The first decade of the 21^st century has seen several harbingers of a troubled future for global food security. But the warning signs could already be seen in the 1990s, as the long-term decline in the number of the world’s poor and hungry stalled, and those numbers began to rise. Population numbers continue their march towards a likely 9 billion by 2050, while higher incomes in hitherto poor countries will lead to increased demand, which in turn puts additional pressures on sustainable food production.To those already daunting challenges, climate change adds further pressure. Because food production is critically dependent on local temperature and precipitation conditions, any changes require farmers to adapt their practices, and this adaptation requires resources that could be used for other purposes. Farmers everywhere will need to adapt to climate change. The agricultural system as a whole will have difficulty supplying adequate quantities of food to maintain constant real prices. And the challenges extend further: to national governments, to provide the supporting policy and infrastructure environment; and to the global trading regime, to ensure that changes in comparative advantage translate into unimpeded trade flows to balance world supply and demand.

While threatened by climate change agriculture also has much to contribute to a low emissions development strategy. Agricultural emissions, direct and indirect, account for more than the energy and transport sectors combined, about one-third of greenhouse gas (GHG) emissions globally. Even if emissions in all other sectors were eliminated by 2050, agricultural emissions growth in a business-as-usual world with a near doubling in food production would perpetuate climate change. Any serious effort to reduce GHG emissions must include agriculture.

Agriculture can contribute to mitigation in three ways:

• Avoiding further deforestation and conversion of  grasslands
• Increasing the store of carbon in vegetation and soil
• Reducing current and avoiding future increases in emissions from nitrous oxide and methane.