Climate Change: Laying out the Problem Science Cafe

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Climate Change Laying out the ProblemScience
Cafe

• Richard B. Rood
• 734-647-3530
• rbrood_at_umich.edu
• January 24, 2007

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Some Climate News

• National Oceanographic and Atmospheric
  Administration (NOAA) // World Data Center for
  Meteorology // National Climatic Data Center
• http//www.ncdc.noaa.gov/oa/wmo/wdcamet.html
• State of the Climate
• http//www.ncdc.noaa.gov/oa/climate/research/monit
  oring.htmlstate

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What is Science?

• When used in the application of the scientific
  method
• Hypothesis is a proposition that can be tested
  whether or not it is valid. Formally, by
  experiment, often by ability to predict.
• Theory is systematically organized knowledge
  based on tested hypotheses and principles.
• Principles are basic truths from which hypotheses
  are drawn and on which theories are built.
• Facts are information that is objectively real or
  true.

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Attributes of Science-based Knowledge

• An important attribute of knowledge derived
  scientifically is that it is based in observation
  and tested. There is also independent testing by
  others (like an audit). Further, new tests are
  posed to challenge theories, which lead to
  refinement and strengthening of the theory.
  Sometimes the theories are proven wrong at
  least in part.

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The motivator Increase of CO2(Keeling et al.,
1996)
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What parameters/events do we care about?

• Temperature
• Water
• Precipitation
• Evaporation
• Humidity
• Air Composition
• Air quality
• Aerosols
• Carbon dioxide
• Winds
• Clouds / Sunlight

• Droughts
• Floods
• Extreme Weather

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What do predictions tell us?
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Note There is consistency from many models, many
scenarios, that there will be warming. (1.5
5.5 C) Also, its still going up in 2100!
Basic physics of temperature increase is very
simple, non-controversial.
The prediction

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Projected Global Temperature Trends
2071-2100 temperatures relative to
1961-1990. Special Report on Emissions Scenarios
Storyline B2 (middle of the road warming).
IPCC 01
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Uncertainty

• If you were to assign uncertainty
• Regional, seasonal predictions are more uncertain
  than latitudinal, annual predictions are more
  uncertain than global, time-average prediction.

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Systematic Temperature Changes

• Global Temperature increase 1.5 4.5 C
• Poles warm faster than globe, especially the
  North Pole.
• Land warms faster than ocean.
• Night warms faster than day
• Spring starts earlier
• Autumn starts later

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Update Troposphere warming is observed.
Correction of satellite temperature
Update 2000s have continued trend
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Water

• Water vapor in atmosphere will increase (Its a
  greenhouse gas.)
• Precipitation will increase
• Evaporation will increase (Its warmer.)
• Snow cover will be less over most continents.
• Snow could increase in Greenland and Antarctica?

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Storms, Drought, Floods

• Extreme events are expected to occur more often
  and to be more extreme.

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Update Papers in 2006 that ice is melting more
rapidly
Update Papers in 2005 that hurricane intensity
has increased
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Sea level predictions

• 0.11 to 0.43 meters due to thermal expansion,
  warming of the ocean water
• 0.01 to 0.23 meters due to melting of continental
  glaciers
• Greenland -0.02 ? 0.09 meters ???
• Antarctica -0.17 ? 0.02 meters ???
• These are likely to change appreciably with the
  new IPCC. Comes out in February.

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Systematic Look

• Freeze-free periods are getting longer
• Snow cover decreasing
• Growing season longer
• Spring is earlier
• CO2 annual cycle is getting larger

• Sea ice is decreasing
• Mountain glaciers are decreasing
• Mountain ecosystems are changing

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Regional issues identified in assessments

• Reduction in water level of the Great Lakes (1-5
  feet)
• Temperature rise (20th Century and predicted)
• Precipitation increase (20th Century and
  predicted)
• Human health in cities
• Heat waves / Reduced extreme cold
• Air quality worse in heat
• Agriculture and forestry
• Soil moisture decrease, more drought
• Growing season longer
• Changes in insects, disease, fire
• Ecosystem water and air quality
• Lower stream flows, punctuated with floods
• Changes in flora and fauna (land and water) due
  to temperature
• Invasive species
• External factors from other regions
• Water for western half of U.S.
• Great Recycling and Northern Development Canal
  (James Bay in Canada)
• Water for eastern half of the U.S.
• Hydroelectric facilities

Ice reduced, shoreline damage decreased, less
snow removal, more land,
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What do with do with this information?

• Is this information about probable climate change
  accurate and interpretable?
• Is it robust?
• How often and fast does it change?
• Is it consequential?
• Are there risks if we ignore it?
• Are there risks if we believe it?
• How does this information about probable climate
  change relate to humans and the things that
  humans do?

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How do we get our information?

• Direct research, generation of new knowledge
• Review of the primary source literature
• Journalism
• Editorials
• Entertainment
• Public Outreach from Information Holders
• Popular literature
• Texts, formal education
• Peer-reviewed evaluations of the state of the
  knowledge of the field

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How do we evaluate this knowledge?

• How do we evaluate (validate?) this information?
• Personal experience
• Is it hotter where I live?
• Relative to what we know and believe
• How does it impact us? Does it cost something?
• In some absolute sense?
• Look at past observations
• Look at ability to predict
• Look at quality of observations
• Look at consistency of theory, robustness of
  hypothesis
• Attribution of change, cause and effect

This is where we will spend most of the first
group of lectures
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What are the pieces which we must consider?(what
are the consequences)
Security Food Environmental National
Societal Success Standard of Living
...???...
ECONOMICS
POLICY
ENERGY
RELIGION
??????
SOCIAL JUSTICE
BUSINESS
PUBLIC HEALTH
information flow research, journals, press,
opinion,
SCIENTIFIC INVESTIGATION OF CLIMATE CHANGE
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Energy

• The climate change problem and energy policy are
  correlated, currently, they are completely
  intertwined.
• By most standards, energy use is directly related
  to societal success.
• Hence virtually all elements of society are
  stakeholders.

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World primary energy supply in 1973 and 2003


Source International Energy Agency 2005
megaton oil equivalent
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    Map ProjectionGeographic Map
DescriptionThis map illustrates historic
cumulative carbon emissions from 1950 - 1999 (as
a percentage of global output) at a country-level
. As indicated on the map, areas with highest
cumulative emissions are predominantly found in
"northern" richer nations such as the U.S. (at
27) and the EU (at 18). Alternatively, lowest
carbon emissions are found in economically
challenged
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Top 20 Emitting Nations, 2000
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Source IEA, Key World Energy Data 2005
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The Result of Global Inequality is Gross Carbon
Inequality
World Average CO2 Emissions Per Capita, 2000
1.56 Tons
Rich countries emit around 2.5-6 metric tons
carbon annually per person, while the middle
income nations are around 0.6 mT and the poorest
around 0.02 mT
Source Boden, 2003
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POLICY
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Science, Mitigation, Adaptation Framework
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Some definitions

• Mitigation The notion of limiting or
  controlling emissions of greenhouse gases so that
  the total accumulation is limited.
• Adaptation The notion of making changes in the
  way we do things to adapt to changes in climate.
• Resilience The ability to adapt.
• Geo-engineering The notion that we can manage
  the balance of total energy of the atmosphere,
  ocean, ice, and land to yield a stable climate in
  the presence of changing greenhouse gases.

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Global cooling?
Why do we think that our predictions today are
more robust than these predictions from the 1970s?
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Lets 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.
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What do we know from model experiments and
evaluation (validation) with observations

• With consideration of solar variability and
  volcanic activity, the variability in the
  temperature record prior to 1800 can be
  approximated.
• After 1800 need to consider the impact of man
• Deforestation of North America
• Fossil fuel emission
• Change from coal to oil economy
• Clean air act?
• Only with consideration of CO2, increase in the
  greenhouse effect, can the temperature increase
  of the last 100 years be modeled.

We will revisit this in more detail after we
learn about models.
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Consideration of the past record

• Recorded human history has taken place in a
  period of relatively warm climate.
• Since the last ice age there have been warm and
  cold periods where the global average temperature
  varies by approximately 0.5 degrees F.
• These changes have been accompanied by
  discernable impact on human activities.
• In the past 100 years we have seen an increase of
  degrees.
• Do you feel that there has been impact on humans?
• In the next 100 years we expect to see 3.0
  10.0 rise in global average temperature.
• It is reasonable to expect impact on human
  activities.

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New Regimes of Climate Behavior?
NEW AGE? 500 ppm

• Differences for the Future (100-200 years)
• 100 ppm CO2 (Already)
• gt 200-300 ppm CO2 certain
• 8-20 C polar T difference
• 2-6 C global average T difference

CURRENT (360 ppm)
Behavior of water Phase change

• Differences from Past (20,000 years)
• 100 ppm CO2
• 20 C polar T difference
• 5 C global average T difference

ICE AGE 200 ppm
Time gradient of CO2 changes, 2 orders of
magnitude (100 times) larger.