One-third of global greenhouse gas emissions, which contribute to global warming, are attributable to agriculture, deforestation and other forms of land use.

The agricultural sector, argues UNEP, could be mostly carbon-neutral by 2030 and produce enough food to feed the projected global population of 9 billion by 2050 if it adopted methods such as agroforestry, reduced soil cultivation and the use of natural nutrients like fertilizer trees.

A study by the World Agroforestry Centre - which will hold its second annual World Congress of Agroforestry, sponsored by UNEP, in Nairobi, Kenya, next month - has found that using fertilizer trees, which trap nitrogen from the air and transfer it to soil, could decrease reliance on commercial fertilizers by up to 75 per cent while boosting crop yields.

Transitioning to a green economy will help tackle a wide range of issues, including the food and fuel crises as well as the scarcity of natural resources, said UNEP Executive Director Achim Steiner.

“Farming will either be part of the problem or a big part of the solution,” he said. “The choice is straightforward: continuing to mine and degrade productive land and the planet's multi-trillion dollar ecosystems or widely adopting creative and climate-friendly management systems of which agroforestry is fast emerging as a key shining example.”

At least one billion hectares of farmland in developing countries can be converted to carbon agroforestry projects, according to the Intergovernmental Panel on Climate Change (IPCC), the Nobel Peace Prize-winning UN scientific body.

Mr. Steiner today underscored the need for nations to “seal the deal” on a “comprehensive and scientifically credible” pact when they meet this December in Copenhagen, Denmark, to wrap up talks on a successor pact to the Kyoto Protocol, whose first commitment period ends in 2012.

“There is a lot at stake, not least the future of agriculture and farmers' livelihoods,” he said.#