Changes in climate are already occurring in most agricultural regions of the world, and most of these changes have negative effects on established patterns of agriculture. Moreover, even if net reductions in greenhouse gas (GHG) emissions began tomorrow, past emissions will cause continuing changes in the climatic environment of agriculture over the foreseeable future. Continued increases in the rate of GHG, which is a more likely scenario, will exacerbate these changes and make their impacts more severe.
The changing global climate affects agriculture through a number of pathways. These include changes in precipitation levels and intensities, inundation of coastal agricultural lands, reductions in groundwater recharge, increased incidence of flooding and droughts, and the effects of higher temperatures themselves on growing crops. The impacts of these effects vary from region to region, but many of the poorest regions of the world are among those that will bear their brunt.
A more extensive treatment of these issues is included in Water and Adaptation to Climate Change.
Roles and responsibilities
Adaptive responses are already occurring as a result of individual actions by farmers, and water suppliers acting independently in response to changing conditions. These include farmers’ decisions on crops to plant, pesticide use, and timing of planting and harvest; and water suppliers’ decisions on scheduling of water deliveries and the quantity of those deliveries.
Other adaptive responses have resulted from government initiatives and have been carried out either directly by government agencies or by universities and other organizations under contract. In general, the role of public sector agencies includes (a) providing public goods such as knowledge, forecasts, and infrastructure; (b) providing quasi-private goods and services, such as irrigation infrastructure and new seed varieties; and (c) providing livelihood assistance through retraining or job creation credits to workers displaced from agriculture, and (d) creating a framework of incentives and sanctions that will guide individual choices that impact adaptation.
Within the public sector, allocation of responsibilities for adaptive action among public agencies is largely a function of the structure and political economy of those government units and varies widely from country to country. Because of the pervasiveness of climate change impacts, a ministry or department with a broad mandate, such as planning or finance, is generally an appropriate choice to coordinate adaptation interventions (Sperling, c. 2002).
International organizations also have a role to play in aiding adaptive action, particularly in lower-income countries. Such organizations can provide goods and services such as knowledge development and dissemination, information exchange, and awareness raising that possess economies of scale or that require an international footprint to be effective. They can also serve to build consensus on the need for action and provide legitimacy and support for reformers at the national level.
Broad Scale Drivers of Adaptive Capacity
In addition to specific actions aimed at adapting to climate change impacts, there are broad cross-cutting drivers that can reduce sensitivity to GCC exposure and enhance adaptive capacity across the board. These should receive priority attention as powerful generic drivers of adaptation and include:
- Controlling population growth
- Improving education
- Improving performance of public agencies
- Creating non-agricultural employment
One important dimension of priority setting is geographic. There is wide agreement that certain regions of the developing world will be more strongly affected by changing temperatures and hydrology than others. In general, the Mediterranean region, Central America, Southern Africa, the Middle East, Sub-Saharan Africa, and the Indian subcontinent are likely to be strongly and negatively affected. Within these regions of vulnerability lies great variability, and assessing adaptation priorities for particular areas requires country and region-specific analysis.
However many of the expected water-related impacts of global warming are not unique and will often simply build on and exacerbate current trends and emerging problems. The foregoing analysis, coupled with the conclusions of the recent Comprehensive Assessment of Water Management in Agriculture (IWMI, 2007), leads to the identification of several robust priorities with widespread applicability.
The first robust priority is to develop measures to deal with growing water scarcity and increased variability. In many of the most vulnerable regions, this is already a problem and climate change impacts are very likely to exacerbate it. This suggests that measures to alleviate existing or impending water scarcity would also be beneficial in ameliorating similar climate change impacts. Such measures include steps to both manage demand for water and to enhance supply. This is very important. It means that we need not wait for ex post evidence of change and precise estimates of its magnitude before beginning to act, since action will be beneficial even in the absence of climate change impacts.
Knowledge base and analytic capacity
Another robust priority is to expand the knowledge base on water resources, climate change exposure, and impacts and to strengthen national analytic capacity. Such knowledge is useful and important regardless the exact magnitude of hydrologic impacts to come. Important knowledge gaps often include quantification of the elements of the hydrologic system, including inflows, outflows, storage, and use of both surface and groundwater. Capacity to adapt and use regional climate models and hydrologic models are also critically important adaptive skills for a country to have. Agricultural research on drought-resistant or heat-tolerant cultivars, in conjunction with international agricultural research centers, is another important adaptive measure.
Integrated planning and management
Another robust priority is strengthening capacity for integrated water resource planning and management. Such capacity will be beneficial under a wide range of climate impact scenarios. Integrated planning to deal with shrinking water availability and expanding demand for water is the bridge that translates knowledge into actions. Emphasis should be on both strengthening planning and management tools and developing mechanisms for broad stakeholder participation in the planning process.
Strategies for adaptive action
The robust priorities identified above suggest a number of specific areas for adaptive action. Adapting to water scarcity is particularly rich in possibilities. Other actions can help integrate climate change impacts into ongoing planning and management processes, and enhance the knowledge base for planning and management. Most of these are “no regrets” measures that will have benefit regardless of the exact pathway that climate change follows in the coming decades. Many of these actions will take time to bear fruit, and so it is important to begin them soon.
Integrate climate change into planning
Evidence suggests that planning for the impacts of climate change alone is not nearly as useful as integrating climate change considerations into more comprehensive planning routines. This is an important action item in enhancing capacity to deal with emerging hydrologic impacts of climate change. Doing this effectively has several components. One is simply to build the capacity to undertake regional climate modeling and hydrological impact assessment within the country. Another is to link the various analysts and institutions working on water related planning across institutional boundaries. This may be a greater challenge. Executive branches of government can also require that ministries and departments (a) include climate change impacts in their planning processes and (b) report regularly on measures being taken and their impacts.
Water resources knowledge base
In many countries expected to experience growing water scarcity as a result of climate change and ongoing population and economic growth, the water resources knowledge base is rudimentary. Basic figures on water resource availability, variability, and use are lacking or badly outdated. This is a prime prerequisite for logical decision making about adaptive measures to undertake. Application of Geographic Information System (GIS) and remote sensing technologies to the assessment process can enhance accuracy and extent of coverage considerably. In addition to building the knowledge base itself, it is equally important to build capacity in at-risk developing countries to prepare national water budgets, assess hydrologic impacts of changes in climate parameters, and assess vulnerability and adaptive capacity.
Water saving technology
Adoption of water saving technology by irrigating farmers is a key to adapting to scarcity. Drip irrigation is a scalable technology that is just as appropriate for a woman tending a 0.2 hectare vegetable plot as it is for one growing 25 hectares of orange trees, and it has enormous water-saving potential. Other possibilities include converting open earthen channels to buried pipelines and adding control gates to free flowing systems. In the domestic water supply arena there also technologies that can reduce water use, such as low volume toilets, low flow showerheads and metering. The private sector should generally be the party to market these technologies. Innovative groups, such as Denver-based IDE, provide early support to nascent manufactures and sellers of very-small-scale irrigation and domestic water supply equipment before they graduate to full private operation.
Management and governance reforms
In addition to technological improvements, and often complementing it, reforms in the management and governance of water distribution offers promise of more efficient water use, and more responsive adaptation to reduced future supplies. These include transfer of irrigation system management responsibility from the state to farmers. Establishing reliable systems of water rights are also essential tools to allow future shortages of water to be allocated equitably. Private sector marketing of water saving equipment and private extension activities can also be a part of such reforms.
Investments in supply augmentation will almost certainly be necessary in many regions as global warming progresses. However, decision makers may be understandably reluctant to commit to such investments until the parameters governing rainfall volume and distribution are better specified. However, alternative non-conventional water sources, such urban wastewater streams, are sure to become an increasingly valuable with time. They currently cause severe environmental degradation, and are often used for irrigation regardless of their poor quality. Investments in treating urban wastewater are a win-win solution for dealing with expected climate-induced water shortages as well as several current problems. An important area for research and development is the use of “constructed wetlands” for treating wastewater streams from smaller communities in warmer climates.
Enhanced groundwater recharge is another promising way of stabilizing water supplies in the face of growing variability. There are a variety of techniques for artificially increased storage of rainfall and surface flows underground, for withdrawal during drier portions of the year. Experiences such as those from India with village-level recharge programs should be evaluated for possible application elsewhere.
The CGIAR centers are already engaged in research aimed at identifying and combating the harmful effects of climate change on crop and livestock agriculture. They have mapped the impact of climate change on maize and wheat production in important producing areas, developed “climate-resistant” varieties of cereals and pulses, and created a “waterproof” rice that will withstand complete submergence during floods for up to two weeks. National research and extension systems need to link to and collaborate with these ongoing international research efforts.
There is scope for insurance programs to even out risks from climate variability. Primary targets would be from risks of crop failure, livestock deaths, and floods. It is important to note, however, that less vulnerable potential buyers of insurance policies will generally be unwilling to share risks with more vulnerable ones, and so the pooling of risk will be across time rather than among say urban and rural policyholders. Moreover, insurance schemes can only smooth variability, and cannot compensate for longer term changes in levels of precipitation, temperature, and so on. In other words, insurers will have to build longer-term secular changes in values of climate variables into their risk calculations, which will often involve steadily increasing premiums for policies with time, while average agricultural productivity may, at the same time, be falling.
While there is widespread and growing awareness of global climate change as a threatening worldwide problem, there is much less understanding of the mechanisms that drive the problem and the options available both to mitigate it and to adapt to it. It is important to raise the awareness of policy makers, opinion leaders, and the general public in this regard. Policy roundtables, seminars conferences, and news features are all effective ways of doing this. Climate change can also be included in school curricula at all levels.
A Framework for Understanding Climate Change Adaptation
Climate Change and Agriculture: Cause and Impact.
GIZ(2013) Adapting agriculture to climate change.pdf
Svendsen, M, and N. Künkel (2008): Water and adaptation to climate change: consequences for developing countries. GTZ, Eschborn.
IWMI (2007): Water for food water for life, a comprehensive assessment of water management in agriculture. Earthscan, London.
Sperling, Frank, managing editor (c. 2002): Poverty and climate change, reducing the vulnerability of the poor through adaptation. AfDB, ADB, DfID, EC, BMZ, MA-DC (Netherlands), OECD, UNDP, UNEP, WB. Publisher unknown.