The requirements for water in agriculture will need to increase in order to meet the Millennium Development Goal 1, target 2 'Halve, between 1990 and 2015, the proportion of people who suffer from hunger'. To decrease hunger the outputs in agriculture will need to increase, and thus the water use.

Accessibility to food is also determined by the long-term trend in food prices (which is a different issue from price volatility). The rising trend in global food prices is likely to persist in the next decade. In the long run, however, prices will decline (OECD-FAO, 2008).

Figure 8: Global trends (1960–2005) in cereal and meat production, use of fertilizer, irrigation and pesticides. (Source: Tilman, 2002; FAO, 2003; International Fertilizer Association, 2008; FAOSTAT, 2009).

With our climate changes, we have to adapt our ways to a new environment – in most cases warmer and possibly wetter and drier. Projections on the climate in the future provide some guidance for us, but how can we create models for how the human society reacts? This map presents a rough idea of changes in agricultural output from increased temperatures, precipitation differences and also from carbon fertilization for plants. Projecting climate is ...

Food losses in the field (between planting and harvesting) could be as high as 20–40% of the potential harvest in developing countries due to pests and pathogens (Kader, 2005). Postharvest losses vary greatly among commodities and production areas and seasons. In the United States, the losses of fresh fruits and vegetables have been estimated to range from 2% to 23%, depending on the commodity, with an overall average of about 12% losses b...

A central component in preventing loss of biodiversity and ecosystem services, such as provisioning of water, from expanding agricultural production is to limit the trade-off between economic growth and biodiversity by stimulating agricultural productivity and more efficient land use. Further enhancement of agricultural productivity (‘closing the yield gap’) is the key factor in reducing the need for land and, consequently, the rate of bio...

The availability of food within a specific country can be guaranteed in two ways: Either by food production in the country itself or by trade. The first option has been discussed extensively in the previous chapters. The second option has become more and more important (Figure 29), with increasing transport possibilities and storing capacities and the growing challenges faced by some countries in their domestic production, including becaus...

Water scarcity in terms of drought or depleted groundwater could therefore have great impacts on livestock and rangelands. These interactions are also complex. While drought can directly threaten livestock, other factors that influence water availability for livestock are seasonal droughts and socio-economic changes, such as permanent settlement and occupation of seasonal pastures by people other than pastoralists, availability and quality...

According to the latest UN estimates, almost all of the world’s population growth between 2000 and 2030 will be concentrated in urban areas in developing countries (Figure 32). By 2030, almost 60% of the people in developing countries will live in cities (FAO, 2003). If present trends continue, urban population will equal rural population by around 2017.

Production of crops for biofuels also competes with food production (Banse et al., 2008). Indeed, the corn equivalent of the energy used on a few minutes drive could feed a person for a day, while a full tank of ethanol in a large 4-wheel drive suburban utility vehicle could almost feed one person for a year. A recent OECD-FAO (2007) report expected food prices to rise by between 20% and 50% by 2016 partly as a result of biofuels. Already,...

Globally, over 1,000 (87%) of a total of 1,226 threatened bird species are impacted by agriculture. More than 70 species are affected by agricultural pollution, 27 of them seriously. Europe’s farmland birds have declined by 48% in the past 26 years (European Bird Census Council, 2008). Pesticides and herbicides pose a threat to 37 threatened bird species globally (BirdLife, 2008), in addition to deleterious effects of agricultural chemica...

Carbon cycle, carbon fluxes and stocks.

Terrestrial ecosystems store about 2100 Gt C in living organisms, litter and soil organic matter, which is almost three times that currently present in the atmosphere.

Temperate forests are active carbon sinks and deforestation in the temperate zone has largely stopped. Where demand for land and/or water allows, reforestation would enable carbon sequestration and could provide other benefits including higher biodiversity and recreation opportunities.

The boreal forest biome holds the second largest stock of carbon; most of this is stored in the soil and litter. The draining of boreal forest peatlands, inappropriate forestry practices and poor fire management may all cause significant losses of the carbon stored in this ecosystem.

Peatland soils store a large amount of carbon but there is a grave risk that much of this will be lost as peatland ecosystems worldwide are being converted for agriculture, plantations and bioenergy. Conservation and restoration of tropical peatlands should be considered a global priority.

Without the contribution of oceans and coastal ecosystems to global biological carbon sequestration today’s CO2 concentration in the atmosphere would be much larger than it is. But the uptake capacity of oceans and coasts is both finite and vulnerable. Minimisation of pressures, restoration and sustainable use are management options that can help these ecosystems maintain their important carbon management function.

Tundra ecosystems are dense in carbon. They have little potential to gain more carbon but a huge amount could be lost if the permafrost were to thaw. Prevention of climate change is currently the only failsafe method of minimising this loss.

Dividing the world into seven biomes, we estimate that tropical and subtropical forests store the largest amount of carbon, almost 550 Gt.

Temperate forests are active carbon sinks and deforestation in the temperate zone has largely stopped. Where demand for land and/or water allows, reforestation would enable carbon sequestration and could provide other benefits including higher biodiversity and recreation opportunities.