective, a 2.4% per year rate of yield gains is needed to double crop production by 2050.

This high level analysis masks a lot of geographic variation. For example, maize yields are improving in Ethiopia, Angola, South Africa, and Madagascar but decreasing in such countries as Morocco, Chad, Somalia, Kenya and Zambia. There is a similar diversity in yield changes for soybean, wheat and rice.

One answer is to expand the amount of land we grow crops on (extensify), a solution that would be disastrous for the environment, for carbon emissions and for biodiversity, for which habitat loss is the biggest threat. The other is to intensify, increase the yields from existing agricultural land. Often intensification is associated with large-scale high-input commercial agriculture, also detrimental to the natural resource base. The UN estimates that 80% of the required increase in food production between 2015 and 2030 will have to come from intensification. Additionally strategies to reduce food loss and waste, change consumer eating preferences and ensure the food system is more equitable could also have a large impact.

In another recent article in Science, Garnett et al discuss a new paradigm that is gaining traction, one outlined by the Montpellier Panel in their 2013 Report, Sustainable Intensification: A New Paradigm for African Agriculture. Sustainable intensification (SI), which aims to reconcile food production and environmental protection, has been much discussed on this blog and is receiving increasing attention from decision makers. Garnett et al outline the four premises underlying SI: