Climate change will lead to adverse and immediate impact on world food security, the UN Food and Agriculture Organization (FAO) warned on Wednesday.
FAO director general Jacques Diouf told the UN climate change conference in Bali that it will "also increase the vulnerability of poor people everywhere."
FAO's 2006 State of Food Insecurity Report estimated that about 854 million people worldwide suffer from hunger, of which more than 820 million live in developing countries, Diouf said.
"If we do not act immediately, climate change will increase hunger and malnutrition," Diouf said, explaining that medium-term effects of climate change are anticipated from changes in mean temperatures and rainfall, increased weather variability and sea levels rise.
Vulnerable people and food systems would be particularly affected by climate change, he warned, saying that three out of four of the world's one billion poorest and most vulnerable people live in rural areas of developing countries and depend on agriculture, forestry and fishing for their livelihoods.
"Inhabitants of coasts, floodplains, mountains, drylands, and the Arctic are most at risk," Diouf said. "Low-income people everywhere will be at risk of food insecurity due to loss of assets, absence of alternative livelihood options, and lack of adequate insurance coverage from extreme weather events."
Diouf said deforestation was responsible for an estimated 17 percent of global greenhouse gas emissions, and one of the challenges is how to provide adequate incentives to reduce deforestation and forest degradation.
He said effective strategies would require increased investment in agricultural development and natural resources management at local and national levels.