Errr, okc, you're turned in the wrong direction. Turn the other way: On Jan 17, 5:15 pm, okc chemist <[EMAIL PROTECTED]> wrote: ... > ... like you say, 100 more years of research are > required. ... > > On Jan 16, 5:52 pm, "David B. Benson" <[EMAIL PROTECTED]> wrote: ... > > Once the physics of global warming gases is understood (at least 100 > > years now) ...
The century he's referring to is described here: http://www.aip.org/history/climate/ You're appearing confused on levels of carbon isotopes. This may help: "... Only 14C is radioactive with a half-life of 5730 years. In the atmosphere, 14C occurs principally as 14CO2 and is usually produced by nuclear reactions between cosmic ray neutrons and the nitrogen atoms of the air (Libby 1952). Solar (heliomagnetic), geomagnetic, and ocean forcing all play a role in atmospheric 14CO2 (Stuiver and Braziunas 1993). Before nuclear bomb testing during the 1950s and early 1960s, radiocarbon levels in the atmosphere had been in decline. Suess (1955) demonstrated that forests grown between 1930 and 1950 had 14C values 20-40 per mil below those of pre-1890 woods as a result of anthropogenic 14C-free CO2 emissions since the Industrial Revolution. Nuclear bomb testing has since swamped the "Suess Effect(1)." ..." http://cdiac.ornl.gov/epubs/ndp/ndp057/ndp057.htm --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups Global Change ("globalchange") newsgroup. Global Change is a public, moderated venue for discussion of science, technology, economics and policy dimensions of global environmental change. Posts will be admitted to the list if and only if any moderator finds the submission to be constructive and/or interesting, on topic, and not gratuitously rude. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/globalchange -~----------~----~----~----~------~----~------~--~---
