Governing Complexity in the Anthropocene
Prof Will Steffen
Executive Director The ANU Climate Change Institute The Australian National University
More is Different, NTU Singapore, 26-29 February 2012
Outline of Talk
1. The Anthropocene
2. The Governance Challenge
The Anthropocene
Human Development and Earth System Dynamics
Evolution of fully modern humans in Africa
Hunter-gatherer societies only
Beginning of
agriculture
Adapted from Steffen et al. 2004; ice core data from Petit et al. 1999
Aborigines arrive in Australia
Beginning of agriculture
Great European civilisations: Greek, Roman
Human Development and Earth System Dynamics
Source: GRIP ice core data (Greenland) And S. Oppenheimer, ”Out of Eden”, 2004
First migration of fully modern humans
out of Africa
Migrations of fully modern humans
from South Asia to Europe
Fires, Floods and Cyclones: A window into the future under a changing climate?
Northern hemisphere surface temperature
Mann et al. 2003 (EOS)
Post-industrial temperature rise
Climate change: Beyond the envelope of natural variability
Human Imprint on Marine Ecosystems
Fisheries collapse – The Atlantic cod stocks off the east
coast of Newfoundland collapsed in 1992, forcing the closure of the fishery
– Depleted stocks may not recover even if harvesting is significantly reduced or eliminated entirely
– About 50% of all fish stocks are fully exploited, 15-18% are overexploited, and 9-10% have been depleted or are recovering from depletion
Millennium Ecosystem Assessment 2005, Steffen et al. 2004
Human Imprint on the Terrestrial Biosphere
From landscapes to genes…
Global Change and the Anthropocene
From Steffen et al. 2004
The Anthropocene
The changing human enterprise, from 1750
to 2000
The period from 1950 to 2000 is often called
The Great Acceleration
National Geographic, March 2011
I = P x A x T
• Equity issues profoundly complicate the challenge of global change. • In the Great Acceleration technology and especially consumption have overtaken population as a driver of change.
From: Steffen et al. 2004
The Anthropocene
The human imprint on the global environment,
from 1750 to 2000
The Complexity Challenge
•Dealing with uncertainties. The Earth is a complex system, and is not entirely “deterministic”. Intrinsic uncertainties will remain, even with “perfect” models. • Capacity to assimilate new information. Science is continually producing more knowledge about global change, especially about the risks to societies and natural ecosystems. • Early warning systems. Dealing with thresholds & abrupt change; tipping elements. Transitions of the Earth System as a whole.
Source: Young and Steffen 2009
Uncertainties: water resources
Strong evidence of a climate change signal
Source: Steffen 2009
Possible climate change signal, but evidence is not yet conclusive
We don’t know; no convincing evidence yet for climate change signal
Observed changes in rainfall (1970-2005) and possible causes
From Rahmstorf and Alley 2002
Abrupt change
(D-O events)
during the last
glacial period
Biodiversity in the 21st century
– Humans have increased the species extinction rate by as much as 1,000 times over background rates typical over the planet’s history (medium certainty)
– 10–30% of mammal, bird, and amphibian species are currently threatened with extinction (medium to high certainty)
Source: Millennium Ecosystem Assessment 2005
The Importance of Biodiversity
Source: Millennium Ecosystem Assessment 2005
Scenarios: MA 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.
Millennium Ecosystem Assessment 2005
Scenarios: MA 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.
Millennium Ecosystem Assessment 2005
(Smith et al. 2009 PNAS)
Assimilating new knowledge
EU 2°C-Guardrail
Source: H.J. Schellnhuber
Change in mass of Greenland ice sheet
Dahl-Jensen and Steffen 2011
Seeing into the ice
Early Warning System: Tipping Elements in the Earth System
Source: Schellnhuber, after Lenton et al, PNAS, 2008
Vulnerable tipping elements in the climate system
Tipping Element
Warming level
Transition Timescale
Impact
Greenland ice sheet
+1-2 oC >300 yr (slow) Sea level: +2-7 m
W. Antarctic ice sheet
+3-5 oC
>300 yr (slow) Sea level: +5 m
Indian summer monsoon
N/A
ca 1 yr (fast) Drought;
starvationD
Amazon rainforest
+3-4 oC
ca 50 yr (gradual)
Extinctions;
decrease in rainfall
Atlantic THC (Gulf stream)
+3-5 oC
ca 100 yr (gradual)
Regional cooling; ITCZ shift
Lenton et al. 2008
The critical decade
Meinshausen et al. 2009
An Anthropocene Context
Tipping Elements in the Earth System
Source: Schellnhuber, after Lenton et al, PNAS, 2008
ENSO Triggering
Indian Monsoon
Transformation
Bodele Dust Supply Change?
Bistability of Saharan Vegetation
Bistability / Collapse of Amazonian
Forest?
Reduced Performance
of Marine Carbon Pump
Tibetan Albedo Change?
Interactions & Complex
Connections
Atlantic Deep Water Formation
Southern Ocean Upwelling / Circumpolar Deep Water Formation
Instability of West Antarctic Ice Sheet?
Instability of Methane Clathrates
Instability of Greenland Ice Sheet?
ENSO Triggering Bodele Dust
Supply Change?
Bistability of Saharan Vegetation
Bistability / Collapse of Amazonian
Forest?
Reduced Performance
of Marine Carbon Pump
Tibetan Albedo Change?
Indian Monsoon
Transformation
Interactions & Complex
Connections
Temperature Change through Earth History
Zalasiewicz and Williams 2009
Petit et al. 1999
Variation of CO2, T, CH4 in the late Quaternary
The Earth as a complex system
Scheffer 2009
Petit et al. 1999; Keeling and Whorf 2000
Atmospheric CO2: outside the Holocene envelope
2
4
3
5
6
1
0
Glo
bal T
em
pera
ture
(°C
)
IPCC Projections 2100 AD
N.H
. Tem
pera
ture
(°
C)
0
0.5
1
-0.5
1000 1200 1400 1600 1800 2000
Now
“Committed” Climate Change
Earth System moves to a new state; modern civilisation collapses?
IGBP PAGES
The Earth as a complex system
Scheffer 2009
Anthropocene
Holocene Pre-Anthropocene events
Anthropocene as a new, long-term epoch in Earth history
Great Acceleration
Planetary Boundaries
Planetary Boundaries: Exploring the safe operating space for humanity in the Anthropocene
(Nature, 461 : 472 – 475, Sept 24 - 2009)
Johan Rockström, Will Steffen, Kevin Noone, Åsa Persson, F.
Stuart Chapin, Eric F. Lambin, Timothy M. Lenton, Marten
Scheffer, Carl Folke, Hans Joachim Schellnhuber, Björn Nykvist,
Cynthia A. de Wit, Terry Hughes, Sander van der Leeuw,
Henning Rodhe, Sverker Sörlin, Peter K. Snyder, Robert
Costanza, Uno Svedin, Malin Falkenmark, Louise Karlberg, Robert
W. Corell, Victoria J. Fabry, James Hansen, Brian Walker, Diana
Liverman, Katherine Richardson, Paul Crutzen, Jonathan A. Foley
Climate Change
Ocean acidification
Ozone depletion
Global Freshwater Use
Rate of Biodiversity
Loss
Biogeochemical loading: Global
N & P Cycles
Atmospheric Aerosol Loading
Land System Change
Chemical Pollution
Planetary Boundaries
E.S. Process Control Variable Boundary State of Knowledge Climate change CO2 conc 350 ppm Good, but debate on energy change +1 W m2 boundary position Ocean acidif. arag. sat ratio 20% reduction Process understood Stratospheric O3 conc, DU 5% reduction Boundary agreed O3 loss from pre-indust and respected Atmos aerosols part. conc. TBD Thresholds unknown P & N cycles N: amt fixed 35 Tg N/yr Boundaries are P: inflow to ocean 10 x pre-indust educated guesses Freshwater use Blue water use 4000 km3/yr Global aggregate Land system Fraction of land 15% ice-free Regional distribution change cultivated land surface is critical Biodiversity Extinction rate
Defining the safe operating space
Rockström et al. 2009