  Carbon dioxide (CO2) increase has been well documented, and global net
primary production is of importance to a variety of ecological topics. Since
CO2 increases primary production in laboratory experiments, the global effects
of increasing CO2 on global primary production are of interest in both climate
science and ecology. Various studies have considered increases in primary
production over different regions and time scales, but the global effects of
increased atmospheric CO2 and primary production remain unquantified. This
study aims to compare these two variables globally to assist in determining the
potential for increases in primary production to contribute to carbon
sequestration, possibly slowing increases in atmospheric CO2 resulting from
fossil fuel emissions. Monthly CO2 concentration data from 1985 through 2015 in
distinct latitude bands (every 10 degrees) was retrieved from the NOAA Earth
System Research Laboratory for a total of 18 datasets. As a proxy to quantify
net primary production, the magnitude of annual CO2 cycling was computed for
each dataset through Fourier analysis. Relative increases were then calculated
for both CO2 increase and amplitude increase to compare the pace of carbon
cycling with the pace of increases in atmospheric CO2. Globally, the increase
in primary production determined by using annual CO2 cycling as a proxy was
3.75% (+/- 1.82%) per decade over the time interval studied. In contrast, the
measured increase in CO2 abundance was 4.75% (+/- 0.02%) per decade. Increases
in carbon cycling appear to be slightly smaller than increases in CO2 globally
and in both the Northern and Southern Hemispheres, but the uncertainties in the
estimate for increases in carbon cycling are too large to draw that conclusion
with statistical confidence.
