吃虫代替吃肉 环保又健康

全球气候日益暖化，世界人口不断增长，联合国粮农组织呼吁“肉食者”改吃昆虫，并正在考虑推广昆虫食品，以减少温室气体排放量。研究显示，饲养牛、羊等家畜需要占用全球三分之二的农田，而且导致全球变暖的温室气体中有五分之一是家畜及其饲养过程中排放出来的。联合国粮农组织的专家表示，到2050年，世界人口将从目前的60亿增长到90亿，随着人口的增长，人们对肉类的需求也将增加。到时候，人类将可能面临“肉危机”。如果人们改为食用昆虫，这一问题将得到解决。养殖昆虫所产生的温室气体远比养殖家畜低，饲养常见的食用昆虫（如蝗虫、蟋蟀和膳食蠕虫）所排放的甲烷比家畜排放的少10倍；而且昆虫含有高蛋白、维生素和矿物质，吃起来更健康。

Saving the planet one plateful at a time does not mean cutting back on meat, according to new research: the trick may be to switch our diet to insects and other creepy-crawlies.

The raising of livestock such as cows, pigs and sheep occupies two-thirds of the world's farmland and generates 20% of all the greenhouse gases driving global warming. As a result, the United Nations and senior figures want to reduce the amount of meat we eat and the search is on for alternatives.

A policy paper on the eating of insects is being formally considered by the UN Food and Agriculture Organization. The FAO held a meeting on the theme in Thailand in 2008 and there are plans for a world congress in 2013.

Professor Arnold van Huis, an entomologist at Wageningen University in the Netherlands and the author of the UN paper, says eating insects has advantages.

"There is a meat crisis," he said. "The world population will grow from six billion now to nine billion by 2050 and we know people are consuming more meat. Twenty years ago the average was 20kg, it is now 50kg, and will be 80kg in 20 years. If we continue like this we will need another Earth."

Van Huis is an enthusiast for eating insects but given his role as a consultant to the FAO, he can't be dismissed as a crank. "Most of the world already eats insects," he points out. "It is only in the western world that we don't. Psychologically we have a problem with it. I don't know why, as we eat shrimps, which are very comparable."

The advantages of this diet include insects' high levels of protein, vitamin and mineral content. Van Huis's latest research, conducted with colleague Dennis Oonincx, shows that farming insects produces far less greenhouse gas than livestock. Breeding commonly eaten insects such as locusts, crickets and meal worms, emits 10 times less methane than livestock. The insects also produce 300 times less nitrous oxide, also a warming gas, and much less ammonia, a pollutant produced by pig and poultry farming.

Being cold-blooded, insects convert plant matter into protein extremely efficiently, Van Huis says. In addition, he argues, the health risks are lower. He acknowledges that in the west eating insects is a hard sell: "It is very important how you prepare them, you have to do it very nicely, to overcome the yuk factor."

More than 1,000 insects are known to be eaten by choice around the world, in 80% of nations. They are most popular in the tropics, where they grow to large sizes and are easy to harvest.