Climate Change: The Move to Action (AOSS 480 // NRE 480)

1. Climate Change: The Move to Action(AOSS 480 // NRE 480) Richard B. Rood Cell: 301-526-8572 2525 Space Research Building (North Campus) rbrood@umich.edu http://aoss.engin.umich.edu/people/rbrood Winter 2010 February 4, 2010

2. Class News • Ctools site: AOSS 480 001 W10 • On Line: 2008 Class • Reading • IPCC Working Group I: Summary for Policy Makers

3. Make Up Class / Opportunity • Make up Class on March 8, Dana 1040, 5:00 – 7:30 PM, Joint with SNRE 580 • V. Ramanathan, Scripps, UC San Diego • Please consider this a regular class and make it a priority to attend. • Pencil onto calendar on April 6, Jim Hansen, time TBD.

4. Class Projects • Think about Projects for a while • The role of the consumer • Energy efficiency / Financing Policy • Science influence on policy, Measurements of carbon, influence • Role of automobile, transportation, life style • Water, fresh water, impact on carbon, • Geo-engineering, public education, emergency management, warning, • Water, insurance, Midwest development, Michigan, regional • Dawkins, socio-biology • What leads to a decision • What does it really mean in the village • Geo-engineering, urban sustainability • US Policy, society interest, K-12, education

5. Projects; Short Conversation • Finance/Energy Efficiency/Development of Technology/Reduction of Emissions • “Geo-engineering” --- managing heating in the near-term/Role of Attribution/Managing the climate, what climate information is needed

6. Next week • Groups that have organized a short presentation, discussion • Title • Your vision • What disciplines are present in your group

7. Today • Foundation of science of climate change (continued)

8. Some Basic References • Rood Climate Change Class • Reference list from course • Rood Blog Data Base • Koshland Science Museum: Global Warming • IPCC (2007) Working Group 1: Summary for Policy Makers • IPCC (2007) Synthesis Report, Summary for Policy Makers • Osborn et al., The Spatial Extent of 20th-Century Warmth in the Context of the Past 1200 Years, Science, 311, 841-844, 2006

9. Some points that I think I have made • We know that CO2 and water in the atmosphere holds thermal energy close to the surface. They keep the surface “warm.” • We know that the past several hundred thousand years there have been oscillations in temperature and carbon dioxide that we identify with “climate” ice ages and temperate periods. • Carbon dioxide and temperature variations are correlated for time periods longer than, say, a few hundred years. • Carbon dioxide and temperature variations are not obviously correlated for time periods shorter than, say, 100 years. • Carbon dioxide is increasing in the atmosphere. • Carbon dioxide and water are important to the variation of temperature of the Earth’s surface.

10. Some points that I think I have made • Theory: The basic theory that we use to quantify the Earth’s climate is based on the conservation principle  balanced budgets • Conversation of energy (Sun-Earth-Space) • Conservation of mass (CO2 in atmosphere)

11. Some points that I think I have made • Balance: The climate of the Earth is in a complex balance. • CO2 in atmosphere (ocean-land-fossil fuel burning) • Phase of water in current climate (vapor, liquid, ice) • Energy and exchange of energy within the Earth’s system • ?????

12. Radiative Balance of The Earth • Over some suitable time period, say a year, maybe ten years, if the Earth’s temperature is stable then the amount of energy that comes into the Earth must equal the amount of energy that leaves the Earth. • Energy comes into the Earth from solar radiation. • Energy leaves the Earth by terrestrial (mostly infrared) radiation to space. • (Think about your car or house in the summer.)

13. Radiation Balance Figure

14. Let’s build up this picture • Follow the energy through the Earth’s climate. • As we go into the climate we will see that energy is transferred around. • From out in space we could reduce it to just some effective temperature, but on Earth we have to worry about transfer of energy between thermal energy and motion of wind and water.

15. But the Earth’s surface temperature is observed to be, on average, about 15 C (~59 F). The sun-earth system(What is the balance at the surface of Earth?) SUN Based on conservation of energy: If the Earth did NOT have an atmosphere, then, the temperature at the surface of the Earth would be about -18 C ( ~ 0 F). Welcome Back Radiative Balance. This is conservation of energy, which is present in electromagnetic radiation. Earth

16. Energy is coming from the sun. Two things can happen at the surface. In can be: Reflected Or Absorbed Building the Radiative Balance What happens to the energy coming from the Sun? Top of Atmosphere / Edge of Space

17. Reflect or Absorb Building the Radiative Balance What happens to the energy coming from the Sun? Top of Atmosphere / Edge of Space We also have the atmosphere. Like the surface, the atmosphere can:

18. Reflect a lot Absorb some Building the Radiative Balance What happens to the energy coming from the Sun? Top of Atmosphere / Edge of Space In the atmosphere, there are clouds which :

19. Building the Radiative Balance What happens to the energy coming from the Sun? RS Top of Atmosphere / Edge of Space For convenience “hide” the sunbeam and reflected solar over in “RS”

20. Building the Radiative Balance What happens to the energy coming from the Sun? RS Top of Atmosphere / Edge of Space Consider only the energy that has been absorbed. What happens to it?

21. Building the Radiative Balance Conversion to terrestrial thermal energy. RS Top of Atmosphere / Edge of Space 1)It is converted from solar radiative energy to terrestrial thermal energy. (Like a transfer between accounts)

22. Building the Radiative Balance Redistribution by atmosphere, ocean, etc. RS Top of Atmosphere / Edge of Space 2)It is redistributed by the atmosphere, ocean, land, ice, life. (Another transfer between accounts)

23. It takes heat to • Turn ice to water • And water to “steam;” • that is, vapor RADIATIVE ENERGY (infrared) PHASE TRANSITION OF WATER (LATENT HEAT) WARM AIR (THERMALS) Building the Radiative Balance Terrestrial energy is converted/partitioned into three sorts RS Top of Atmosphere / Edge of Space 3) Terrestrial energy ends up in three reservoirs (Yet another transfer ) CLOUD ATMOSPHERE SURFACE

24. Building the Radiative Balance Which is transmitted from surface to atmosphere RS Top of Atmosphere / Edge of Space 3) Terrestrial energy ends up in three reservoirs CLOUD CLOUD ATMOSPHERE (LATENT HEAT) (THERMALS) (infrared) SURFACE

25. 1) Some goes straight to space 4) Some is absorbed by clouds and atmosphere and re-emitted upwards 2) Some is absorbed by atmosphere and re-emitted downwards 3) Some is absorbed by clouds and re-emitted downwards Building the Radiative Balance And then the infrared radiation gets complicated RS Top of Atmosphere / Edge of Space CLOUD CLOUD ATMOSPHERE (LATENT HEAT) (THERMALS) (infrared) SURFACE

26. Put it all together and this what you have got.The radiative balance

27. Thinking about the greenhouse A thought experiment of a simple system. Top of Atmosphere / Edge of Space • Let’s think JUST about the infrared radiation • Forget about clouds for a while • 3) Less energy is up here because it is being held near the surface. • It is “cooler” ATMOSPHERE • 2) More energy is held down here because of the atmosphere • It is “warmer” (infrared) SURFACE

28. Remember we had this old idea of a temperature the Earth would have with no atmosphere. • This was ~0 F. Call it the effective temperature. • Let’s imagine this at some atmospheric height. 3) Up here it is cooler than Teffective T < T effective T > T effective 2) Down here it is warmer than Teffective Thinking about the greenhouse A thought experiment of a simple system. Top of Atmosphere / Edge of Space ATMOSPHERE T effective (infrared) SURFACE

29. 3) The part going to space gets a little smaller • It gets cooler still. • 2) The part coming down gets a little larger. • It gets warmer still. Thinking about the greenhouse Why does it get cooler up high? Top of Atmosphere / Edge of Space 1) If we add more atmosphere, make it thicker, then ATMOSPHERE (infrared) SURFACE The real problem is complicated by clouds, ozone, ….

30. Changes in the sun THIS IS WHAT WE ARE DOING Things that change reflection Things that change absorption If something can transport energy DOWN from the surface. So what matters?

31. CLOUD-WORLD The Earth System SUN ATMOSPHERE OCEAN ICE (cryosphere) LAND

32. CLOUD-WORLD The Earth System SUN Where absorption is important ATMOSPHERE OCEAN ICE (cryosphere) LAND

33. CLOUD-WORLD The Earth System SUN Where reflection is important ATMOSPHERE OCEAN ICE (cryosphere) LAND

34. CLOUD-WORLD The Earth System SUN Solar Variability ATMOSPHERE OCEAN ICE (cryosphere) LAND

35. CLOUD-WORLD The Earth System SUN ATMOSPHERE OCEAN ICE (cryosphere) LAND Possibility of transport of energy down from the surface

36. From Warren Washington

37. Conservation equation • Could you write the conservation equation, at least symbolically, for surface temperature and atmospheric carbon dioxide.

38. Energy doesn’t just come and go • The atmosphere and ocean are fluids. The horizontal distribution of energy, leads to making these fluids move. That is “weather” and ocean currents and the “general circulation.”

39. Transport of heat poleward by atmosphere and oceans • This is an important part of the climate system • One could stand back far enough in space, average over time, and perhaps average this away. • This is, however, weather ... and weather is how we feel the climate day to day • It is likely to change because we are changing the distribution of average heating

40. While Building the Radiative Balance Figure Redistribution by atmosphere, ocean, etc. RS Top of Atmosphere / Edge of Space 1)The absorbed solar energy is converted to terrestrial thermal energy. 2)Then it is redistributed by the atmosphere, ocean, land, ice, life. CLOUD ATMOSPHERE SURFACE

41. After the redistribution of energy, the emission of infrared radiation from the Earth is ~ equal from all latitudes. Because of tilt of Earth, Solar Radiation is absorbed preferentially at the Equator (low latitudes). Another important consideration. Latitudinal dependence of heating and cooling Top of Atmosphere / Edge of Space CLOUD ATMOSPHERE SURFACE South Pole (Cooling) Equator (On average heating) North Pole (Cooling)

42. Transfer of heat north and south is an important element of the climate at the Earth’s surface. Redistribution by atmosphere, ocean, etc. Top of Atmosphere / Edge of Space This predisposition for parts of the globe to be warm and parts of the globe to be cold means that measuring global warming is difficult. Some parts of the world could, in fact, get cooler because this warm and cool pattern could be changed. CLOUD ATMOSPHERE heat is moved to poles cool is moved towards equator cool is moved towards equator SURFACE This is a transfer. Both ocean and atmosphere are important!

43. Hurricanes and heat: Sea Surface Temperature

44. Weather Moves Heat from Tropics to the Poles HURRICANES

45. Mid-latitude cyclones & Heat

46. CLOUD-WORLD The Earth System SUN ATMOSPHERE OCEAN ICE (cryosphere) LAND

47. CLOUD-WORLD SUN Earth System: Sun • SUN: • Source of energy • Generally viewed as stable • Variability does have discernable signal on Earth • Impact slow and small relative to other changes Lean, J., Physics Today, 2005 Lean: Living with a Variable Sun ATMOSPHERE OCEAN LAND ICE (cryosphere)

48. CLOUD-WORLD SUN Earth System: Atmosphere • The Atmosphere: • Where CO2 is increasing from our emissions • Absorption and reflection of radiative energy • Transport of heat between equator and pole • Weather: Determines temperature and rain • What are the most important greenhouse gasses? • Water (H2O) • Carbon Dioxide (CO2) • Methane (CH4) ATMOSPHERE Change CO2 Here OCEAN LAND ICE (cryosphere)

49. Cloudy Earth

50. CLOUD-WORLD SUN Earth System: Cloud World • Cloud World: • Very important to reflection of solar radiation • Very important to absorption of infrared radiation • Acts like a greenhouse gas • Precipitation, latent heat • Most uncertain part of the climate system. • Reflecting Solar Cools • Largest reflector • Absorbing infrared Heats ATMOSPHERE OCEAN LAND ICE (cryosphere)