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Climate Change: The Move to Action (AOSS 480 // NRE 480) Richard B. Rood Cell: 301-526-8572 2525 Space Research Building (North Campus) [email protected] http://aoss.engin.umich.edu/people/rbrood Winter 2010 February 11, 2010 Class News • Ctools site: AOSS 480 001 W10 • On Line: 2008 Class – Reference list from course • Rood Blog Data Base • Reading 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. 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 Project Teams • Michigan Coal / Energy: Maggiet Allan, Meghan Reynard, Evan Oswald, Yoichi Shiga • Efficiency as effective mitigation: Rebecca Taylor, Erin Kashawlic, Rajesh Nerlikar, Amanda Herrick 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 Next week • Groups that have organized a short presentation, discussion – Title – Your vision – What disciplines are present in your group 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 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” 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? Aerosols • Aerosols are particulate matter in the atmosphere. – They impact the radiative budget. – They impact cloud formation and growth. 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 Radiative Forcing IPCC 2007 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. 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 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. GISS Temperature 2002 1997-98 El Nino An interesting time to study? 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 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 Changes in the sun So what matters? THIS IS WHAT WE ARE DOING Things that change reflection Things that change absorption If something can transport energy DOWN from the surface. 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 The Earth System: Feedbacks 1 Infrared Proportional to Temperature Top of Atmosphere / Edge of Space Assume that greenhouse gases remain the same • Infrared emission is proportional to temperature • Temperature increases emission increases T H T 0 t H T ATMOSPHERE (infrared) SURFACE The Earth System: Feedbacks 2 Water Vapor When it gets warmer more water, a greenhouse gas, will be in the atmosphere Top of Atmosphere / Edge of Space • 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 … ATMOSPHERE (infrared) SURFACE The Earth System: Feedbacks 3 Ice - Albedo When it gets warmer less ice Top of Atmosphere / Edge of Space • Less ice means less reflection warmer • Warmer means less ice • This could runaway! • Cooler works the other way ice-covered ICE The Earth System: Feedbacks 4 Clouds? Clouds are difficult to predict or to figure out the sign of their impact Top of Atmosphere / Edge of Space • 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 CLOUD ATMOSPHERE (infrared) SURFACE 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. 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” – Too cold run away to “snowball” ice vapor – 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? 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. OCEAN CLOUD-WORLD ATMOSPHERE LAND ICE (cryosphere) The Earth System: ICE (Think a little more about ice) non-polar polar glaciers glaciers and (Greenland) snow (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) The Cryosphere • TOUR OF CRYOSPHERE: MAIN NASA SITE Let’s think about the Arctic for a while • WWF: Arctic Feedbacks Assessment 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 The Thermohaline Circulation (THC) (Global, organized circulation in the ocean) (The “conveyer belt”, “rivers” within the ocean) Blue shading, low salt Where there is localized exchange of water between the surface and the deep ocean (convection) Green shading, high salt Warm, surface currents. Cold, bottom currents. From Jianjun Yin, GFDL, see J. Geophysical Research, 2006 The Earth System Increase greenhouse gases reduces cooling rate Warming SUN Solar variability Cloud feedback? Aerosols cool? ATMOSPHERE Water vapor feedback accelerates warming Cloud feedback? OCEAN ICE LAND Changes in land use impact absorption and reflection Ice-albedo feedback accelerates warming 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? 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 What is a stable climate? LIQUID - ICE NOAA Paleoclimate Schlumberger Younger Dryas POSSIBLE EVIDENCE OF CHANGE IN OCEAN CIRCULATION WHAT DOES THIS MEAN? Next time: Fundamental Science of Climate