[28-Food 视频] 失控的农业 | Food and environment

Intensive farming methods – on bigger farms with better machines – have meant we're now able to produce more food than ever before.

But people are beginning to ask – at what cost to the environment?

Cutting down trees to plant crops or graze animals is one of the biggest drivers in the loss of the world’s forests.

In South America, tens of thousands of square kilometres of the Amazon rainforest have been destroyed and cleared to create pasture for beef cattle – feeding the demand in North America for meat, such as burgers and steak.

In Southeast Asia, rainforests are being cleared to grow oil palm trees. Palm oil is now the world’s most commonly produced vegetable oil. It is found in products such as biscuits, pizza and margarine. At the current rate, it is estimated that all the rainforests in the world could vanish within the next 100 years.

So, why does this matter?

Deforestation drives climate change – trees absorb the greenhouse gases, like carbon dioxide, that damage our environment. Cutting down too many trees can also turn fertile land - into barren desert, and endanger some of our rarest creatures: wild animals, such as the orangutan, are under threat because of the loss of their forest habitat and are being pushed closer to extinction.

Growing vast areas of the same crop also has an impact on biodiversity – the different kinds of animals, plants and insects that live in our countryside – and having too many of one kind of animal can also have an unexpected impact on global warming: cows, like sheep and goats, are called ruminant animals. The way they chew and digest their food releases a gas called methane, in burps and farts! Methane is a greenhouse gas that stops the planet from cooling down and causes climate change. The sheer quantity of methane now being released into the air by the farming of millions of these animals is a serious problem!

But farms are only part of the environmental story. Once food has been produced, it must be sent to market.

The distance food travels from producer to consumer is called a 'food mile' or 'food kilometre'. It's one way of measuring how environmentally friendly the food is. But we also need to think about how our food travelled to reach us – because every journey we make produces carbon dioxide, another gas which contributes to global warming.

Ships have the lowest carbon emissions. Aeroplanes have the highest. So, perhaps we should only try to buy food that is grown locally, supporting our farmers and producers at the same time?

But, things are not always that simple. Imagine an apple - brought on a long boat journey to Europe from New Zealand. How does that apple compare environmentally to a local apple that has been kept in cold storage to keep it fresh, out of season? Perhaps surprisingly, its the local apple that's used more energy.

The idea of thinking about the amount of energy required to produce our food – and get it to market – is now more important than ever. And it has raised questions for many about the true cost of food and its impact on the environment.