|Agriculture is having to adapt to significant impacts of climate change, while at the same time providing food for a growing population.
Meeting climate change, food security and trade commitments presents both challenges and opportunities for the agri-food sector.
Agriculture is one of the few sectors that can both contribute to mitigation and sequestration of carbon emissions and accounting for agriculture’s carbon footprint is necessary, particularly if agriculture is included in greenhouse gas reduction commitments. However, the range and variability of estimates, and the complexity and uncertainty of accounting for indirect land use change remain to be resolved.
Policies will play a role in enhancing the ability of agriculture to adapt to climate change, while also contributing to other environmental goals. Work in the OECD will continue to support the process following the Copenhagen Climate Change Conference in December 2009.
In 2004 agriculture directly contributed about 14% of global anthropogenic greenhouse gas (GHG) emissions, according to the Intergovernmental Panel on Climate Change (IPCC), although scientific uncertainty suggests it could be much higher. Land use, land use change and forestry account for a further 17%.
Global GHG emissions by sector
Agriculture is particularly vulnerable to climate change. Projections to 2050 suggest both an increase in global mean temperatures and increased weather variability, with implications for the type and distribution of agricultural production worldwide. Climate change will also worsen the living conditions for many who are already vulnerable, particularly in developing countries because of lack of assets and adequate insurance coverage.
These impacts highlight key policy issues, including the need to produce more food for an increasing population. Projections of more than 9 billion people in 2050 suggest that food production will need to double from current levels.
Impact of climate change on OECD agriculture
At the same time, in order to limit future global warming to a 2°C temperature increase as recommended by IPCC, anthropogenic GHG emissions will have to decrease globally by at least 50% by 2050 from 1990 levels. Agriculture is not currently subject to emissions caps, although several OECD countries are already implementing mitigation action plans.
In addition to reducing its own emissions, carbon sequestration in agricultural soils can play an important role in offsetting emissions from other sectors. Some agricultural GHG mitigation options are cost competitive with a number of non-agricultural options in achieving long-term climate objectives.
Quantifying GHG emissions from agricultural activities is complex. First, the atomistic nature of production (many individual farmers) in a wide range of geographic and climatic conditions means that emissions are not only highly variable but also difficult and costly to measure precisely. Second, there continues to be a great deal of scientific uncertainty as GHG emissions from agriculture are subject to a complex interplay of many factors such as climate, soil type, slope, and production practices.
Accounting for the indirect land use changes arising from agricultural production is another important challenge. The recent global surge in food prices highlighted the importance of agricultural policies for world food and energy markets. In particular, the links between production of biofuels from feedstock (in many cases subsidised), consequent land use changes, and food prices demonstrate the importance of foreseeing the range of consequences.
Of the options to reduce GHG emissions in agriculture using currently available technologies, significant mitigation can be achieved through improved cropland and grazing land management, restoration of degraded lands, and land use change (e.g. agro-forestry). Emissions from livestock production can be reduced through improved nutrition and better management of manure.
In addition, crop and pasture lands can sequester significant amounts of carbon, and therefore contribute to offsetting emissions from other sources, while improving soil quality and health.
More research is needed, notably to determine:
While some regions of the world may benefit from improved conditions, the overall effect of climate change is nonetheless expected to be negative for global agricultural production if no action is taken. Increased concentrations of GHGs in the atmosphere already lock-in a certain amount of climate change.
Moreover, given the long time-lags that will be required for GHG mitigation efforts to have an impact, adaptation will have to occur. This may range from altering farm management practices to adoption of new varieties, crops, and animal breeds more appropriate to future climate conditions.
As agricultural production increases, resource constraints, particularly water, will become tighter. Agriculture globally accounts for about 70% of the world’s freshwater withdrawals (45% in OECD countries). Climate change is expected to alter the seasonal timing of rainfall and snow pack melt and result in a higher incidence and severity of floods and droughts. Both rain-fed and irrigated agriculture will need to be managed more sustainably to reduce resulting production risks.
Government policy can play an important role in maintaining a viable agriculture in the face of climate change. Reforms of agricultural policies, in particular the shift to decoupling, have reduced specific commodity-related production distortions. Future reforms might better target specific environmental outcomes, such as encouraging production techniques with low GHG emissions or that minimise them.
Mitigation and adaptation approaches will need to be strengthened. These are likely to be more effective if they are embedded in longer-term strategies linked to agricultural policy reform, risk management, research and development, and market-based approaches. Examples include crop and disaster insurance, research into crop varieties and breeds better adapted to changing climatic conditions, and incentives for more efficient use of water.
In responding to the future challenges for agriculture of addressing climate change and increasing food demand, a coherent policy approach is needed that:
Following Copenhagen, the OECD will continue to examine the role of land use change in agriculture (and the links with forestry), develop tools to analyse the design and implementation of cost effective policies so that agriculture can adapt to and mitigate climate change, and facilitate the sharing of experiences amongst countries on policies to address climate change in agriculture.
OECD (2009), "Climate Change and Agriculture: Impacts, Adaptation, Mitigation and Options for the OECD" [COM/TAD/CA/ENV/EPOC(2009)13].
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|To find out more about OECD work on climate change, visit www.oecd.org/env/cc and www.oecd.org/cop15.|