Reports of record high values from Mauna Loa Observatory in Hawaii made international headlines four weeks ago. Exceeding 400 parts per million (ppm) at Mauna Loa was significant because scientists have been monitoring CO2 emissions there since 1958, longer than any other observatory in the world.

"Levels of 400 ppm and the steady increase we observe every year means that it is unlikely global warming will stay below the 2°C target that governments around the world have pledged not to exceed," says Hans- Christen Hansson, Professor at ITM, and one of the scientists involved in monitoring CO2 levels in Svalbard.

Already in 2012, the monthly average levels for CO2 in March recorded at Zeppelin Observatory exceeded 400 ppm for the first time since measurements began 25 years ago. Parallel readings at monitoring stations in Alaska and northern Canada showed similar concentrations.

More worryingly, this year's readings for January 2013 showed that monthly average CO2 levels rose above 400ppm again and these levels persisted well into late May, five months in all. Scientists at the Norwegian Institute for Air Research (NILU) who have been monitoring CO2 levels at Zeppelin Observatory since 2011 reported the same trend.

"Soon we will observe not only monthly or seasonal averages but yearly averages of 400ppm and above. We are undoubtedly moving in this direction," says Hans-Christen Hansson.

Ny Ålesund
 

The picture shows the Zeppelin Observatory, Svalbard. At 474m (1600ft) above sea level, the Zeppelin Observatory is located in an undisturbed arctic environment near Ny-Ålesund in Svalbard. The unique location of the station makes it an ideal platform for the monitoring of global actmospheric changes and long-range pollution transport. The Swedish Environmental Protection Agency (Naturvårdsverket) has funded CO2 measurement since 1988 and ITM has been taking daily readings. In 2011, NILU installed an additional instrument for monitoring different greenhouse gases, of which CO2 is one.