Carbon has several isotopes.

Post #283,095 by Another Scott 4/25/07 8:31:28 PM 5/7/07 8:21:36 PM Reply	Carbon has several isotopes. [link\|http://www2.glos.ac.uk/gdn/origins/life/carbon.htm\|Carbon] has 3 common isotopes that differ in the number of neutrons in the nucleus of the atom. Carbon 14 is radioactive - it decays into lighter elements over time, with an accurately known rate. By comparing the ratio of isotopes of carbon in a formerly living material, you can get information about how long ago it died - that's the basis of "carbon dating". Carbon 12 and Carbon 13 are both stable isotopes of carbon. Since Carbon 13 is heavier than Carbon 12, it behaves slightly differently in plants. And one can get information about the [link\|http://www.jhu.edu/news_info/news/home00/feb00/fossil.html\|CO2 in the atmosphere] during the time the plants were alive. CO2 from burning ancient coal or oil is going to have carbon isotope ratios different from CO2 from forest fires or from other natural sources. That's my understanding of the issue. Corrections welcome. HTH a bit. [edit:] RealClimate has an article that addresses [link\|http://www.realclimate.org/index.php?p=87\|how we know that the rise in CO2 in the atmosphere is due to man]. Cheers, Scott. Edited by Another Scott May 7, 2007, 08:21:36 PM EDT Carbon has several isotopes. [link\|http://www2.glos.ac.uk/gdn/origins/life/carbon.htm\|Carbon] has 3 common isotopes that differ in the number of neutrons in the nucleus of the atom. Carbon 14 is radioactive - it decays into lighter elements over time, with an accurately known rate. By comparing the ratio of isotopes of carbon in a formerly living material, you can get information about how long ago it died - that's the basis of "carbon dating". Carbon 12 and Carbon 13 are both stable isotopes of carbon. Since Carbon 13 is heavier than Carbon 12, it behaves slightly differently in plants. And one can get information about the [link\|http://www.jhu.edu/news_info/news/home00/feb00/fossil.html\|CO2 in the atmosphere] during the time the plants were alive. CO2 from burning ancient coal or oil is going to have carbon isotope ratios different from CO2 from forest fires or from other natural sources. That's my understanding of the issue. Corrections welcome. HTH a bit. Cheers, Scott. Collapse All History
Post #283,110 by boxley 4/25/07 9:59:19 PM Reply	so co2 from cars is much more dangerous than bbqing? Any opinions expressed by me are mine alone, posted from my home computer, on my own time as a free american and do not reflect the opinions of any person or company that I have had professional relations with in the past 51 years. meep reach me at [link\|mailto:bill.oxley@cox.net\|mailto:bill.oxley@cox.net]
Post #283,125 by Another Scott 4/25/07 11:09:54 PM Reply	No. (I haven't seen the Gore comment you're referring to, so I'm just trying to address what I think you're writing about.) If you think of the Earth as a sealed terrarium, then there's some equilibrium concentration of water vapor, oxygen, CO2, etc., in the air and in the soil that will depend on (among other things) how much plant and animal life is there. If you dig up some deep coal and burn it, you're going to quickly change the amount of CO2 in the air and it can't easily be absorbed by the water or the plants (because the system has developed under a lower concentration). Burning wood isn't as bad as burning coal, because the CO2 in trees is part of the carbon that rapidly gets recycled between the air, water, and plant life. And that's why just planting billions of trees isn't going to quickly solve the CO2 problem introduced by our burning of ancient coal and oil. When most trees die, their carbon will just get released back into the carbon cycle in a relatively short period of time (say a few hundred years). It takes a very long time for plant life to significantly change the CO2 concentration. Carbon in deep coal and oil is locked up and is no longer part of the natural cycle - until we dig it up and burn it. That's what's bad about adding vast amounts of ancient carbon to the air - it's not that it's "more dangerous" than burning wood, it's that it is driving the atmosphere and the carbon cycle out of equilibrium on a very short time scale (compared to the millions of years that it took to lock the carbon up in the Earth). HTH. Cheers, Scott.
Post #283,146 by boxley 4/26/07 7:35:10 AM Reply	"Burning wood isn't as bad as burning coal" did you think before you posted? thanx, bill Any opinions expressed by me are mine alone, posted from my home computer, on my own time as a free american and do not reflect the opinions of any person or company that I have had professional relations with in the past 51 years. meep reach me at [link\|mailto:bill.oxley@cox.net\|mailto:bill.oxley@cox.net]
Post #283,147 by Another Scott 4/26/07 7:36:34 AM Reply	Yes. Did I say something you disagree with?

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