OSLO, Wed Sep 24,(bdnews24.com/Reuters) - Eating less meat can help rich nations to combat global warming but may not work for poor countries where people depend on livestock for survival, a leading expert said on Wednesday. UN reports show that the livestock sector accounts for about 18 percent of greenhouse gas emissions blamed for global warming -- more than the transport industry. Eating less beef, pork or chicken is often advocated as a way to cut emissions. "We agree that the world as a whole could eat less meat," said Carlos Sere, head of the Nairobi-based International Livestock Research Institute, which is backed by governments around the world. "But we are concerned that the message is too generic. You do not want to get governments and development agencies to forget about livestock in Asia and Africa," he told Reuters in a telephone interview. More than 600 million people in developing nations depend on livestock to some extent, he said. In India, for instance, milk is a key source of protein and calcium for a huge vegetarian population. Raising livestock "is a key survival instrument...you are allowing poor people to make an income," Sere said. bdnews24.com/lq/1828 hrs. Other benefits include meat, hides, use of animals for transport and dung for fertilizers. Meat consumption is far lower in developing nations than in rich countries. Rajendra Pachauri, the head of the U.N. Climate Panel, suggested this month that people should have a meat-free day every week to help slow global warming that could bring more floods, droughts and rising seas. VEGETARIAN Others have also advocated a shift away from meat. "The biggest change anyone could make in their own lifestyle would be to become vegetarian," former Beatle Paul McCartney said earlier this year of ways to fight global warming. Sere said the messages should be focused on rich nations, where livestock are often fattened on food that could otherwise be used for human consumption. Farm animals emit large amounts of methane, a powerful greenhouse gas, from their digestive tracts. Use of fossil fuels for everything from fertilizers to harvesting feed for animals also contributes to greenhouse gas emissions. In developing nations, smallholders with a few buffaloes or cows often fed them waste from crops such as sorghum, rice or millet, "turning resources humans can't eat into something of value," he said. In the longer term, rising incomes in developing nations are spurring a surge in demand for meat. The UN's Food and Agriculture Organization has projected that world meat production will more than double to 465 million tons in 2050, from 229 million in 1990-91.