1

The Future of the BiosphereWhere are we heading?

Wolfgang Lucht Potsdam Institute for Climate Impact Research

Earth is (we think) a special place.

It has a Biosphere.

Earth‘s chemical state (e.g. as seen from far away in space) is definitely not that of a dead planet

Source: Lenton, 1998

But do we understand what this thing„Biosphere“ really is (as a planetary phenomenon)?

Things we don‘t really understand:• Does life occur easily on planets?

(it happened early on Earth, but not again since)• Why do all organisms have to die?

(and pretty quickly, too)• Why is there (bio)diversity of life?

(and not green super-slime)• Was life just lucky to persist?

(it was pretty close a few times)

What about us and our global change?• Are humans part or spoilers of it?

(we‘re changing a lot for being just another animal)

2

We think we understand why evolution happened

But not whether reflective intelligence necessarily emerges from evolution or not.

Is reflective intelligence a next step in evolution, an emergent Earth system property or not?

What does that mean for how to view Global Change from a planetary evolutionary perspective?

(because of natural selection on a hereditary genetic code carried by individuals that undergo mutations and adaptations)

ClimateChange

Land UseChange

The biosphere is (at least) under double pressure:

Alley et al., Science, 2003

Arctic Ecosystem LossMontane Ecosystem Loss

(competition loss, ice/snow loss)

Boreal Forest Die-Back(heat stress, grassland increase)

Tree-Line Shift Greenup(T ▲, soil moisure ▲, fire ▼)

Tropical Forest Die-Back(precip ▼, drought stress)

Semi-Arid Land Aridification(precip ▼, drought stress)

Semi-Arid Land Greening(CO2 ▲, water use efficiency ▲, precip ▲)

Woody Encroachment(CO2 ▲, water use efficiency ▲)

Surface Ocean Ecosystem Degradation (acidification ▲, stratification ▲)

Deep Ocean Extinctions(heat stress)

Coastal Zone Die-Backs (anoxia ▲, acidification ▲, coral bleaching)

Luch

t, P

rent

ice

& Ti

ppin

g P

oint

Wor

ksho

p B

iosp

here

Gro

up, 2

005

Draft only!

3

Haberl et al., to be subm.

Natural (GtC/yr)ActualHuman alterationHuman harvestHuman firesTotal

Backflows

65.559.26.37.21.1

14.7

1.5

100%90%10%11%

2%22%

2%

CropsGrazingForestUrban/Infrast.

56%24%11%

9%

= 270 EJ/yr (caloric)(incl. 35-55 EJ/yr biofuels)Biofuel Projections: 200-300 EJ/yr = 4-7 GtC/yr

Human Appropriation of Net Primary Production

Unpublished: do not quote,

reproduce or circulate

Year: 2000

Cardillo et al., PNAS, 2006

Extinction Risk in Terrestrial Mammals

Current

Predicted

Latent (i.e. if human pressure occurred)

How can far-reaching human change of the biospherebe understood?

Are humans just another agent of change of the biosphere?

Or are we at the beginning of

something bigger?

4

The „Garden of Ediacara“

no life on landno predators

few species

mysterious semi-soft, quilted body plans

but: first-ever multicellular organisms

Last period of the Proteozoic: 630 – 542 mio years before presentIs there life on this planet?

Is there life on this planet?

Atacama Desert, Chile Husband Hill, Mars

Jan 2006

Is there life on this planet? Is there life on this planet?

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It‘s not much better on Venus …

Earth and its Biosphere: A Statistical Sample of Size 1

Can we learn anything from it about biospheres in general?

Did life originate on Earth?It started soon after Earth‘s formation.But as far as we know, not again since. There are no documents of the event! The mechanisms are still unclear.

Stromatolite, Australia, 3.5 bn yr

Life originated early in Earth history

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For 3.5 bn years, Earth has remained habitable • it was close a few times (snowball Earth, meteorite impacts)?• an intriguining question: why no runaway effects?• self-regulation as an emerging systems phenomenon (Gaia)?• or simply observer bias self-selection?

So what happened on Mars?Could the same happen with Earth?

Could we be the cause of it?

CambrianExplosion

Life evolves to increa-singly higher complexity

• naturalselection

• majortransitions

7

i

t

itetP i

αα ≅−=

−1)(

0.000.100.200.300.400.500.600.70

00.

5 11.

5 2

2.5 3

3.5 4

4.5 5

5.5 6

Time (Billion Years)

Prob

abili

tyPi(t; t0=5)P(t; n=3)P(t; n=5)P(t; n=10)

)(tPi Probability of i-thtransition

Probability for a difficult („major“) transition at time t :

∏=

=n

i in

ttP1

)(α

Simplifying assumption: statistical independence of major transitions (an optimisticassumption!); then n (improbable) major transitions occur with probability:

αi ≈ t0 (life span of the biosphere; appearance of humans before t0)

n

n tttP ⎟⎟⎠

⎞⎜⎜⎝

⎛=

0

)(

iα 1/e time scaling for transition i;improbable: large.iα

!)();(

ktekNP

kt

tλλ

λ−

==Poisson statistics (for rates λ) – Statistics for rare events and long periods:Probability of no event:So: Probability for at least 1 event:

tt etNP λλ −== );0(

tt etNP λλ −−=> 1);0(

after Carter, 1973

0

1

2

3

4

5

6

1 3 5 7 9 20 40 60 80 100

Number of major transitions

Tim

e (B

illio

n Ye

ars)

Time to transition Time left (t0=5 Bn Yrs)

nn

n tPtPttttP /1

00

)()()( =⇒⎟⎟⎠

⎞⎜⎜⎝

⎛= ∫ ∫ ===

0 0

0 0

/10)(

t tndPPtdPPtt

1001

11/11

0

1/1

00

1/1

0

0

00

0

1/10

0

+=

⎥⎥⎦

⎤

⎢⎢⎣

⎡⎟⎟⎠

⎞⎜⎜⎝

⎛==−⎟⎟

⎠

⎞⎜⎜⎝

⎛==

+=⎥⎦

⎤⎢⎣⎡

+=

+++

nnt

ttt

tt

tt

nntP

nt

nntn

10

0 +=−

nttt

Time left for the futureevolution of the biosphere:

Expectance value for the time of the n-th major transition:

!!1011,100!!505,100

!!44,5..

00

00

0

ByrtByrttnorMyrttByrtnor

nByrtByrtge

=⇒=−==−⇒===⇒==

today

remaining time

after Carter, 1973

Lenton et al., Nature, 2004

8 Major Transitions of Evolution

(1) Replicating Molecules Molecule Populations in Protocells

(2) Independent Replicators Chromosomes

(3) RNA as Gen and Enyzm DNA as Gen, Proteins as Enzymes

(4) Bacterial Cells (Prokaryotes) Cells with Cell Nuclei and Organelles (Eukaryotes)

(5) Asexual Clones Sexual Populations

(6) Single-Celled Organisms Animals, Plants, Fungi

(7) Solitary Individuals Colonies with unreproductiveCasts (Bees)

(8) Primate Societies Human Societies (Languages)

Smith and Szathmary, 1995

Climbing the Coevolution Ladder Life evolves intelligencebut the effects really only exploded in the Holocene – or even in the last 1000 years?

(1) Emergence of homo sapiens with large brain.(2) Discovery of the use of fire (250 kaBP)

forest clearing, fire-aided hunting, expansion into cold climates, cooking of food(3) Emergence of language (100 kaBP ???)

collective action, planing, teaching, travel, societies(4) Emergence of agriculture (11 kaBP)

villages and cities, deforestation, storage, specialisation of workforce, hierarchies(5) Emergence of civilisations (4 kaBP)

states, warfare, trade, bureacracy, political inequalities, mechanical devices, script(6) European voyages of discovery (1 kaBP)

globalisation, exchange of species, exploitation of resources, navigation(7) Science and technology (0.3 kaBP)

disease control, population growth, internet, resource exploitation

Intelligence starts changing the whole planet(or is it just some of us?)

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FuturePast

… from Coevolution to AutoevolutionGenetic to Nongenetic Information Transmission, Synaptic to Electronic Information Processing

C. Darkin / Alamy / Nature 2005

Anthropogenic changes due to gene manipulationwill probably have a longer-lasting effect inthe biosphere!

Maschines & Cyborgs: The next stage of evolution?Autoevolution of the Biosphere?Darwin: Culture is Autoevolution

We can• adapt to nature (green movement)• adapt nature to us (global change, terraforming)• detach from nature (dematerialisation)

too coldtoo dry

too hottoo dry

Schellnhuber, Nature, 1999

dN/dt = f(N) dN/dt = f(N,A) dN/dt=f(N,A,S) „Global Subject(s)“

Can we understand this system?Can we understand the consequences of human actions?

Can we consciously steer this system?

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1.Digital Mimicry PrincipleEarth System Modelling of Intermediate Complexity

How can Earth be understood as a system?

2. Bird‘s Eye PrincipleRemote Sensing, Makroscopes

3. Lilliput PrincipleEnvironmental Experiments

Schellnhuber, 1999

Earth SystemModelling

Seconds Minutes Hours Years Decades Centuries

Molecules

Cells

Leaves

Plants

Ecosystems

Biosphereglobal biogeochemistry

evolution

disturbance and sucsessionstorms, fire

photosynthesis

plant metabolism

water- andnutrient budget

Interaction of Scales in Biogeochemistry

carbon allocationand growth

competition for ressourcesand ecological strategies

geographical distribution ofvegetation types

plant seasonality

Tran

sfor

med

by

proc

ess

mod

ules

into

Climate, Soil, CO2

C budget, H20 Budget,Vegetation Composition

10 plant functional types

competition, mortality, establishment

fire, permafrost

photosynthesis: coupled C and H2O cycles

C allocation (funct. and struct. relations)

Carbon pools: 4 in vegetation, 4 in litter/soil

Full hydrologyAET

Ci

AET

Ci

crown area

height

fine roots

leaves

LAI

sapwoodheartwood

0-50 cm50-150 cm

stemdiameter

Spa

ce &

Ti

me

Loop

s

Dynamic Global Vegetation Model LPJ-DGVM (Sitch et al., 2003) LPJLPJ A Dynamic Global Vegetation Model

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RunoffGerten et al., J. Hydrol., 2004

Fire FrequencyThonicke et al., GCB, 2001

Distribution ofVegetation TypesSitch et al., GCB, 2003

Soil Carbon ChangeSitch et al., GCB, 2003

Soil Carbon

Biomass

Net PrimaryProduction

LPJ

Sim

ulat

ion

Res

ults

Schaphoff et al., Clim. Change, in press

LPJ Temperature Change 2100 vs. 2000

1900 2000 2100

1900 2000 2100

CO2 concentration

IS92a-Scenario (1% GHG Increase)

IS92a-Scenario (1% GHG Increase)

Schaphoff et al., Clim. Change, in press

LPJ Precipitation Change 2100 vs. 2000

1900 2000 2100

1900 2000 2100

CO2 concentration

1900 2000 2100

1900 2000 2100

CO2 concentration

Schaphoff et al., Clim. Change, in press

LPJ Total Land Carbon Change 2100 vs. 2000

IS92a-Scenario (1% GHG Increase)

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Schaphoff et al., Clim. Change, 2006

Carbon Balance Vegetation+Soils

Water Stresson Vegetation(NPP Limitation)

Gerten et al., GRL, 2005

Example:ECHAM/IS92a

Carbon and Water Balance Future ProjectionsLPJ

about neutral sink source

Source:Schaphoff et al., Climatic Change, 2006

Large differences in regional precip patterns between different GCMs

0%

20%

40%

60%

80%

100%

1900 1940 1980 2020 2060 2100years

Temperategrass

Tropical grass

Temperate trees

Tropicalseasonaltrees

today

Barren

IS92a, Echam4+LPJ

Vegetation Shift under Climate Change in a Southern African Temperate Mountain Highland

Deciduous Forests

Evergreen Forests

Grasses/Herbaceous Vegetation

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Global Agriculture Modelling

LPJ

LPJ

irrigation

multiplecropping

grazing

computed sowing & harvesting dates

harvesting,residues

fully mechanistic “crop functional types”

Climate andCO2 change

mosaics of natural and agricultural lands

fractional landuse shares

mechanistic vegetationand soil processes

Land use change

mLPJ

Compare:Fossil CO2 Emissions: ca. 290 GtC

Compare: Fossil CO2 Emissions: ca. 7 GtC/yr

Bondeau et al., GCB, in press

LPJ/mL Global Agriculture & Carbon Cycle

studies of supply

studies of demand

Berndes et al., 2003

model calculations

MacroscopicObservation

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NASA/TerraKey tounderstanding:GlobalObservation

„Socializing the pixel, pixelizing the social.“

F/ Mwages Child

weight CMR

Lifeexpectancy

Sanitation

Safewater Access to

health Immunization

Contracep Persistence

Illiteracy

Crowding

Crime

PopGrowth Urban%

Chad

Soc

F/ Mwages Child

weight CMR

Lifeexpectancy

Sanitation

Safewater Access to

health Immunization

Contracep Persistence

Illiteracy

Crowding

Crime

PopGrowth Urban%

Botswana

Soc

Social issues

Soci

al In

dica

tor

(UN

CSD

Inde

x)

Observations of Sustainability: What data are needed?

Entfernung / Nähe? Phantasies about Nature Which phantasies play a role in our constructions of what „post-Nature“ is to be?

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Coevolution

Language

Material Flows

Biogeochemical Evolution of Life

Evolution of Planning& Biogeochemical

Shaping Ability

Evolution of EarthSystem ProcessUnderstandingand Intentional Biogeochemical

Control

BiologicalWorld

Formation ofFunctionalDiversity

MismanagementCollaps

EliminationOf Humans

MentalWorld

RegionalMetabolic

Feedback Cycles(GeoGraphy)

EconomicStructuring

of Matter Flows(GeoAction)

Social Perceptionsand Reflections

(GeoMind)

Interlinkages ofSocietal Instruments

(GeoScope)

ExtremePoverty

VirtualRealities

PositivisticTrap

Collaps

Atmospheric& Soil Chemical

Composition

Astronomical Formation/Perturbation & Geologic Chemical Transformation

GlobalBiomass

PhysicalWorld

Fatal Perturbations

RunawayEffects

Extinction

Oceanic HeatBalance

Three Worldsin the Earth System

Lucht and Pachauri, 2004

Despite all we do know (and that is: that a lot of change is coming), I don‘t think we know very well yet …… as we still don‘t understand the Earth system includingus humans all that well.

The Future of the BiosphereWhere is our journey headed?

1336Francesco Petrarca

1802Alexander von Humboldt

1962Robert Buckminster Fuller

What does it mean to observe the world? Three stories.