Transcript Document

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
MODELS
SCENARIOS
STORIES
Nakićenović et al. 2000
Conceptual Framework
DIRECTHuman
DRIVERS
Behavior
Human
Well-being
INDIRECT
DRIVERS
CHANGES IN:
Indirect
Drivers
*
••POPULATION
LAND USE GROWTH
••DEGREE
CLIMATEOF GLOBALIZATION
••SOCIO-ECONOMIC
DEVELOPMENT
ATMOSPHERIC COMPOSITON
Ecosystem
••TECHNOLOGICAL
PROGRESS Direct
NITROGEN DEPOSITION
Functioning
• BIOTIC EXCHANGE
Biodiversity
*
Drivers
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 watershedscale 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
Fair Global
ADAPTIVE MOSAIC
Local/Regional
Global Orchestration
focus on macro-scale policy reform together with a
socially conscious globalization, reactive approach to
env. management
Potential Benefits
Potential Risks
Decreasing economic
inequality
Ecological crises
accelerate inequality
Economic prosperity
Reactive mgmt proves to
be more costly
Order from Strength
retreat from global institutions results in a fragmented
world, focus on national security and protectionism,
reactive approach to env. mgmt
Potential Benefits
Potential Risks
•Increased security
•High inequality/social
tension
•Less expansion of
invasive species
•Islands of quality
ecosystems
•Security breaches
•Global environmental
degradation
•Lower economic growth
•Malnutrition
Adapting Mosaic
retreat from global institutions, focus on
strengthened local institutions and local learning,
proactive approach to env. mgmt
Potential Benefits
Potential Risks
•High coping capacity
with local changes
•Neglect of global
commons
•Win-win management
of ecosystem services
•Inattention to inequality
•Less economic growth
than the max possible
TechnoGarden
emphasis on development of technologies to substitute
for ecosystem services, globalized world, proactive
approach to manage ES via technology
Potential Benefits
Potential Risks
•Highly effective
utilization of ecosystem
services
•Technological failures
have far-reaching effects
with big impacts
•Enhancing ecosystem
services
•Wilderness eliminated
•Increasing gap between
people and nature
•Less economic growth
than the max possible
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
Greenhouse Gas
Emission in
1995
Global
Orchestration
Order of
Strength
Adapting
Mosaic
Techno-Garden
(emissions in GtCequivalenta)
CO2
7.3
20.1
15.4
13.3
4.7
CH4
1.8
3.7
3.3
3.2
1.6
N2O
0.7
1.1
1.1
0.9
0.6
Other GHG
0.0
0.7
0.5
0.6
0.2
34
29
22
(percent)
OECD and former
Soviet Union as
share of total
emissions
a
48
30
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
Sea Level Rise in MA
Scenarios
Cereal Production by World Region in MA
Scenarios in 2050
Development of MA Biodiversity
Scenarios
Direct Drivers
Land-Use
Change
Biodiversity
Scenarios
Climate
Change
Species Area Relationship (SAR)
No. of species
3000
2500
S = C * Az
2000
1500
1000
UNKNOWNS
500
0
0
200
400
600
Area (km2)
800
• D A = changes in area
• C = Original species
density
• Z = slope of the speciesarea curve
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 change
MA Scenarios
Global Orchestration
Order from Strength
Technogarden
Adaptive Mosaic
Sala et al., 2005, Millennium Assessment
Total
0.75
0.5
0.25
Tundra
1
0.75
0.5
0.25
0
0.75
0.5
0.25
0
Climate Change
Habitat Loss
Tropical Forest
Climate Change
Habitat Loss
0.25
0
1
Biodiversity impact
Biodiversity impact
1
0.5
0.75
0.5
0.25
0
Habitat Loss
Climate Change
Warm Mixed
Temperate Forest
1
0.75
Boreal Forest
1
0
Habitat Loss
Biodiversity impact
Biodiversity impact
1
Biodiversity impact
Biodiversity impact
Comparison of major drivers on biodiversity loss
0.75
0.5
0.25
0
Climate Change
Habitat Loss
OS
GO
Climate Change
TG
Habitat Loss
Climate Change
AM
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 20002050-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 20002050 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