A surprising rise in atmospheric carbon dioxide concentration has been witnessed in 2015, the highest level of CO2 rise in the last 56 years. For the last four years, CO2 level in the atmosphere has gone up by two or more parts per million each year. The increase is more than the level seen in other periods dating back to 1959, said a scientist from the National Oceanic and Atmospheric Administration’s Earth System Research Laboratory.
Pieter Tans, lead scientist of NOAA’s Global Greenhouse Gas Reference Network, said that the change in the average concentrations between February 2015 and February 2016 was 3.76 parts per million at the Mauna Loa Observatory in Hawaii.
The increase represented a record year-over-year growth for Mauna Loa. Tans affirmed that not only a shocking rise has been witnessed in carbon dioxide levels, but they have also observed four straight years of increase of more than two parts per million in the level of CO2 in the atmosphere.
NOAA said that the average annual increase during 2015 was the highest on record. For 2015, the level rise stood at 3.05 parts per million and crossed the previous record of 2.93 parts per million in 1998. When the measurement record started at Mauna Loa, pre-industrial levels of carbon dioxide were just 280 parts per million and now they stand at more than 400 parts per million.
Tans said that rate of fossil fuel burning has remained significantly at high levels releasing 10 billion metric tons of carbon dioxide into the atmosphere on annual basis. Ralph Keeling, director of the Scripps Institution of Oceanography carbon dioxide program said that El Nino phenomenon also has a role to play. He said so as carbon dioxide increases at faster rate during and just following El Nino events.
Keeling said that the loss of carbon from tropical forests during El Nino years is temporary as the forests re-grow in normal years. “But the eventual recovery from this El Niño won’t bring us back below 400 ppm, because its impact will be dwarfed by the global consumption of fossil fuels, pushing CO2 levels ever higher”, affirmed Keeling.