Why is a loss of agricultural resources a global threat?
Because it compromises our ability to generate the most important product of the global economy: our food. It also increases the possibility that some countries have to depend on international markets for food, putting these countries in a position of increasing vulnerability.
California, the region where you live, offers us a symbolic case of a loss of natural resources and is suffering a particularly severe drought. Here - as in many other parts of the world - a degradation of agricultural land and climate change can be added to water scarcity. What are the economic consequences of this phenomenon?
In California, the worst drought in a century has devastated farmers. Three years of poor rains have reduced the availability of surface water for agricultural use by 36%, forcing ground water to be extracted. But even the traditional groundwater was not enough. So 173 thousand hectares of irrigated land, about 5% of agricultural land was left fallow. The economic cost is estimated at $2.2 billion with the loss of 17,000 jobs.
Irrigation uses 16% water, but produces 44% of the food in the world. Climate change, however, is compromising water reserves. What are the main factors causing water shortages?
We can point to four main factors. One driver of water scarcity is population growth.
Water is a renewable resource, but the availability of fresh water is generally well defined in most countries. When populations grow, the amount of fresh water per capita decreases.
But there are also economic factors. If some countries export goods that require intensive use of water - such as agricultural products - these countries are essentially exporting water, and this can put pressure on national water supplies.
Even physical factors play a role in determining water scarcity. If groundwater is overexploited (that is, it is extracted more than compensated by the rains) it reduces or even eliminates a major water reservoir. Currently, about 20% of the world's aquifers are overexploited. Through the use of satellites, it was noted that for example, between 2003 and 2011, the Tigris and the Euphrates have lost as much water as the Dead Sea and 60% of this decline is due to overpumping.
Ultimately, climate change can produce water scarcity, both creating droughts and reducing the snowpack, a reserve of natural water that when it melts in spring and summer acts as a source of water in many regions. In California, it is expected that snow will be reduced by 12%-40% by mid-century, and 90% by 2100. A study in 2012 of 405 river basins, which provide 75% of global irrigation resources were experiencing severe water shortages for at least one month a year in about 200 of these basins, and for six months a year in 35 basins.
The demand for food is expected to increase by 60% by 2050, but the same IPCC estimates that there will be a decline in net crop yields globally by 0.2% every ten years, then 2% per century. From 15% to 24% of global land is subject to degradation, but demand is expected to increase by 14% per decade. How can we deal with these challenges?
The global agricultural system has three great 'reserves' of food which can be drawn down in the event of scarcity: crops currently given to livestock, used for biofuels, and food waste.
About 36% - more than a third - of cereal crops in the world has been used to produce meat in 2014. The production of biofuels 'eats up' about 40% of cereal flour in the United States, 50% of sugar beet in Brazil, and 80% of the production of oil seeds in the European Union.
Meanwhile, about a third of food produced in the world is wasted: on farms, on production, distribution or domestic consumption.
Among these three large reserves of food, there is ample room to recover production losses due to soil degradation.
But are we doing this? Are consumers in rich countries prepared to reduce their consumption of meat? The programs of biofuel will be scaled down, even as they become more scarce fossil fuels? And how will producers and consumers be persuaded to reduce food waste? Although these reserves are large, their use can be limited by political considerations.
You have stated that in the last 25 years, the United States has lost an agricultural area the size of the State of Indiana and in California alone, between 2008 and 2010, an area equal to three-quarters of San Francisco has been lost. Many agricultural areas are being turned over to urban development. What answers can be put forward?
We can proceed with certain technical and economic solutions. When it comes to water scarcity, for example, drip irrigation can produce great efficiency, while farmers can be pushed to choose crops that require less water. But more in general, agricultural resources should be considered strategic, and not commodities subject to market conditions, thereby creating incentives for their conservation. Facilities for privately owned farms, for example, could ensure that productive land is not sold for development or for other non-agricultural developments. Similarly, food should not be treated merely as a market commodity. There should be protective measures to ensure adequate supplies to the market and to avoid overly erratic price fluctuations.
What kind of governance is needed to ensure access to food?
In recent times, an interesting development was the announcement of the 'right to food'. FAO introduced this concept in 2004 adopting Guidelines on the Right to Food, and at least 28 countries have an explicit mention of the right to food in their constitutions. Access to food may need to encode in international trade agreements, so that the food cannot be withheld for political reasons.