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