4 Environmental Challenges
21
Environmental Challenges
AGRICULTURAL PRODUCTIVITY has increased over the past 50 years, but the adverse environmental impacts of those changes have often not been included in commercial prices and so have been mostly tolerated or ignored. It is now clear that the pollution, soil degradation, and loss of habitat and biodiversity caused by current methods of food production and transport are going to make it difficult for current levels of productivity to be maintained or improved on in the future. In an attempt to reduce carbon-dioxide emissions, crops are being grown for biofuels, to substitute for fossil fuels. This is proving ecologically counter- productive, however, and is diminishing the amount of food produced worldwide. Soil degradation caused by wind or water erosion, nutrient depletion, chemical pollution or salinization is a problem in all regions of the world, with an assessment in 1990 concluding that a quarter of the soil used for growing crops or grazing livestock showed signs of degradation. Ongoing research using satellite imagery to assess changes in productivity indicates that productivity declined on 12 percent of all land between 1981 and 2003. The study of soils and their degradation is increasingly being recognized as a key issue in the context of food production, and of climate change, with an evaluation of the work of the Food and Agriculture Organization concluding, in 2007, that conservation of lands and soils should be given greater priority. There is considerable scope for reducing waste, pollution and soil degradation, as well as the use of energy and water in the food chain. Social and technological changes could enable many of those problems to be addressed, with some forms of land degradation reversed, and the rate of progression of others slowed. International co-operation is essential, however, to reduce greenhouse gas emissions, make food production systems more ecologically and economically sustainable, and to extend educational and economic opportunities to poor people in developing countries, to allow them
Deforestation
The increasing demand for agricultural land is contributing to the destruction of rainforests around the globe. While tropical timber is the immediate product of this deforestation, around two-thirds of the cleared land is subsequently used for pasture, and a third for arable farming, much of it managed by large companies responding to an increase in meat and dairy consumption worldwide, and a growing market in soybean and oil palm products. While attention has been turned to losses in the Amazon and Congo forests, Indonesia has lost a quarter of its forest, and the Philippines a third. Because the soils in rainforests are generally shallow and low in nutrients, they are susceptible to erosion, which quickly leaves the land unsuitable for agriculture and leads to further deforestation.
3 Unequal Distribution
22
Predicting the impact of climate change on food production is difficult because so many factors are involved. It is reasonable to assume that a rise in sea-level, already occurring as a result of thermal expansion, will affect low-lying cropland in countries such as Bangladesh, either by inundating it, or by leading to the intrusion of saltwater into underground aquifers, making the land too saline for agriculture, and reducing the availability of fresh water for irrigation or drinking. Weather patterns are becoming increasingly unpredictable. Intense tropical storms at unseasonable times damage crops and increase food insecurity, as do prolonged droughts. Agriculture is adaptable, however. Crops can be planted and harvested at different times, and new varieties developed that are more tolerant of stress than those now in use. In Asia, where there is little room for expansion of the agricultural area, global warming may actually enable farmers to move higher up mountain slopes and to more northerly latitudes. But even if, with a changing climate, the total quantity of food produced remained stable by increasing production in some regions, it is probable that productivity in other regions, including South Asia, and Sub-Saharan Africa, will decline, making hundreds of millions of people increasingly dependent on imported food, with serious political, economic and social consequences.
Copyright © Myriad Editions
22 Organic Farming; 23 Greenhouse Gases
23
Water Pressure
MANY COUNTRIES already have insufficient fresh water. An increase in population will see many more experiencing water scarcity or water stress by 2050, while climate change will also undoubtedly have an impact on water supplies. A country’s average water supply obscures much regional variation. California’s burgeoning urban population is putting an increasing strain on the state’s limited resources, and in China the wheat-growing north is more water-stressed than its largely rice-growing south. Some countries, such as Egypt, are heavily dependent on water flowing in from another country, increasing their vulnerability. Irrigated crops are crucial to food security, and since 1950 the area under irrigation has doubled. Some methods are very wasteful of water, however, and badly drained irrigation can also lead to increased salinity. But support for farmers to enable them to develop small-scale, low-tech irrigation systems is vital to improving food security in poorer regions. Some countries are able to compensate for a scarcity of water by importing food. In China, much river water in the north is diverted from the fields to more profitable industrial uses, generating currency to pay for imported wheat to offset any shortfall. However, this makes China dependent on the global wheat market, and increases its food insecurity. Many less industrialized countries, especially those in Africa, are much more vulnerable to water stress: when they experience drought they are too poor to buy food elsewhere. Although the effects of climate change on water supplies are difficult to predict with precision, it is possible that the Middle East, Central Asia and southern Europe, already experiencing water stress, will see decreased river flows by the end of this century. Elsewhere, increased temperatures may initially increase glacial melt water flows from mountain ranges, but ultimately the flow may dry up, leading to devastating water shortages in areas such as northeast India, Bangladesh, and China – some of the most intensively farmed areas of the world.
24
Copyright © Myriad Editions
11 Animal Feed
25
Nutritional Deficiencies