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 2014 February 20, 2014
Class News
• Ctools site: AOSS_SNRE_480_001_W14
• Something I am playing with – http://openclimate.tumblr.com/
• Assignment – Emailed – Posted
Politics of Dismissal Entry Model Uncertainty
Description
Projects
• Fracking (Omar, Jeffrey, Austin, Megan, Ranya) – With the recent technological advances in hydraulic fracturing,
the U.S. has become the world’s largest producer of oil and is projected to become an exporter of natural gas. Natural gas has been posed as a “bridge fuel” to displace coal in the production of electricity, and to reduce the emissions of carbon dioxide. As a policy advisor on climate change, I need to know whether or not a transition to natural gas serves to reduce the emissions of greenhouse gases and the impact on water resources. I am especially concerned about the leakage of methane and huge amount of water that is required. I have another team working on public health effects air quality and water quality are out of your domain.
Projects
• Agricultural (Edwin, Rachel, Kathleen, Chris) – The accounting of greenhouse gas emissions from agriculture is
difficult. I have read that something like 30% of the total emissions are agriculturally related. This requires that those emissions used in, say, fertilizer manufacturing are accounted in agriculture rather than industry. Recently, I read a blog http://www.wunderground.com/blog/RickyRood/greenhouse-emissions-of-agriculture that said there was one group who claimed all by itself, livestock was responsible for more than 52% of the emissions. This seems enormous and challenges many conventional strategies for greenhouse gas management. The CEO of my company has announced a sustainability effort, and I want to know what decisions my food manager can make the matter to climate change, including water resources. Should I emphasize vegetarian meals, or is it better to buy local, “sustainable,” or organic?
Projects
• Air Travel (Meng, Arnav, Mason, John, Justin) – There is no doubt that airplanes emit carbon dioxide and other
greenhouse gases. Air travel is an important part of the economy. When I read about air travel and climate impacts, the information is complicated. Often the discussion ends with the admission that there are not obvious options to make air travel and transport “sustainable” in the sense of climate change. The European Union has been considering a way to reduce emissions from air travel. Their efforts have only revealed even more complexity in reducing the environmental impact of aircraft. In order to know how much priority to give to sustainable air travel in my research and development portfolio, I need a knowledge-based assessment of the impact of air travel on climate, risks associated with “doing nothing” and the viable strategies for making air travel “sustainable.”
Today
• Scientific investigation of the Earth’s climate: Foundational information – “Internal Variability” – Abrupt climate change
In Class Exercise (from last time)
• Economist: – Temperature not going up, but carbon dioxide is.
Look! Warming has stopped.
Analysis of Problem
• Length of “trend” • Buffering by ocean • Internal variability • “presentation” • Sampling • Changes in forcing
– Aerosols
• Solar Variability
England et al. 2014
Pacific Decadal Oscillation
• Does the Pacific Decadal Oscillation operate regularly lasting 20-30 years, and does southern California experience droughts during that period?
• The Pacific Decadal Oscillation is one of several “oscillations” that are important to weather and climate.
• Some attributes of the Pacific Decadal Oscillation
Pacific Decadal Oscillation: Basics
Better version of figure from JISAO
Colors: Sea Surface Temperature difference from long term average. Arrows: Stress on the ocean surface caused by winds
Warm here Cool here
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
Bumps and Wiggles
• Rood’s Series on Bumps and Wiggles
Today
• Scientific investigation of the Earth’s climate: Foundational information – “Internal Variability” – 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?
Abrupt climate change
Abrupt Climate Change (NRC)
• Abrupt Climate Change (2013), National Research Council
• Abrupt Climate Change (2002), National Research Council
• Rood Summary Blog
• Wunderground: Abrupt Climate Change
What is a stable climate?
NOAA Paleoclimate
LIQU
ID - IC
E
Younger Dryas
POSSIBLE EVIDENCE OF CHANGE IN OCEAN CIRCULATION
WHAT DOES THIS MEAN?
Abrupt Climate Change
• Most scenarios of abrupt climate change are related to a phase change in some way or another. Does the albedo change quickly? Is there a change in the fresh water in the ocean? Is there a release of gas stored in something that is frozen?
• It is also possible to define rapid changes in ocean (land?) ecosystems, that leads to composition changes in the atmosphere. Biology – sensitive to temperature, water, salinity, ph, etc.
Lamont-Doherty: Abrupt Climate Change
The Earth System: ICE (Think a little more about ice)
non-polar glaciers
and snow
polar glaciers
(Greenland) (Antarctica)
sea-ice
Impacts regional water supply,
agriculture, etc.
Solar reflection, Ocean density, Sea-level rise
Solar reflection, Ocean-atmosphere
heat exchange
(Tour of the cryosphere, Goddard Scientific Visualization Studio)
The Cryosphere
• TOUR OF CRYOSPHERE: MAIN NASA SITE
There could be changes in the way the atmosphere and ocean transport heat
(An excursion to the North Atlantic)
• Remember that the atmospheres and ocean carry heat from the equator to the pole. – This is done at preferential locations. – One especially important mechanism of heat transport is the Gulf
Stream, along the eastern coast of the U.S, which transports heat to the North Atlantic. This keeps much of Europe much warmer than it would be based on the position of the sun.
– The Gulf Stream is part of a large organized circulation in the oceans.
• Connects north and south • Connects top and bottom of ocean (which is not very common)
– This organized circulation is sometimes called the ocean “conveyor” belt. It is named the thermohaline circulation because it depends on both the thermal structure and the saltiness (“haline”) of the water.
The Thermohaline Circulation (THC) (Global, organized circulation in the ocean)
(The “conveyer belt”, “rivers” within the ocean)
Where there is localized exchange of water between the surface and the deep ocean (convection)
From Jianjun Yin, GFDL, see J. Geophysical Research, 2006
Warm, surface currents.
Cold, bottom currents.
Green shading, high salt Blue shading, low salt
Importance of the Thermohaline Circulation in the Present Climate
• The deviation of the surface air temperature from the zonal average (NCAR/NCEP reanalyses); • The THC is responsible for most northward heat transport in the Atlantic (> 1 PetaWatts = 1015 Watts); • High surface air temperature over the North Atlantic and Europe
If the thermohaline circulation shut down, then the climate, the mean surface temperature, would be abruptly and significantly changed.
From Jianjun Yin, GFDL, see J. Geophysical Research, 2006
Some aspects of the thermohaline circulation
• Salt is important to the density of sea water. • Warm, salty water on the surface moves to high northern and
southern latitudes, where it sinks. • The area where there is strong, localized exchange, bottom water
currents develop which return cold water towards the equator (heat exchange).
• The area where there is strong localized exchange is significantly warmer than it would be in the absence of the ocean currents. (see next figure)
• Saltiness is very important. If the North Atlantic were flooded with fresh water from Greenland ice melting or much more precipitation, then the thermohaline circulation might shut down. – There is evidence that this has happened before (look up the Younger
Dryas) – Hence melting of Greenland impacts both sea-level rise and the
thermohaline circulation
Some model predictions of what would happen if the thermohaline circulation shutdown
• From From Jianjun Yin, GFDL, see J. Geophysical Research, 2006
• Fresh water is added in the model simulation to the North Atlantic, in the vicinity of Greenland and Iceland.
• With the addition of fresh water the thermohaline circulation shuts down
• There are global consequences – See plots below.
Predicted Sea Surface Temperature • Bipolar Seesaw 3oC decrease NA • Extension of icy seawater and sea ice
coverage in North Atlantic • Spread of warmer seawater via ACC • Feedback on the THC intensity • (This dipole has the characteristic of a
dynamical response)
Predicted Sea Surface Salt (SSS)
• 1.2 psu decrease in 50~70oN belt • SA and Gulf of Mexico become more
saline • Sharp SSS gradient at 40oN • Labrador Sea: the most susceptible
region to freshwater perturbation
Predicted Sea Ice • Thickness increases and coverage
extends in the Labrador Sea • Thickness decreases in the Nordic
Seas the Barents Sea and the Weddell Sea due to enhancement of deep convection (part of a dynamical response?)
From Jianjun Yin, GFDL, see J. Geophysical Research, 2006
Abrupt climate change
• Changes in the ocean circulation. – Remember Younger Dryas
• Remember the ice-age turn around: – Need some sort of positive feedback to amplify the solar forcing
• Ice-albedo feedback // – Sea ice collapse in Arctic? – Land ice sheet collapse à sea level rise
• Sudden release or absorption of greenhouse gas from ocean – Schmittner: Oceans & Greenhouse
• Sudden release or absorption of greenhouse gas from land – Permafrost
• Sudden change in the biological balance of plants and animals – Ocean temperature and acidification
Abrupt Climate Change: Definition from NRC (2013)
• … changes “come faster than expected, planned, or budgeted for, forcing more reactive, rather than proactive, modes of behavior”
Summary from NRC (2013)
• The near-term outlook: abrupt change in current trends incorporated into planning and management during the next century.
– Likelihood is listed as low, moderate and high.
• Moderate: – decrease in ocean oxygen – increase in intensity, frequency and duration of heat waves – increase in frequency and intensity of extreme precipitation events (droughts /
floods / hurricanes / major storms) – rapid state changes in ecosystems, species range shifts and species boundary
changes
• High: – late-summer Arctic sea ice disappearance and – increases in extinctions of marine and terrestrial ecosystems
• Low: – rapid destabilization of ice sheets leading to greatly accelerating sea level
The Arctic
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
Let’s think about the Arctic for a while
• WWF: Arctic Feedbacks Assessment
• This assessment of the most recent science shows that numerous arctic climate feedbacks will make climate change more severe than indicated by other recent projections, including those of the Intergovernmental Panel on Climate Change Fourth Assessment report (IPCC 2007). Some of these feedbacks may even interact with each other.
Arctic Feedback
• Atmospheric Circulation Feedbacks • Ocean Circulation • Ice Sheets and Sea-level Rise Feedbacks • Marine Carbon Cycle Feedbacks • Land Carbon Cycle Feedbacks • Methane Hydrate Feedbacks
What about the Antarctic
• Pine Island Glacier: Wikipedia • Pine Island Glacier: Irreversible
Summary Points: Science
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 à Concept of “Forcing”
Prediction Earth Will
Warm
Validation Evaluation
Consequences
Land Use / Land Change Other Greenhouse Gases Aerosols Internal Variability
Feedbacks
Air Quality “Abrupt” Climate Change
Iconic and Fundamental Figures
Scientific investigation of Earth’s climate
SUN: ENERGY, HEAT EARTH: ABSORBS ENERGY
EARTH: EMITS ENERGY TO SPACE à BALANCE
Sun-Earth System in Balance
The addition to the blanket is CO2
SUN EARTH
EARTH: EMITS ENERGY TO SPACE à BALANCE
PLACE AN INSULATING
BLANKET AROUND EARTH
FOCUS ON WHAT IS
HAPPENING AT THE
SURFACE
Increase of Atmospheric Carbon Dioxide (CO2)
Data and more information
Primary increase comes from burning fossil fuels – coal, oil, natural gas
Temperature and CO2: 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.
q Medieval warm period
q “Little ice age”
q Temperature starts to follow CO2 as CO2 increases beyond approximately 300 ppm, the value seen in the previous graph as the upper range of variability in the past 350,000 years.
CLOUD-WORLD
The Earth System
ATMOSPHERE
LAND
OCEAN ICE (cryosphere)
SUN
Radiation Balance Figure
Radiative Balance (Trenberth et al. 2009)
Hansen et al: (1998) & (2001)
(-2.7, -0.6)
(-3.7, 0.0)
1998
2001
Climate Forcing
