Where has all the Carbon Gone? Atmospheric oxygen, carbon fluxes and the implications for climate change. Mark Battle (Bowdoin College) Michael Bender (Princeton) Ralph Keeling (Scripps Institute of Oceanography) Pieter Tans (NOAA/CMDL) Jesse Bastide, Carrie Simonds, Blake Sturtevant, Becca Perry Bates College, 12/3/2004 Funding from: NSF, EPA, NOAA GCRP, BP-Amoco, Bowdoin College
Organizing Principle: 1 topic superficially
Organizing Principle: 1 topic superficially Several topics with vanishing content
Outline: Context: –Climate Change –CO 2 as an agent of change Where does the CO 2 go? How does O 2 tell us this? The basic answer A more refined answer Related work in progress
Why should we care about climate change? “An increasing body of observations gives a collective picture of a warming world…” “…most of the warming observed over the last 50 years is attributable to human activities.” “ Anthropogenic climate change will persist for many centuries.” “Emissions of greenhouse gases… continue to alter the atmosphere in ways that are expected to affect the climate.” IPCC, 2001
Why CO 2 ? IPCC, 2001
Why CO 2 ? “ The atmospheric concentration of CO 2 has increased by 31% since The present CO 2 concentration has not been exceeded during the past 420,000 years and likely not during the past 20 million years. The current rate of increase is unprecedented during at least the past 20,000 years.” IPCC, 2001
Where does anthropogenic CO 2 end up?
Recap: The planet is warming Human activities are to blame CO 2 is the primary culprit Future buildup depends on Atm vs. Land vs. Ocean Land/Ocean partition is tough to measure
The link between O 2 and CO 2 CO 2 = Land biota + Industry + Ocean O 2 = Land biota + Industry
O 2 /N 2 changes are small O 2 /N 2 per meg (O 2 /N 2sa – O 2 /N 2st )/(O 2 /N 2st ) x per meg = % 1 GtC = 10 9 metric tons C = g C 1 GtC from FF 3.2 per meg O 2 /N 2
Graphically…
The Princeton cooperative flask sampling network
Ships of opportunity
Research Vessels
Automatic Air Recovery Device Version ARK-5 In use at: Cape Grim Ka’imimoana Samoa Barrow Sable Macquarie Princeton
Our measurement technique: IRMS (Finnigan Delta+XL) 32/28 and 40/28 (as well as 44/28 and 29/28) Custom dual-inlet system Indirect comparison with standards For more details: Bender et al., In review
Battle et al., Science 2000
1991 – 1997 Land sink = 1.4 ± 0.8 GtC/yr Ocean sink = 2.0 ± 0.6 GtC/yr Battle et al. Science 2000 ( )
Is it really that simple? O 2 = Land biota + Industry + Ocean CO 2 = Land biota + Industry + Ocean HeatBiology
Longer records from more sites…
Longer records from more sites + Solubility correction + Stratification correction Ocean uptake = 1.7 ± 0.5 Net Land uptake = 1.0 ± 0.6 (1994 – 2002) Bender et al. In review
Summary The climate is changing Anthropogenic CO 2 is to blame O 2 can tell us about the fate of CO 2 The O 2 -CO 2 linkage isn’t trivial We find a substantial terrestrial sink (volatile?) But the story doesn’t end here…
Measurements of O 2 and CO 2 O 2 = Land biota + Industry CO 2 = Land biota + Industry + Ocean f land & f ocean > 0 for carbon storage by land and ocean
Measurements of O 2 and CO 2 O 2 = Land biota + Industry CO 2 = Land biota + Industry + Ocean f land & f ocean > 0 for carbon storage by land and ocean
Determining the O 2 :CO 2 stoichiometry for the land biota
What else might we learn? O 2 = Land biota + Industry CO 2 = Land biota + Industry + Ocean f land & f ocean > 0 for carbon storage by land and ocean
APO: an ocean-only “tracer” APO O 2observed CO 2observed (I have ignored units)
APO: an ocean-only “tracer” APO O 2observed CO 2observed (I have ignored units) So what?
Ocean biology and circulation
fluxes of CO 2 and O 2
Ocean biology and circulation fluxes of CO 2 and O 2 atmospheric transport
Ocean biology and circulation fluxes of CO 2 and O 2 atmospheric transport atmospheric composition at observing stations
fluxes of CO 2 and O 2 atmospheric transport atmospheric composition at observing stations
APO measurements + good flux estimates rigorous test of atmospheric transport
Is this different from other models?