Emerging Issues that Influence the Future

352 | IAASTD Global Report ever very little change will occur if no major effort is made in educating local consumers and developing AKST to produce for the export market. 5.5.4 Biotechnology and biodiversity 5.5.4.1 The reference case A number of challenges—scientiic, regulatory, social and economic—will fundamentally inluence the degree to which genetic engineering is used in crop and livestock improve- ment research over the coming decades. Greater or lesser use of genetic engineering will, in turn, shape the evolution of the agricultural sector and biodiversity. Conventional breeding and genetic engineering are complements; thus the reference case development pathway includes a combina- tion of a strong traditional plant breeding capacity together with the use of transgenic traits when useful, cost-eficient, pro-poor, and environmentally sustainable. A wide range of new traits are at various stages of development, some of which are likely to lead to varieties that are drought-resis- tant, exhibit improved nutritional content of feed and feed- stuffs, and offer enhanced shelf-life Graff et al., 2005. It is likely that a combination of transgenic and conventional breeding approaches will be necessary to meet the crop im- provement requirements of the next 50 years. Factors shap- ing future adoption of new technologies include improved proits, decreased risk, increased health and well-being, and reduced effort, compared to earlier technologies used. They also include institutional and physical constraints affecting farming, like availability and terms of credit, information and product support provided by extension and technology pro- viders, tenure conditions, and land ownership. Furthermore, the availability and quality of technology are dependent on policy and institutional variables, such as national agricultural research capacity, environmental and food safety regulations, intellectual property rights protection, and the existence of eficient agricultural input and output markets, which mat- ter at least as much as the technology itself in determining the level and distribution of economic beneits Raney, 2006. Potential constraints include property rights constraints, as well as evolving biosafety and food safety regulations around the world. Based on the literature assessing both constraints and beneits of crop technologies, the status quo pathway will involve continued rapid adoption of insect resistant and herbicide tolerant maize, soybean, cotton and canola varieties in the developing countries where they are already approved. More developing countries are likely to approve these crops—especially Bt cotton and yellow maize—under status quo conditions. Adoption of Bt maize in Europe will continue to expand slowly due to consumer resistance, de- spite growing tension between consumers and farmers who see their competitiveness eroding in the face of competition from countries where adoption is proceeding.

5.5.4.2 Alternative pathways—more biotechnology

In spite of the limited growth in the development of trans- genics, it is possible that these technologies will reemerge as a major contributor to agricultural growth and productivity. The continued safe introduction and use of the current gen- eration of genetically engineered crops and the emergence of transgenic innovations of direct beneit to consumers or Reidhead, 2000. One way small scale producers could meet increased food safety requirements in the future is by pur- suing the direction of fewer and less persistent pesticides. However in the short term the cost of these new environ- mentally friendly pesticides seems higher than older pesti- cides. Many cases aren’t affordable to producers in the least developed world, where low-cost labor often compensates for the multiple applications, needed with some of the old pesticides, which might be of low quality or adulterated Dinham, 2003; Carvalho, 2006. Countries in the tropical belt are challenged by environmental conditions and by not enough AKST developed to overcome their intrinsic pro- ductivity limitations, while complying with acceptable food safety guidelines.

5.5.3.3 Challenges as affected by policies

The main challenges for the next decades will be irst to ensure safer food to consumers and raise the quality of life without creating a barrier to poor countriesproducers for opportunities of success. Food security is a concern as food safety may only be “purchased” by some consumers, a situation that could be particularly notorious with prod- ucts sourced from long-distance areas Schillhorn van Veen, 2005. Secondly, in our search for mechanisms to improve food security in the world we are challenged to develop a system that will not cause the emergence of currently un- known health problems. The free trade market movement and the need to reduce internal hunger will likely result in more governments imposing their own rules or mandating the established international regulations. This will certainly create a major challenge as there are concerns about the possibility of mishandled information to affect the percep- tion of the international consumer Schlundt, 2002. Thus, governments will act inluenced by how the actions will af- fect the distribution of beneits across the entire population Codron et al., 2005. It will become particularly dificult to control factors that compromise outbreak risks without collaborative in- ternational effort Burlingame and Pineiro, 2007. A new approach will be necessary, one that incorporates food safety issues into the development of trade negotiations. Enhancing communication among policy makers from countries with common interests will allow the transfer of successful schemes to those in more need Babu, 2004. The two future paths on food safety regulatory mechanisms de- scribed above private sector providing education, auditing and analyses or government enforcement and monitoring will be affected by the type of market to which products are directed. Moreover, even with national enforcements, some countries might continue to have regulation that dif- fers substantially from those required in the export market and other local markets. The pressure over natural resources will determine some “natural” differences among countries Hamilton, 2005. Some countries with known overdepen- dence on pesticides but with the potential capacity to de- velop a more systematic approach will have the opportunity to improve internal standards and increase presence in the export market Gupta, 2004. In this regard, the narrower the gap between the traditional and urban market, the more likely a country will ind its way to comply with food safety expectations in the international arena Kurien, 2005, how- Looking Into the Future for Agriculture and AKST | 353

5.5.4.4 Implications for the agricultural sector

For new technologies to be pro-poor, they need to relate to crops consumed by subsistence and small-scale farmers, allow for small-scale cultivation practices, and they need to be adapted to the human, physical, inancial and social capital of the rural poor. Economic impacts tend to be more pro-poor where signiicant market competition exists in the supply of new technologies. The increased supply, as well as enhanced quality of improved technologies could contribute to reduced food prices, providing extra beneits to the urban poor. Improved food productivity can also be an important force to counter increased energy prices that are likely to contribute to increased food prices, which have a dispropor- tionate negative effect on the poor.

5.5.4.5 Implications for biodiversity

The impacts of a rapid expansion of transgenic crops on natural and agricultural biodiversity over the next 50 years could be signiicant and will depend in part on how regula- tory regimes evolve. Natural biodiversity could be affected through crop yields and the implications of transgenic crops for land use, potential outcrossing of transgenic material to related crop and wild species, and direct and indirect effects on non-target species. Agricultural biodiversity could be af- fected indirectly, much as it was by the spread of modern green revolution varieties, as well as directly through the use of the technology. The most direct way transgenic crops could affect natu- ral biodiversity is through their effect on crop yields and associated pressures inluencing land use. To the extent that transgenic innovations support yield growth or reduce crop losses to pests and diseases, they could alleviate pressure to expand crop production into currently uncultivated areas, endangering the natural biodiversity that exists there. The potential for outcrossing to wild or agricultural relatives varies by crop. Transgenic varieties of crops that have a high propensity to outcross typically have not been approved for cultivation in areas where wild relatives are endemic. Most crop species, whether transgenic or not, are unlikely to be able to reproduce and persist in the wild, and management strategies can be used to minimize the risk FAO, 2004. The potential for transgenic crop varieties to cross with conventional varieties clearly exists, although transgenic traits that do not confer a competitive advan- tage are unlikely to persist in farmers’ ields unless they are speciically selected. Outcrossing to wild or cultivated rela- tives could be prevented by the use of genetic use restric- tion technologies, but this approach is controversial and has not been developed commercially. Whether the existence of an otherwise benign transgenic trait in an agricultural crop constitutes a meaningful loss of biodiversity is a matter of debate, particularly if it is a trait farmers have selected for Raney and Pingali, 2005. Whether modern variety adoption necessarily reduces agricultural biodiversity is a matter of debate. Agricultural biodiversity is important because it inluences the resilience of crop ecosystems and maintains a “library” of genetic resources for current and future breeding activities. The domestication of wild plants into landraces narrowed the genetic base for these crops as farmers selected among the full range of plant types for those that produced more desir- the environment could lead to greater public acceptance of transgenic approaches and ultimately to a rationalization of regulatory regimes across countries, traits and crops. This in turn could mean that the costs monetary and temporal of transgenic research, development and deployment could fall signiicantly, leading to the rapid growth in the num- ber of transgenic events and their pace of adoption. New biotechnological discoveries and their successful applica- tion in a country like China, where experimentation and investment in crop biotechnology continue, may lead other countries to follow suit. Finally, the concern about climate change and increasing energy prices could lead to signiicant investment in the development of biofuels, which, in turn, would increase rapidly growing resource scarcity and possi- bly higher food prices. Higher food scarcity, in turn, would increase the value of improved agricultural productivity and may lead countries to reassess the regulations restricting the growth of biotechnology. Furthermore, the development of biofuel crops may also rely on transgenic varieties and lead to enhancement of agricultural biotechnology and increase their acceptance. Under such an alternative pathway, oilseeds with im- proved lipid proiles and staple grains with vitamin and mineral fortiication could be introduced, and three major transgenic food crops that are already on the brink of ap- proval Bt rice, herbicide tolerant wheat and nutrient re- inforced rice could expand in developing countries and industrial countries alike. Furthermore, such a pathway could see traits for the remediation of polluted or degraded land or adaptation to heat and drought, which could assist in dealing with current agroenvironmental challenges and in the adaptation to rapid climate change.

5.5.4.3 Alternative pathways—less biotechnology

If society determines that the risks associated with trans- genesis in agriculture exceed the beneits, the tool might be abandoned over the next several decades. Agricultural improvement research would continue, however, as it must to meet current and future challenges. Other research tools would be used more intensively, including conventional and mutagenic breeding. Non-transgenic molecular tools would also be used, such as marker assisted breeding. Under this alternative pathway, it is likely that a wider range of genetic variation would be sought within crops and wild relatives, and molecular tools would facilitate this search. In industrial countries, more than half of all agricul- tural research expenditures are currently made by the pri- vate sector. Much of that research is aimed at developing patentable genetic constructs for use in crop and livestock improvement through transgenesis. The overall level of agri- cultural research expenditures in industrial countries could be reduced substantially if transgenic tools were abandoned, unless irms could assert binding intellectual property rights over discovered traits. At the same time, the costs associ- ated with the regulation of transgenic crops would also be avoided. Overall, it is likely that the elimination of a power- ful tool like transgenesis would slow but not stop the pace of agricultural research and improvement. As a result, human- ity would likely be more vulnerable to climatic and other shocks and to increased natural resource scarcity under this alternative pathway. 354 | IAASTD Global Report and biodiversity are complementary. Furthermore, biotech- nology provides tools to restore local varieties after slight modiication allowing them to withstand disease or other pressures. The development of precision farming technolo- gies that allow for the modiication of application of inputs, including seeds, in response to changes in ecological condi- tions will provide impetus to increase crop diversity to take advantage of these new possibilities.

5.6 Implications of Policy Simulations and Emerging Policy Issues: Synergies and

Tradeoffs

5.6.1 Poverty and equity Chapter 5 examined projected changes in agriculture and

AKST out to 2050 based on existing assessments and meth- odologies. At this point there are no established methodolo- gies to adequately describe changes in poverty and equity out to 2050. This can only be inferred based on the state of literature and the analyses presented here. Increased agricul- tural productivity has been a key driver for economic and income growth in most countries at some stage of economic development and will continue to be key to growth in many agriculture-dependent developing countries out to 2050. However, although agricultural and economic growth are critical drivers for poverty reduction and explain a signii- cant share of the historical decline in poverty in most re- gions of the world, policies and investments in the ields of education, health, and infrastructure are also essential for sustained poverty reduction. Lipton and Sinha 1998 argue that, while globalization is changing the outlook for the ru- ral poor by raising average incomes, it also tends to increase income variability both across regions leaving some regions and countries behind and across time, thus increasing the vulnerability of those who can least afford it. Moreover, while changes in macroeconomic and trade policy tend to produce large gains for both rural and urban areas, poor farmers and landless agricultural laborers, who often lack the skills, health, information, or assets needed to seize new opportunities Sinha and Adam, 2006, 2007, tend to be left out of the general economic growth process, as they may be concentrated in remote rural areas or geographic regions ill- equipped to gain from globalizationliberalization. To redress potentially adverse impacts on equity, invest- ments in human capital are crucial for the poor. Moreover, given emerging health and food safety issues, investments in health and nutrition are similarly important. Even with rapid economic growth and active investment in social ser- vices, some of the poor will be reached slowly if at all. And even among those who do beneit to some extent, many will remain vulnerable to adverse events. These groups will need to be reached through income transfers, or through safety nets that help them through short-term stresses or disasters.

5.6.2 Hunger, health and food security The reference run has shown that a substantial increase in

food prices will cause relatively slow growth in calorie con- sumption, with both direct price impacts and reductions in real incomes for poor consumers who spend a large share of their income on food. This in turn contributes to slow im- able results Smale, 1997. Although more genetically uni- form than their early relatives, landraces are characterized by a high degree of genetic diversity within a particular ield. Modern varieties, on the other hand, tend to exhibit little diversity within a particular ield, but each plant contains genetic material from a wide variety of progenitors and is adapted to perform well across a wide range of agroclimatic conditions. A simple count of the varieties in a particular area or measures of genetic distance among varieties thus may not tell us much about the resilience of crop ecosys- tems or the availability of crop genetic resources for breed- ing programs Raney and Pingali, 2005. Transgenic techniques can directly affect agricultural genetic diversity. Transgenesis permits the introduction of ge- netic materials from sexually incompatible organisms, greatly expanding the range of genetic variation that can be used in breeding programs. Transgenesis allows the targeted trans- fer of the genes responsible for a particular trait, without otherwise changing the genetic makeup of the host plant. This means that a single transgenic event can be incorpo- rated into many varieties of a crop, including perhaps even landraces. Compared with conventional breeding in which an innovation comes bundled within a new variety that typically displaces older varieties, transgenesis could allow an innovation to be disseminated through many varieties, preserving desirable qualities from existing varieties and maintaining or potentially increasing crop genetic diversity Raney and Pingali, 2005. On the other hand, the widespread incorporation of a single innovation, such as the Bt genes, into many crops may constitute a kind of genetic narrowing for that particular trait. Furthermore, transgenic crops that confer a distinct advantage over landraces may accelerate the pace at which these traditional crops are abandoned or augmented with the transgenic trait Raney and Pingali, 2005. Regulatory regimes are concerned with the potentially harmful con- sequences of gene low from transgenic crops to conven- tional varieties or landraces. In this context, it is important to recognize that gene low from conventional varieties to landraces frequently occurs especially for open-pollinated crops such as maize and is often consciously exploited by farmers. It is likely that, in the same way, farmers would consciously select for transgenic traits that confer an advan- tage de Groote et al., 2005. Regulatory decisions inluence the implications of trans- genic approaches for biodiversity, often in unexpected ways. For example, when biosafety procedures require the sepa- rate approval of each plant variety containing a transgenic event, it slows the development of new varieties and narrows the range of genetic diversity available to farmers. Similarly, when new transgenic approaches to address a given produc- tion constraint such as herbicide tolerance are delayed, the approved technology may be overused with negative conse- quences for biodiversity and other environmental indicators. Finally, genetic engineering allows scientists to take advantage of biodiversity. Increased documentation of ge- nomes and understanding of functional genomics provides information that is needed to develop new traits and new varieties that are of high value. Thus, the availability of tools for biotechnology and their development enhance the value of biodiversity, and to some extent, biotechnology Looking Into the Future for Agriculture and AKST | 355 in water demand in all sectors and declining water availabil- ity resulting from climate change in this baseline, developing countries are substantially more negatively affected by de- clining water supply reliability for irrigation and other uses than developed countries. This is especially so for develop- ing countries with arid climates, poor infrastructure devel- opment, and rapidly increasing populations. Overall, to satisfy future water demand and secure food supply, invest- ments in maintenance, new technology and policy reform in water and irrigation management are all necessary to maintain water supply reliability and to reduce water supply vulnerability for irrigation, especially in developing coun- tries. Besides water supply augmentation, demand manage- ment is also of high importance in balancing future water demand and supply. Other research indicates that more in- vestment in basin eficiency improvement would potentially bring similar effects in securing irrigation water supply as more investment is made in water infrastructures. Likewise, water saving technology and conservation measures in the industrial, rural and urban domestic sector would result in more reliable water supply in nonirrigation sectors and re- lieve the increasingly intensiied intersectoral competition for water. On the isheries front, although small pelagic species are robust, the behavior of the small pelagic ish towards the end of the modeled period 2048 indicate that policies of mining small pelagic isheries to support a growing aquacul- ture industry may not be sustainable in the long-term except in a limited part of the world’s oceans. Caution needs to be taken even with this interpretation since small pelagic ish are extremely sensitive to oceanographic changes and if the predictions for changes in sea temperature come about, the species dynamics within this group will change signiicantly with potential reverberating effects up through higher trophic levels since most animals, especially marine mammals and seabirds, rely on this group of ish for much of their food. Therefore, a policy of increasing landings would need to be carefully considered in the light of climate change. The tradeoffs between increased income for small farm- ers via crop production for food and fuel, livestock pro- duction, conservation and marketing of native varieties and species, and soil and water management for sustainability, will require a balancing act over the next 50 years. However, synergies do exist; biofuel crops, biotechnology, ICT, food safety standards, and globalization and trade liberalization can offer new opportunities to smallholders—if supporting policies and investments are implemented—and large agri- cultural producers alike making an ever more diverse range of products available to consumers.

5.7 Implications for AKST in the Future

As the reference world in 2050 and the various policy dis- cussions show, agriculture will have to face a number of new and dificult challenges. Food security and food sover- eignty are likely to still be problems 50 years from now. Ag- ricultural production is likely to be increasingly constrained by competition for land and water and by climate change. Strategies for adapting to new regulations for food safety, and the development of biotechnology and bioenergy pose signiicant challenges and opportunities. provement in food security for the poor and in food sover- eignty for many regions. Progress is slowest in sub-Saharan Africa—despite rapid income growth and signiicant area and yield growth as well as substantial progress in sup- porting services that inluence well-being outcomes, such as female secondary education, and access to clean drinking water. By 2050, there will be a reduction by only 7 in the number of malnourished children in sub-Saharan Africa. Alternative policy experiments show that with higher investments in AKST, the share of malnourished children in the group of developing countries is projected to decline from a baseline of 99 million by 2050 to only 74 million. If these higher investments in AKST are combined with im- provements in complementary service sectors, such as health and education, the projections show that an even greater re- duction, to 43 million, could be achieved. By contrast, either latlined or slowed rates of investments in AKST will nega- tively affect regional food security and exacerbate childhood malnutrition, with levels that could easily surpass current malnutrition levels. Moreover, uncertainties regarding a whole range of emerging issues, ranging from public health and food safety to policies in the areas of climate change and bioenergy could worsen or improve projected quantitatively mod- eled outcomes.

5.6.3 Natural resources and environmental sustainability

Regarding resources, scarcity is expected to become a prominent challenge for policy makers. In particular, grow- ing water and land scarcity are projected to increasingly constrain food production growth with adverse impacts on food security and human well-being goals. Growth of population combined with shifts towards high landfodder- intensive meat diets is resulting in additional demands for land. Although crop productivity is expected to increase as described in the reference run the uncertainty as to whether this productivity increase can actually be met is also increas- ing. The increased production of livestock is expected to come from the same or a declining resource base, and with- out appropriate action there are prospects that this could lead to degradation of land, water, and animal genetic re- sources in both intensive and extensive livestock systems. In addition, new demands on land for products such as biofuels stimulated by concerns about climate change and energy self-suficiency are very likely to grow exponentially in the coming decades. This will not only impact food prices but will also lead to greater competition for land. The com- bination of demand factors will lead to rather grim impacts on biodiversity. The target of the Convention on Biological Diversity CBD to reduce the rate of loss of biodiversity signiicantly by 2010 seems impossible to reach. Moreover, some policy options to reduce pressures on the natural sys- tem e.g., climate mitigation strategies as described in this chapter have a negative impact on biodiversity through ad- ditional land-use change required for biofuels. Water demand is projected to grow rapidly, particularly in developing countries. Irrigation remains the single largest water user over the 50-year projection period, but the in- crease in demand is much faster for domestic and industrial uses than for agriculture. Given signiicantly faster growth 356 | IAASTD Global Report rigation water as a residual. Environmental lows are in- cluded as constraints. The food module is speciied as a set of 115 country or regional sub-models. Within each sub-model, supply, demand and prices for agricultural commodities are deter- mined for 32 crop, livestock, ish commodities and ishmeal, sugar and sweeteners, fruits and vegetables, and low value and high value ish. These country and regional sub-models are intersected with 126 river basins—to allow for a bet- ter representation of water supply and demand—generating results for 281 Food Producing Units FPUs. The “food” side of IMPACT uses a system of food supply and demand elasticities incorporated into a series of linear and nonlinear equations, to approximate the underlying production and demand functions. World agricultural commodity prices are determined annually at levels that clear international mar- kets. Demand is a function of prices, income and popula- tion growth. Growth in crop production in each country is determined by crop prices and the rate of productivity growth. Future productivity growth is estimated by its com- ponent sources, including crop management research, con- ventional plant breeding, wide-crossing and hybridization breeding, and biotechnology and transgenic breeding. Other sources of growth considered include private sector agricul- tural research and development, agricultural extension and education, markets, infrastructure and irrigation. IMPACT projects the share and number of malnourished preschool children in developing countries as a function of average per capita calorie availability, the share of females with second- A.5.1 The International Model for Policy Analysis of Agricultural Commodities and Trade IMPACT A.5.1.1 Introduction IMPACT was developed in the early 1990s as a response to concerns about a lack of vision and consensus regarding the actions required to feed the world in the future, reduce poverty, and protect the natural resource base Rosegrant et al., 1995. In 2002, the model was expanded through inclusion of a Water Simulation Model WSM as water was perceived as one of the major constraints to future food pro- duction and human well-being Rosegrant et al., 2002. A.5.1.2 Model structure and data The current IMPACT model combines an extension of the original model with a WSM that is based on state-of-the-art global water databases Rosegrant et al., 2002. The water module projects the evolution of availability and demand with a base year of 2000 average of 1999-2001, taking into account the availability and variability in water re- sources, the water supply infrastructure, and irrigation and nonagricultural water demands, as well as the impact of alternative water policies and investments. Water demands are simulated as functions of year-to-year hydrologic luc- tuations, irrigation development, growth of industrial and domestic water uses, and environmental and other low re- quirements committed low. Off-stream water supply for the domestic, industrial, livestock, and irrigation sectors is determined based on water allocation priorities, treating ir- an important role here. To adapt to and mitigate the various effects from climate change requires the development of new cultivars. Likewise, CO 2 emissions can be reduced through new crop management practices supported by appropri- ate technologies. To achieve such breakthroughs, existing global and regional research-for-development networks for agricultural production technologies and knowledge need to work closely together so that technology and knowledge can low to allow farmers to face the risks associated with future harvests. Information and communication technologies and traditional and local knowledge could play key roles in the regeneration of future productivity growth. As the alterna- tive policy experiments in this chapter have shown, higher, judiciously placed investments in technology, development can signiicantly improve outcomes for food availability and food security. Food prices will most likely rise as a result of these op- portunities and constraints. In addition, regional and na- tional income growth, urbanization and growing global interconnectedness are expected to increase diet diversiica- tion and homogenization. Trade liberalization and greater integration of global food markets can support more reli- able food supplies and lowered food prices in real terms. But as the reference run shows this is unlikely to be achieved in the coming decades. With declining availability of water and land that can be proitably brought under cultivation, expansion in area will contribute very little to future production growth. The pro- jected slow growth in crop area places the burden to meet future cereal demand on crop yield growth. The key to im- proving yields under increasingly constrained conditions lies in technology to improve agricultural productivity in order to regenerate productivity growth. Biotechnology could play APPENDIX Model descriptions Looking Into the Future for Agriculture and AKST | 357 ary schooling, the ratio of female to male life expectancy at birth, and the percentage of the population with access to safe water see also Rosegrant et al., 2001; Smith and Haddad, 2000. The model incorporates data from FAOSTAT FAO, 2003; commodity, income, and population data and pro- jections from the World Bank 2000, the Millennium Eco- system Assessment MA, 2005, and the UN 2000 and USDA 2000; a system of supply and demand elasticities from literature reviews and expert estimates Rosegrant et al., 2001; and rates for malnutrition UN ACCSCN, 1996; WHO, 1997 and calorie-child malnutrition relationships developed by Smith and Haddad 2000. A.5.1.3 Application IMPACT has been used for analyzing the current and fu- ture roles of agricultural commodities and impacts on food security and rural livelihoods, including the future of isher- ies Delgado et al., 2003; the role of root and tuber crops Scott et al., 2000a, 2000b; and the “livestock revolution” Delgado et al., 1999. IMPACT has also been applied to regional analyses as well as selected country-level studies, for example, China Huang et al., 1997, Indonesia SEARCA IFPRICRESECENT 2004, sub-Saharan Africa Rosegrant et al., 2005a and Central Asia Pandya-Lorch and Roseg- rant, 2000. IMPACT has also been used to analyze struc- tural changes, including the impact of the Asian economic and inancial crisis Rosegrant and Ringler, 2000; longer- term structural changes in rural Asia Rosegrant and Hazell, 2000; as well as global dietary changes Rosegrant et al., 1999. The model has also been used to describe the role of agriculture and water for achieving the Millennium De- velopment Goals von Braun et al., 2004; Rosegrant et al., 2005b. Model runs have been carried out for individual centers of the CGIAR, the World Bank and the Asian Development Bank. The model has also been used for agricultural scenario analysis of the Millennium Ecosystem Assessment Alcamo et al., 2005; MA, 2005, and is currently being used for the Global Environmental Outlook GEO-4 assessment carried out by UNEP. Other work includes investigations into re- gional and global scale impacts of greenhouse gas mitiga- tion in agriculture and theoretical large-scale conversion to organic food production. A.5.1.4 Uncertainty In the following tables, the points related to uncertainty in the model are summarized, based on the level of agreement and amount of evidence. A.5.2 The Integrated Model to Assess the Global Environment IMAGE 2.4 A.5.2.1 Introduction The IMAGE modelling framework had been developed origi- nally to study the causes and impacts of climate change within an integrated context. Now the IMAGE 2.4 is used to study a whole range of environmental and global change problems, in particular aspects of land use change, atmospheric pollu- tion and climate change. The model and its submodels have been described in detail in several publications Alcamo et al., 1998; IMAGE team 2001; Bouwman et al., 2006. A.5.2.2 Model structure and data The IMAGE 2.4 framework describes global environmen- tal change in terms of its cause-response chain, and belongs to the model family of integrated assessment models. The IMAGE model consists of two major parts: the socioeco- nomic system, elaborating on future changes in demograph- ics, economy, agriculture and the energy sector, and the bio- physical system, comprising land cover and land use, atmo- spheric composition and climate change. The IMAGE model focuses on linking those two parts through emissions and land allocation. Land allocation follows inputs from the IM- PACT model, allowing an assessment of the environmental consequences of changes in the agricultural sector. One of the crucial parts of the IMAGE 2.4 model is the energy mod- el, Targets IMage Energy Regional TIMER. The TIMER model describes the chain, going from demand for energy services useful energy to the supply of energy itself through different primary energy sources and related emissions. The steps are connected by demand for energy and by feedbacks, mainly in the form of energy prices. The TIMER model has three types of sub-models: 1 a model for energy demand, 2 models for energy conversion electricity and hydrogen production and 3 models for primary energy supply. The inal energy demand for ive sectors and eight energy car- riers is modelled as a function of changes in population, economic activity and energy eficiency. The model for elec- tricity production simulates investments in various electric- ity production technologies and their use in response to elec- tricity demand and to changes in relative generation costs. Supply of all primary energy carriers is based on the interplay between resource depletion and technology de- velopment. Technology development is introduced either as learning curves for most fuels and renewable options or by exogenous technology change assumptions for thermal power plants. To model resource depletion of fossil fuels and uranium, several resource categories that are depleted in order of their costs are deined. Production costs thus rise as each subsequent category is exploited. For renewable energy options, the production costs depend on the ratio between actual production levels and the maximum production level. Climate change mitigation policies can be implemented in the TIMER model, allowing assessing changes in the energy composition due to these policies Van Vuuren et al., 2006; Van Vuuren et al., 2007. The TIMER model also simulates the potential impor- tance of biomass as an energy category. The structure of the biomass sub-model is similar to that of the fossil fuel supply models but with a few important differences see also Hoog- wijk et al., 2005. First, in the bioenergy model, depletion is not governed by cumulative production but by the degree to which available land is being used for commercial energy crops. Available land is deined as abandoned agricultural land and part of the natural grasslands in divergent land use variants for the twenty-irst century and is based on IMAGE alternative variant calculations. This assumption excludes any possible competition between bioenergy and food pro- duction, which is a simpliication of reality. The potential available land is categorized according to productivity levels 358 | IAASTD Global Report in each region driven by demands for food, including crops, feed, and grass for animal agriculture, timber and biofuels in addition to changes in climate Bouwman et al., 2005; Eickhout et al., 2007. The model distinguishes 14 natural and forest land cover types and six land cover types created by people. A crop module based on the FAO agroecologi- cal zones approach computes the spatially explicit yields of the different crop groups and grass and the areas used for their production, as determined by climate and soil quality Alcamo et al., 1998. In case expansion of agricultural land is required, a rule-based “suitability map” determines which grid cells are selected. Conditions that enhance the suitabil- that are assumed to relect the cost of producing primary biomass. The biomass model also describes the conversion of biomass such as residues, wood crops, maize and sugar cane to two generic secondary fuel types: biosolid fuels BSF and bioliquid fuels BLF. The solid fuel is used in the industry and power sector, and the liquid fuel in other sec- tors, in particular, transport. The output of TIMER is affecting the biophysical sys- tem of IMAGE through land use changes for bioenergy and emissions from the energy sector. Changes in food production are taken from IMPACT. The land cover model of IMAGE simulates the change in land use and land cover Table A.5.1 Overview of major uncertainties in IMPACT Source: Based on MA, 2005 Model Component Uncertainty Model structure • Based on partial equilibrium theory equilibrium between demand and supply of all commodities and production factors • Underlying sources of growth in areanumbers and productivity • Structure of supply and demand functions and underlying elasticities, complementary and substitution of factor inputs. • Water simulations and connection between Water and Food modules Parameters Input parameters: • Base year, 3-year centered moving averages for area, yield, production, numbers for 32 agricultural commodities and 115 countries and regions, and 281 Food Producing Units • Elasticities underlying the country and regional demand and supply functions • Commodity prices • Drivers Output parameters: • Annual levels of water supply and demand withdrawals and depletion, both agricultural and nonagricultural, food supply, demand, trade, international food prices, calorie availability, and share and number of malnourished children Driving Force Economic and demographic drivers: • Income growth GDP • Population growth Technological, management, and infrastructural drivers: • Productivity growth including management research, conventional plant breeding for rainfed and irrigated areas • Rainfed and irrigated area growth • Livestock feed ratios • Changes in nonagricultural water demand • Supply and demand elasticity systems Policy drivers: • Commodity price policy as defined by taxes and subsidies on commodities, drivers affecting child malnutrition, food demand preferences, water infrastructure, etc. Initial Condition Baseline: 3-year average centered on 2000 of all input parameters and assumptions for driving forces Model operation Optimization in Water Simulation Model using GAMS Looking Into the Future for Agriculture and AKST | 359 A.5.2.3 Application The IMAGE model has been applied to a variety of global studies. The speciic issues and questions addressed in these studies have inspired the introduction of new model fea- tures and capabilities, and in turn, the model enhancements and extensions have broadened the range of applications that IMAGE can address. Since the publication of IMAGE 2.1 Alcamo et al., 1998, subsequent versions and interme- diate releases have been used in most of the major global assessment studies and other international analyses, like the IPCC Special Report on Emissions Scenarios Nakicenovic et al., 2000, UNEP’s Third and Fourth Global Environment Outlook UNEP, 2002; 2007 , The Millennium Ecosystem Assessment MA, 2006, the Second Global Biodiversity Outlook SCBDMNP, 2007 and Global Nutrients from Watersheds Seitzinger et al., 2005. A.5.2.4 Uncertainty As a global Integrated Assessment model, the focus of IM- AGE is on large scale, mostly irst order drivers of global environmental change. This obviously introduces some im- portant limitations to its results, and in particular the in- terpretation of its accuracy and uncertainty. An important method for handling some of the uncertainties is by using a scenario approach. A large number of relationships and model drivers whose linkages and values are either current- ly not known or depend on human decisions are varied in these scenarios. To explore their uncertainties, see IMAGE Team, 2001. In 2001 a separate project was performed to evaluate the uncertainties in the energy model using both quantitative and qualitative techniques. With this analy- sis the model’s most important uncertainties were seen to be linked to its assumptions for technological improve- ment in the energy system, and how human activities are translated into a demand for energy including human life- styles, economic sector change and energy eficiency, seen in Table A.5.3. ity of a grid cell for agricultural expansion include potential crop yield which changes over time as a result of climate change and technology development, proximity to other agricultural areas and proximity to water bodies. The land cover model also includes a modiied version of the BIOME model Prentice et al., 1992 to compute changes in poten- tial vegetation. The potential vegetation is the equilibrium vegetation that should eventually develop under a given cli- mate. The shifts in vegetation zones, however, do not occur instantaneously. In IMAGE 2.4 such dynamic adaptation is modelled explicitly according to the algorithms developed by Van Minnen et al. 2000. This allows for assessing the consequences of climate change for natural vegetation Lee- mans and Eickhout, 2004.The land use system is modelled on a 0.5 by 0.5 degree grid. Both changes in energy consumption and land use pat- terns give rise to emissions that are used to calculate changes in the atmospheric concentration of greenhouse gases and some atmospheric pollutants such as nitrogen and sulphur oxides Strengers et al., 2004. Changes in the concentration of greenhouse gases, ozone precursors and species involved in aerosol formation form the basis for calculating climatic change Eickhout et al., 2004. Next, changes in climate are calculated as global mean changes which are downscaled to the 0.5 by 0.5 degree grids using patterns generated by a General Circulation Model GCM. Through this approach, different GCM patterns can be used to downscale the glo- bal-mean temperature change, allowing for the assessment of uncertainties in regional climate change Eickhout et al., 2004. An important aspect of IMAGE is that it accounts for crucial feedbacks within the system, such as among tem- perature, precipitation and atmospheric CO 2 on the selec- tion of crop types and the migration of ecosystems. This allows for calculating changes in crop and grass yields and as a consequence the location of different types of agricul- ture, changes in net primary productivity and migration of natural ecosystems Leemans et al., 2002. Table A.5.2 Level of confidence in different types of scenario calculations from IMPACT Source: Based on MA, 2005 Level of Agreement Assessment High Established but incomplete: • Projections of Rainfed Area, Yield • Projections of Irrigated Area, Yield • Projections of Livestock Numbers, Production • Number of Malnourished Children • Calorie availability • Climate variability Well established: • Changes in Consumption Patterns and Food Demand Low Speculative: Competing explanations: • Projections of Commodity Prices • Commodity Trade • Climate change Low High Amount of evidence theory, observations, model outputs 360 | IAASTD Global Report The carbon cycle model has also recently been used for a sensitivity analysis to assess uncertainties in carbon cycle modeling in general Leemans et al., 2002. Finally, a main uncertainty in IMAGE’s climate model has to do with 1 “climate sensitivity,” i.e., the response of global tem- perature computed by the model to changes in atmospheric greenhouse gas concentrations, and 2 regional patterns of changed temperature and precipitation. IMAGE 2.2 has actually been set up in such a way that these variables can be easily manipulated on the basis of more scientiically-de- tailed models. To summarize, most of IMAGE would need to go into the category of established but incomplete knowl- edge Table A.5.4. Table A.5.3 Overview of major uncertainties in IMAGE 2.4 Model component Uncertainty Model structure • TIMER Energy model: Integration in larger economy and dynamic formulation in energy model learning by doing • Land model: Rule-based algorithm for allocating land use • Environmental system: Scheme for allocating carbon pools in the carbon cycle model Parameters • Energy: Resource assumption and learning parameters • Land: Biome model parameter setting and CO 2 fertilization • Environment: Climate sensitivity, climate change patterns and multipliers in climate model Leemans et al., 2002 Driving force • Income growth GDP • Population growth • Assumptions on technology change in energy model • Environmental policies Initial condition • Emissions in base year 2000 • Historic energy use • Initial land useland cover map • Historical land use data from FAO • Climate observations in initial year Model operation • Downscaling method in climate change model Eickhout et al., 2004 Table A.5.4 Level of confidence in different types of scenario calculations from IMAGE Level of Agreement Assessment High Established but incomplete • Climate impacts on agriculture and biomes • Carbon cycle Well established • Energy modeling and scenarios Low Speculative • Grid-level changes in driving forces • Impacts of land degradation Competing explanations • Global climate change, including estimates of uncertainty • Local climate change • Land use change Low High Amount of evidence theory, observations, model outputs A.5.3 The Global Trade and Environment Model GTEM A.5.3.1 Introduction GTEM has been developed by the Australian Bureau of Ag- ricultural and Resource Economics ABARE speciically to address policy issues with global dimensions and issues where the interactions between sectors and between econo- mies are signiicant. These include issues such as interna- tional climate change policy, international trade and invest- ment liberalisation and trends in global energy markets.