Carbon dioxide levels 2002–12

Time series of atmospheric carbon dioxide over the northern hemisphere retrieved from the Sciamachy instrument on Envisat and the TANSO instrument on Japan’s GOSAT.  While carbon dioxide increases over the ten-year period, it experiences annual fluctuations caused by vegetation’s absorption and release of the gas due to photosynthesis and respiration. The different colours represent different methods of extracting carbon dioxide measurements from the measured spectra of reflected solar radiation.