[Editor's note: This article originally appeared at Ecosystem Marketplace and is reprinted with permission.]

Can carbon save cocoa? That, some say, is the million-dollar question -- or, more accurately, the US$2.2 billion question, since industry insiders estimate that's the value of carbon stored in Ghana's cocoa landscapes.

That value could play an important role in ensuring the long-term survival of the nation's cocoa industry, which faces existential threats in the wake of depleted soil fertility, reduced water supplies, and various diseases worldwide. Already Brazil, once the second-leading cocoa producer in the world, has seen its cash cow fall victim to a massive fungal disease. Now, instead of making money from cocoa, Brazil pays to import it.

Meanwhile Ghana -- which is second only to Côte d'Ivoire in world cocoa production -- has experienced a decades-long decline in cocoa yield per acre farmed, spurring farmers to abandon the livelihood that supported their families for generations. That decline and the accompanying flight from farming have been in remission for three years -- thanks largely to the current high price of cocoa -- but current agricultural techniques are unsustainable over the long haul.

Two-thirds of Ghana's stored carbon lies in its high-forest region. The country has already lost most of this, seeing it shrink from 8.2 million hectares in 1900 to less than 1.2 million hectares today.

The Cocoa Conundrum and the Sun Curse

Cocoa has always been rough on land. Under the best of circumstances, the cacao trees from which cocoa is harvested suck nutrients out of the soil at rates that require massive infusions of chemical fertilizer, which only 3 percent of cocoa famers use, and also require heavy doses of insecticides, which are also not in wide use.

Traditional cocoa-farming techniques recommend leaving much of the standing forest intact, because traditional strains of cacao tree grow best in filtered sunlight. Over time, hybrid varieties have improved yields, beginning with strains that can be harvested twice per year instead of once. Newer plantations, however, are shifting to even newer hybrid trees that tolerate more direct sunlight. This makes it possible for farmers to chop down larger shade trees and plant more cacao trees, an apparent improvement over traditional farming because it, like earlier hybrids, offers higher yields.

Unfortunately, sun-free or low-shade systems suck even more nutrients out of the soil than do the already ravenous multi-harvest varieties. They also encourage some pests and, more importantly for the world at large, rob the planet of both carbon-sequestering trees and of valuable habitat for various species of rare animals and plants by encouraging the destruction of natural shade trees that store carbon and provide shelter.

As a result, these newer plantations are often abandoned within a few decades and replaced with newly deforested land, says Michael Richards, a natural resources economist with Forest Trends, publisher of the Ecosystem Marketplace. Cocoa farmers often then extend their farms or move into other forested areas, bringing deforestation with them and releasing more carbon into the atmosphere.

Most Ghanaian farmers still use the shaded variety of cacao tree, but the hybrids are taking hold, especially in the Western part of the country, and the global atmosphere is paying the price. Long-term, farmers are paying a price as well.

Soil fertility has shrunk noticeably; the newer hybrid-cocoa trees' lifespan is growing shorter, and farmers are struggling to survive. Climate change and unsustainable farming techniques have decreased the amount of land supporting cocoa crops by 40 percent in the past four decades alone, reports the Ghanaian Nature Conservation Research Center, the leading conservation NGO in West Africa -- although that amount has been increasing in recent years as cocoa prices rise.

Some experts believe that if nothing is done, Ghana's cocoa sector could go the way of Brazil's.

"The world is focusing on whether Kraft is going to buy Cadbury and how much it'll pay for it, but it may not be a great long-term investment, if we run out of cocoa in 30 years," says John Mason, executive director of the Nature Conservation Research Centre (NCRC).

Preliminary research by the University of Reading in the U.K. suggests that traditional shaded-cocoa farms store more than twice as much carbon as shade-free farms. Farmers could be persuaded to increase their tree canopy and decrease their cocoa yield if carbon trading makes it worth their while.