Inconvenient Truth

Ice cores can tell temperature and CO2 levels of that years snowfall

http://www.gisp2.sr.unh.edu/MoreInfo/Ice_Cores_Past.html

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  Broecker, W. S. and G. H. Denton. (1990). "What drives the glacial cycles?" Sci. Am. 262(1): 48 - 56.
  Dansgaard, W., J. W. C. White and S. J. Johnsen. (1989). "The abrupt termination of the Younger Dryas climate event." Nature. 339: 532-533.
  Mayewski, P. A., W. B. Lyons, M. J. Spencer, M. Twickler, W. Dansgaard, B. Koci, C. I. Davidson and R. E. Honrath. (1986). "Sulfate and nitrate concentrations from a south Greenland ice core." Science. 232: 975-977.
  Lorius, C., J. Jouzel, C. Ritz, L. Merlivat, N. I. Barkov, Y. S. Korotkevich and V. M. Kotlyakov. (1985). "A 150,000-year climatic record form Antarctic Ice." Nature. 316: 591-596.
  Boyle, E. A. (1986). "Paired carbon isotope and cadmium data for benthic foraminifera: Implication for changes in oceanic atmospheric carbon dioxide." Glob. Biogeochem. Cycles. 3(3): 21 - 239.
• Authors of their own books
• Somewhat credible
• Ice cores can tell climate 20,000 years back
• Yes, all of these authors were in agreement that this was true

http://www.talkorigins.org/faqs/icecores.html

• C. Lorius et al., NATURE 316 (1985) 591-596. [2] F. Yiou et al., NATURE 316 (1985) 616-617. [3] J. Jouzel et al., NATURE 329 (1987) 403-408. [4] J.M. Barnola et al., NATURE 329 (1987) 408-414. [5] van Nostrands' SCIENTIFIC DICTIONARY [6] THE ENCYCLOPEDIA OF SCIENCE AND TECHNOLOGY [7] E. Wolff, GEOGRAPHICAL MAGAZINE 59 (1987) 73-77. [8] Julie M. Palais OCEANUS 29 (Winter 86/87) 55-60. [9] W. Dansgaard et al., SCIENCE 218 (1982) 1273-1277. [10] C.U. Hammer et al., NATURE 288 (1980) 230-235.
  
• All scientific authors
• Credible
• Ice cores tell temperatures, ph balance, oxygen levels
• Yes, these scientists are in agreement over these things

http://www.daviesand.com/Choices/Precautionary_Planning/New_Data/

• NOAA Paleoclimatology Program
• US gavernment agency
• Credible
• Provides data on temperature variations and atmospheric concentrations of CO2, methane and other greenhouse gases up to 420,000 years ago
• Yes, NOAA supports this data

Yes, this fact is true. Scientists use ice core data like carbon dating to determine the climatic conditions of Earth.