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23 paź 2020 · Carbon isotopes, 14 C and 13 C, in atmospheric CO 2 are changing in response to fossil fuel emissions and other human activities. Future simulations using different SSPs show continued changes in isotopic ratios that depend on fossil fuel emissions and, for 13 C, BECCS.
1. Introduction. Carbon isotopes are present in the atmosphere, ocean, and terrestrial biosphere in ratios of approximately 99% 12C/C, 1% 13C/C, and 1 × 10−1214C/C. 12C and 13C are stable isotopes while 14C is a radioactive isotope called radiocarbon.
17 sty 2018 · Atmospheric effects must be taken into account when interpreting terrestrial stable carbon isotopes, with important implications for past environments and climates, and understanding plant ...
15 lis 2020 · Emissions of CO2 from fossil fuel combustion and land use change reduce the ratio of 13C/12C in atmospheric CO2 (δ13CO2). This is because 12C is preferentially assimilated during photosynthesis...
1 sty 2004 · Iso- topic analyses of CO2 and CH4 provide key tools for better understanding global bud- gets of these trace gases. In this chapter we describe two different methods for measuring carbon and oxygen isotopes in atmospheric CO2 and a method for measur- ing carbon isotopes in atmospheric CH4.
NOAA Carbon Cycle and Greenhouse Gases scientists measure the carbon isotopic composition in each air sample. For 14 C, this ratio is given as a Δ 14 C value (pronounced delta 14-cee–the triangle is a capital delta, which is the Greek symbol for a “D”).
14 mar 2016 · Here we help to constrain changing sources with a high-precision, high-resolution deglacial record of the stable isotopic composition of carbon in CO 2 (δ 13 C-CO 2) in air extracted from ice samples from Taylor Glacier, Antarctica.
