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Intergovernmental Panel on Climate Change (IPCC). Established by the UN and World Meteorological Organization in 1988 Role of the IPCC: to assess the scientific, technical, and socio-economic information relevant for the understanding of the risks of human-induced climate change. - PowerPoint PPT Presentation
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Intergovernmental Panel on Intergovernmental Panel on Climate Change (IPCC)Climate Change (IPCC)
• Established by the UN and World Meteorological Established by the UN and World Meteorological Organization in 1988Organization in 1988
• Role of the IPCC: to assess the scientific, Role of the IPCC: to assess the scientific, technical, and socio-economic information technical, and socio-economic information relevant for the understanding of the risks of relevant for the understanding of the risks of human-induced climate change.human-induced climate change.
• Assessments based on published and peer-Assessments based on published and peer-reviewed literaturereviewed literature
Intergovernmental Panel on Intergovernmental Panel on Climate Change (IPCC)Climate Change (IPCC)
• 2,500 of the world’s leading climate scientists and 2,500 of the world’s leading climate scientists and technical experts contribute to reportstechnical experts contribute to reports
• Provides comprehensive and balanced assessments Provides comprehensive and balanced assessments of climate change science, impacts, and adaptation of climate change science, impacts, and adaptation and mitigation optionsand mitigation options
• Extensive peer-review and governmental review Extensive peer-review and governmental review ensures scientific credibility and policy relevanceensures scientific credibility and policy relevance
Intergovernmental Panel on Climate Change (IPCC)Intergovernmental Panel on Climate Change (IPCC)
Working Group IWorking Group IClimate changeClimate change
sciencescience
Working Group IIWorking Group IIImpacts, Impacts,
adaptation andadaptation andvulnerabilityvulnerability
Working Group IIIWorking Group IIIMitigationMitigation
Task forceTask forceon nationalon national
greenhouse gasgreenhouse gasinventoriesinventories
Technical supportTechnical supportunit (TSU) inunit (TSU) in
United KingdomUnited Kingdom
TSU inTSU inUnited StatesUnited States
TSU inTSU inThe NetherlandsThe Netherlands
TSU inTSU inJapanJapan
PlenaryPlenaryIPCC SecretariatIPCC Secretariat
WMO/UNEPWMO/UNEPSwitzerlandSwitzerland
Experts, authors, contributors, reviewersExperts, authors, contributors, reviewers
Source: Redrawn from Vital Climate Graphics
IPCC Assessment ReportsIPCC Assessment Reports
• Standard reference workStandard reference work• First Assessment Report (FAR) - published in 1990First Assessment Report (FAR) - published in 1990
– Projected increase in temperature of 3 - 8 °FProjected increase in temperature of 3 - 8 °F
– Consequences: rising sea levels, increase in extreme Consequences: rising sea levels, increase in extreme weather events, serious pressure on aquatic and terrestrial weather events, serious pressure on aquatic and terrestrial ecosystemsecosystems
– ““The size of the warming is broadly consistent with The size of the warming is broadly consistent with predictions of climate models, . . . but the unequivocal predictions of climate models, . . . but the unequivocal detection of the enhanced greenhouse effect from detection of the enhanced greenhouse effect from observations is not likely for a decade or moreobservations is not likely for a decade or more.”.”
IPCC Assessment report foci
19901995
2001
• Climate has changed over the past centuryClimate has changed over the past century– Global mean surface air temperature has increased .5-1Global mean surface air temperature has increased .5-1oo FF– Global sea level has risen 4-10 inchesGlobal sea level has risen 4-10 inches– Global precipitation over land has increased 1%Global precipitation over land has increased 1%
• “ “ Human signal still building . . . Nevertheless, the balance Human signal still building . . . Nevertheless, the balance of evidence suggests a discernible human influence on global of evidence suggests a discernible human influence on global climate.”climate.”
IPCC Second Assessment IPCC Second Assessment Report ConclusionsReport Conclusions
• Climate has changed over the past centuryClimate has changed over the past century– Global mean surface air temperature has increased .5-1Global mean surface air temperature has increased .5-1oo FF– Global sea level has risen 4-10 inchesGlobal sea level has risen 4-10 inches– Global precipitation over land has increased 1%Global precipitation over land has increased 1%
• “ “ Human signal still building . . . Nevertheless, the balance of Human signal still building . . . Nevertheless, the balance of evidence suggests a discernible human influence on global evidence suggests a discernible human influence on global climate.”climate.”
• Climate is expected to continue to change in the futureClimate is expected to continue to change in the future– Projected temperature increase of 1.8-6.3Projected temperature increase of 1.8-6.3ooF by 2100F by 2100– Projected sea-level rise of 6-37 inches by 2100Projected sea-level rise of 6-37 inches by 2100– Likely increase in extreme weather eventsLikely increase in extreme weather events
IPCC Second Assessment IPCC Second Assessment Report ConclusionsReport Conclusions
Kyoto ProtocolKyoto Protocol
• SAR provided key input to the negotiations SAR provided key input to the negotiations that led to the adoption of the Kyoto that led to the adoption of the Kyoto Protocol in 1997Protocol in 1997
• Is an international agreement that Is an international agreement that establishes binding targets for reduction of establishes binding targets for reduction of greenhouse gases emitted by developed greenhouse gases emitted by developed countries.countries.
Emission ScenariosEmission Scenarios• SAR - used scenarios developed in 1992, known as the SAR - used scenarios developed in 1992, known as the
IS92 seriesIS92 series • Alternative projections of population, affluence, and Alternative projections of population, affluence, and
technological change were used to come up with a technological change were used to come up with a range of future GHG emission scenariosrange of future GHG emission scenarios
• 1995 - IPCC evaluated the IS92 scenarios, 1995 - IPCC evaluated the IS92 scenarios, recommended that a new set of scenarios be developed recommended that a new set of scenarios be developed - Special Report on Emission Scenarios- Special Report on Emission Scenarios
• TAR - projections are underlain by the full range of TAR - projections are underlain by the full range of SRES scenariosSRES scenarios
Third Assessment Report Third Assessment Report of the IPCCof the IPCC
• Published in 2001Published in 2001
• Emphasizes information from the last 5 Emphasizes information from the last 5 yearsyears
• Places climate change in the context of Places climate change in the context of sustainable development, emphasizing sustainable development, emphasizing equity issuesequity issues
• Policy relevant, but not policy prescriptivePolicy relevant, but not policy prescriptive
IPCC Third Assessment ReportIPCC Third Assessment ReportKey Findings of Working Group IKey Findings of Working Group I
““An increasing body of observations gives a An increasing body of observations gives a collective picture of a warming world and collective picture of a warming world and other changes in the climate system.”other changes in the climate system.”
Source: IPCC TAR 2001
Variations of the Variations of the Earth’s Surface Earth’s Surface Temperature*Temperature*
*relative to 1961-1990 average*relative to 1961-1990 average
Global Annual Temperature Trends:Global Annual Temperature Trends:1901 - 19901901 - 1990
Source: Watson 2000
U.S. Temperature Trends: 1901 to 1998U.S. Temperature Trends: 1901 to 1998
Red circles = warming; Blue circles = coolingRed circles = warming; Blue circles = coolingAll stations/trends displayed regardless of statistical significance.All stations/trends displayed regardless of statistical significance.
Source: National Climatic Data Center/NESDIS/NOAA
U.S. Precipitation Trends: 1901 to 1998U.S. Precipitation Trends: 1901 to 1998
Source: National Climatic Data Center/NESDIS/NOAA
GreenGreen •• = increasing, Brown= increasing, Brown •• = decreasing= decreasingAll stations/trends displayed regardless of statistical significanceAll stations/trends displayed regardless of statistical significance
Extreme Precipitation Events in the U.S.Extreme Precipitation Events in the U.S.
Source: Karl, et.al. 1996.
Increase in catastrophic flood eventsIncrease in catastrophic flood events
Increase in frequency and Increase in frequency and intensity of droughtsintensity of droughts
Source: OSTP
Snow cover and ice extent have decreasedSnow cover and ice extent have decreased
Global average sea level has risen Global average sea level has risen and ocean heat content has increasedand ocean heat content has increased
IPCC Third Assessment ReportIPCC Third Assessment ReportKey Findings of Working Group IKey Findings of Working Group I
““Emissions of greenhouse gases and aerosols Emissions of greenhouse gases and aerosols due to human activities continue to alter the due to human activities continue to alter the atmosphere in ways that are expected to atmosphere in ways that are expected to affect the climate.”affect the climate.”
Indicators of the Human InfluenceIndicators of the Human Influenceon the Atmosphere during the Industrial Eraon the Atmosphere during the Industrial Era
Source: IPCC TAR 2001
IPCC Third Assessment ReportIPCC Third Assessment ReportKey Findings of Working Group IKey Findings of Working Group I
““Confidence in the ability of models to Confidence in the ability of models to project future climate has increased.”project future climate has increased.”
IPCC Third Assessment ReportIPCC Third Assessment ReportKey Findings of Working Group IKey Findings of Working Group I
““There is new and stronger evidence that most There is new and stronger evidence that most of the warming observed over the last 50 of the warming observed over the last 50 years is attributable to human activities.”years is attributable to human activities.”
IPCC Third Assessment ReportIPCC Third Assessment ReportKey Findings of Working Group IKey Findings of Working Group I
““Human influences will continue to change Human influences will continue to change atmospheric composition throughout the atmospheric composition throughout the 21st century.”21st century.”
IPCC Third Assessment ReportIPCC Third Assessment ReportKey Findings of Working Group IKey Findings of Working Group I
““Global average temperature and sea level Global average temperature and sea level are projected to rise under all IPCC are projected to rise under all IPCC scenarios.”scenarios.”
Main Findings of WG I Main Findings of WG I • Extensive and wide-spread evidence that the earth is warming; Extensive and wide-spread evidence that the earth is warming;
we are already seeing the first clear signals of a changing we are already seeing the first clear signals of a changing climate.climate.
• Human activities are changing the atmospheric concentrations Human activities are changing the atmospheric concentrations of greenhouse gases.of greenhouse gases.
• New and stronger evidence of a human influence on climate.New and stronger evidence of a human influence on climate.
• Global temperature will rise from 2.5 to 10.4°F over this Global temperature will rise from 2.5 to 10.4°F over this century. century. Precipitation patterns will change, sea level will rise Precipitation patterns will change, sea level will rise
and extreme weather events will increase.and extreme weather events will increase. • Human influence will continue to grow during the next century Human influence will continue to grow during the next century
unless measures are taken to reduce GHG emissions.unless measures are taken to reduce GHG emissions.
IPCC History: Evolution of IPCC History: Evolution of Our KnowledgeOur Knowledge
• FAR (1990): “FAR (1990): “The size of the warming is broadly The size of the warming is broadly consistent with predictions of climate models, . . . but the consistent with predictions of climate models, . . . but the unequivocal detection of the enhanced greenhouse effect unequivocal detection of the enhanced greenhouse effect from observations is not likely for a decade or more.”from observations is not likely for a decade or more.”
• SAR (1996):SAR (1996): “The balance of evidence suggests a “The balance of evidence suggests a discernible human influence on climate.”discernible human influence on climate.”
• TAR (2001):TAR (2001): “There is new and stronger evidence that “There is new and stronger evidence that most of the warming observed over the last 50 years is most of the warming observed over the last 50 years is attributable to human activities.”attributable to human activities.”
IPCC Scenario formulation
Data vs. Models in Science
Data tell us about the past– But in nonlinear systems (like climate), past trends not
necessarily predictive of future
Models project the future– Connect theory with data– Can work with nonlinear systems
But how do we know models are correct?– Right answers for wrong reasons
Climate Models
3-dimensional mathematical simulations – based on “first principles”: physical equations of motion and
state
– transport of heat, moisture, energy– grids (4-5° latitude, or 400-500 km)– time steps (15-30 minutes)– long-term simulations (years to centuries)
Computationally expensive– hundreds of supercomputer hours per run
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General Circulation Models
Governed by physics:
- Law of Continuity- Equation of State- Conservation of energy- Conservation of momentum
Input: solar forcing, Earth rotation, seasons, initial conditions, greenhouse gas levels
Output: temperature, precip, pressures, winds, ocean currents, heat transport, deep ocean circulation…
Run a GCM on your computer?http://www.edgcm.org/
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One “experiment” takes 3-4 days of cpu time
SRES Scenarios
The A1 storyline and scenario family describes a future world of very rapid economic growth, low population growth, and the rapid introduction of new and more efficient technologies. Major underlying themes are convergence among regions, capacity building, and increased cultural and social interactions, with a substantial reduction in regional differences in per capita income.
The A2 storyline and scenario family describes a very heterogeneous world. The underlying theme is self-reliance and preservation of local identities. Fertility patterns across regions converge very slowly, which results in high population growth. Economic development is primarily regionally oriented.
The B1 storyline and scenario family describes a convergent world with the same low population growth as in the A1 storyline, but with rapid changes in economic structures toward a service and information economy, with reductions in material intensity, and the introduction of clean and resource-efficient technologies. Global solutions to economic, social, and environmental sustainability, including improved equity, but without additional climate initiatives.
The B2 storyline and scenario family describes a world in which the emphasis is on local solutions to economic, social, and environmental sustainability. It is a world with moderate population growth, intermediate levels of economic development, and less rapid and more diverse technological change than in the B1 and A1 storylines. While the scenario is also oriented toward environmental protection and social equity, it focuses on local and regional levels.
COCO22 and SO and SO22 in the 21 in the 21stst Century Century
Source: IPCC TAR 2001
Global average temperature Global average temperature is projected to increase by is projected to increase by 1.4 - 5.8°C by 21001.4 - 5.8°C by 2100
Projected temperature Projected temperature increases are increases are greatergreater than than those in the SARthose in the SAR
Projected rate of warming is Projected rate of warming is unprecedented for last unprecedented for last 10,000 years10,000 years
Temperature ProjectionsTemperature Projections
Source: IPCC TAR 2001
1000AD to 1861, N. 1000AD to 1861, N. Hemisphere, proxy Hemisphere, proxy data data
1861 to 2000, Global, 1861 to 2000, Global, instrumentalinstrumental
2000 to 2100, SRES 2000 to 2100, SRES projectionsprojections
Source: IPCC TAR 2001
Variations of the Earth’s SurfaceVariations of the Earth’s SurfaceTemperature - 1000 to 2100Temperature - 1000 to 2100
Projected Changes in Annual Temperatures for the 2050sProjected Changes in Annual Temperatures for the 2050s
The projected change is compared to the present day with a ~1% increase per year in equivalent COThe projected change is compared to the present day with a ~1% increase per year in equivalent CO 22
Source: The Met Office. Hadley Center for Climate Prediction and Research
A probabilistic view…
“With the climatological probability of a hot summer represented by two faces (say painted red) of a six-faced die, judging from our model by the 1990s three or four of the six die faces will be red. It seems to us that this is a sufficient ‘loading’ of the dice that it will be noticeable to the man in the street.”
Hansen et al., J. Geophys. Res. 93, 9341-9364, 1988.
Metro NYC region: Impact study
Ulster
Suffolk
Sullivan
Orange
Litchfield
Ocean
Dutchess
Fairfield
Morris
Sussex
New Haven
Warren
Monmouth
Hunterdon
Westchester
Nassau
Bergen
Putnam
Mercer
Somerset
Middlesex
Passaic
Essex
Rockland
Union
QueensKings
Bronx
Hudson
Richmond
New York
31 counties in 3 states (NY, NJ, CT)21 million residents13,000 square milesVariety of pop densities & land uses
Estimated Increases in Ozone Excedences ( 1 hour >120 ppb)for the New York Metro Region by 2050
1990 Hottest Summer Climate
2050 A2 Hottest
Summer Climate
1990 air pollutant emissions
786 3,266
2050 A2 air pollutant emissions
1,745 7,489
(from C. Hogrefe et al, 2003)
(+122%)
(+315%)
(+749%)
Temperature & Mortality Relationship in 11 Eastern US Cities
(Curreiro et al, 2002)
Public Health Impacts(PHI) Model
•STUDY•POP •x
•BASE•RISK •x
•CHANGE
•IN ENV •x
•EXP-•RISK•COEF
F •=
•# ADD’L•PHIs IN
•FUTURE
Public Health Impacts(PHI) Model
•STUDY•POP •x
•BASE•RISK •x
•CHANGE
•IN ENV •x
•EXP-•RISK•COEF
F •=
•# ADD’L•PHIs IN
•FUTURE
Census 2000 county pop
Public Health Impacts(PHI) Model
•STUDY•POP •x
•BASE•RISK •x
•CHANGE
•IN ENV •x
•EXP-•RISK•COEF
F •=
•# ADD’L•PHIs IN
•FUTURE
1990-1999 average annual
non-heat-rel mortality risk
Public Health Impacts(PHI) Model
•STUDY•POP •x
•BASE•RISK •x
•CHANGE
•IN ENV •x
•EXP-•RISK•COEF
F •=
•# ADD’L•PHIs IN
•FUTURE
(# days > MMT range)* (average #degrees F above
MMT range on those days)
Source: R Goldberg & C Rosenzweig, NASA-GISS
Public Health Impacts(PHI) Model
•STUDY•POP •x
•BASE•RISK •x
•CHANGE
•IN ENV •x
•EXP-•RISK•COEF
F •=
•# ADD’L•PHIs IN
•FUTURE
1.305% increase RR mortality per
deg F>MMT range (“hot
slope”)
Public Health Impacts(PHI) Model
•STUDY•POP •x
•BASE•RISK •x
•CHANGE
•IN ENV •x
•EXP-•RISK•COEF
F •=
•# ADD’L•PHIs IN
•FUTURE
Additional # impacts (e.g. deaths) from env
change
NYC “optimal mortality temperature range” ~ 53.14 F – 73.54 F
from Curreiro et al. (2002 revision, ms. submitted)
Rel
ativ
e R
isk
of
Mor
talit
y
Average Daily Temperature (deg F)
NYCHP, Phase I: Preliminary Heat-Mortality Results Summers: Observed 1990s vs. GISS-modeled 2050s
Population Growth consistent with IPCC A2 & B2 scenarios*
In a typical SUMMER(June 1 - August 31):
1990s GISS A2 2050s GISS B2 2050s
Regional non-temperature-related deaths, all internal causes
42,117 64,509 52,312
Regional population 21,491,898 32,917,889 26,694,229
# Heat-related deaths 1,734 4,759 3,272
% Heat-related vs. Same-yrnon-temperature-related deaths
4.1% 7.4% 6.3%
# Additional heat-related deaths, 2050s vs. 1990s
3,025 1,538
% Increase above 1990s heat-related deaths
174.5% 88.7%
Heat-related mortality risk in regional population
8.1/100K 14.5/100K(6.4/100 K incr)
12.3/100K(4.2/100K incr)
* Regional population growth consistent with B2 population growth projections in 5-yr steps from 1990 to 2100 by Stuart Gaffin & Xiaoshi Xing (CIESIN, 2002); same for A2 population growth projections by Wolfgang Lutz at IIASA (CIESIN, 2002)
Precipitation ProjectionsPrecipitation Projections
• Global average water vapor and global mean Global average water vapor and global mean precipitation will increaseprecipitation will increase
• Larger year to year variations in precipitationLarger year to year variations in precipitation
Projected Changes in Annual Precipitation for the 2050sProjected Changes in Annual Precipitation for the 2050s
Source: The Met Office. Hadley Center for Climate Prediction and Research
The projected change is compared to the present day with a ~1% increase per year in equivalent COThe projected change is compared to the present day with a ~1% increase per year in equivalent CO 22
Change in Phenomenon Confidence in projected change*
Increase in tropical cyclone peak wind and precipitation intensities Likely, over some areas
Increased summer continental drying & associated risk of drought
More intense precipitation events
Increase of heat index
Higher minimum temperatures, fewer cold days and frost days
Higher maximum temperatures, more hot days
Likely, over most mid-latitude continental interiors
Very likely, over most areas
Very likely, over many areas
Very likely
Very likely
Extreme EventsExtreme Events
*Judgmental estimates of confidence by IPCC: *Judgmental estimates of confidence by IPCC: very likelyvery likely - 90-99% chance, - 90-99% chance,likelylikely - 66-90% chance. - 66-90% chance.
Source: IPCC TAR 2001
• Global average sea level is Global average sea level is projected to rise by 4 to 35 inches projected to rise by 4 to 35 inches between 1990 and 2100between 1990 and 2100
• Projected rise is slightly lower Projected rise is slightly lower than the range presented in the than the range presented in the SAR (6 to 37 inches)SAR (6 to 37 inches)
• Sea level will continue to rise for Sea level will continue to rise for hundreds of years after hundreds of years after stabilization of greenhouse gas stabilization of greenhouse gas concentrationsconcentrations
Sea-Level Rise ProjectionsSea-Level Rise Projections
Source: IPCC TAR 2001
Sea-Level Rise CommitmentSea-Level Rise Commitment
Thermal expansion and land ice melt after an initial 1% increase in COThermal expansion and land ice melt after an initial 1% increase in CO22 for 70 years for 70 years
Source: The Met Office. Hadley Center for Climate Prediction and Research
Jim Hansen’s View (NASA/GISS)
1. Climate is Changing (Global Warming)
2. Human (Greenhouse Gas) Role is Probable
3. Global Warming Increases Hydrologic Extremes
(droughts/fires and heavy rain/floods)
4. With Large Climate Change, Detrimental Effects
Probably Exceed Beneficial Ones
5. Common Sense Steps to limit emissions are
warranted
6. Steps also to reverse CO2 trends (sequestration)
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Discussion question
What should we do?Nothing, it’s a hoax.
Wait until climate change is certain?
Take precautionary measures to reduce emissions?
Take drastic measures to reduce emissions?
Acknowledgement
For more information about UCS, visit <www.ucsusa.org>.