In the past year, coffee prices have soared to an all-time high as production of the most aromatic and widely used type of bean, arabica, has suffered from unusual weather conditions worldwide.
Toby Quantrill, head of public policy for the foundation, which aims to guarantee a fair price for farmers in developing countries, said: "We are very concerned. The small-scale and poorer farmers we work with are the most vulnerable, and they need support."
The organisation wants to act as a broker between retailers, which can buy carbon credits as a way of offsetting their energy use, and small farmers who can create credits to earn money by planting trees or using more environmentally friendly ways to light or heat their homes.
Fairtrade's move comes amid increasing concern among coffee buyers, particularly those working with small-scale farmers, about the security of supply. They fear not merely disappointment for those who enjoy their caffeine hit with a little more flavour and fragrance, but a global disaster for the coffee industry.
Andrea Olivar at Twin Trading, which buys Fairtrade-approved coffee for supermarkets including Sainsbury's, as well as specialist labels such as Traidcraft and Equal Exchange, said: "If roasters and supermarkets want to continue buying good-quality coffee, with all the changes in the climate, it could get difficult in future. The high-quality arabica bean only grows in specific conditions."
The problem is already apparent to coffee farmers in the Mbale region of Uganda, on the slopes of Mount Elgon, where it is feared that production of arabica beans could cease in the next decade. They are experiencing unprecedented levels of pests and disease, and struggling to deal with unpredictable weather conditions that are dramatically affecting coffee production.
The bean flourishes at 18-23C (64-73F), and in Mbale temperatures appear to be rising – a view held by local farmers and backed up by a recent study by Oxfam.
Willington Wamayeye, managing director of the Gumutindo Fairtrade coffee co-operative in Mbale, which buys from about 6,000 farmers in the region, said: "When temperatures rise we have a humid environment and it enables diseases and pests to grow, and we have unprecedented levels of pest attack of the coffee. In the past it was manageable – now it's running out of control and you can see a whole garden of plants drying up. It's like an epidemic."
He said 80% of coffee trees were now affected by pests compared with about 10% three or four years ago. In the past a coffee tree used to produce an average 2kg of beans a year but now farmers are barely collecting 0.5kg a tree. Quality is also being affected.
While politicians stall on action to tackle climate change, Ugandan farmers are already being forced to deal with the daily reality of higher temperatures, drought and ill-timed or extreme rainfall. Wamayeye said: "The rivers I used to jump in when I was a small boy are completely dried up apart from when it rains heavily."
Heavy rains coupled with deforestation have also increased the incidence of landslides in the region, which can devastate farms and communities. In March last year, a school, a health centre and several farms were buried after torrential rain.
The fall in coffee production may be a less immediate problem but it does have implications for people in Uganda and beyond. As a lucrative cash crop, coffee is vital to smallholders in providing the money they need for medicines, daily household necessities such as soap and their children's school fees.
While coffee prices are high at the moment, amid increasing demand for high-quality Fairtrade organic coffee of the kind grown by the Gumutindo co-operative, farmers' income is under pressure because yields are falling.
Wamayeye says that, although his co-operative has taken on new farmers, this year he will not be able to meet demand: "I need to raise 40 containers of coffee. I have just fewer than 20 now and I think I will fall short by maybe 10 containers by the end of the season."
That reflects a wider problem in Uganda, where the government says exports of the lower-quality robusta coffee bean have also been hit. Between October and December, 692,485 bags of robusta coffee were shipped, down from 705,277 in the same quarter a year before.
The Fairtrade Foundation is not alone in its endeavours to improve the situation. Partly thanks to the National Assembly for Wales, Mbale is being used to pilot schemes that can help these farmers adapt to climate change.
A project orchestrated by the Welsh assembly is aiming to return Mbale's bare hillsides to the lushly forested slopes they once were. The Cardiff-based Waterloo Foundation, set up by David and Heather Stevens, co-founders of part of insurers Admiral Group, has given £150,000 over three years towards planting about 1m trees in Uganda.
The Waterloo Foundation project is seen as a pilot for a broader scheme, backed by the UN Development Programme (UNDP), to fund tree planting and other climate change adaptation initiatives. It has just secured $1m (£630,000) of funding for work in Mbale, one of 10 regions around the world that are expected to participate. After months of political wrangling, the UK's Department for International Development has put up £300,000 over three years, with the rest coming from Denmark's international development agency and the UNDP.
Meanwhile other smaller projects are forging ahead. Twin Trading is asking coffee roasters in the UK to pay a slightly higher price in order to guarantee the future of supply through climate change-related projects, including responsible livestock farming, tree-planting and fuel-efficient stoves. Its cow-sharing project is starting this month and it is hoping to find a retail or roaster partner to help it continue the work. It is encouraged by a deal in which Cadbury's, the British chocolate manufacturer acquired last year by the US group Kraft Foods, has committed to help cocoa farmers in Ghana adapt to climate change.
But, as Wamayeye says, the farmers can only help themselves so much: "What we can do, we are doing. We can plant trees. We can't stop people from driving or flying."