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 2, 2010

2. Class News Ctools site: AOSS 480 001 W10AOSS 480 001 W10 On Line: 2008 Class2008 Class Reading –IPCC Working Group I: Summary for Policy MakersIPCC 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 DiegoV. 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 courseReference list from course Rood Blog Data Base Koshland Science Museum: Global Warming IPCC (2007) Working Group 1: Summary for Policy MakersIPCC (2007) Working Group 1: Summary for Policy Makers IPCC (2007) Synthesis Report, Summary for Policy MakersIPCC (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, 2006Osborn 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 CO 2 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 (CO 2 in atmosphere)

11. Some points that I think I have made Balance: The climate of the Earth is in a complex balance. –CO 2 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 Earth 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.

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

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

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

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

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

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

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

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

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

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

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. SURFACE Top of Atmosphere / Edge of Space ATMOSPHERE (infrared) 1)Let’s think JUST about the infrared radiation Forget about clouds for a while 2) More energy is held down here because of the atmosphere It is “warmer” 3) Less energy is up here because it is being held near the surface. It is “cooler”

28. Thinking about the greenhouse A thought experiment of a simple system. SURFACE Top of Atmosphere / Edge of Space ATMOSPHERE (infrared) T effective 1)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. 2) Down here it is warmer than T effective T > T effective 3) Up here it is cooler than T effective T < T effective

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

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

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

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

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

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

35. CLOUD-WORLD The Earth System ATMOSPHERE LAND OCEAN ICE (cryosphere) SUN 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. SURFACE 2) Then it is redistributed by the atmosphere, ocean, land, ice, life. Top of Atmosphere / Edge of Space ATMOSPHERE CLOUD RS 1) The absorbed solar energy is converted to terrestrial thermal energy.

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

42. Transfer of heat north and south is an important element of the climate at the Earth’s surface. Redistribution by atmosphere, ocean, etc. SURFACE Top of Atmosphere / Edge of Space ATMOSPHERE CLOUD heat is moved to poles cool is moved towards equator This is a transfer. Both ocean and atmosphere are important! 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.

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 ATMOSPHERE LAND OCEAN ICE (cryosphere) SUN

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

48. CLOUD-WORLD Earth System: Atmosphere ATMOSPHERE Change CO2 Here LANDOCEAN ICE (cryosphere) SUN The Atmosphere: Where CO 2 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 (H 2 O) Carbon Dioxide (CO 2 ) Methane (CH 4 )

49. Cloudy Earth

50. CLOUD-WORLD Earth System: Cloud World ATMOSPHERE LANDOCEAN ICE (cryosphere) SUN 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

51. CLOUD-WORLD Earth System: Land ATMOSPHERE LAND Change Land Use Here OCEAN ICE (cryosphere) SUN Land: Absorption of solar radiation Reflection of solar radiation Absorption and emission of infrared radiation Plant and animal life Impacts H 2 O, CO 2 and CH 4 Storage of moisture in soil CO 2 and CH 4 in permafrost Land where consequences are, first and foremost, realized for people. What happens to atmospheric composition if permafrost thaws? Can we store CO 2 in plants? Adaptability and sustainability?

52. CLOUD-WORLD Earth System: Ocean ATMOSPHERE LAND OCEAN ICE (cryosphere) SUN Ocean: Absorption of solar radiation Takes CO 2 out of the atmosphere Plant and animal life Impacts CO 2 and CH 4 Takes heat out away from surface Transport of heat between equator and pole Weather regimes: Temperature and rain What will the ocean really do? Will it absorb all of our extra CO 2 ? Will it move heat into the sub-surface ocean? Changes in circulation? Does it buy us time? Does this ruin the ocean? Acidification Doney: Ocean Acidification

53. Next time: Fundamental Science of Climate