London: People should cut their consumption of meat to help combat climate change, a top UN expert said. Rajendra Pachauri, chair of the UN Intergovernmental Panel on Climate Change (IPCC), told the Observer that people should start by having one meat-free day per week then cut back further. The 68-year-old Indian economist, who is a vegetarian, said diet change was important in reducing greenhouse gas emissions and environmental problems associated with rearing cattle.