Final 2 weeks of class… Final exam will be posted on-line next week…

1. Final 2 weeks of class… Final exam will be posted on-line next week… Next week - Dale Lockwood: The “should ecologists be neutral or advocates” debate…

2. What is “Global Change”? • Established in 1989 and codified in 1990 by the Global Change Research Act • An Act - To require the establishment of a United States Global Change Research Program aimed at understanding and responding to global change, including the cumulative effects of human activities and natural processes on the environment, to promote discussions toward international protocols in global change research, and for other purposes. • Global change—”changes in the environment that may alter the capacity of the Earth to sustain life”

3. What most people hear when you say Global Change (Global warming or increasing air temperatures…) Time series of departures from the 1961 to 1990 base period for an annual mean global temperature of 14.0°C (bars) and for a carbon dioxide mean of 334 ppmv (solid curve) during the base period, using data from ice cores and (after 1958) from Mauna Loa (4). Many other factors (such as the effects of volcanic eruptions and solar irradiance changes) are also important. (Karl and Trenberth 2003)

4. Dave Theobald

6. Dave Theobald

7. Reid & Miller (1989) the Scientific Basis for Conserving Biodiversity, World Resources Institute; Vitousek (1994) Ecology 75:1861-1876; • National Oceanic and Atmospheric Administration (NOAA), USA. (Slide courtesy of Berrien Moore, USA) Climate change is only one aspect of Global Change D. Wall

8. Global Change Goldewijk and Battjes (1997) Reid & Miller (1989) NOAA Vitousek (1994) Ecological Systems J.A. Klein

9. But climate and CO2, biodiversity and even land cover have varied in the past. Can’t we learn from the past? Paleoclimatic Studies • Understanding how earth systems (biotic and physical) have changed on a range of time scales in the past can help us understand what the future may hold. But….

10. The past can provide insight, but history provides few analogs for the type of climate change forecast… IPCC predictions Overpeck et al. 2003

11. Global change “heading towards the unknown” • Ecological world today • new global drivers of change • rapid pace of change Local change within a “backdrop of the known” • Ecological world in textbooks • natural systems in equilibrium • local disturbance drives change Is the situation likely to get any better?

12. 10 Total CO2 emissions 8 6 CO2 Partitioning (PgC y-1) 4 Atmosphere 2 1970 1980 2010 2000 1960 1990 Time (y) Key Diagnostic of the Carbon Cycle Evolution of the fraction of total emissions that remain in the atmosphere Updated from Le Quéré et al. 2009, Nature Geoscience; Data: NOAA 2010, CDIAC 2010

13. 1.0 Trend: 0.31 % y-1 (p=~0.9) 0.8 45% 40% 0.6 Airborne Fraction 0.4 0.2 1970 1980 2010 2000 1960 1990 Time (y) Airborne Fraction Fraction of total CO2 emissions that remains in the atmosphere Updated from Le Quéré et al. 2009, Nature Geoscience; Raupach et al. 2008, Biogeosciences; Canadell et al. 2007, PNAS

14. 2000-2009 (PgC) 10 fossil fuel emissions 7.7±0.5 5 Source deforestation CO2 flux(PgC y-1) 1.1±0.7 atmospheric CO2 4.1±0.1 land 5 2.4 (Residual) Sink 2.3±0.4 ocean (5 models) 10 1950 2000 1900 1850 Time (y) Human Perturbation of the Global Carbon Budget Global Carbon Project 2010; Updated from Le Quéré et al. 2009, Nature Geoscience; Canadell et al. 2007, PNAS

15. 10 Observed Projected A1B Models Average 9 A1FI Models Average A1T Models Average A2 Models Average 8 B1 Models Average B2 Models Average Fossil Fuel Emission(PgCy-1) Full range of IPCC individual scenarios used for climate projections 7 6 5 1990 1995 2000 2005 2010 2015 Time (y) Fossil Fuel Emissions: Actual vs. IPCC Scenarios Updated from Raupach et al. 2007, PNAS; Data: Gregg Marland, Thomas Boden-CDIAC 2010;International Monetary Fund 2010

16. Hang on tight… As Ecologists, what do we do? • Appreciate that drivers “then” and drivers “now” may differ… • Re-assess as well as push forward… • Take advantage of this “global experiment”…

17. No one is saying that this will be easy…

18. Opportunities afforded by Global Change that did not exist previously (when Ecology was “easy”) “The rates, scales, kinds, and combinations of changes occurring now are fundamentally different from those at any other time in history…” - Vitousek et al. 1997 Some examples: Reassessing what we “know”…

19. Biotic change(species introductions) Abiotic change(Climate change and resource alterations) Novel interactions

20. Moving from a “disturbance centric” to a global change world Define “Disturbance” CO2 N H2O Global change leads directly to resource alterations – new types of drivers of ecological dynamics.

21. Gradual change does not mean gradual response – responses are occurring quickly… Desertification… Thresholds and alternative stable states have always existed, but thresholds are being crossed more frequently and alternative states are more commonly manifest today…

22. Total Area Burned Fire Season Direct Climate Change Hypothesis Bonanza Creek LTER

23. Direct effect Indirect effect of warming Outbreak dynamics Increased fuel loads Shift in Bark Beetle life cycle from two years to one –threshold response… Gradual warming Biotic Interactions can accelerate responses to climate change…

24. CO2 CH4 Warmer temperatures Microbial decomposition of stored Carbon Unfrozen Frozen Permafrost loss in the Arctic: another threshold response Biotic Interactions can feedback on drivers…

25. Evaluating Controls on Productivity in Ecosystems: Can we use successful exotic invasive species to learn more about abiotic controls and biotic constraints on productivity? (the Dov Sax approach: (2007) Trends in Ecology and Evolution 22:465-471 - Ecological and evolutionary insights from species invasions)

26. Exotic “bluestems” invading native grassland in Kansas Response? Herbicide…

27. A Nightmare for Long-term Experiments… Can something “good” come out of something “bad”?

28. Biotic Constraints Community Gene Pool S speciesS genes • Biotic Interactions • Competition • Herbivory • Predation • Mutualisms Determinants of Productivity in Ecosystems • Abiotic Drivers & Resources • Solar radiation • Temperature • Precipitation • Edaphic Factors Environmental • Nutrients Limitations Traditional ecological manipulations Productivity Autotrophs Invasive Exotic Species

29. A major challenge for research ecologists (you)… There are more fundamentally important questions to answer and more problems to solve than we have ecologists or resources available ($)… or (gulp) time (?). How do we prioritize? What if you were the “Czar of Global Ecological Crises”? How would you decide? ------------------------------------------------------------------------------------------- Individual/Class exercise (Groups of 4) Provide specific prioritizing criteria that you think we should use to determine what ecological research we fund and what we do not… Rare vs. dominant? Unique vs. broadly applicable? Aesthetic vs. economic Urgent vs. best science?