1. Climate Change: The Move to Action (AOSS 480 // NRE 480)
Richard B. Rood
Cell:
2525 Space Research Building (North Campus)
Winter 2010
February 11, 2010

2. Class News Ctools site: AOSS 480 001 W10 On Line: 2008 Class
Reference list from course
Rood Blog Data Base
Reading

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. Project Teams
Michigan Coal / Energy: Maggie Allan, Meghan Reynard, Evan Oswald, Yoichi Shiga
Efficiency as effective mitigation: Rebecca Taylor, Erin Kashawlic, Rajesh Nerlikar, Amanda Herrick

6. Projects; Short Conversation
“Geo-engineering” --- managing heating in the near-term / Role of Attribution / Managing the climate, what climate information is needed / Air quality
Transportation / Automobiles / Energy / Market /
Weather / Extreme Events / Agriculture / Carbon Sinks / Local Adaptation

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

8. Today: complete the basic picture we need
Aerosols
Internal Variability
Feedbacks: Response to a change in forcing
Important details that we have to remember
Land surface / land use changes
Other green house gases
Air quality
Abrupt climate change

9. Summary Points Theory / Empirical Evidence
CO2 and Water Vapor Hold Heat Near Surface
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)
Observations
CO2 is Increasing due to Burning Fossil Fuels
Theory / Conservation Principle
Mass and Energy Budgets
 Concept of “Forcing”

10. Let’s look at just the last 1000 years
Surface temperature and CO2 data from the past 1000 years. Temperature is a northern hemisphere average. Temperature from several types of measurements are consistent in temporal behavior. {
Note that on this scale, with more time resolution, that the fluctuations in temperature and the fluctuations in CO2 do not match as obviously as in the long, 350,000 year, record.
What is the cause of the temperature variability? Can we identify mechanisms, cause and effect? How?
This is an important point in the ultimate argument, on short time scales co2 and T are not so well correlated. T responds to other factors. These factors will be evaluated based on modeling experiments, which follow from (imperfect) observations of cause and effect as determined by observable events, e.g. volcanos.

11. Aerosols are particulate matter in the atmosphere.
They impact the radiative budget.
They impact cloud formation and growth.

12. Aerosols: Particles in the Atmosphere
Water droplets – (CLOUDS)
“Pure” water
Sulfuric acid
Nitric acid
Smog …
Ice
Dust
Soot
Salt
Organic hazes
AEROSOLS CAN:
REFLECT RADIATION
ABSORB RADIATION
CHANGE CLOUD DROPLETS

13. Earth’s aerosols

14. Natural Aerosol Extreme

15. Alan Robock: Volcanoes and Climate Change (36 MB!)
Department of Environmental Sciences

16. Department of Environmental Sciences
Explosive
backscatter
absorption (near IR)
Solar Heating
More Reflected
Solar Flux
absorption (IR) IR
Heating
emission
IR Cooling
More
Downward
IR Flux
Less
Upward
Stratospheric aerosols
(Lifetime » 1-3 years)
H2S
SO2
® H2SO4
NET HEATING
Heterogeneous ® Less
O3 depletion Solar Heating
CO2
H2O
forward scatter
Enhanced
Diffuse
Flux
Reduced
Direct
Less Total
Solar Flux
Ash
Effects
on cirrus
clouds
Tropospheric aerosols
(Lifetime » 1-3 weeks)
This diagram shows the main components of non-explosive and explosive volcanic eruptions, and their effects on shortwave and longwave radiation.
Quiescent
Indirect Effects on Clouds
SO2 ® H2SO4
NET COOLING
Alan Robock
Department of Environmental Sciences

17. Superposed epoch analysis of six largest eruptions of past 120 years
Year of eruption
Superposed epoch analysis of six largest eruptions of past 120 years
Significant cooling follows sun for two years
Robock and Mao (1995)
Robock and Mao (1995) removed the ENSO signal, and averaged the temperature change for the six largest recent eruptions, showing the anomaly from the preceding 5-year period. The cooling follows the sun for two years after the eruptions, but is displaced north of the Equator because there is more land in the Northern Hemisphere, so the cooling is larger there. The volcanic aerosol clouds were fairly evenly distributed in latitude.
Robock, A. and J. Mao, The volcanic signal in surface temperature observations, J. Climate, 8, , 1995.
Alan Robock
Department of Environmental Sciences

18. The Earth System Aerosols (and clouds)
Aerosols impact clouds and hence indirectly impact radiative budget through clouds
Change their height
Change their reflectivity
Change their ability to rain
Change the size of the droplets
Top of Atmosphere / Edge of Space
CLOUD
ATMOSPHERE
(infrared)
SURFACE

19. Aerosols and Clouds and Rain

20. Some important things to know about aerosols
They can directly impact radiative budget through both reflection and absorption.
They can indirectly impact radiative budget through their effects on clouds  both reflection and absorption.
They have many different compositions, and the composition matters to what they do.
They have many different, often episodic sources.
They generally fall out or rainout of the atmosphere; they don’t stay there very long compared with greenhouse gases.
They often have large regional effects.
They are an indicator of dirty air, which brings its own set of problems.
They are often at the core of discussions of geo-engineering

21. Radiative Forcing IPCC 2007

22. Today: complete the basic picture we need
Aerosols
Internal Variability
Feedbacks: Response to a change in forcing
Important details that we have to remember
Land surface / land use changes
Other green house gases
Air quality
Abrupt climate change

23. Let’s look at just the last 1000 years
Surface temperature and CO2 data from the past 1000 years. Temperature is a northern hemisphere average. Temperature from several types of measurements are consistent in temporal behavior. {
Note that on this scale, with more time resolution, that the fluctuations in temperature and the fluctuations in CO2 do not match as obviously as in the long, 350,000 year, record.
What is the cause of the temperature variability? Can we identify mechanisms, cause and effect? How?
This is an important point in the ultimate argument, on short time scales co2 and T are not so well correlated. T responds to other factors. These factors will be evaluated based on modeling experiments, which follow from (imperfect) observations of cause and effect as determined by observable events, e.g. volcanos.

24. Sources of internal variability
This is natural variability.
Solar variability
Volcanic activity
Internal “dynamics”
Atmosphere - Weather
Ocean
Atmosphere-ocean interactions
That does not mean that these modes of variability remain constant as the climate changes.

25. Changes during El Nino

26. Internal Variability?
There are modes of internal variability in the climate system which cause global changes.
El Nino – La Nina
What is El Nino
North Atlantic Oscillation
Climate Prediction Center: North Atlantic Oscillation
Annular Mode
Inter-decadal Tropical Atlantic
Pacific Decadal Oscillation

27. Times series of El Nino (NOAA CPC)
LA NINA
OCEAN TEMPERATURE
EASTERN PACIFIC
ATMOSPHERIC
PRESSURE
DIFFERENCE

28. Some good El Nino Information
NOAA Climate Prediction: Current El Nino / La Nina
NOAA CPC: Excellent slides on El Nino
This is a hard to get to educational tour. This gets you in the middle and note navigation buttons on the bottom.

29. An interesting time to study?
GISS Temperature 2002
El Nino
An interesting time to study?

30. Pacific Decadal Oscillation
Does the Pacific Decadal Oscillation operate regularly lasting years, and does southern California experience droughts during that period? How is information gathered to support that?
The Pacific Decadal Oscillation is one of several “oscillations” that are important to weather and climate.
Some attributes of the Pacific Decadal Oscillation
Information is gathered in the same way as climate and weather observations.
Routine
Focused

31. Pacific Decadal Oscillation: Basics
Colors: Sea Surface Temperature difference from long term average.
Arrows: Stress on the ocean surface caused by winds
Cool here
Warm here
Better version of figure from JISAO

32. Some information on Pacific Decadal Oscillation
Joint Institute for Study of Atmosphere and Ocean (JISAO):
Pacific Decadal Oscillation
Climate Prediction Center (CPC):
90 Day Outlook Summary
Weather and Climate Linkage
National Climatic Data Center (NCDC):
Decadal Oscillations
Review Paper from Rood Class References
Mantua and Hare (2002) J of Oceanography

33. Today: complete the basic picture we need
Aerosols
Internal Variability
Feedbacks: Response to a change in forcing
Important details that we have to remember
Land surface / land use changes
Other green house gases
Air quality
Abrupt climate change

34. So what matters? 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.

35. More consideration of radiative energy in the atmosphere
FEEDBACKS ....
The idea that one thing causes a second thing to happen.
That second thing then does something to the first thing
It damps it, negative feedback
It amplifies it, positive feedback
Technical Reference: Soden and Held

36. The Earth System: Feedbacks 1 Infrared Proportional to Temperature
SURFACE
Top of Atmosphere / Edge of Space
ATMOSPHERE
(infrared)
Assume that greenhouse gases remain the same
Infrared emission is proportional to temperature
Temperature increases  emission increases
This is key to stabilizing the Earth’s climate!

37. The Earth System: Feedbacks 2 Water Vapor
When it gets warmer more water, a greenhouse gas, will be in the atmosphere
Higher temperature increases evaporation from land and ocean
Higher temperature allows air to hold more water
Increase of water increases thickness of blanket – increases temperature more
This could runaway!
Natural limit because of condensation  clouds, rain?
Compensating circulation changes?
Think deserts …
SURFACE
Top of Atmosphere / Edge of Space
ATMOSPHERE
(infrared)

38. The Earth System: Feedbacks 3 Ice - Albedo
When it gets warmer less ice
Less ice means less reflection  warmer
Warmer means less ice
This could runaway!
Cooler works the other way  ice-covered
Top of Atmosphere / Edge of Space
ICE

39. The Earth System: Feedbacks 4 Clouds?
Clouds are difficult to predict or to figure out the sign of their impact
Warmer  more water  more clouds
More clouds mean more reflection of solar  cooler
More clouds mean more infrared to surface  warmer
More or less clouds?
Does this stabilize?
Water in all three phases essential to stable climate
Top of Atmosphere / Edge of Space
CLOUD
ATMOSPHERE
(infrared)
SURFACE

40. The Earth System: Feedbacks 5 Something with the Ocean?
Is there something with the ocean and ice?
Land ice melting decreases ocean salinity (density)
Sea-ice impacts heat exchange between ocean and atmosphere
Sea-ice impacts solar absorption of ocean
North Atlantic sea-ice and ocean interaction very important to the climate
Think Gulf Stream
Think climate and people and economy
Is there a natural feedback that stabilizes climate?
Even if there is, it would be very disruptive, perhaps not stable from a societal point of view.

41. Cloud-Ice-Atmosphere Feedback
Some carry away messages
This is where much of the discussion about scientific uncertainty resides.
The Earth is at a complex balance point
That balance relies on water to exist in all three phases.
Too warm could run away to “greenhouse” vapor
Too cold run away to “snowball” ice
How clouds change is not well understood and much argued.
The Iris Effect?
Is there something in all of this that changes the sign; namely, that CO2 warming will be compensated by more cooling?

42. Earth System: Ice SUN ICE:
Very important to reflection of solar radiation
Holds a lot of water (sea-level rise)
Insulates ocean from atmosphere (sea-ice)
Ice impacts both radiative balance and water – oceans and water resources on land. .
Large “local” effects at pole.
Large global effects through ocean circulation and permafrost melting.
Might change very quickly.
CLOUD-WORLD
ATMOSPHERE
OCEAN
LAND
ICE
(cryosphere)

43. The Earth System: ICE (Think a little more about ice)
non-polar
glaciers
and
snow
polar
(Greenland)
(Antarctica)
sea-ice
Impacts regional water supply, agriculture, etc.
Solar reflection, Ocean-atmosphere heat exchange
Solar reflection,
Ocean density,
Sea-level rise
(Tour of the cryosphere, Goddard Scientific Visualization Studio)

44. The Cryosphere
TOUR OF CRYOSPHERE: MAIN NASA SITE

45. Let’s think about the Arctic for a while
WWF: Arctic Feedbacks Assessment

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

47. The Thermohaline Circulation (THC) (Global, organized circulation in the ocean) (The “conveyer belt”, “rivers” within the ocean)
Blue shading, low salt
Green shading, high salt
Where there is localized exchange of water between the surface and the deep ocean (convection)
Warm, surface currents.
Cold, bottom currents.
From Jianjun Yin, GFDL, see J. Geophysical Research, 2006

48. The Earth System
SUN
Increase greenhouse gases reduces cooling rate  Warming
Changes in land use impact absorption and reflection
Solar
variability
Cloud feedback?
Aerosols cool?
Cloud feedback?
ATMOSPHERE
LAND
OCEAN
ICE
Water vapor feedback accelerates warming
Ice-albedo feedback accelerates warming

49. The predictions and observations so far are either in the sense of:
Abrupt climate change
The predictions and observations so far are either in the sense of:
Relatively small changes in the dynamic balance of the climate system
Incremental changes to the stable climate.
What about “abrupt” climate change?

50. Note to professor: Force students to think and speak
What might cause something to change abruptly in the climate system?
Lamont-Doherty: Abrupt Climate Change
NAS: Abrupt Climate Change
Wunderground.com: Abrupt Climate Change

51. What is a stable climate?
LIQUID - ICE
NOAA Paleoclimate
Schlumberger

52. Younger Dryas POSSIBLE EVIDENCE OF CHANGE IN OCEAN CIRCULATION
WHAT DOES THIS MEAN?

53. Next time: Fundamental Science of Climate
Figure SPM.5. Solid lines are multi-model global averages of surface warming (relative to 1980–1999) for the scenarios A2, A1B and B1, shown as continuations of the 20th century simulations. Shading denotes the ±1 standard deviation range of individual model annual averages. The orange line is for the experiment where concentrations were held constant at year 2000 values. The grey bars at right indicate the best estimate (solid line within each bar) and the likely range assessed for the six SRES marker scenarios. The assessment of the best estimate and likely ranges in the grey bars includes the AOGCMs in the left part of the figure, as well as results from a hierarchy of independent models and observational constraints. {Figures 10.4 and 10.29}