The average concentration of carbon dioxide in the Earth’s atmosphere increased to a record level in 2015-2016, reaching a significant value of 400 parts per million, according to the annual Bulletin of the world meteorological organization (WMO) on greenhouse gases on Monday.
According to the WMO CO2 levels had previously reached the threshold level of 400 parts per million in certain months of the year and in certain parts of the world, but never before has this level was not observed in the global average scale for an entire year. According to forecasts monitoring station greenhouse gases at Mauna Loa (Hawaii), the CO2 concentration will remain at a level above 400 parts per million throughout 2016, and will not fall below this level during the life of many generations.
The reason for such a jump in CO2 meteorologists call a powerful phenomenon El niño, which was the impetus for the development of droughts in tropical regions and decrease in the ability of forests, vegetation and oceans to absorb carbon dioxide. These sinks currently absorb about half the CO2 emissions, however, there is a risk of saturation which will lead to an increase in the share of carbon dioxide emissions that remains in the atmosphere.
In addition to reducing the capacity of vegetation to absorb CO2, El Nino also led to the increase in carbon dioxide emissions as a result of forest fires. CO2 emissions in Equatorial Asia, where in August-September 2015 in Indonesia experienced large-scale forest fires was more than twice higher average values for the years 1997-2015.
Without solving the problem of CO2 emissions we will not be able to solve the problem of climate change and keep temperature rise to below 2 °C in comparison with the values of the pre-industrial period. In this regard, it is crucial that the Paris agreement came into force with significant ahead of schedule on 4 November, and also that we have accelerated its implementation, — said the Secretary-General of WMO, petteri Taalas, commenting on the data published in the WMO Bulletin.
Carbon dioxide accounts for about 65 % of the total radiative forcing by long-lived greenhouse gases. The level of CO2 concentration in preindustrial level was 278 ppm. The increase in the average annual concentration of CO2 in 2015 amounted to 144 % from pre-industrial levels, reaching 400 parts per million. The increase of CO2 from 2014 to 2015 was greater than the average for the previous 10 years.
The second most important long lived greenhouse gas is methane. It accounted for approximately 17 % of the contribution to radiative forcing. Currently, his concentration is 256 % from pre-industrial levels. The concentration in the atmosphere is the third greenhouse gas — nitrous oxide – in the past year amounted to about 328 parts per billion, which is 121% of pre-industrial levels. Nitrous oxide also plays an important role in the destruction of the stratospheric ozone layer that protects us from the harmful effects of UV sun rays.