Page 1
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Radiative Forcing (from IPCC WG-I, Chapter 2)Radiative Forcing (from IPCC WG-I, Chapter 2)
Changes in Radiative ForcingChanges in Radiative Forcing
Primary Source: Primary Source:
IPCC WG-I Chapter 2 - IPCC WG-I Chapter 2 - Changes in Atmospheric Constituents and in Radiative ForcingChanges in Atmospheric Constituents and in Radiative Forcing
Page 2
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Radiative Forcing (from IPCC WG-I, Chapter 2)Radiative Forcing (from IPCC WG-I, Chapter 2)
Key FindingsKey Findings
1. Extremely likely (> 95%) that humans have exerted a substantial warming influence on climate since 1750.
2. Likely (> 66%) that the human influence by radiative forcing is at least 5 times greater than solar influence since 1750.
3. Exceptionally unlikely (< 1%) that solar + volcanic radiative forcing for 1950-2005 was comparable to anthropogenic radiative forcing.
Page 3
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Radiative Forcing (from IPCC WG-I, Chapter 2)Radiative Forcing (from IPCC WG-I, Chapter 2)
Major Types of Radiative ForcingsMajor Types of Radiative Forcings
Changes in …Changes in …
• Greenhouse GasesGreenhouse Gases
• Aerosols (particles)Aerosols (particles)
• Surface albedoSurface albedo
• ContrailsContrails
• Solar variabilitySolar variability
• Volcanic activityVolcanic activity
Page 4
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Radiative Forcing (from IPCC WG-I, Chapter 2)Radiative Forcing (from IPCC WG-I, Chapter 2)
Radiative Forcing: Balanced StateRadiative Forcing: Balanced State
Radiative BalanceRadiative Balance
Radiative-Dynamic BalanceRadiative-Dynamic Balance
Page 5
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Radiative Forcing (from IPCC WG-I, Chapter 2)Radiative Forcing (from IPCC WG-I, Chapter 2)
Radiative ForcingRadiative Forcing
Change in net radiative energy flux at the tropopause with …Change in net radiative energy flux at the tropopause with …(a) stratospheric temperatures readjusted to radiative equilibrium(a) stratospheric temperatures readjusted to radiative equilibrium(b) surface and tropospheric temperatures and state held fixed at (b) surface and tropospheric temperatures and state held fixed at
original valuesoriginal values(Ramaswamy et al., 2001)(Ramaswamy et al., 2001)
Page 6
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Radiative Forcing (from IPCC WG-I, Chapter 2)Radiative Forcing (from IPCC WG-I, Chapter 2)
Carbon Dioxide Carbon Dioxide (CO(CO22))
Pre-industrial: ~ 280 ppmPre-industrial: ~ 280 ppm
Sources:Sources:
1.1. Fossil fuelsFossil fuels
2.2. Cement productionCement production
3.3. DeforestationDeforestation
4.4. Biomass burningBiomass burning
Page 7
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Radiative Forcing (from IPCC WG-I, Chapter 2)Radiative Forcing (from IPCC WG-I, Chapter 2)
COCO22 Emissions Emissions
1313C/C/1212C: C:
Atmosphere > Terrestrial SourcesAtmosphere > Terrestrial Sources
OO22 as CO as CO22 : :
- CombustionCombustion
- Plant respiration/photosynthesisPlant respiration/photosynthesis
Page 8
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Radiative Forcing (from IPCC WG-I, Chapter 2)Radiative Forcing (from IPCC WG-I, Chapter 2)
Methane (CHMethane (CH44))
NOAA Global Monitoring Division (GMD)
Advanced Global Atmospheric Gases Experiments (AGAGE)
Sources:Sources:
1.1. Biogenic:Biogenic:
- WetlandsWetlands
- RiceRice
- Biomass burningBiomass burning
- RuminantsRuminants
2.2. Fossil fuel mining Fossil fuel mining and distributionand distribution
3.3. Living vegetation?Living vegetation?
Mt. Pinatubo?
Economic Incentives?
Warm 1998?
Page 9
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Radiative Forcing (from IPCC WG-I, Chapter 2)Radiative Forcing (from IPCC WG-I, Chapter 2)
Nitrous Oxide (NNitrous Oxide (N22O)O)
Sources:Sources:
1.1. Coastal areas:Coastal areas:
- continental continental shelvesshelves
- estuariesestuaries
- riversrivers
2.2. Land processesLand processes
Page 10
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Radiative Forcing (from IPCC WG-I, Chapter 2)Radiative Forcing (from IPCC WG-I, Chapter 2)
HalocarbonsHalocarbons
Small amounts, but Small amounts, but effective absorbers of effective absorbers of infrared radiationinfrared radiation
Factors:Factors:
1.1. Industrial Industrial processesprocesses
2.2. Partly regulated Partly regulated by Montreal by Montreal ProtocolProtocol
Page 11
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Radiative Forcing (from IPCC WG-I, Chapter 2)Radiative Forcing (from IPCC WG-I, Chapter 2)
Other GasesOther Gases
• Stratospheric OzoneStratospheric Ozone
• Tropospheric OzoneTropospheric Ozone
• Stratospheric Water VaporStratospheric Water Vapor
Page 12
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Radiative Forcing (from IPCC WG-I, Chapter 2)Radiative Forcing (from IPCC WG-I, Chapter 2)
Aerosol EffectsAerosol Effects
Page 13
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Radiative Forcing (from IPCC WG-I, Chapter 2)Radiative Forcing (from IPCC WG-I, Chapter 2)
Aerosol TypesAerosol Types
• SulphateSulphate
• Organic Carbon from Fossil FuelsOrganic Carbon from Fossil Fuels
• Black Carbon from Fossil FuelsBlack Carbon from Fossil Fuels
• Biomass BurningBiomass Burning
• NitrateNitrate
• Mineral DustMineral Dust
Page 14
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Radiative Forcing (from IPCC WG-I, Chapter 2)Radiative Forcing (from IPCC WG-I, Chapter 2)
Aerosol Aerosol DistributionsDistributions
Biomass BurningBiomass Burning
Optical Depth ~ Radiative “Thickness”Optical Depth ~ Radiative “Thickness”
White = measurement not possibleWhite = measurement not possible
Mineral DustMineral Dust
IndustrialIndustrial
Sea SaltSea Salt
Page 15
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Radiative Forcing (from IPCC WG-I, Chapter 2)Radiative Forcing (from IPCC WG-I, Chapter 2)
Land Use ChangesLand Use Changes
Albedo DifferencesAlbedo Differences
Forest < CroplandForest < Cropland
Snow-covered forest < Snow-covered forest < Snow-covered croplandSnow-covered cropland
Page 16
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Radiative Forcing (from IPCC WG-I, Chapter 2)Radiative Forcing (from IPCC WG-I, Chapter 2)
Other Surface EffectsOther Surface Effects
• Black Carbon on Snow/IceBlack Carbon on Snow/Ice
• Land-Use Changes on Surface FluxesLand-Use Changes on Surface Fluxes
• Anthropogenic Water Vapor ReleaseAnthropogenic Water Vapor Release
• Anthropogenic Energy ReleaseAnthropogenic Energy Release
• COCO22 Influence on Plant Physiology Influence on Plant Physiology
Page 17
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Radiative Forcing (from IPCC WG-I, Chapter 2)Radiative Forcing (from IPCC WG-I, Chapter 2)
Solar Heating: ChangeSolar Heating: Change
Variability due to Variability due to
1. Changes in sunspots and faculae1. Changes in sunspots and faculae
2. Changes in solar diameter?2. Changes in solar diameter?
Page 18
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Radiative Forcing (from IPCC WG-I, Chapter 2)Radiative Forcing (from IPCC WG-I, Chapter 2)
Reconstructed Solar HeatingReconstructed Solar Heating
Page 19
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Radiative Forcing (from IPCC WG-I, Chapter 2)Radiative Forcing (from IPCC WG-I, Chapter 2)
Volcanic AerosolsVolcanic Aerosols
Page 20
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Radiative Forcing (from IPCC WG-I, Chapter 2)Radiative Forcing (from IPCC WG-I, Chapter 2)
Time Evolution of Time Evolution of Forcing Forcing
(Representative GCM)(Representative GCM)
Page 21
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Radiative Forcing (from IPCC WG-I, Chapter 2)Radiative Forcing (from IPCC WG-I, Chapter 2)
Net RF: Net RF: 1750 to 20051750 to 2005
Page 22
(Mt/Ag/EnSc/EnSt 404/504 - Global Change)(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Radiative Forcing (from IPCC WG-I, Chapter 2)Radiative Forcing (from IPCC WG-I, Chapter 2)
ENDEND
Changes in Radiative ForcingChanges in Radiative Forcing