originally posted 8 february 2007; reposted here 24 september 2014
Using the Lutz et al. median population estimate in “The end of world population growth” Nature 412, 543-545, combined with a constant CO2 per capita emission of 1.2 tC (as observed since 1973 by Marland et al.) I created the following alternative emission storyline:
Using Fick law diffusion with 1.7% of pre-industrial CO2 surplus sinks annually,(Dietze) and a climate sensitivity of 1.3 K/2xCO2 (Nir Shaviv) I get the following alternative temperature scenario:
Notice that the technological SRES A1T scenario is without additional CO2 limiting measures.
Wolfgang Lutz, Warren Sanderson and Sergei Scherbov, “The end of world population growth” Nature 412, 543-545 http://anquetil.colorado.edu/physics3070/Lectures/L8/nature_population2.pdf
Marland, G., T.A. Boden, and R. J. Andres. 2006. Global, Regional, and National CO2 Emissions. In Trends: A Compendium of Data on Global Change. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tenn., U.S.A http://cdiac.esd.ornl.gov/trends/emis/tre_glob.htm
Peter Dietze, Carbon Model Calculations, Online: http://www.john-daly.com/dietze/cmodcalc.htm
Nir Shaviv, On Climate Sensitivity and why it is probably small, Online: http://www.sciencebits.com/OnClimateSensitivity
Note added 24 september 2014:
My old post from 2007 was very predictive wrt the used climate sensitivity as published this week by Lewis and Curry The implications for climate sensitivity of AR5 forcing and heat uptake estimates
Decrease of CO2 in the atmosphere if the emissions would stop today,
Based on observed uptake in the past 50 years (blue) using a simple Fick’s diffusion law,
and as modeled in the Bern Model (orange).