Climate Change and Food Systems: Global assessments and implications for food security and trade

Climate change and Food systems


Published on: 2015-06



The growing threat of climate change to the global food supply, and the challenges it poses for food security and nutrition, requires urgent concerted policy responses and the deployment of all the scientific knowledge and accumulated evidence at our disposal. It also requires a sharper focus on the important drivers of climate adaptation, including the potential role of trade to mitigate some of the negative impacts of climate change on global food production.

Knowledge of climate change impacts on agriculture has significantly expanded over the past 20 years. Convergent results are showing that climate change will fundamentally alter global food production patterns. Crop productivity impacts are expected to be negative in low-latitude and tropical regions but somewhat positive in high-latitude regions. Adverse climate impacts on health, including through malnutrition, are gaining increased attention. Higher carbon dioxide concentration [CO2] is shown to lower concentrations of zinc, iron and protein and raise starch and sugar content in crop plants that use three-carbon (C3) fixation pathway such as wheat, rice and soybeans. These findings exacerbate the malnutrition challenges, including obesity and nutrition deficits in poor communities.

Since water mediates much of the climate change impacts on agriculture, increased water scarcity in many regions of the world presents a major challenge for climate adaptation. Addressing the implications of future water availability for food security is paramount and requires coherent cross-sectoral, national and regional strategies that address water management supply and demand. Market-based instruments (water pricing, water trading) could enhance efficient water use and improve water demand management. However, strong institutional structures are also required to ensure people’s rightful access to this indispensable and geographically bound resource. Climate change mitigation measures that affect food security involve emission reductions from many sources. Several technologies targeting adaptation can also have mitigation co-benefits.

At the same time, many technologies critical for food security present dilemmas and trade-offs in climate mitigation. Current crop-based biofuels contribute to mitigation as a renewable energy, but can exacerbate emissions through indirect land use change (e.g. deforestation). Nitrogen fertilizer – a critical input for agricultural productivity – also presents trade-offs between food production and climate mitigation. A win-win solution requires ensuring that fertilizer is accessible to farmers through efficient delivery technologies, but that its use is reduced without negatively affecting yields or exacerbating greenhouse gas emissions.

Climate impact assessments strongly indicate that trade will probably expand from the mid- to high-latitude regions to the low-latitude regions, where production and export potential could be reduced. At the same time, more frequent extreme weather patterns can also adversely impact trade by disrupting transportation, supply chains and logistics. While global markets can play a stabilizing role for prices and supplies, and provide alternative food options for regions negatively impacted by changing conditions, trade alone is not a sufficient adaptation strategy. Trade requires a balance with a domestic adaptation strategy that avoids too much dependence on imports, which may increase a country’s risk of and exposure to higher market and price volatility expected under climate change.

Trade policy plays an important role in affecting future trade flow patterns. Progress on climate-compatible trade policies requires ensuring that climate measures do not distort trade and, alternatively, that trade rules do not prevent progress on climate change. In the longer term, trade rules should evolve to allow internalization of the cost of carbon to avoid negatively affecting climate change mitigation. Likewise, future climate change mitigation policies should include measures designed to internalize the environmental costs of resources.

Combatting climate change must go hand in hand with alleviating poverty. Adverse effects of climate change are greater among poor people in developing countries who are highly dependent on climate-sensitive natural resources yet have the least adaptive capacity to cope with climate impacts. Consequently, there is increasing support for mainstreaming climate change responses within pro-poor development strategies. Mainstreaming offers the opportunity to implement ‘no regrets’ actions that can improve resiliency to current and future climate impacts for the most vulnerable groups while avoiding potential trade-offs between adaptation and development strategies.

Although our understanding of climate change impacts on food systems has expanded, more policy-relevant evidence is required. Stronger emphasis needs to be placed on other important drivers like bioenergy, water and trade. Climate impact science also needs to become more systems-based and improve cross-sectoral frameworks to examine a number of critical linkages: climate-food-trade, climate-nutrition-health, climate-food-water, and climate-food-energy. Since the effects of food insecurity and environmental impacts are felt locally, more focus should be given to local validation of climate impacts, taking into account spatial variability, possible adaptation responses, local resource availabilities and constraints, and socio-economic determinants. Robust and reliable evidence is critical to the development of policies to address climate change impacts on agriculture, water and trade. This is critical since climate policy must cope with a certain level of unavoidable uncertainty in the evidence base. Consequently, a structured multi-partner dialogue and information exchange between the scientific community and policy makers is necessary to provide evidence-based support to climate-compatible food security policies.

This book examines these issues in detail and is the outcome of an expert consultation organized by FAO in November 2013 which gathered acknowledged experts in climate impact research. The 11 chapters cover the latest scientific and economic evidence on climate impact assessments of crop and livestock systems. The chapters cover methodological overviews of global climate impact assessments (biophysical and economic) of food systems, as well as specific model-based analyses focusing on a particular region (Africa, Europe, Asia, Eastern Europe and Central Asia, South East Asia) and food systems (small grains, rice, livestock, bananas). Each chapter starts with take-home messages for non-specialist readers.