>10^11 (∼15% of the atmospheric total) tons of carbon/year
||Ma F, Jazmin LJ, Young JD, Allen DK. Isotopically nonstationary 13C flux analysis of changes in Arabidopsis thaliana leaf metabolism due to high light acclimation. Proc Natl Acad Sci U S A. 2014 Nov 25 111(47):16967-72. doi: 10.1073/pnas.1319485111. p.16967 left column 2nd paragraphPubMed ID25368168
|| Raines CA (2011) Increasing photosynthetic carbon assimilation in C3 plants to improve crop yield: Current and future strategies. Plant Physiol 155(1):36–42. DOI: 10.1104/pp.110.168559PubMed ID21071599
||Abstract: "[Investigators] performed in vivo isotopic labeling of Arabidopsis thaliana rosettes with (13)CO2 and estimated fluxes throughout leaf photosynthetic metabolism by INST-MFA [Isotopically nonstationary metabolic flux analysis]. Plants grown at 200 µmol m^(-2)s^(-1) light were compared with plants acclimated for 9 d at an irradiance of 500 µmol⋅m^(-2)⋅s^(-1)."
||P.16967 left column 2nd paragraph: "Photosynthetic organisms assimilate more than 100 billion tons of carbon, ∼15% of the atmospheric total, each year and generate organic compounds for food and renewable chemicals (primary source). However, photosynthesis is a complex process that responds to heterotrophic tissue demands and environmental stimuli such as drought, temperature, and light intensity (refs 2, 3). The light incident on the plant varies with intensities in the range of 0–2,000 µmol photons×m^−2×s^−1 and can change dramatically because of passing clouds, shading, and the position of the sun. Thus, plants adjust light harvesting and carbon assimilation steps to accommodate many fluctuations, resulting in changes in plant morphology, physiology, and metabolism (ref 4)."