Agroforestry offers real potential for carbon sinks and poor farmers

Agroforestry would be a more profitable land-use system for many of the world's poor farmers than traditional methods such as slash-and-burn, and could make a greater contribution to offsetting the developing world's carbon emission reductions than conventional large-scale plantations, according to new research.

Economic analyses to determine the relative profitability of different farming systems studied by the Alternatives to Slash-and-Burn (ASB) consortium at sites in five countries in southeast Asia, Latin America and sub-Saharan Africa found that tree-based farming systems can be more profitable for small-scale farmers than annual cropping.

The research also showed that tree-based farming systems, whether mixed or monocultural, store up to 35 percent of the carbon stored by a primary forest, compared with only 10 percent at the most in annual cropping systems. The shorter the fallow period in cropping systems – during which vegetation grows back – the less carbon stored.

If the carbon offset payments made to developing countries under the Kyoto Protocol’s Clean Development Mechanism were used to encourage some of the world’s poorest farmers to adopt tree-based production systems, the ASB believes agroforestry could make a greater contribution to storing atmospheric carbon than conventional large-scale plantations.

The research found that tree-based farming systems, such as rubber agroforestry in Indonesia and intensive cocoa production in Cameroon can offer smallholders respectable profits. Although intensive monoculture agroforestry is more profitable than mixed, the latter has the advantage of being more resistant to extreme weather conditions, price fluctuations and diseases, the research found. Such systems are also better at preserving biodiversity.

The research was carried out to discover how much carbon dioxide is reabsorbed by the various crop production systems used by farmers around the world. Previous assessments had relied on guesswork because the amounts of carbon stored in constantly changing production systems can vary significantly. To overcome this, researchers divided the total amount of carbon stored in a system throughout its cycle of fallow and cropping phases by the number of years in the cycle, giving ‘time averaged’ carbon figures which allowed the comparison of the carbon storage aspect of different land-use systems.

Each year eight billion tonnes of carbon are released into the atmosphere each year. A quarter comes from the conversion of tropical forests to other land uses. Two billion tonnes of carbon are reabsorbed by land plants, mainly in the temperate and boreal zones.

The ASB believes the findings could encourage policymakers in the developing world to promote agroforestry – thus improving economic development as well as increasing carbon storage. The move to agroforestry could be speeded up if agroforestry could be linked to the Kyoto Protocol’s Clean Development Mechanism which allows industrialised countries to offset their carbon dioxide emissions by investing in energy efficiency projects, renewable energy supplies and tree planting in the developing world. Carbon offset payments could be made either directly to smallholders or to governments which introduce policy reforms promoting adoption of tree-based systems.

“The financial costs of setting up agroforestry systems are entirely borne by small-holder farmers in developing countries,” Anne-Marie Izac, Director of Research at the International Centre for Research in Agroforestry (ICRAF) told edie. “We thus have a situation which is not efficient from an economic perspective, nor is it equitable: small-holder farmers in developing countries are incurring financial costs for adopting more sustainable and environmentally friendly practices that generate environmental benefits received by large numbers of people, including people with a much higher standard of living in developed countries. In other words, poor farmers in developing countries are currently subsidising the environmental well-being of people in the North, who are by far better off than themselves. The financial ‘contribution’ that carbon offsets represent will provide small-holder farmers with an additional incentive to adopt agroforestry on a larger scale than in the absence of carbon offsets.”

At present, most of the tree planting projects undertaken in the developing world under the Kyoto Protocol have involved large-scale afforestation rather than the generation of income for small farmers. Small-scale tree planting schemes are not recognised under current international conventions and agreements. Furthermore, ‘clean development’ investment programmes are unwilling to put carbon offset money into agroforestry because farmers tend not to make carbon storage a priority when taking decisions on land use.

There are also questions over how to prevent a farmer from cutting down natural forest, grazing animals on it for a season and then applying for a carbon offset payment to reforest the area. Farmers could also pocket their payment and then chop the trees down. The ASB says such problems could be overcome using baseline estimates of current land use and stipulating the number of years the land must have increased tree cover.

It would also be necessary not to pay a farmer for trees he would have planted anyway, such as fast-growing trees with a ready local market at hand. The payments would probably focus on species such as mahogany for which there is unmet international demand and which grow slowly.

Action inspires action. Stay ahead of the curve with sustainability and energy newsletters from edie