PowerPoint PresentationSlide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8But climate and CO2, biodiversity and even land cover have varied in the past. Can’t we learn from the past? Paleoclimatic StudiesSlide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Slide 28Slide 29Final 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…What is “Global Change”?Established in 1989 and codified in 1990 by the Global Change Research ActAn 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”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)What most people hear when you say Global Change (Global warming or increasing air temperatures…)Dave TheobaldDave TheobaldReid & 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 ChangeD. WallEcological SystemsGoldewijk and Battjes (1997)Reid & Miller (1989)Vitousek (1994)NOAAGlobal Change J.A. KleinBut 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….Overpeck et al. 2003The past can provide insight, but history provides few analogs for the type of climate change forecast…IPCC predictionsEcological world today• new global drivers of change• rapid pace of changeGlobal change “heading towards the unknown”Ecological world in textbooks• natural systems in equilibrium• local disturbance drives changeLocal change within a “backdrop of the known”Is the situation likely to get any better?Updated from Le Quéré et al. 2009, Nature Geoscience; Data: NOAA 2010, CDIAC 2010Key Diagnostic of the Carbon CycleEvolution of the fraction of total emissions that remain in the atmosphereTotal CO2 emissionsAtmosphereCO2 Partitioning (PgC y-1)196020101970199020001980108642Time (y)Fraction of total CO2 emissions that remains in the atmosphereAirborne FractionUpdated from Le Quéré et al. 2009, Nature Geoscience; Raupach et al. 2008, Biogeosciences; Canadell et al. 2007, PNASAirborne FractionTrend: 0.31 % y-1 (p=~0.9)45%1960201019701990200019801.00.80.60.40.240%Time (y)Human Perturbation of the Global Carbon BudgetGlobal Carbon Project 2010; Updated from Le Quéré et al. 2009, Nature Geoscience; Canadell et al. 2007, PNAS51010518501900195020002000-2009(PgC)atmospheric CO2oceanlandfossil fuel emissionsdeforestation(Residual)SinkSourceTime (y)CO2 flux (PgC y-1)2.3±0.4(5 models)4.1±0.17.7±0.51.1±0.72.4Fossil Fuel Emissions: Actual vs. IPCC ScenariosUpdated from Raupach et al. 2007, PNAS; Data: Gregg Marland, Thomas Boden-CDIAC 2010; International Monetary Fund 2010 Fossil Fuel Emission (PgCy-1)567891019901995 2000 2005 2010 2015Full range of IPCC individual scenarios used for climate projectionsA1B Models AverageA1FI Models AverageA1T Models AverageA2 Models AverageB1 Models AverageB2 Models AverageObservedProjectedTime (y)• Appreciate that drivers “then” and drivers “now” may differ…• Re-assess as well as push forward…• Take advantage of this “global experiment”…Hang on tight… As Ecologists, what do we do?No one is saying that this will be easy…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. 1997Some examples: Reassessing what we “know”…Novel interactionsBiotic change (species introductions)Abiotic change (Climate change and resource alterations)ResourcesBiotaA. DisturbanceResourcesBiotaB. Global ChangeChronic resourcealterationDiscretedisturbanceMoving from a “disturbance centric” to a global change worldGlobal change leads directly to resource alterations – new types of drivers of ecological dynamics.Define “Disturbance”CO2N H2OGradual change does not mean gradual response – responses are occurring quickly…Thresholds and alternative stable states have always existed, but thresholds are being crossed more frequently and alternative states are more commonly manifest today…Desertification…Direct Climate Change HypothesisBonanza Creek LTERTotal Area BurnedFire SeasonGradual warmingShift in Bark Beetle life cyclefrom two years to one –threshold response…Outbreak dynamicsIncreased fuel loadsIndirect effect of warmingDirect effectBiotic Interactions can accelerate responses to climate change…Permafrost loss in the Arctic: another threshold response CO2CH4Warmer temperaturesUnfrozen  Frozen Microbial decomposition of stored CarbonBiotic Interactions can feedback on drivers…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)Exotic “bluestems” invading native grassland in KansasResponse?Herbicide…A Nightmare for Long-term Experiments…Can something “good” come out of something “bad”?ProductivityAbiotic Drivers & Resources• Solar radiation• Temperature• Precipitation• Edaphic Factors Environmental• Nutrients