Feeding the World
First broadcast March 2007
This BBC World Service series investigates the growing but often under-reported challenges facing the world's food supply.
Global Warming, soil erosion and a world population that is set to grow by a further two and half billion in the next 30 years, are just some of the pressures that could undermine the current state of relative abundance.
The BBC's World Affairs correspondent Mark Doyle assesses which outcome will prevail and the factors that will decide it. He discovers what policies need to be put in place now to ensure the world can feed itself in the future.
Part One: Growing Pains
The first programme in the series begins by charting the recent history of food production, the so-called "Green Revolution" of the 1960s and 70s, that transformed Asian and Latin American crop yields in particular.
Today in India some of the less-sustainable technologies that made that revolution possible, like heavy use of pesticides and deep-well irrigation, are beginning to take their toll.
According to the UN, India could soon become a net grain importer for the first time in decades, partly owing to its growing affluence and consumption patterns.
And with the increasingly apparent effects of climate change, and with global grain reserves at their lowest level in thirty years, some are suggesting that the world's food supply could be in for a shock - an event that could have consequences for us all.
Consider: What are the issues that we face with increase use of pesticides and irrigation? Why are they taking a toll? What are they taking a toll on?
Explain how India became a net grain importer? Explain how India's consumption patterns actually help India become a net grain importer!
How may climate change affect food supply? (Think about the temperatures, amount of rainfall, stability of rainfall patterns.)
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Consider: What are the issues that we face with increase use of pesticides and irrigation?
ReplyDeletePesticides is used to destroy pests which affect crop growth, but when people starts to misuse it they'll kill the plants. When rainfalls, the excess pesticides are washed to the nearby rivers or seep into the groundwater, hence it causes water pollution. The chemicals in the water will harm or kill the aquatic plants and animals, people who unknowingly drink the contaminated water may be poisoned.
Irrigation enables farmers to control the amount of water supplied to crops, when there is insufficient rainfall. This ensures that the crops recieve enough water during the dry season. But when irrigation is poorly managed or used excessively it affects the quality of the soil in farms.
Poor management of irrigation cause salinisation and waterlogging.
Salinisation is the building up of salts within the soil. In flood irrigation, the farmer allows water to cover the surface of a feild. When the water in the field is used up by plants or has evaporated into the atmosphere, the salts in the water are left behind. The salts in the soil build up, thus lowering the quality of soil. It can take place in areas where dams are constructed.
Waterlogging happen when too much water is used in the fields, causing the soil to become saturated with water. Famers over irrigate the land or use large amouths of irrigated water to wash excess salt from the land to reduce salinisation. Air and nutrients cannot reach the roots of the crops, hence cause them to wither and die. This causes crop output and food production to decrease
How may climate change affect food supply? (Think about the temperatures, amount of rainfall, stability of rainfall patterns.)
ReplyDeleteThe rainfall and average temperature experienced in that place are important, as they determine the types of crops that can be grown in an area and the productivity of the land. In areas with high temperature and high rainfall, usually it's more favourable for plant growth. Places where rainfall are well distributed are places where plants is suitable to be grown throughout the year. Places where rainfall are seasonal are places where plants are not suitable to grow all year through. Usually farmer are introduced to use irrigation methods. It enables farmers to control the amount of water supplied to the crops, when rainfall is insufficient and dry season. By using this methold, farmers can grow crops all year round, without having to wait for the rain season.
Good answers to the questions from Miaoling.
ReplyDeleteIn addition, note that climate change affects rainfall, rainfall patterns. It changes them, and the temperatures. Just look at how the sakura flowers have been affected recently. They are blooming MUCH earlier!!!!
If the flowers are blooming earlier, what effect can there be? The time of the harvest may be shifted, and this might clash with the rainfall periods!