Quantification of Greenhouse Gas Emissions:A NOAA PerspectiveDr. Arlyn E. AndrewsNOAA Earth System Research LaboratoryGlobal Monitoring DivisionE-mail: Arlyn.Andrews@noaa.gov5 th Annual California Climate Change Conference, 8-10 Sept 2008
•Atmospheric concentration measurements are criticalfor understanding the sources and sinks of long-livedgreenhouse gases. Examples: CO 2 , CH 4 , N 2 O, SF 6•Objective, independent evaluation of inventories willbe needed to verify emissions changes if internationalGHG emissions reduction targets are implemented.‣CO 2 emissions inventories for the US are likelyhighly accurate, but globally are less reliable‣“Top-down” estimates of emissions provideindependent check on inventories for CO 2 and otherGHGs with poorly known sources (CH 4 , N 2 O, etc.).•Highly precise and accurate long-term measurementsof atmospheric abundance are essential to quantifyfuture spatial and temporal changes in emissions
NOAA Earth System Research LaboratoryCarbon Cycle/GHG Measurement ProgramsTowerAircraftFlaskObservatory
NOAA Earth System Research LaboratoryCarbon Cycle/GHG Measurement Programs• CO 2 , CH 4 , N 2 O, SF 6 measured at all sites• CFCs, HCFCs, HFCs and other minorgreenhouse gases measured at manysites• CarbonTracker-CH 4 is coming soon!
CO 2CH 4http://www.esrl.noaa.gov/gmd/aggi/
97% of forcing
3% of forcing•CFC-113•CCl 4•CH 3 CCl 3•HCFCs: 22, 141b and142b,•HFC134a•SF 6•Halons: 1211 and 1301
CO 2 : Land and ocean are large sinks4Expected increase if all fossil emissionsremained in the atmosphereCO 2Growth Rate, ppm/year3210Observed atmosphericincrease from NOAA GlobalObserved IncreaseCooperative Expected SamplingIncrease No UptakeNetwork1990199520002005
CO 2 : Land and ocean are large sinks4Expected increase if all fossil emissionsremained in the atmosphereCO 2Growth Rate, ppm/year3210Observed IncreaseObserved IncreaseExpected Increase No Uptake•2001-2004: 58% of emissions stayed in atmosphere1990 22.5% absorbed 1995 by ocean 19.5% 2000 taken up 2005 by landbiosphere•Emissions inventories don’t tell the whole story
NOAA’s CarbonTracker•Observing Network•Data Assimilation Frameworkcarbontracker.noaa.gov
CarbonTracker Overview:Optimization step is Ensemble Kalman Filter
CarbonTracker Mechanics:OptimizedFIRES= GFED2Specifiedhttp://carbontracker.noaa.gov
CarbonTracker Products:Maps: weekly, monthly, annualNorth America and Global
CarbonTracker Products:Tablulated results: e.g., Jan 1-6 2000Region NameTotal NorthAmericaBoreal NorthAmericaTemperate NorthAmericaEstimatedMeanFossilEmissionsFireEmissions2.73 ± 0.60 2.14 0.010.72 ± 0.21 0.01 0.002.01 ± 0.53 2.12 0.01TotalFlux4.88 ±0.600.74 ±0.214.14 ±0.53
CarbonTracker Products:Tablular output: e.g., Jan 1-6 2000Region NameTemperate NorthAmericaEstimatedMeanFossilEmissionsFireEmissions2.01 ± 0.53 2.12 0.01TotalFluxModel Total North output available for download:2.73 ± 0.60 2.14 0.01Gridded America 4-dimensional CO 2 fields 6-hourly avgGridded Boreal North 3-hourly0.72average± 0.21fluxes0.01 0.00America(global 6x4 degrees, North America 1x1 degrees)4.88 ±0.600.74 ±0.214.14 ±0.53
Automated Flask Sampling from Aircraft:•One twelve-pack per flight•Typical profile from 500 m AGL to 8000 m ASL• Species: CO 2 , CO, CH 4 , N 2 O, SF 6 ,stable isotopes, halocarbons, COS, hydrocarbons…14CO 2 on a limited number of samples
Automated Flask Sampling from Aircraft:•One twelve-pack per flight•Typical profile from 500 m AGL to 8000 m ASL• Species: CO 2 , CO, CH 4 , N 2 O, SF 6 ,stable isotopes, halocarbons, COS, hydrocarbons…14CO 2 on a limited number of samplesRadiocarbon is uniquely valuable tracer forCO 2 from fossil fuel combustion—fossil fuelscontain no 14 CO 2 (τ 1/2 =5730 yrs)
Multiple species analysis:Eastern USANov 2005Strong anthropogenicinfluenceSurface uptakeMultiple species aid in quantitativesource attribution for GHGs.
NOAA ESRL Tall Tower NetworkSNPSCT
CALGEM pilot project joint withLBNL funded by CaliforniaEnergy Commission's PublicInterest Energy ResearchProgram (M. Fischer PI)SNPSCT
Fires in California: June/July 2008ESRL/LBNL talltower site in WalnutGrove, CA+Sutro TowerMODIS Image 6-27-2008
Fires in California: June/July 2008Carbon Monoxide, ppb700600500400300200100afternoon data only11/1/2007 1/1/2008 3/1/2008 5/1/2008 7/1/2008Carbon Dioxide, ppm410400390+11/1/2007 1/1/2008 3/1/2008 5/1/2008 7/1/2008
Fires in California: June/July 2008800Carbon Monoxide, ppb700600500400300Coefficient values ± one standard deviationa =-22201 ± 4.62e+003b =58.109 ± 11.9Methane, ppb2100200019002001001800Coefficient values ± one standard deviationa =1781.5 ± 4.25b =0.24008 ± 0.00902385390395400405Carbon Dioxide, ppm410415100200300400500Carbon Monoxide, ppb600700
NOAA Tall Tower Measurement SystemsNominal 3 levels: 30, 100, 500m AGL•Semi-continuous CO 2•Semi-continuous CO•Automated Flask Sampler: one 12-pack per week-CO 2 , CO, CH 4 , N 2 O, SF 6 , Halocarbons, stableisotopes of CO 2 , working to start 14 CO 2 and 13 CH 4on select samples-Important part of QA/QC strategy•Basic Meteorology: horizontal wind, airtemperature, relative humidity, photosyntheticallyactive radiation, rainfall, surface pressure•CH 4 & CO 2 (Picarro Cavity Ring Down):Sacramento tower only (purchased for CALGEM)•Radon-222: two sitesCO 2 precision better than 0.1 ppm (30-sec average)CO precision better than 3 ppb (2-min average)CH 4 precision better than 1 ppb (30-sec average)
Tall Tower Sampling FootprintNormalized Footprint: Log10 Color ScaleComposite: MAY-JULY 2004 LEF, 19GMT
Hypothetical Future CarbonTrackerObserving Network for North AmericaNOAA Tall TowerNOAA Aircraft (~weekly)Partner regional networks
NOAA Network also tracks othergreenhouse gases: e.g., SF 6Global average
•Total SF 6 emissions inferred from global growthrate are inconsistent with latest UNFCCCInventory (factor of 2-3)•Long-lived gases with slow emission rates are anespecially difficult inventory problemCourtesy of Molly Heller and Gabrielle Petron (CIRES) and Ed Dlugokencky (NOAA)
Radiocarbon measurements have the potential to improve“top-down” estimates of GHGs:summerwinter•Δ 14 CO 2 is insensitive tobiological influences on CO 2•Robust emissions ratios canbe computed for a large suiteof gases.•Data are from Northeast USCourtesy of John Miller (CIRES), Scott Lehman (INSTAAR) and Steve Montzka (NOAA)
‘USA’ Emission EstimatesGg; Tg CO; 0.1 Gg SF6400350300250200150100Note: assumes that emission factorsderived from NE US radiocarbon dataare valid for entire country14CO2EPA500CO SF6 HFC134a HCFC22 HCFC142b PCE CH2Cl2 C6H6•US EPA Report on "Inventory of US Greenhouse Gas Emissions and Sinks, 1990-2004, updated” for HFC134a, HCFC22, HCFC142b; 2006/2007 values•US EPA NEI 2002 for CO, PCE, CH 2 Cl 2 , and C 6 H 6•INVENTORY OF U.S. GREENHOUSE GAS EMISSIONS AND SINKS: 1990-2006(April 2008) USEPA #430-R-08-005 for SF 6Courtesy of John Miller (CIRES), Scott Lehman (INSTAAR) and Steve Montzka (NOAA)
Summary Points•Accurate tracking of GHG emissions using “top-down”methods is critically needed to monitor compliance inan international regulatory context.•The precision and accuracy requirements formonitoring long-lived GHGs far exceed those for criteriapollutants e.g. Target accuracy for O 3 is ±1%, WMOrecommended target for CO 2 is ±0.04% CH 4 is ±0.1%•NOAA has an established record of making highlyprecise and accurate measurements of all major GHGs,but the scope of the needed future monitoring effortgreatly exceeds any single organization’s currentcapabilities.
The challenge for satellite-based CO 2 sensors:•Major urban centers notapparent in month-longaverage of total column CO 2 .•Column shows no evidenceof surface uptake over activeecosystemsSignature of surface sources and sinks is diluted andindistinct for satellite column measurements
Full scale for column plotSource and sink patterns are the dominant featuresin the planetary boundary layer.
CH 4 global average and growth rate:
CH 4 Polar Difference(North-South)Change in CH 4 polar difference is consistentwith major emissions reduction in formerUSSR.
INVENTORY OF U.S. GREENHOUSE GAS EMISSIONS AND SINKS: 1990-2006(April 2008)USEPA #430-R-08-005Trends: Table 2.1TgCO2Eqiv Gg (GWP=SAR value=23900)1990 32.7 1.371995 28.0 1.172006 17.3 0.72
COSF 6HFC134AHCFC22HCFC142BPCECH 2 Cl 2BENZ“Fossil Fuel CO 2 ” derived fromΔ 14 CO 2 Enhancement (Boundary Layer – Free Troposphere)
Sampling footprint for radiocarbon analysis: