What can Ecologists tell us about Sustainability?

2. What can Ecologists tell us about Sustainability? Charles J. KrebsInstitute 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 3 White, L., Jr. 1967. The historical roots of our ecologic crisis. Science 155: 1203-1207.

4. Outline of Talk • Ecology to what purpose? • What is sustainability? • A triumvirate of problems: Agriculture Biodiversity Population • The Politics of Ignorance • Summary

5. The Politics of Ignorance

6. Basic Principle # 1 The earth has physical, chemical, and biological limitations- it is the only planet we have

7. 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

8. 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 intergenerationalequity

9. 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

10. Are Current World Practices Sustainable ? • Three key areas - Agriculture - Biodiversity - Population • Two steps for ecologists: - evaluate the current situation - suggest solutions to current problems

11. 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.

12. The World’s Ecological Footprint Source: Living Planet Guide 2010

13. Living Planet Index Based on trends in 7953 populations Of 2544 vertebrate species 28% drop Source: Living Planet Guide 2010

14. 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?

15. 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?

16. 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

17. Output is 2.6 times input Output is 3.3 times input Pimentel, D. (2009). Energy inputs in food crop production in developing and developed nations. Energies 2: 1-24.

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

19. 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

20. World Rock Phosphate Production Production (Mg/year) Year Dery, P. and Anderson, B. 2007. Peak phosphorus. Energy Bulletin 13 August 2007.

21. Source: USDA (2010).

22. 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

23. 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

24. Biodiversity Premise: biodiversity provides a planet that is inhabitable by humans - if this is correct, protectingbiodiversity must become a major societal goal What principles of applied ecology are applicable to biodiversity conservation ?

25. 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

26. 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

27. 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

28. 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. 28

29. Coffee Yields and Insect Pollinators Roubik, D.W. (2002) Tropical agriculture: The value of bees to the coffee harvest. Nature 417: 708.

30. Ecosystem Services # 4 Coda:- there is an ever growing literature about the value of ecosystem services- much of this discussion is good politicalecology 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. 30

31. Strips of flowering alyssum in California lettuce crops Photo courtesy of Dr. C.Picket, CDFA, USA

32. Strips of buckwheat sown between vine rows in New Zealand to provide nectar and pollen for beneficial insects Photo courtesy of Dr. C.Picket, CDFA, USA

33. 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?

34. 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. 34

35. 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

36. 0.01% of budget

37. 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 ?

38. 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

39. 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.

40. Human Population Growth – 1500 to 2010 Population Reference Bureau, http://www.prb.org/30 December 2010

41. Population Growth # 1 Two ways to stop population growth: High birth rate = high death rate 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

42. Population Growth # 2 But if this is correct….

43. Population Decline The human population must decline over the next 2 centuries Birth rate < high death rate Low birth rate < low death rate - no one advocates solution # 1- solution # 2 is already underway!

44. Human Fertility Change – 1970 to 2010 Population Reference Bureau. 2010. World Population Data Sheet.http://www.prb.org/

45. 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

46. 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

47. 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

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

49. 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

50. 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