• Dlugokencky, E. J., K. A. Masarie, P. M. Lang, and P. P. Tans, Continuing decline in the growth rate of the atmospheric methane burden, Nature, 393, 447450, 1998.
  • Etheridge, D. M., L. P. Steele, R. J. Francey, and R. L. Langenfelds, Atmospheric methane between 1000 A.D. and present: Evidence of anthropogenic emissions and climate variability, J. Geophys. Res., 103, 15,97915,993, 1998.
  • Hofmann, D. J., J. H. Butler, E. J. Dlugokencky, J. W. Elkins, K. Masarie, S. A. Montzka, and P. Tans, The role of carbon dioxide in climate forcing from 1979-2004: Introduction of the Annual Greenhouse Gas Index, Tellus, 58B, 614619, 2006.
  • , Intergovernmental Panel on Climate Change, Climate Change 2001: The Scientific Basis, Cambridge Univ Press, New York., 2001.
  • Keeling, C. D., Rewards and penalties of monitoring the Earth, Annu. Rev. Energy Environ., 23, 2582, 1998.
  • Keeling, C. D., and Whorf, T. P. (2005), Atmospheric CO2 records from sites in the SIO air sampling network, in Trends: A Compendium of Data on Global Change, Carbon Dioxide Inf. Anal. Cent., Oak Ridge Natl. Lab., Oak Ridge, Tenn..
  • Montzka, S. A., J. H. Butler, J. W. Elkins, T. M. Thompson, A. D. Clarke, and L. T. Lock, Present and future trends in the atmospheric burden of ozone-depleting halogens, Nature, 398, 690694, 1999.