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Escenarios Globales de Biodiversidad. Osvaldo E. Sala Brown University. Scenarios. Scenarios are plausible, challenging, and relevant stories about how the future may unfold that can be told both in words and numbers Scenarios are not forecasts, projections or predictions
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Escenarios Globales de Biodiversidad Osvaldo E. Sala Brown University
Scenarios • Scenarios are plausible, challenging, and relevant stories about how the future may unfold that can be told both in words and numbers • Scenarios are not forecasts, projections or predictions • Scenarios illuminate costs and benefits of different paths • Scenarios should provide guidance for action
QUANTITATIVE QUALITATIVE MODELS SCENARIOS STORIES Nakićenović et al. 2000
Conceptual Framework • DIRECT DRIVERS • CHANGES IN: • LAND USE • CLIMATE • ATMOSPHERIC COMPOSITON • NITROGEN DEPOSITION • BIOTIC EXCHANGE • INDIRECT DRIVERS • POPULATION GROWTH • DEGREE OF GLOBALIZATION • SOCIO-ECONOMIC DEVELOPMENT • TECHNOLOGICAL PROGRESS Human Behavior Human Well-being Indirect Drivers * Ecosystem Functioning Direct Drivers * Biodiversity
Scenario Storylines • Global Orchestration Globally connected society that focuses on global trade and economic liberalization and takes a reactive approach to ecosystem problems but that also takes strong steps to reduce poverty and inequality and to invest in public goods such as infrastructure and education. • Order from Strength Regionalized and fragmented world, concerned with security and protection, emphasizing primarily regional markets, paying little attention to public goods, and taking a reactive approach to ecosystem problems.
Scenario Storylines • Adapting Mosaic Regional watershed-scale ecosystems are the focus of political and economic activity. Local institutions are strengthened and local ecosystem management strategies are common; societies develop a strongly proactive approach to the management of ecosystems. • TechnoGarden Globally connected world relying strongly on environmentally sound technology, using highly managed, often engineered, ecosystems to deliver ecosystem services, and taking a proactive approach to the management of ecosystems in an effort to avoid problems.
TECHNOGARDEN Technological GLOBAL ORCHESTRATION ADAPTIVE MOSAIC Local/Regional Fair Global
Global Orchestration focus on macro-scale policy reform together with a socially conscious globalization, reactive approach to env. management
Order from Strength retreat from global institutions results in a fragmented world, focus on national security and protectionism, reactive approach to env. mgmt
Adapting Mosaic retreat from global institutions, focus on strengthened local institutions and local learning, proactive approach to env. mgmt
TechnoGarden emphasis on development of technologies to substitute for ecosystem services, globalized world, proactive approach to manage ES via technology
Changes in indirect drivers In MA Scenarios: • Population projected to grow to 8–10 billion in 2050 • Per capita income projected to increase two- to fourfold
Changes in direct drivers Changes in crop land and forest area under MA Scenarios Crop Land Forest Area
Kyoto Greenhouse Gas Emissions in 1995 and Assumptions in MA a GtC-equivalent emissions are the contribution of different greenhouse gases in tons of carbon based on 100-year global warming potentials.
Change in Global Average Surface Temperature in MA Scenarios 1970-2100
Biodiversity Scenarios Development of MA Biodiversity Scenarios Direct Drivers Land-Use Change Climate Change
Species Area Relationship (SAR) 3000 2500 S = C * Az 2000 No. of species 1500 1000 • UNKNOWNS • D A = changes in area • C = Original species density • Z = slope of the species-area curve 500 0 0 200 400 600 800 Area (km2)
Changes in direct drivers Changes in crop land and forest area under MA Scenarios Crop Land Forest Area
Land cover change in IMAGE scenarios 1970 2050 : Global Orchestration 2050: Order from Strength
Species numbers of vascular plants 18 regions 14 biomes Estimate species density for each combination of IMAGE region and each biome type Matrix Source: Barthlott et al., University of Bonn
Species-area relationships of vascular plants Sala et al., 2005
Losses of Habitat in 2050 Relative to Habitat Availability in 1970 for the MA Scenarios
Relative Losses of Global Vascular Plant Biodiversity when Populations Reach Equilibrium with Reduced Habitat for MA Scenarios
Losses of Habitat in 2050 Relative to 1970 for Different Biomes and Realms for Two Scenarios
Losses of Habitat in 2050 Relative to 1970 for Different Biomes and Realms for Two Scenarios
Climate change Future VEGETATION CURRENT VEGETATION Future VEGETATION Sala et al., 2005, Millennium Assessment
Effects of climate changeMA Scenarios Sala et al., 2005, Millennium Assessment
Boreal Forest 1 0.75 Biodiversity impact 0.5 0.25 0 Habitat Loss Climate Change Warm Mixed 1 0.75 0.5 Biodiversity impact 0.25 0 Habitat Loss Climate Change GO TG AM OS Comparison of major drivers on biodiversity loss Total Tundra 1 1 0.75 0.75 Biodiversity impact 0.5 Biodiversity impact 0.5 0.25 0.25 0 0 Habitat Loss Climate Change Habitat Loss Climate Change Tropical Forest Temperate Forest 1 1 0.75 0.75 Biodiversity impact Biodiversity impact 0.5 0.5 0.25 0.25 0 0 Habitat Loss Climate Change Habitat Loss Climate Change Sala et al., in press, Millennium Assessment
Convention on Biological Diversity Target • Significantly reduce the rate of loss of biodiversity by 2010
Potential Species Loss for MA Scenarios Compared with Historic Rates Sala et al., 2005, Millennium Assessment
Millennium Development Goals • Eradicate extreme poverty and hunger • Achieve universal primary education • Promote gender equality & empower women • Reduce child mortality • Improve maternal health • Combat HIV/AIDS, malaria • Ensure environmental sustainability • Develop a global partnership for development
Conclusions • Diversity of vascular plants sharply declined in all four MA scenarios during the 2000-2050-time period • At the global level and across all scenarios, land-use change was the dominant driver of biodiversity change • The different biomes and regions of the Earth lost species at different rates during the 2000-2050 period
Conclusions • Order from Strength was the scenario that experienced the largest losses of vascular-plant species whereas Technogarden and Adapting Mosaic were the scenarios with the smallest losses. • Biodiversity Millennium Development Goals (MDG) • not met by Order from Strength and Global Orchestration • barely met by Technogarden and Adaptive Mosaic • Scenarios could be a powerful tool to assist policy makers and communicate to the general public
...the short version of the MA results Washington Post, 30 March 2005
Changes in ecosystem services under MA Scenarios • Demand for food crops is projected to grow by 70–85% by 2050, and water withdrawals by 30-85% • Food security is not achieved by 2050, and child undernutrition would be difficult to eradicate (and is projected to increase in some regions in some MA scenarios) • Globally, the equilibrium number of plant species is projected to be reduced by roughly 10–15% as the result of habitat loss over the period of 1970 to 2050 (low certainty) Child undernourishment in 2050 under MA Scenarios
Changes in ecosystem services under MA Scenarios Water Availability • Global water availability increases under all MA scenarios. By 2050, global water availability increases by 5–7% (depending on the scenario) • Demand for water is projected to grow by between 30% and 85% Water Withdrawals in 2050 under MA Scenarios