Chart of the Week: Arctic CO₂ Levels Up

credit: P.Tans et al, NOAA

NOAA reports that their arctic monitoring stations in high latitudes have registered CO₂ levels of 400ppm this spring. Because of the stations' remoteness in Alaska, Canada, Finland, Norway and the North Pacific, the readings reflect a rising background level of global carbon dioxide consistent with human emissions.  A scientist with NOAA said the network is reporting what will become a global average in about 2016. More southerly stations have been reporting 400ppm for years in the early spring. As plant growth begins, concentrations fall, then rise in summer in an annual cycle.

The good news in an otherwise ominously warming world, is that natural carbon sinks such as tropical forests are still sucking up atmospheric carbon dioxide contrary to some recent studies suggesting these sinks have reached capacity [grey line, chart].  These latest, optimistic findings were reported at a May 15th conference hosted by NOAA's Earth Systems Research Laboratory in Boulder, CO. Exactly where the unused capacity is located is not clear given the worldwide destruction of forests. There may be sufficient forest regrowth to keep up with increasing levels of atmospheric CO₂ or the oceans may be absorbing more than previously estimated. Read outs from Mauna Loa on Hawaii show carbon dioxide levels rising steadily from 316 ppm in 1959 to 392ppm today.