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Detection and attribution of changes in arctic ecosystems and atmospheric CO 2. P. K. Patra , H. Kobayashi and T. Saeki Department of Environmental Geochemical Cycle Research At A-CG36 Science in the Arctic Region, JpGU Yokohama, 30 April 2014. Talk outline. Introduction
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Detection and attribution of changes in arctic ecosystems and atmospheric CO2 P. K. Patra, H. Kobayashi and T. Saeki Department of Environmental Geochemical Cycle Research At A-CG36Science in the Arctic Region, JpGU Yokohama, 30 April 2014
Talk outline • Introduction • Recent results of atmospheric detection • Changes in phenology • Implications for atmospheric CO2 uptake
Why arctic? Picture of temperature increase (Latitude – longitude distributions) CO2 seasonal cycle amplitude
Atmospheric Concentrations CO2:+40% since 1750 CH4:+150% since 1750 N2O:+20% since 1750 IPCCAR5, WGI, Chapter 6, Ciais et al. 2013
Manifestations of global climate change Global average sea level rise (mm) (IPCC AR5, WGI SPM, 2013) Arctic summer sea-ice extent (106 km2) Atmospheric CO2 concentration (ppm) Global upper ocean heat content (1022J) Insitu pH Oceanic pCO2 (μatm)
Identification of large change in land carbon exchange (between IGY and IPY) Lack of representation in CMIP5/IPCC-AR5 models (independent evaluation critical) Graven, Keeling, Piper, Patra et al., Science, 2013
Attribution of changes Atmospheric CO2 = fossil fuel emission + terrestrial biosphere + oceanic exchange + atmospheric transport Strong trends Strong seasonality Weaker seasonality Weaker trends Most studies looked in to a particular aspect: Graven et al. : atmospheric CO2 Piao et al. : terrestrial ecosystem model Wang et al. : terrestrial indicators Role of fossil fuel emissions, oceanic exchange and atmospheric transport remained relatively unexplored
Partitioning of global CO2 sources and sinks 2002 - 2011 1750 - 2011 2011 365±30 8.3±0.4 9.5±0.5 180±80 1.0±0.5 0.9±0.5 CO2 Fluxes (PgC y-1) 150±90 2.6±0.8 3.8±0.9 (Residual) (Residual) (Residual) 240±10 4.3±0.1 4.1±0.1 (Observations) (Observations) (Observations) 155±30 2.5±0.5 2.7±0.5 (5 models) (5 models) (5 models) Le Quere et al. 2013, ESSD; update from www.whrc.org