Negotiators at the Paris climate talks in December (COP 21) will focus on reaching a truly universal and legally binding agreement to drive the world’s transition towards resilient, low-carbon societies and economies. This is being talked about as humanity’s last chance to avoid truly disastrous effects for our planet — the floods in the Philippines and persistent drought in Thailand are just two current examples of the types of events that climate change makes more likely.
In parallel, the scientific community’s focus will be on using and creating practical solutions to complex climate challenges. This week, scientists are gathering in France for a conference hosted by UNESCO (the UN Educational, Scientific and Cultural Organization) to debate evidence-based solutions.
Agricultural scientists are getting organised to increase their involvement in such climate meetings, which the energy and transport sectors often dominate.
Food systems’ high sensitivity to climate is well-known — maize production, for example, could fall by a whopping 40 per cent by the end of this century. Less widely recognised is that agriculture is also a major driver of climate change. Agrifood systems — systems involved in producing, processing and transporting food — are estimated to contribute at least a quarter of global, human-caused greenhouse emissions. It is therefore hard to imagine a successful climate treaty without agrifood systems as a central element.
Agricultural scientists at this week’s meeting will lay the groundwork for a more ‘climate smart’ agriculture, and wider recognition of soil as a carbon reservoir with a major impact on the climate system.
There are already good examples of agriculture turning climate smart. In Uganda, for example, prolonged drought and erratic rains threaten yields of coffee, the country’s most important cash crop. And pests and diseases such as leaf miners, mealy bugs and leaf rust appear to be more common.
Coffee is the main income of many farmers in the East African highlands. Research by CGIAR’s International Institute of Tropical Agriculture and International Center for Tropical Agriculture has shown that areas below 1,300 metres are likely to become completely unsuitable for Arabica coffee production by the 2050s unless production systems are adapted. 
The region stands to lose more than US$100 million in revenue every year, threatening not only national income but also the livelihoods of millions of smallholder farmers.
CGIAR’s scientists are addressing this concern by turning to bananas — a crop that many of the same farmers often depend on for both food and income throughout the year. Grown alongside coffee, the banana tree can offer shade and reduces the coffee crop’s sensitivity to drought, hail and climate-related pests and diseases. Evidence suggests that banana-coffee intercropping can halve incidents of coffee leaf rust, and several on-farm studies in Burundi, Rwanda and Uganda have shown that it can increase incomes by more than 50 per cent. [1,2]
The practice counts as climate smart because it helps the food system adapt to climate impacts, helps mitigate emissions (by reducing fertiliser use or capturing organic carbon in the soil), and protects food security (by producing more than one crop on the same land) — the ‘three pillars’ of climate-smart agriculture.
In the past, governments, including those of Burundi and Rwanda, banned banana intercropping in favour of monocropping, in the mistaken belief that intercropping would reduce yields and incomes. And until recently, neither the public nor private sector researched this practice. CGIAR’s researchers and partners are now working with authorities to recommend policy changes to at least allow intercropping, and with farmers to examine other ways to cope with higher temperatures.
Turning to soils
At this week’s meeting, the French government, research institutes and CGIAR are also launching an initiative to scale up climate-smart agriculture with a focus on capturing carbon in the soil.
Soil contains 2.6 times more carbon than the atmosphere. Plants capture carbon from the air as they grow, and this carbon-containing biomass material is then deposited and locked into the soil when the plants die and decompose. But standard agricultural practices release much of this carbon back into the air. On average, cultivated soils around the world have lost 50 to 70 per cent of their historical carbon stocks.
Reversing this trend, at least partly, would shift agriculture from being part of the problem to being part of the solution. According to the French National Institute for Agricultural Research, raising carbon stocks in soil by 0.4 per cent a year would be enough to immediately compensate for global greenhouse gas emissions. Tools already exist to help contribute to this ambitious goal. They include intercropping with nitrogen-fixing plants to avoid unnecessary use of mineral fertilisers that emit greenhouse gases either when they decompose or during their manufacture; and they include growing trees (as part of agroforestry), which naturally capture a lot of carbon. No-till agriculture that causes minimum soil disturbance, therefore preserving carbon stocks, is another. Planting more cover crops, like the banana trees that shelter coffee crops, can also contribute biomass that nourishes soil.
Making our food more climate smart is part of a larger drive to properly recognise agriculture’s role in adaptation to and mitigation of climate change, at COP 21 and in the climate treaty that will hopefully follow. Concrete solutions related to agrifood systems need to become part of follow-up actions such as the Green Climate Fund. Only then might the world succeed in keeping global warming within the two degree Celsius target and adapting agrifood systems to the changes that are already unavoidable.
“The practice counts as climate smart because it helps the food system adapt to climate impacts, helps mitigate emissions, and protects food security — the ‘three pillars’ of climate-smart agriculture.”
Frank Rijsberman is CEO of the CGIAR consortium. He can be contacted at @frankrijsberman