What can Ecologists tell us about Sustainability?

Charles J. Krebs

Institute for Applied Ecology

University of Canberra

3

A Little History and Philosophy

“the present increasing disruption of the global environment is the product of a dynamic technology and science which originated in the Western medieval world” (p.1207)

White (1967) contrasted two views of man and nature:

- a Christian and post-Christian view that humans should dominate nature

- an ecological world view of the equality of all creatures which he attributed to St. Francis

White, L., Jr. 1967. The historical roots of our ecologic crisis. Science 155: 1203-1207.

Outline of Talk

Ecology to what purpose? What is sustainability? A triumvirate of problems:

AgricultureBiodiversityPopulation

The Politics of Ignorance Summary

Ecologicalunderstanding

Managem entrecom m endations

Policyim plem entation

ThePoliticsof Ignorance

Basic Principle # 1

The earth has physical, chemical,

and biological limitations

- it is the only planet we have

A Few Core Points

Scientists do not make policy- provide evidence about issues

Scientists expect rational decisions- evidence-based policies by

governments Scientists must point out when business

or government policies violate scientific knowledge

- a moral obligation

What is Sustainability ?

Brundtland Commission (1987)- sustainable development

Now a ‘buzz’ word that is nearly meaningless

The ecological meaning: to meet our present needs without compromising the needs of future generations

The essential element is intergenerational equity

Basic Ideas for Sustainability

The Precautionary Principle - look before you leap

Protect your capital- biodiversity

Hedge your investments- risk management

Buy insurance- parks and reserves

Are Current World Practices Sustainable ?

Three key areas - Agriculture- Biodiversity- Population

Two steps for ecologists:- evaluate the current situation- suggest solutions to current

problems

Two Broad Measures

Ecological Footprint- what resources do people use?- convert these all to hectares- index against the world supply- 1960-2007

Living Planet Index- state of global biodiversity- based on vertebrate populations- 1970-2007

Butchart, S. H. M. et al. 2010. Global biodiversity: indicators of recent declines. Science 328:1164-1168.

Year

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020

Fra

ctio

n o

f th

e p

lan

etb

ein

g u

tilis

ed

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

Carrying capacity of the Earth

1976

The World’s Ecological Footprint

Source: Living Planet Guide 2010

Year

1970 1975 1980 1985 1990 1995 2000 2005 2010

Liv

ing

Pla

net

Ind

ex

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

1.3

Living Planet Index

Source: Living Planet Guide 2010

Based on trends in 7953 populations Of 2544 vertebrate species

28% drop

Agriculture

Premise: Agriculture is applied ecology - if this is correct, agriculture must

operate under the principles of applied ecology

What principles of applied ecology are applicable?

Agricultural Sustainability - # 1

Ecological Generalisation # 1: ecosystems must run on solar energy - current agriculture runs on non- renewable resources (oil, natural

gas, coal) Agriculture must transition to

renewable energy - whither industrial agriculture?

Agricultural Sustainability - # 2

Ecological Generalization # 2: nutrient input = nutrient output - crop production depends on fertilizer inputs

Nitrogen limits productivity in many soils

Phosphate is also required in fertilizer

Wheat Energy Inputs per ha

USA Kenya

Kilo

ca

lori

es

x 1

00

0

0

1000

2000

3000

4000

Machinery

Diesel

Diesel

Nitrogen

Seeds

Herbicides

Phosphate

Labor

NitrogenPhosphate

Pimentel, D. (2009). Energy inputs in food crop production in developing and developed nations. Energies 2: 1-24.

Output is 2.6 times input

Output is 3.3 times input

Corn Yield - Iowa

Nitrogen fertilizer - kg/ha

0 50 100 150 200 250 300 350

Co

rn g

rain

(to

nn

es p

er h

a)

4

6

8

10

12

Cerrato, M.E., and Blackmer, A.M. 1990. Comparison of models for describing corn yield response to nitrogen fertilizer. Agronomy Journal 82: 138-143.

Agricultural Sustainability - # 3

Fertilizer- nitrogen is produced from natural

gas- phosphate comes from rocks

Nitrogen production is tied to oil in availability and price

Phosphate is limited to rock formations

Dery, P. and Anderson, B. 2007. Peak phosphorus. Energy Bulletin 13 August 2007.

Pro

du

cti

on

(M

g/y

ear

)

Year

World Rock Phosphate Production

Source: USDA (2010).

World Wheat Production

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Wh

eat

yiel

d (

ton

s p

er h

a)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

Are

a cu

ltiv

ate

d (

mill

ion

ha)

180

200

220

240

260

280

300

Yield

Area

increasing 0.7% per year

Agricultural Sustainability - # 4

Solutions- recycle nutrients- reduce fossil fuel use

- low tillage, organic agriculture- develop better crops, diversify- improve grazing management- integrate crops and livestock- stop using food for biofuels- invest in agriculture

What is Biodiversity?

Four levels of biodiversity:- molecular diversity- genetic diversity- species diversity- ecosystem diversity

Species are the key unit in most discussions of biodiversity

Biodiversity

Premise: biodiversity provides a planet that is inhabitable by humans

- if this is correct, protecting biodiversity must become a major societal goal

What principles of applied ecology are applicable to biodiversity conservation ?

A Basic Ecological Principle

Biodiversity is useful for us

- ecosystems provide services to

the Earth and to humans

- this is the utilitarian reason for

protecting biodiversity

Ecosystem Services # 1

Purification of air and water Pollination of crops Decomposition of wastes Moderation of weather Pest control Prevention of soil erosion Aesthetic values for people

Ecosystem Services # 2

Some ecosystem services can be evaluated financially

- pollination in agriculture Many ecosystem services are non-monetary

- prevention of erosion I think it is a mistake to make an economic

argument for the protection of biodiversity but most ecologists use economics to indicate importance

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Ecosystem Services # 3

Some dollar figures for ecosystem services:

- natural enemies suppress soybean aphids in 4 USA states – value US$ 239 million- natural pest control for all US crops valued at $ 13.6 billion per year- insect pollination value to the world’s food production estimated at US $ 100 billion- total for all services $33 trillion per year…..

Power, A.G. (2010) Ecosystem services and agriculture: tradeoffs and synergies. Philosophical Transactions of the Royal Society B 365: 2959-2971.

Co

ffee

yie

ld (

kg/h

a)

0

3000

6000

9000

12000

15000

18000

1961-1980 yield1981-2001 yield

Increasing pollinators Decreasing pollinatorsCosta Rica Panama Kenya Ivory Coast

Roubik, D.W. (2002) Tropical agriculture: The value of bees to the coffee harvest. Nature 417: 708.

Coffee Yields and Insect Pollinators

30

Ecosystem Services # 4

Coda:- there is an ever growing literature about

the value of ecosystem services- much of this discussion is good political ecology but hopeless scientific ecology- we should protect biodiversity because we cannot eat iron ore or coal or paper money…..

Power, A.G. (2010). Ecosystem services and agriculture: tradeoffs and synergies. Philosophical Transactions of the Royal Society B 365: 2959-2971.

Photo courtesy of Dr. C.Picket, CDFA, USA

Strips of flowering alyssum in California lettuce crops

Photo courtesy of Dr. C.Picket, CDFA, USA

Strips of buckwheat sown between vine rows in New Zealand to provide nectar and pollen for beneficial insects

Biodiversity Problems

We do not have an inventory of all the species on earth

Most species are rare so they are difficult to study

For many species that are described, we do not know if they are endangered or not

Should we triage species we cannot easily save and invest conservation dollars wisely?

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Biodiversity Solutions

Set aside large areas and corridors as reserves and parks

Protect these areas from human exploitation

Monitor the populations of selected species

Engender public and political support via sexy species

Possingham, H.P. 2001. The business of biodiversity: applying decision theory principles to nature conservation. Environment, Economy and Society 9: 1-37.

Problem for Biodiversity Solutions

No current national park or reserve is large enough for large species

Off-reserve conservation is essential Climate change will change reserves Biodiversity solutions require money

that is not available

Australia's Spending in 2010

TotalMilitary

AlcoholCigarettes

SportsARC Caring for Country

Do

llars

(b

illio

ns)

0.2

0.5

1

35

10

2030

250

300

2620

7

2

0.7

0.30.01% of budget

Population

Population dynamics is probably the best understood of all the subdisciplines of ecology

- mathematics of population change- extensive experimental studies from

many plants and animals What principles of ecology are applicable

to our population crisis ?

An Ecological Principle

No population increases without limit- there are no ecologists I know that doubt this law- the scientific argument about it is that it

is an automatic consequence of the fact that the world is finite

1975 1980 1985 1990 1995 2000 2005

Den

sity

pe

r km

2

0

5

10

15

20

25

Red Kangaroos – South Australia

Pople, A.R. et al. (2010). Reassessing the spatial and temporal dynamics of kangaroo populations. In Macropods, ed. by G.Coulson and M. Eldridge. CSIRO Publishing. pp. 197-210.

Population Reference Bureau, http://www.prb.org/ 30 December 2010

Year

1500 1600 1700 1800 1900 2000

Po

pu

lati

on

- m

illi

on

s

0

1000

2000

3000

4000

5000

6000

7000

Human Population Growth – 1500 to 2010

Population Growth # 1

Two ways to stop population growth:

1. High birth rate = high death rate

2. Low birth rate = low death rate

- no one advocates solution # 1- if there is a ‘third way’ population ecologists have not discovered it in over 100 years of research

Year

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020

Fra

ctio

n o

f th

e p

lan

etb

ein

g u

tili

sed

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

Carrying capacity of the Earth

1976

Population Growth # 2

But if this is correct….

Population Decline

The human population must decline over the next 2 centuries

1. Birth rate < high death rate

2. Low birth rate < low death rate

- no one advocates solution # 1- solution # 2 is already underway!

Ave

rag

e n

o. c

hild

ren

per

fem

ale

0

2

4

6

8

1970 data 2010 data

Iran India China USA Canada Australia

Population Reference Bureau. 2010. World Population Data Sheet. http://www.prb.org/

Human Fertility Change – 1970 to 2010

The Bottom Line on Population

The women of the world have already sent a message to their governments that they recognize that a population decline is desirable

The governments of most of the western countries are not listening

A few economists and business people are aware but they are drowned out by the growth-at-any-cost world view

The Politics of Ignorance

Operational Principle: what you do not know cannot hurt you

- you can operate in this state by ignoring evidence-based science, or- you can fail to fund the scientific

research that will shed light on specific problems

The Politics of Ignorance # 2

Major current example: climate change- “there is no need to do anything until we have scientific certainty”- how should we respond to scientific uncertainty ?- technological optimists vs. technological pessimists

Krebs, C.J. (2008) The Ecological World View. CSIRO Publishing, Collingwood, p. 508.

  Real state of the world

Optimists correct

Skeptics correct

Current policies to be

used in environmental

decisions

Technological optimists’ policies

High Disaster

Technological skeptics’ policies

Good Very good

Payoff Matrix

The Bottom Line

Scientists do not make policy But we know a great deal about the natural

world that should inform policy but is not used

We must continue to do good science and ask our governments to use evidence-based policies

There is accumulating evidence that the ecological world view is slowly replacing the economic world view

Summary - # 1

Sustainability is an ecological concept that has been abused to become nearly meaningless

Three critical world problems have their roots in ecology:

- agricultural production- biodiversity conservation- human population growth

Summary - # 2

We must wean our world-view away from the simple idea that technological progress will solve all these problems

Remember that infinite growth is the philosophy of the cancer cell and not a philosophy of sustainable land use

For our children we should leave a world that is not diminished

There is much progress in ecological understanding, but much yet to do

Thanks for listening !