Understanding Climate Change: Basics for Students

1. Climate Change: General Introduction(Basic Introduction for Students with Some Science Knowledge) Richard B. Rood Cell: 301-526-8572 2525 Space Research Building (North Campus) rbrood@umich.edu http://aoss.engin.umich.edu/people/rbrood September 30, 2015

2. Getting Started • Rood Blog “Just Temperature” • Rood The Conversation “30 Years”

3. November 2013: Global Temperature

4. August 2015: Global Temperature

5. Overview • Climate Change in a Nutshell • Climate-Energy-Policy Interface

6. Some Basic References • Intergovernmental Panel on Climate Change • IPCC (2007) Working Group 1: Summary for Policy Makers • IPCC (2013) Working Group 1: Summary for Policy Makers • Spencer Weart: The Discovery of Global Warming • Carbon dioxide greenhouse effect: http://www.aip.org/history/climate/co2.htm • Simple climate models http://www.aip.org/history/climate/simple.htm • Paul Edwards: A Vast Machine • Rood • Rood Climate Change Class Naomi Oreskes, Why Global Warming Scientists are Not Wrong

7. Climate Change in a Nutshell • How and what do we know? • Increase of carbon dioxide • Some predictions • Some observations (and attribution) • How do we organize our responses? • Reading about 4 degrees of warming • New et al. 2010, Phil. Trans. Roy. Soc.

8. Starting point: Scientific foundation • The scientific foundation of our understanding of the Earth’s climate is based on budgets of energy, mass, and momentum. (Conservation principles) • The scientific foundation of our understanding of the Earth’s climate is based on an enormous and diverse number of observations.

9. Starting point: A fundamental conclusion • Based on the scientific foundation of our understanding of the Earth’s climate, we observe that with virtual certainty • The average global temperature of the Earth’s surface has increased due to the addition of gases into the atmosphere that hold heat close to the surface. The increase in greenhouse gases is due to human activities, especially, burning fossil fuels.

10. Starting point: A fundamental conclusion • Based on the scientific foundation of our understanding of the Earth’s climate, we predict with virtual certainty • The average global temperature of the Earth’s surface will continue to rise because due to the continuing addition of gases into the atmosphere that hold heat close to the surface. The increase in greenhouse gases is due to human activities, especially, burning fossil fuels. • Historically stable masses of ice on land will melt. • Sea level will rise. • The weather will change.

11. Scientific Approach • Climate science is observationally based • Climate change is computational science • Relies on models

12. Models are an Important Part of Climate ScienceWhat is a Model? • Model • A work or construction used in testing or perfecting a final product. • A schematic description of a system, theory, or phenomenon that accounts for its known or inferred properties and may be used for further studies of its characteristics. • Numerical Experimentation • Given what we know, can we predict what will happen, and verify that what we predicted would happen, happened?

13. Scientific Investigation OBSERVATIONS THEORY PREDICTION Past Present Future Time Understanding Processes Evaluation, Verification Predictions Projections

14. Land Use / Land Change Other Greenhouse Gases Aerosols Internal Variability Validation Evaluation Consequences Feedbacks Air Quality “Abrupt” Climate Change Summary Points: Science Correlated Observations CO2 and Temperature Observed to be strongly related on long time scales (> 100 years) CO2 and Temperature not Observed to be strongly related on short time scales (< 10 years) Theory / Empirical Evidence CO2 and Water Vapor Hold Heat Near Surface Prediction Earth Will Warm Theory / Conservation Principle Mass and Energy Budgets  Concept of “Forcing” Observations CO2 is Increasing due to Burning Fossil Fuels

15. Conservation principle: Energy Energy from the Sun Stable Temperature of Earth could change from how much energy (production) comes from the sun, or by changing how we emit energy. Earth at a certain temperature, T Energy emitted by Earth (proportional to T)

16. The first place that we apply the conservation principle is energy • We reach a new equilibrium

17. The first place that we apply the conservation principle is energy • We reach a new equilibrium Changes in orbit or solar energy changes this

18. Conservation principle: Energy Energy from the Sun Add some detail: Earth at a certain temperature, T Insulating Blanket Surface

19. Changing a greenhouse gas changes this The first place that we apply the conservation principle is energy • We reach a new equilibrium

20. Some basics

21. Observed Increase of Atmospheric Carbon Dioxide (CO2) Primary increase comes from burning fossil fuels – coal, oil, natural gas Data and more information

22. The yearly cycle of CO2

23. Presentation of some results • These are drawn from the Reports of the Intergovernmental Panel on Climate Change. I deliberately mix graphs from reports in 2001, 2007, and 2013. The messages from these reports are quite similar, which is a measure of • Consistent measure • Stable scientific understanding

24. IPCC (2007) projections for the next 100 years.

25. Projected Global Temperature Trends: 2100 2071-2100 temperatures relative to 1961-1990. Special Report on Emissions Scenarios Storyline B2 (middle of the road warming). IPCC 2001

26. Observed Temperature Anomaly in 2005http://data.giss.nasa.gov/gistemp/2005/ See Also: Osborn et al., The Spatial Extent of 20th-Century Warmth in the Context of the Past 1200 Years, Science, 311, 841-844, 2006

27. IPCC 2013: Observed Temperature What does this mean for design and engineering? Rood: What would happen if we stopped emitting now?

28. IPCC 2007: The last ~100 years

29. Correlated behavior of different parameters Fig. 2.5. (State of Climate 2009) Time series from a range of indicators that would be expected to correlate strongly with the surface record. Note that stratospheric cooling is an expected consequence of greenhouse gas increases. A version of this figure with full references is available at www.ncdc.noaa.gov/bams-state-of-climate/.

30. Quick Summary: IPCC(2013)

31. Length of Growing Season From Ranga B. Myneni, Boston University

32. Summary In Progress: Observations • Observations of climate change (global warming) • Average surface temperature of planet is increasing • Ice is melting • Glaciers • Ice sheets • Sea level is rising • Ocean is warming up • From the melting ice • Weather is changing • Coherent and convergent evidence

33. Summary In Progress: Projections • Observations are consistent model projections • Past century • Evolving • Model projections • Planet will warm • Ice will melt • Sea level will rise • Weather will change

34. Summary In Progress: Uncertainty • Identified major categories of uncertainty • Scenario – future emissions • Model – deficiencies in simulation capability • Observational – quality of observations, inability to completely observe • Dynamic variability – internal variability due to transfer of energy between components of a complex system

35. Summary in Progress: Attribution • Have suggested several aspects of extent and attribution of warming to greenhouse gases • Spatial distribution of warming • Decrease of temperature in the stratosphere • Changes in growing season • Changes in seasonal cycle of carbon dioxide • Warming in the ocean • ….

36. Temperature Water Precipitation Evaporation Humidity Air Composition Air quality Aerosols Carbon dioxide Winds Clouds / Sunlight Droughts Floods Extreme Weather The impact of climate change is Water for Ecosystems Water for People Water for Energy Water for Physical Climate What parameters/events do we care about?

37. Science, Mitigation, Adaptation Framework Adaptation is responding to changes that might occur from added CO2 It’s not an either / or argument. Mitigation is controlling the amount of CO2 we put in the atmosphere.

38. Some Points • Science-based conclusions • The surface of the Earth has warmed and this warming is consistent with increasing greenhouse gases. CO2 is most important. • The Earth will continue to warm. • The concept of “stabilization” of CO2 is challenged by the consideration of ocean-land-atmosphere time scales • Accumulated carbon dioxide is important. • 1 trillion tons  440 ppm

39. Break

40. Climate-Energy-Policy Interface • Problem solving: Reduction of complexity • Policy (global): Goals • Climate-Energy-Population-Consumption • Notional Solution Strategy

41. Responses to the Climate Change Problem Policy/ Societal Autonomous/ Individual Anticipatory Reactive Mitigation Adaptation

42. Stabilization / Total burden of Greenhouse Gases • Have this notion of controlling emissions to stabilize the concentration of CO2 in the atmosphere at some value. • That is, there was some value of emissions that would match the loss of CO2 into the plants, soil and oceans. • However, CO2is exchanged between plants, soil and ocean, and it takes a very long time for CO2amounts to decline. • We know that the CO2 that we emit will be with us essentially forever. Therefore, it is the total amount that we emit, rather than controlling emissions. • Arguably, we get to emit 1 trillion tons before climate change is “dangerous” • “Dangerous” = 2 degrees C average surface warming

43. LONG SHORT There are short-term issues important to climate change. What is short-term and long-term? Pose that time scales for addressing climate change as a society are best defined by human dimensions. Length of infrastructure investment, accumulation of wealth over a lifetime, ... ENERGY SECURITY Election time scales CLIMATE CHANGE ECONOMY 25 years 0 years 50 years 75 years 100 years

44. LOCAL GLOBAL SPATIAL Managing Climate Complexity WEALTH TEMPORAL NEAR-TERM LONG-TERM

45. LOCAL GLOBAL SPATIAL Managing Climate Complexity WEALTH TEMPORAL NEAR-TERM LONG-TERM Being Global, Long Term, Wealth connected, degree of difficulty is high

46. Framework Convention on ClimateChange

47. The Rationalist and Policy • Determine what is a tolerable ceiling for carbon dioxide. • Gives cap for a cap and trade system. • Tolerable ceilings have been posed as between 450 and 550 ppm. • Ice sheet melting and sea level? • Oceanic circulation / The Gulf Stream? • Ocean acidification? • Determine a tolerable measure of increased temperature • Copenhagen Accord (2009)  2o C

48. A trillion tons of carbon • We get to emit a trillion tons of carbon to avoid “dangerous” climate change • Where does mitigation, reduction of emissions fit on the spatial and temporal scales?

49. Trillion Tons: Carbon Visuals

50. Mainstream approach – targets and timetables From R. Pielke Jr. The Climate Fix