The state of the world’s land and water resources: Part 2 of 3

December 28th, 2011

Jean-Marc Faurès, Food and Agriculture Organization, Italy

As described in the first part of this article, agriculture plays a vitally important role in feeding us. Because there are so many people on the earth, agriculture has to use a substantial amount of the land and water resources that the earth has. As a result, in places where the population density is high, the impact on land and water resources from agriculture is also high.

Agriculture has done an incredible job in the recent decades in becoming much more productive, and this is extremely important. If we had the productivity level today that we had in the 1940’s or 1950’s, we would need much more land and water than we use today. This is critically important because, without the capacity to increase agricultural productivity, we would not be able to feed the world’s growing population.

Thus, on one hand, the SOLAW report shows that the human footprint through agriculture on the environment is substantial, particularly in areas where land and water are scarce compared to the population. While, on the other hand, incredible progress has been made to contain these impacts.

Threats and risks to the world’s land and water resources

In the SOLAW report we tried to classify the type of threats that we face in terms of the world’s land and water resources. These threats vary across countries and include: flooding, water scarcity, pollution, biodiversity loss, deforestation, droughts, declining soil fertility, erosion, and land scarcity. The distribution and severity of each of these threats is shown in Figure 1 by the size and location of the coloured circles.

One of the main factors contributing to the threats listed in Figure 1 is weak regulation. If you do not set up rules for the sustainable use of land and water resources then there is a high risk that you mine your resources and degrade your environment. This in turn has an impact and risk for future generations. Moreover, if you do not manage your land and water in a way that maintains productive capacity, then productivity is reduced over time and you threaten your own capacity to produce.

A good example of this is soil fertility. Many countries in sub-Saharan Africa do not have very favourable soils and, what’s more, the fertility level is going down. When you have soil that is being eroded because of unsustainable agricultural practices, the most productive parts at the top of the soil are lost and you are left with soil that is less productive. The eroded soil can also lead to other problems such as the sedimentation of dams etc. Therefore, if there are no measures taken to maintain or enhance soil fertility, then we see production going down progressively.

We already have a series of problems related to human pressure on land and water resources that we can see in some areas, and these can be described as ‘today’s risks’. In addition to these, there are also future risks, in particular those related to climate change, that come on top of the problems that already exist.

Due to the variable nature of climate change, there are some areas that are more at risk than others from these future threats. Unfortunately, in many of the areas which face the highest risks, we have a series of very important agricultural production systems that are at risk from a series of climate change related causes. For instance, the large areas of irrigation that are fed through snow melt from mountain ranges are going to experience increased temperatures and changes in the regimes of the rivers that feed them. One of the major risks is that, over the medium term, we may see seasonal changes in the distribution of water flowing in the rivers, i.e. water not coming at the right time for agriculture, which will affect the systems that rely heavily on that water for agriculture (see FAO report on the impacts of climate change on food and water security).

Another example of the areas that are at high risk from climate change are deltas. These, often highly populated areas, face a double threat from climate change as they are likely to experience changes in water supply from above, through changing precipitation and river flows; and also from below, through rising sea levels and the associated problems of sea water entering aquifers and affecting the land. Other areas which are at risk from climate change are the semi-arid tropics in parts of Africa and Asia. Here the increased variability of rainfall due to climate change will affect all farmers, but particularly those who rely on rain fed agriculture.

These are just some of the examples of what we call ‘agricultural systems at risk’. The systems that are more at risk than others, in terms of their capacity to continue to produce, are generally those which sustain very important parts of the world’s population. The focus of this report is on particular agriculture systems that are at risk because we felt it was necessary to go beyond generalities and global assessments. While it is possible to give a global number of how much land is used in the world, it is meaningless because there are places where there is not even a single hectare available, while there are other places where you still have large amounts of land. The same is also true for water resources. Therefore, by focusing on a series of agricultural systems in the report, we aim to give a more concrete analysis in terms of the response that we have to give to the problems of land and water resources scarcity.

References:

1. FAO (2011), The State of the World’s Land and Water Resources for Food and Agriculture – Managing Systems at Risk, Food and Agriculture Organization of the United Nations, Rome and Earthscan, London.

2. Turral, H., Burke, J. & Faurès J-M (2011), Climate Change, Water and Food Security, FAO Water Reports 36, Rome.

Jean-Marc Faurès, is Senior Water Resources Management Officer at FAO’s Land and Water Division. His work includes projects related to water resources assessment, water demand management in agriculture and land and water adaptation to climate change, in the framework of FAO’s programme ‘Coping with water scarcity’. M. Faurès participates in several programmes aimed at analysing trends and assessing future development pathways in agricultural water management. The article is based on an interview with the Global Water Forum, the final part will look at the policies that can be adopted to manage these risks.

The views expressed in this article belong to the individual authors and do not represent the views of the Global Water Forum, the UNESCO Chair in Water Economics and Transboundary Water Governance, UNESCO, the Australian National University, or any of the institutions to which the authors are associated. Please see the Global Water Forum terms and conditions here.