Feeding the World and Protecting Biodiversity Table 431 Millennium Ecosystem Assessment scenarios Global orchestration Order from strength Adapting mosaic TechnoGarden Storyline summary Agricultural land in 2050 (million km2)a Loss of vascular plant diversity 1970–2050 (%)b Global economic liberalization with strong policies to reduce poverty and inequality, substantial investment in public goods, for example, education Economies become more regionalized, nations emphasize their individual security Regionalized economies, but with an emphasis on multiscale, cross-sectoral efforts to sustain ecosystem services Globalized economy with substantial investments in sound environmental technology, engineered ecosystems, and market-based solutions to environmental problems 55 13 60 16 54 12 54 12 a Pasture and cropland Extent of agricultural land in 1970 ¼ 46 million km2 and in 2000 ¼ 51 million km2 Relative loss when populations reach equilibrium at reduced habitat levels The table above summarizes possible agricultural land extent and vascular plant diversity in 2050 under four scenarios Note that moderate biodiversity losses at the global level can translate to dramatic losses at the regional level or for particular species groups b important (Leadley et al., 2010) Projections of the impacts of these drivers on biodiversity show continuing and, in many cases, accelerating species extinctions and loss of natural habitat, as well as significant changes in the distribution and abundance of species and biomes over the twenty-first century The greatest impacts involve large, highly visible modifications of ecosystems, including widespread conversion of tropical forest to pastures and croplands, climate-induced invasion of tundra by boreal forest, and reductions in the abundance of top predators in marine systems (Pereira et al., 2010) However, all is not doom and gloom Analysis across different scenario studies highlights that there exist plausible development pathways with low greenhouse gas emissions and low land conversion rates, which could lead to much lower biodiversity impacts These optimistic scenarios require fundamental changes in development paradigms, but are consistent with known constraints on economics, resource use, and human development goals (Pereira et al., 2010) However, if greenhouse gas emissions continue along current trajectories, several new models indicate that this will result in far greater climate-induced transformations of terrestrial biomes and marine biota than previously estimated Furthermore, lags in the underlying socio-economic, climate, and biogeochemical drivers make increased biodiversity impacts inevitable over the next several decades These lags mean that mitigation and adaptation measures aimed at reducing biodiversity impacts must be taken well before large impacts on biodiversity are observed Focusing Agriculture-Related Conservation Strategies Strategies that aim to both increase food production and protect biodiversity need to focus on reducing the main negative effects of agriculture on biodiversity summarized above (see Effects of Agriculture on Biodiversity) Foley et al (2011) advocate four strategies that would greatly increase food production while improving the environment First, stopping agricultural expansion will reduce the rate of biodiversity loss as well as reduce greenhouse gas emissions Second, improving yields on existing croplands increases food production and reduces the need for expansion Third, water availability and quality can be improved by increasing the resource efficiency of agricultural production Many gains in efficiency can be made through existing practices, such as changing fertilization rates and timing, irrigation methods, and livestock feed (reducing methane gas) Genetic improvements are a longer term solution that may generate more nutrient and water-efficient crop varieties Finally, shifting our diets to be more plant based would reduce the need for agricultural expansion because a greater portion of the crops grown would be directly consumed by people, bypassing the inefficiencies of growing feed to produce livestock Meeting Agriculture and Conservation Goals: Mechanisms for Change Implementing these four strategies will require a mix of policy and market-based incentives at multiple levels The agricultural and conservation communities have made substantial progress increasing crop yields and protected areas, respectively Regarding crop yields, agricultural investments in regions with low yields and inefficient use of water, fertilizers, and pesticides offer major opportunities for simultaneously enhancing food production Underinvestment in agriculture, particularly in Africa, Latin America, and Eastern Europe, have led to significant yield gaps when compared with similar growing regions elsewhere around the world (Licker et al., 2010; Neumann et al., 2010) By one estimate, worldwide crop production could be increased by 60% if the yield gaps were closed for 17 major crops, thereby alleviating the demand to put new areas into cultivation (Johnston et al., 2009) Investments in increased production must also enhance resource efficiency and farm management, including improvements in irrigation management, water harvesting and conservation, and integrated pest management (IAASTD, 2009; ten Brink et al., 2010)