CO2, Methane and Temperature: More Insights from the Dome Concordia and Vostok Ice Cores
Volume 8, Number 49: 7 December 2005

Climate alarmists have long contended that the historical and still-ongoing rise in the air's CO2 content - aided and abetted by the historical increase in atmospheric methane concentration - will lead to dangerous global warming that could rival temperature increases experienced during prior glacial-to-interglacial transitions.  Now, new light has been shed on the subject by two reports that provide CO2, methane and temperature data stretching a full 650,000 years back in time (Siegenthaler et al., 2005; Spahni et al., 2005), based on measurements made on East Antarctica's Dome Concordia ice core, which was originally extracted and cursorily analyzed by Augustin et al. (2004).

What are politically-correct scientists saying about the new findings?  Los Angeles Times staff writer Usha McFarling (25 Nov 2005) reports they claim "the work provides more evidence that human activity since the Industrial Revolution has significantly altered the planet's climate system."  As an example, she quotes Penn State University's Richard Alley as stating the new results may be interpreted as "saying, 'Yeah, we had it right' ... we can pound on the table harder and say, 'this is real'."  Likewise, Associated Press writer Lauran Neergaard (24 Nov 2005) quotes Edward Brook, who wrote a Perspective piece in Science about the new findings, as saying "these studies tell us that there's a strong relationship between temperature and greenhouse gasses ... which logically leads you to the conclusion that maybe we should worry about temperature change in the future."  Echoing this sentiment, Jerry McManus of the Woods Hole Oceanographic Institution was quoted by BBC News staff writer Julianna Kettlewell (28 Nov 2005) as saying "it is something of grave concern to someone like me, who sees the strong connection between greenhouse gases and climate in the past."

Actually, the ice core data do not strengthen the climate-alarmist claim that we should be concerned about greenhouse gas-induced global warming, and for two different reasons.  We discussed the first of these reasons in our Editorial of 30 Nov 2005, where we indicated that the ice core data: (1) clearly demonstrate the important role of climate in CO2 regulation, but (2) provide no evidence for the inverse relationship, i.e., a regulation of climate by CO2.  Here, we discuss the second reason.

We begin with the fact that the new ice core data indicate the atmosphere's current CO2 concentration is about 30% higher than it has been at any other time in the last 650,000 years, and that the atmosphere's current methane concentration is 130% higher.  These extremely high concentrations, in the words of McManus (as quoted by Kettlewell), "are geologically incredible."  Hence, if the world's climate alarmists are correct about the tremendous warming power they attribute to these two top greenhouse gases, one would logically expect the earth to be currently experiencing some incredibly high temperatures.  So what do the ice core data indicate in this regard?

Both the Dome Concordia and Vostok data sets suggest that the peak temperature of the current interglacial or Holocene was not incredibly higher than the peak temperatures of all of the past four interglacials, the earliest of which is believed to have been nearly identical to the Holocene in terms of earth's orbit around the sun.  In fact, the Holocene's peak temperature was not higher than those of the preceding four interglacials by even a tiny fraction of a degree.  In fact, it was lower.  In fact, the work of Petit et al. (1999) revealed that the peak temperature of the Holocene was more than 2C lower than the average peak temperature of the prior four interglacials.  What is more, earth's current temperature is lower still.

In light of these several real-world observations, we conclude that if there is anything unusual or unnatural about earth's current climatic state compared to the climates of the past four interglacials, it is that it is so much colder in spite of there being so much more (dare we say incredibly more?) CO2 and methane in the air.  Clearly, the planet's climate system is not operating the way the world's climate alarmists and politically-correct scientists claim it does.

Sherwood, Keith and Craig Idso

Augustin, L., Barbante, C., Barnes, P.R.F., Barnola, J.M., Bigler, M., Castellano, E., Cattani, O., Chappellaz, J., Dahl-Jensen, D., Delmonte, B., Dreyfus, G., Durand, G., Falourd, S., Fischer, H., Fluckiger, J., Hansson, M.E., Huybrechts, P., Jugie, G., Johnsen, S.J., Jouzel, J., Kaufmann, P., Kipfstuhl, J., Lambert, F., Lipenkov, V.Y., Littot, G.C., Longinelli, A., Lorrain, R., Maggi, V., Masson-Delmotte, V., Miller, H., Mulvaney, R., Oerlemans, J., Oerter, H., Orombelli, G., Parrenin, F., Peel, D.A., Petit, J.-R., Raynaud, D., Ritz, C., Ruth, U., Schwander, J., Siegenthaler, U., Souchez, R., Stauffer, B., Steffensen, J.P., Stenni, B., Stocker, T.F., Tabacco, I.E., Udisti, R., van de Wal, R.S.W., van den Broeke, M., Weiss, J., Wilhelms, F., Winther, J.-G., Wolff, E.W. and Zucchelli, M.  2004.  Eight glacial cycles from an Antarctic ice core.  Nature 429: 623-628.

Petit, J.R., Jouzel, J., Raynaud, D., Barkov, N.I., Barnola, J.-M., Basile, I., Bender, M., Chappellaz, J., Davis, M.., Delaygue, G., Delmotte, M., Kotlyakov, V.M., Legrand, M., Lipenkov, V.Y., Lorius, C., Pepin, L., Ritz, C., Saltzman, E. and Stievenard, M.  1999.  Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica.  Nature 399: 429-436.

Siegenthaler, U., Stocker, T., Monnin, E., Luthi, D., Schwander, J., Stauffer, B., Raynaud, D., Barnola, J.-M., Fischer, H., Masson-Delmotte, V. and Jouzel, J.  2005.  Stable carbon cycle-climate relationship during the late Pleistocene.  Science 310: 1313-1317.

Spahni, R., Chappellaz, J., Stocker, T.F., Loulergue, L., Hausammann, G., Kawamura, K., Fluckiger, J., Schwander, J., Raynaud, D., Masson-Delmotte, V. and Jouzel, J.  2005.  Atmospheric methane and nitrous oxide of the late Pleistocene from Antarctic ice cores.  Science 310: 1317-1321.