As reported on my weblog since its inception, a focus on CO2 as the main driver of the climate system is grossly inadequate in terms of how the real climate system works.
The failure of this narrow perspective has been reported in several multi-authored papers and assessment reports; e.g.
Kabat, P., Claussen, M., Dirmeyer, P.A., J.H.C. Gash, L. Bravo de Guenni, M. Meybeck, R.A. Pielke Sr., C.J. Vorosmarty, R.W.A. Hutjes, and S. Lutkemeier, Editors, 2004: Vegetation, water, humans and the climate: A new perspective on an interactive system. Springer, Berlin, Global Change – The IGBP Series, 566 pp.
National Research Council, 2005: Radiative forcing of climate change: Expanding the concept and addressing uncertainties. Committee on Radiative Forcing Effects on Climate Change, Climate Research Committee, Board on Atmospheric Sciences and Climate, Division on Earth and Life Studies, The National Academies Press, Washington, D.C., 208 pp.
Rial, J., R.A. Pielke Sr., M. Beniston, M. Claussen, J. Canadell, P. Cox, H. Held, N. de Noblet-Ducoudre, R. Prinn, J. Reynolds, and J.D. Salas, 2004: Nonlinearities, feedbacks and critical thresholds within the Earth’s climate system. Climatic Change, 65, 11-38.
Pielke Sr., R., K. Beven, G. Brasseur, J. Calvert, M. Chahine, R. Dickerson, D. Entekhabi, E. Foufoula-Georgiou, H. Gupta, V. Gupta, W. Krajewski, E. Philip Krider, W. K.M. Lau, J. McDonnell, W. Rossow, J. Schaake, J. Smith, S. Sorooshian, and E. Wood, 2009: Climate change: The need to consider human forcings besides greenhouse gases. Eos, Vol. 90, No. 45, 10 November 2009, 413. Copyright (2009) American Geophysical Union.
McAlpine, C.A., W.F. Laurance, J.G. Ryan, L. Seabrook, J.I. Syktus, A.E. Etter, P.M. Fearnside, P. Dargusch, and R.A. Pielke Sr. 2010: More than CO2: A broader picture for managing climate change and variability to avoid ecosystem collapse. Current Opinion in Environmental Sustainability, 2:1–13, DOI 10.1016/j.cosust.2010.10.001.
The need to broaden out the assessment of the human role on the climate system, as well as to more accurately consider natural climate forcings and feedbacks has received important new confirmation from a new article in the Bulletin of the American Meteorological Society.
The excellent new article is
Nobre et al, 2010: Addressing the complexity of the Earth system. Bull. Amer. Met. Soc. DOI:10.1175/2010BAMS3012.1.
The abstract reads
“Integration of physical, biogeochemical, and societal processes would accelerate advances in Earth system prediction”
with the following excerpts from the text
“Earth system science addresses natural and human-driven processes affecting the evolution and ultimately the habitability of the planet. We must recognize that the Earth system encompasses interactions among the atmosphere, ocean, ice, land, biochemistry, and humanity. Humanity has advertently and inadvertently perturbed the entire system, with both positive and negative consequences. Thus, the accelerated development of a monitoring and prediction system that integrates physical, biogeochemical, and societal processes is essential if we are to provide quantitative information that can initiate and guide the mitigation of, and adaptation to, future changes in the Earth system.”
“The role of the biosphere. The biosphere is the “life zone” of Earth system. It is composed of living beings and their multi-way interaction with the geophysical and biological elements within the lithosphere (solid Earth), hydrosphere, and atmosphere. Until recently, the biosphere was primarily studied within the context of its response to geophysical influences, with less attention to the feedback of biospheric processes on weather and climate. However, this is beginning to change with new components of land cover, including urban areas (e.g., Oleson et al. 2008) and fire (e.g., Golding and Betts 2008), being implemented in the global models.”
“Many active biogeochemical feedback systems exhibit highly nonlinear behavior. Changes of system dynamics can be initiated by both natural and human activities. These changes can be abrupt “tipping points” between significantly differing states of the Earth system that society might not want to transgress (Steffen et al. 2003; Lenton et al. 2008; Rockström et al. 2009). The biosphere is also intertwined in the geochemical cycling that can contribute to natural and anthropogenic contributions to climate variability and change. The examples below illustrate this for anthropogenic changes in global nitrogen and ocean carbon cycles.”
The excellent Nobre et al 2010 paper provides further evidence that the 2007 IPCC WG1 report was much too narrow in terms of its assessment of the climate system. While we first need to assess the predictability of the Earth system (as a necessary condition before we can possibly provide accurate forecasts (predictions), the recognition that
“…. the Earth system encompasses interactions among the atmosphere, ocean, ice, land, biochemistry, and humanity. Humanity has advertently and inadvertently perturbed the entire system, with both positive and negative consequences.”
is an important major step forward in better reporting on the climate system.