ATMOS 397G Biogeochemical Cycles and Global Change Lecture 12: Carbon and Climate

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ATMOS 397GBiogeochemical Cycles and Global
ChangeLecture 12 Carbon and Climate

• Don Wuebbles
• Department of Atmospheric Sciences
• University of Illinois, Urbana, IL
• February 27, 2003

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Climate change is one of the biggest issues
confronting humanity in the 21st century

• However,
• Global climate change much better understood
  than regional changes
• Large uncertainties remain in interpreting
  climate change to the local and regional scale

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0.7 oC ( 1.3 oF) increase in global surface
temperature during last 140 years (IPCC, 2001)
Mann et al. (1999) 1000 year reconstruction
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The Evidence for Global Warming

• Warmest temperatures in 1000 years
• 13 of last 15 years highest in 150 years of
  global surface data
• 1998 warmest, then 2001
• Major decline in glacier extent
• Increase in water vapor
• Increase in cloud cover (than 1950s)
• Increase in precipitation at higher latitudes and
  decrease in tropics
• Shortened seasons of lake ice
• Decrease in extent of snow cover
• Large decrease in Arctic sea ice extent
• Increase in sea level

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1000 Year Temperature Records

• Annual Temperatures
• Mann et al., GRL, 1999
• Global Proxies (tree rings, ice cores, and other
  data)
• Crowley and Lowery, AMBIO, 2000
• N.H. Proxies (tree rings, corals, ice cores, and
  other data) and temperature records
• Huang et al., Nature, 2000
• Global Boreholes
• Warm Season Temperatures
• Jones et al., Holocene, 1998
• Briffa, Quat. Sci. Rev., 2000

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T. Crowley, Science, July 2000

• the agreement between modeling results and
  observations for past 1000 years is sufficiently
  compelling to allow one to conclude that natural
  variability plays only a subsidiary role in the
  20th century warming and that the most
  parsimonious explanation is that is due to the
  anthropogenic increase in GHGs (greenhouse
  gases).

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The Evidence for Global Warming

• Major decline in glacier extent

Example The Rhone glacier in the Bernese
Oberland, Switzerland
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IPCC (1996) International assessment Climate
Change 1995, The Science of Climate Change
Nonetheless, the balance of evidence suggests a
discernible human influence on global
climate IPCC (2000) New climate assessment
(gt500 scientists) there has been a discernible
human influence on global climate
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The Drivers of Climate Change
There have been large increases in atmospheric
concentrations of greenhouse gases and in
aerosols over the last century --- Human
activities predominate as the causes of these
increases
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The Effect of a Gas on Climate?

• Determined by its radiative forcing relative to
  other forcings on climate
• What is radiative forcing?
• Increase in concentration of a greenhouse gas
  allows more of the outgoing infrared radiation of
  the Earth to be absorbed by the atmosphere
• This reduces the efficiency by which the Earth
  cools to space
• Tends to warm the lower atmosphere and surface

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Radiative Forcing on Climate
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The Evidence for a Human Effect on Climate

• Both land and ocean temperatures increasing
• Largest changes at higher latitudes
• Patterns of climate change
• Stratosphere is cooling
• Diurnal cycle is decreasing
• Modeling studies can only explain the 20th
  century climate trends if include greenhouse gas
  forcing effects
• Cannot explain in terms of natural variability or
  natural forcing alone

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Constant Emissions of CO2 Does Not Mean Constant
Concentration
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IPCC SRES SCENARIOS
A1 A world of rapid economic growth and rapid
introduction of new and more efficient
technologies A2 A very heterogenous world with
an emphasis on familiy values and local
traditions. B1 A world of dematerialization and
introduction of clean technologies B2 A world
with an emphasis on local solutions to economic
and environmental sustainability
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IPCC (2000) SRES Scenarios ---Business as Usual

• SRES MARKER Scenarios A1, A2, B1, and B2 are
  based on narrative storylines, describe
  alternative future developments in economics,
  technical, environmental and social dimensions.
• A1 rapid economic growth, low population
  growth, rapid introduction of new and more
  efficient technology. In this world, people
  pursue personal wealth rather than environmental
  quality.
• A2 emphasis on family values and local
  traditions, high population growth, and less
  concern for rapid economic development.
• B1 rapid change in economic structures,
  "dematerialization" and introduction of clean
  technologies. The emphasis is on global solutions
  to environmental and social sustainability.
• B2 emphasizes local solutions to economic,
  social, and environmental sustainability, with
  less rapid and more diverse technological change
  but a strong emphasis on community initiative and
  social innovation to find local, rather than
  global solutions.

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Emissionsfor the SRESScenarios
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CO2 Emissions for the SRES Scenarios
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Gas Concentrations derived for the SRES Scenarios
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Derived CO2 Concentration SRES Scenarios
All SRES envelop including climate sensitivity
uncertainty
All SRES envelop reference case
A1B Scenario envelop including climate
sensitivity uncertainty
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Uncertainty in projecting CO2
Model studies of uptake of Anthropogenic CO2 show
possible saturation effects.
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Projected temperature response
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Projected sea level response
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Sea Level Rise has Societal and Ecological
Implications
Coral Bleeching and Destruction
Toxic Algae Blooms
Sandbags in Alaska
Coastal Florida
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Concerns about Impacts of Climate Change are at
the Local to Regional Level

• Concerns
• Temperature, precipitation, winds
• Changes in sea level
• Severe weather (heat waves, cold snaps, floods,
  droughts)
• Impacts
• Water quality / quantity
• Air quality
• Agriculture
• Forests
• Ecosystems
• Communities, cities
• Human health (disease and health patterns)
• Infrastructure (transportation, energy systems)

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Achieving a Sustainable Climate (ASC)Positioning
National Resources to Resolve Climate Change

• Improving definition of the problem
• Diagnosis and understanding (climate, carbon
  cycle, etc.)
• Evaluating the impacts
• Determine ability to adapt to some climate change
• Solving the problem
• Technology to increase conservation / efficiency
• Reduced-carbon energy technology development
• Public acceptance of nuclear technology
• Fuel cells, etc.
• Carbon capture and sequestration
• ASC would also help solve other energy issues
  (e.g., California 2001 Reliance on foreign
  oil)

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ASC---The Climate Change Challenge

• The IPCC business-as-usual scenarios

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ASC---The Climate Change Challenge

• 1992 United Nations Framework Convention on
  Climate Change (FCCC)
• GOALstabilization of greenhouse gas
  concentrations in the atmosphere at a level that
  would prevent dangerous anthropogenic
  interference with the climate system. (Article
  2)
• Stabilizing Concentrations Is not the Same as
  Stabilizing Emissions
• Stabilizing Concentrations Implies Human-related
  Emissions Must (approximately) Go to ZERO.
• Cumulative Emissions?Concentrations

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ASC---The Climate Change Challenge

• Changes Required in Human-related CO2 Emissions
  to Stabilize Atmospheric Concentrations
• Requires peak then decline in emissions

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The Challenge Achieving a Sustainable Climate
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Hoffert et al. (Nature, 1998)
IS92a Business-as-Usual scenario assumes 11 TW
Carbon Free Energy by 2050
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Without New Technology Carbon Emissions
Concentrations Will Rise
Emissions
Concentrations
Current Energy ST can reduce carbon emission.
But stabilization requires additional Carbon ST!
Preindustrial CO2
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Climate policy requires a portfolio of responses,
including

• Resolving scientific uncertainty
• Emissions mitigation,
• Technology development,
• Climate adaptation

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Need flexibility while developing technology
Uncertain Technology
AOG 550
CBF 550
Analyses from Jae Edmonds, 2001
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When take a cost effective technology out of the
portfolio, the costs of stabilizing CO2 are
raisedThe Value of Carbon Capture Sequestration
CBF
NOTES CPCarbon capture sequestration from
fossil fuels used to generate electric power. H2
Seq.Fossil fuels used as feedstocks for hydrogen
production with carbon capture and
sequestration. Results from Jae Edmonds, 2001
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ASC---The Climate Change Challenge

• Stabilization requires fundamental change in the
  energy system
• Technology advances are key to stabilizing CO2
  concentrations and controlling costs
• Diversified technology portfolios are essential
  to manage risk
• Technologies that fill the gap are not part of
  the current energy system.
• Carbon capture and sequestration technologies
  expand dramatically.
• The technology portfolio changes over time.
• Some technologies are more important when others
  are also available.
• Some technologies expand their relative
  importance without expanding their absolute
  deployment.
• Need to revisit the technology strategy
  frequently
• Energy RD funding needs to be extensively
  increased as part of ASC
• Solution will also require public-private
  partnerships

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Energy Research
Declining,
Uncoordinated,
Not Climate Focused.
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Energy RD What is done in the next 10 years will
strongly influence what is possible in the next
50 years
It traditionally has taken 50 years or more for a
technology to grow from 1 to 50 of the market.