400ppm, March 2015
2015 March, 400 Parts Per Million (global)
Edition of 5
Pigment ink on cotton rag
Figures released by the US science agency NOAA for March, 2015 show that for the first time since records began the parts per million (ppm) of CO2 in the atmosphere were over 400 globally for an entire month. This concentration has not occurred in over a million years.
This grid illustrates the days photographed in March 2015, multiplied by 25, in order to mark this milestone event with a work of 400 parts.