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23 paź 2020 · Key Points. 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.
17 sty 2018 · The 13C/12C ratio of C3 plant matter is thought to be controlled by the isotopic composition of atmospheric CO2 and stomatal response to environmental conditions, particularly mean annual ...
1 paź 2019 · Here we review the application of stable carbon isotope ratios in ocean water and biogenic carbonates as proxies in paleoceanography, including the atmospheric and sedimentary reservoirs oceanic carbon is in exchange with.
7 sty 2008 · Stable carbon isotopes are used extensively to examine physiological, ecological, and biogeochemical processes related to ecosystem, regional, and global carbon cycles and provide information at a variety of temporal and spatial scales.
Photosynthesis (Fig. B1.1) is the process by which autotrophic organisms (plants, algae, and many bacteria) produce organic matter and oxygen from CO 2 and water using light as an energy source. Figure B1.1: Chemical Reaction for Photosynthesis. Carbon dioxide and water is converted to carbohydrates and oxygen. This process uses energy.
Carbon isotope systematics on Earth are dominated by the large kinetic fractionation associated with assimilation of CO 2 by autotrophic organisms, which lead to marked enrichment in 12 C relative to 13 C in the generated organic matter. In contrast, the isotope effects related to the precipitation of carbonate sediments are relatively small ...
Carbon has two stable (non-radioactive) isotopes. In nature, the 12 C isotope comprises 98.89% of all carbon and 13 C makes up the remaining 1.11%. A variety of physico-chemical processes whose rates are mass-dependent, such as kinetic reactions involving diffusion, and temperature-controlled equilibrium reactions serve to “fractionate” the ...
