Showing papers by "Minze Stuiver published in 1978"
TL;DR: The net release of CO2 from the biosphere to the atmosphere between 1850 and 1950 is estimated to amount to 1.2 x 109 tons of carbon per year, and changes in land use reduced the total terrestrial biomass by 7 percent.
Abstract: The net release of CO2 from the biosphere to the atmosphere between 1850 and 1950 is estimated to amount to 1.2 x 109 tons of carbon per year. During this interval, changes in land use reduced the total terrestrial biomass by 7 percent. There has been a smaller reduction in biomass over the last few decades. In the middle 19th century the air had a CO2 content of approximately 268 parts per millon, and the total increase in atmospheric CO2 content since 1850 has been 18 percent. Major sinks for fossil fuel CO2 are the thermocline regions of large oceanic gyres. About 34 percent of the excess CO2 generated so far is stored in surface and thermocline gyre waters, and 13 percent has been advected into the deep sea. This leaves an airborne fraction of 53 percent.
254 citations
TL;DR: In this paper, a comparison of conventional radiocarbon years with calendar years covering the past four centuries is given, and it is shown that even very precise 14C dating cannot entirely solve the problems of age calibration.
Abstract: A detailed comparison of conventional radiocarbon years with calendar years covering the past four centuries is given. Relatively large atmospheric 14C changes are encountered over this time, and even very precise 14C dating cannot entirely solve the problems of age calibration. By matching radiocarbon ages with ages derived from 230Th/234U, thermoluminescence and magnetic dating, the 14C timescale is shown to deviate by a maximum of 2,000 yr over the 9,000–32,000 yr BP interval.
123 citations
TL;DR: A solution to the background variability has to be found before ion counting can be used to date samples back to the 75,000-year limit of beta counting.
Abstract: Accelerator ion counting compares favorably with conventional beta counting. The major advantage of ion counting is that milligram samples can be analyzed. When sample size is not limiting, ion counting complements beta counting for the more routine carbon-14 determinations. Further development is needed before ion counting can achieve the same high precision as beta counting for large samples (+- 2 per mil). A solution to the background variability has to be found before ion counting can be used to date samples back to the 75,000-year limit of beta counting.
28 citations
4 citations