While climate sceptics continue to muddy the waters, African farmers know from their day to day experience that the climate is changing and they are having to adapt.
I am writing this in the savannah zone of northern Ghana where the rainfall is normally erratic, but has become increasingly more so in recent years. This year has been particularly bad, the rains starting a month late and ending a month early. Rice yields have been low, and the quality has suffered as high temperatures cause grains to shatter on milling.
At the southern end of the continent the Conference of the Parties (COP) to the United Nations Framework Convention on Climate Change (UNFCCC) is meeting for COP 17 in Durban, South Africa. But will the links between climate change and agriculture get the attention they deserve in these discussions?
Agriculture is both a victim and culprit of climate change, and I believe there is a critical need to bring it into the heart of climate change negotiations.
Agriculture as a sector is particularly vulnerable to climate change. In Africa and parts of South Asia, subsistence farmers rely on natural rainfall which means they are affected by quite small changes in rainfall patterns.
Climate change is likely to change rainfall patterns and bring a shorter growing season in the future. Many parts of the developing world are already experiencing water shortages and these may increase in scope and severity.
Here at the University of Ghana in the West Africa Centre for Crop Improvement a new generation of plant breeders from Anglophone and Francophone countries in the region are gaining their doctorates tackling the challenge of breeding new drought tolerant varieties of maize, sorghum and other staples. As they know, it is a race against time.
But, in general, developing country governments and institutions are often poorly resourced and unprepared; many rural people will have to cope on their own. Without access to microcredit and microinsurance they cannot afford new seed and crop failure is devastating. The famines in Ethiopia and Kenya are harbingers of what is likely to be a more frequent occurrence.
On the other side of the coin are the greenhouse gases which farmers are unwittingly producing. The Intergovernmental Panel on Climate Change (IPCC) estimates that global greenhouse gas emissions generated by the agricultural sector account for 10-12% of total global emissions. When emissions from agricultural fuel use, fertiliser production and land use change are included, this percentage increases to around 30%. These are very high levels given that agriculture's share in global GDP is only around 4%.
While we know that climate change is occurring and the causes, we still have little knowledge of the regional dynamics and of the consequences for agriculture. We need to design adaptation measures to cope both with relatively predictable climatic stress and with much less predictable but even more catastrophic extreme climatic events. Adaptation depends on developing resilience in the face of uncertainty.
Building resilience involves not only technologies, but also appropriate economic policies and institutional arrangements. It is the poor who will be most vulnerable to the effects of climate change. To some extent, the process of development itself will help them to adapt. If people are better fed and in better health, and have access to education, jobs and markets they will have the capacity to be more resilient.
Traditionally poor people have developed various forms of resilient livelihood strategies to cope with a range of natural and manmade stresses and shocks. But these may be inadequate in the future or may have been lost in the development process. The urgent need is for governments, NGOs and the private sector to work together with local communities to enhance the resilience of the poor.
Reducing greenhouse gas emissions from agriculture is, if anything, an even bigger challenge. On a small-scale we know how to reduce emissions of nitrous oxide and methane and how to sequester carbon in the soil. But how do we do this for agricultural landscapes? How do we measure the emissions and how do we reward farmers for reducing the emissions or returning large quantities of carbon to the soil?
In 2009, I spoke at the first Agriculture and Rural Development Day ahead of COP 15, and this year the third annual Agriculture and Rural Development Day will take place on the 3rd December. If you can't make it to Durban, you can join the discussion virtually through Facebook, Twitter, the blog.
We have to do more to build adaptation and resilience for rural communities and significantly reduce the emissions of greenhouse gases if we are truly serious about tackling climate change globally.
Follow Professor Sir Gordon Conway on Twitter: www.twitter.com/ag4impact