Botany online 1996-2004. No further update, only historical document of botanical science!
The concentration of carbon dioxide fluctuates in the course of the year as a result of the differences in the plants' photosynthetic activities. The data were captured at Mauna Loa, Hawaii between 1958 and 1979. The abscissa covers the range between 300 and 340 part per million (ppm). The measurements are continued (D. M. GATES et al., 1983).