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The Terrestrial Carbon Balance of East Asia
Piao, S., Ciais, P., Lomas, M., Beer, C., Liu, H., Fang, J., Friedlingstein, P., Huang, Y., Muraoka, H., Son, Y. and Woodward, I. 2011. Contribution of climate change and rising CO2 to terrestrial carbon balance in East Asia: A multi-model analysis. Global and Planetary Change 75: 133-142.

Many people worry about the oft-predicted negative impacts of CO2-induced global warming upon earth's biosphere. However, the authors of an important new paper (Piao et al., 2011) provide evidence which suggests that just the opposite (of what the concern of these people implies) may be more likely to occur, beginning with their declaration that "in the past two decades" -- which the world's climate alarmists contend were the warmest of the past thousand or more years -- "inversion models of atmospheric CO2 concentration have provided evidence that terrestrial ecosystems of the Northern Hemisphere are a large carbon sink (Gurney et al., 2002; Peylin et al., 2005; Stephens et al., 2007)," which is indicative of vibrant vegetative growth. But is the "large carbon sink" that has thereby been identified currently growing or shrinking?

What was done
In a study designed to answer this question for a large portion of the Northern Hemisphere (East Asia, including China, Japan, Korea and Mongolia), the eleven researchers used three process-based ecosystem models -- the Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ-DGVM) described by Sitch et al. (2003), the ORganizing Carbon and Hydrology In Dynamic Ecosystems (ORCHIDEE) model described by Krinner et al. (2005), and the Sheffield model described by Woodward and Lomas (2004) -- to investigate East Asia's net primary productivity (NPP) response to the climatic change and rising atmospheric CO2 concentration of the past century, which they did by running each of the three models from 1901 to 2002, using observed values of monthly climatology and annual global atmospheric CO2 concentrations.

What was learned
Piao et al. report that between 1901 and 2002, modeled NPP "significantly increased by 5.5-8.5 Tg C per year (15-20% growth)," and they say that this increase in NPP "caused an increased cumulated terrestrial carbon storage of about 5-11 Pg C," about 50-70% of which "is located in vegetation biomass." And they add that "40-60% of the accumulated carbon uptake of the 20th century is credited to the period of 1980-2002."

What it means
Interestingly, this latter 22-year interval (which represented only 22% of the full duration of the 101-year study period) was responsible for somewhere between 40 and 60% of the accumulated carbon uptake of the entire period; and this intensified carbon uptake occurred at the end of that period, which climate alarmists contend was the warmest two-decade-interval of that century-long period. Thus, it is readily evident that as the air's CO2 concentration and temperature rose to their highest values of the past century -- or millennium (purportedly) -- they only served to enhance the terrestrial vegetative productivity of East Asia.

Gurney, K.R., Law, R.M., Denning, A.S., Rayner, P.J., Baker, D., Bousquet, P., Bruhwiler, L., Chen, Y.-H., Ciais, P., Fan, S., Fung, I.Y., Gloor, M., Heimann, M., Higuchi, K., John, J., Maki, T., Maksyutov, S., Masarie, K., Peylin, P., Prather, M., Pak, B.C., Randerson, J., Sarmiento, J., Taguchi, S., Takahashi, T. and Yuen, C.-W. 2002. Towards robust regional estimates of CO2 sources and sinks using atmospheric transport models. Nature 415: 626-630.

Krinner, G., Viovy, N., de Noblet-Ducoudre, N., Ogee, J., Polcher, J., Friedlingstein, P., Ciais, P., Sitch, S. and Prentice, I.C. 2005. A dynamic global vegetation model for studies of the coupled atmosphere-biosphere system. Global Biogeochemical Cycles 19: 10.1029/2003GB002199.

Peylin, P., Bousquet, P., Le Que´re´, C., Sitch, S., Friedlingstein, P., McKinley, G., Gruber, N., Rayner, P. and Philippe Ciais. 2005. Multiple constraints on regional CO2 flux variations over land and oceans. Global Biogeochemical Cycles 19: 10.1029/2003GB002214.

Sitch, S., Smith, B., Prentice, I.C., Arneth, A., Bondeau, A., Cramer, W., Kaplan, J.O., Levis, S., Lucht, W., Sykes, M.T., Thonicke, K. and Venevsky, S. 2003. Evaluation of ecosystem dynamics, plant geography and terrestrial carbon cycling in the LPJ dynamic global vegetation model. Global Change Biology 9: 161-185.

Stephens, B.B., Gurney, K.R., Tans, P.P., Sweeney, C., Peters, W., Bruhwiler, L., Ciais, P., Ramonet, M., Bousquet, P., Nakazawa, T., Aoki, S., Machida, T., Inoue, G., Vinnichenko, N., Lloyd, J., Jordan, A., Heimann, M., Shibistova, O., Langenfelds, R.L., Steele, L.P., Francey, R.J. and Denning, A.S. 2007. Weak northern and strong tropical land carbon uptake from vertical profiles of atmospheric CO2. Science 316: 1732-1735.

Woodward, F.I. and Lomas, M.R. 2004. Vegetation dynamics-simulating responses to climatic change. Biological Reviews 79: 643-670.

Reviewed 6 April 2011