CANCUN (Mexico): Most of the world's 500 million small farmers who own two hectares or less of land use traditional cropping methods which are more eco-friendly. They end up taking carbon dioxide from the air and putting it into the soil.

This has made them the target of rich countries that want to buy this carbon and offset it against their legal requirement to reduce carbon dioxide emissions.

At the Nov 29-Dec 10 UN climate summit in this Mexican beach resort, many researchers and policymakers from industrialised countries are talking of how this can be a win-win solution to the global warming crisis - at least in part, since agriculture accounts for 14 percent of the greenhouse gas emissions that are warming the planet.

But there are very complicated calculations ahead before capturing carbon in the soil can be paid for under the UN's clean development mechanism, and not everyone is convinced of the principle anyway. NGOs like the Malaysia-based Third World Network (TWN) have warned against "turning agriculture into a commodity".

The proponents point out that if they can evolve a methodology, this payment for carbon would be extra income for an estimated 1.5 billion people who live in the 500 million small farmer households. Such small holdings account for 85 percent of the world's farms.

They also claim this will transform villages in Asia, Africa and Latin America, as about 75 percent of the world's poor live in rural areas. A recent World Bank study said for the poorest people, GDP growth originating in agriculture is about four times more effective in reducing poverty than that originating outside the sector.

The numbers are indeed huge. In Asia, a majority of the 200 million rice farmers cultivate two hectares or less, and still make up the bulk of the rice produced.

In Latin America, about 17 million smallholdings occupying 34.5 percent of the total cultivated land with average farm sizes of about 1.8 hectares, produce 51 percent of the maize, 77 percent of the beans and 61 percent of the potatoes for domestic consumption.

In Africa, which has approximately 33 million small farms, representing 80 percent of all farms in the region, the majority of the farmers are smallholders.

These farmers end up being more eco-friendly and store more carbon in the soil than large monoculture farms because they use natural seeds, fertilizers and pesticides, according to Lim Li Ching of TWN.

Traditionally, they sow nutrient-enriching plants in fallow fields, and use insect predators, pollinators, nitrogen-fixing and nitrogen-decomposing bacteria. They also store more genetic varieties of each crop, as they rarely buy seeds from the market. In the process, they provide an important gene bank that scientists can use to study productivity and resistance to various diseases.

Such gene banks are crucial to making agriculture more resilient to climate change, as scientists are now studying crop varieties that can grow with less water or on more saline land, for example.

A year-long study of rainfed agriculture in the semi-arid regions of India - coordinated by various NGOs - reported last month that small farmers are now looking for these new varieties that they can grow when the monsoon fails or is weak.

In this whole process, mainly by using organic fertilisers, small farmers store carbon in the soil, and now the question here is: Can they make extra money out of this by selling these carbon "credits" to rich countries.

Ching said, "The idea is fairly simple in concept and complicated in practice: quantify the amount of carbon in agricultural soils. When farmers adopt certain crop management practices that will increase the amount of soil carbon, they receive payment for the amount of carbon they are able to sequester in the soil. Those carbon credits purchased as offsets can then replace developed country (emission) mitigation obligations, or they can be traded as commodities on the speculative market."

But she opposed it on principle, saying "creating a commodity out of soil carbon is an inappropriate means to provide support to small-scale farmers for their climate-resilient practices".

However, policymakers in developed countries are unlikely to pay much heed to such opposition as they search the globe for ways to offset their own emissions, and policymakers in developing countries see this as a lucrative source of income for something that their small farmers were doing anyway.