While agriculture needs new varieties if it is to cope with climate change, they will not be enough. They must be part of an overall agro-ecological approach. This will allow agriculture, notably in the tropics, to continuer to produce our staple foods and some of our favourites, such as chocolate. Cocoa can now be grown in agroforestry systems in areas that initially seemed to be unsuitable.
Contrary to the press scaremongering of recent months, chocolate is unlikely to disappear as a result of climate change. On two conditions, however: on the one hand that we avoid the worst climate scenario  , and on the other that we adapt how we grow cocoa. This does not just mean using more drought-tolerant varieties, but also adopting more agro-ecological cropping techniques.
"Agro-ecology is based on the principles of diversity, efficient use of natural resources, nutrient recycling, and synergy between the different components of an agro-ecosystem" , Emmanuel Torquebiau, agroforestry officer at CIRAD. "Agroforestry is an agro-ecological practice that consists in associating trees with crops, either within existing forests or in specific plantings. It has substantial positive effects, such as restoring soil fertility or regulating pests." Such systems are self-sufficient and do not require irrigation, other than rainwater.
Cocoa agroforestry systems on grasslands
"Agroforestry practices have made it possible to grow cocoa in zones previously considered unsuitable. In Cameroon, for instance, cocoa has been grown since the 1930s in agroforestry systems on grasslands in the Mbam and Inoubou zones" , says Patrick Jagoret, an agronomist with CIRAD. Such agroforestry systems maintain soil humidity and limit evapotranspiration from the cocoa trees. "This reduces the constraints related to the long dry season in the zone." And contrary to popular belief, yields are no lower than in monoculture systems. "In Cameroon, cocoa yields in agroforestry systems can exceed 900 kilos per hectare after twenty years or so." The same goes for Latin America (Colombia, Peru and Ecuador). Moreover, the lifespan of cocoa agroforestry systems often exceeds fifty years.
More fertile soils and pests kept under control
Cocoa was originally an understorey tree in the Amazon rainforest, sensitive to temperature variations, which required constant humidity. This is why it appreciates the shade and soil humidity found in agroforests. Associating trees with cocoa  boosts soil quality, which helps reduce fertilizer use. "This fosters soil biological life , water infiltration, organic matter incorporation and carbon capture in biomass and in the soil."
Agroforestry practices can also help regulate pests and thus reduce pesticide use. "The shade provided by the trees limits attacks by mirids and sucking insects, the main cocoa pests in Africa", Christian Cilas, cocoa supply chain correspondent at CIRAD. Moreover, planting cocoa and other trees in a specific layout can limit the impact of certain diseases, such as monoliasis in Central America.
Agroforestry, an ancestral practice modernized over time that is not only more resilient...
Farmers have developed and improved agroforestry systems over the centuries. However, many farmers abandoned cocoa agroforestry systems in Africa as long ago as the 1970s, in an attempt to boost yields by using chemical inputs and varieties bred to be grown in full sunlight. This resulted in episodes of deforestation and soil degradation, notably in Ghana and Ivory Coast, which now account for some 70% of the cocoa produced worldwide.
However, agroforestry systems are more flexible than growing cocoa under shade, as Patrick Jagoret stresses. Not only are they less subject to climate hazards (for the reasons given above), they are also less sensitive to global cocoa price fluctuations. "Cocoa agroforestry systems can be given minimum attention during less favourable periods. It is even possible to resume managing abandoned systems." The presence of trees in cocoa agroforestry systems slows cocoa tree degradation and facilitates their restoration. Some of those trees may also provide saleable products, such as fruit, supplementing the income derived from selling cocoa  .
…but also more sustainable
Agroforestry practices also serve to capture more carbon than systems without shade, hence indirectly help mitigate carbon emissions and this the greenhouse effect. "The carbon capture capacity of a mature cocoa agroforest is between 5 and 10 tonnes per hectare. We have measured as much as 180 tonnes per hectare in certain zones in Cameroun. That is almost 50% less than in natural forests, but much better than cocoa monocultures", according to Stéphane Saj, an agro-ecologist with CIRAD.
Cocoa agroforestry systems have therefore proved themselves in Cameroon and in many Latin American countries, by reducing the environmental cost and farmers' dependence on chemical inputs and global change.
Other agro-ecological innovations are being developed in Ivory Coast, the world's leading cocoa producer. "New types of crop-livestock systems, combining sheep farming with fodder trees in cocoa plantings, are emerging" , François Ruf, an agro-economist with CIRAD. "Using organic fertilizers and crop residues seems to be playing an increasing part in growers' strategies in response to climate change", he observes.
These various smallholder agro-ecology practices could well serve to inspire other players in the cocoa supply chain, in the light of increased demand from emerging countries. "Provided we take care to share added value equitably", says François Ruf.
Agroforestry will be centre stage in Europe in 2019
The 4th World Congress on Agroforestry is to be held in Montpellier from 20 to 25 May 2019. Organization of the congress, which is held every five years (this will be the first time in Europe), is being led by CIRAD and INRA, in partnership with Agropolis International. Over a thousand participants from all over the world are expected. The congress will centre on three plenary sessions on climate change, food security and poverty alleviation, and identifying agroforestry research requirements on a global level.
 2°C is the desired maximum rise in temperature on which the world's countries settled when signing the Paris Agreement (COP21) in 2015. Above that figure, the effects of climate change, notably on agriculture, would be devastating.
 In Ivory Coast, Ghana and Cameroun, cocoa trees are grown with fruit trees such as avocado, mango, palms, safou, cola nut or forest species grown for their wood or their medicinal properties. In Ivory Coast, rubber is sometimes grown for its latex. In Latin America (Colombia, Peru, Ecuador), various species (generally timber species but also fruit trees) are grown with cocoa.