Global CO2 concentration reaches 400 parts per million in 2015: WMO

The World Meteorological Organization (WMO) on 24 October 2016 released annual Greenhouse Gas Bulletin. As per the bulletin, the average level of carbon dioxide in the atmosphere across the globe passed 400 parts per million (ppm) in 2015.

The statistics released by WMO is a symbolic and worrying milestone in growth of manmade climate change.

Key highlights of the Greenhouse Gas Bulletin

• The WMO Greenhouse Gas Bulletin reports on atmospheric concentrations of greenhouse gases.

• Carbon dioxide (CO2) accounted for about 65% of radiative forcing by long-lived greenhouse gases. The pre-industrial level of about 278 ppm represented a balance between the atmosphere, the oceans and the biosphere.

• Human activities such as the burning of fossil fuels has altered the natural balance and in 2015, globally averaged levels were 144% of pre-industrial levels.  

• In 2015, global annual average concentration of CO2 concentrations reached 400.0 ppm. The increase of CO2 from 2014 to 2015 was larger than the previous year and the average over the previous 10 years.

• In addition to reducing the capacity of vegetation to absorb CO2 the powerful, El Nino also led to an increase in CO2 emissions from forest fires.

• Methane (CH4) is the second most important long-lived greenhouse gas and contributes to about 17% of radiative forcing. Atmospheric methane reached a new high of about 1845 parts per billion (ppb) in 2015 and is now 256% of the pre-industrial level.

• Nitrous oxide (N2O) is emitted into the atmosphere from both natural (about 60%) and anthropogenic sources (approximately 40%), including oceans, soil, biomass burning, fertilizer use and various industrial processes. Its atmospheric concentration in 2015 was about 328 parts per billion. This is 121% of pre-industrial levels. It also plays an important role in the destruction of the stratospheric ozone layer, which protects us from the harmful ultraviolet rays of the sun.

About World Meteorological Organization

• The World Meteorological Organization is an intergovernmental organization with a membership of 191 Member States and Territories.

• It originated from the International Meteorological Organization (IMO), which was founded in 1873.

• It was established in 1950.

• It became the specialised agency of the United Nations for meteorology (weather and climate), operational hydrology and related geophysical sciences.

• It has its headquarters in Geneva, Switzerland.

• It is a member of the United Nations Development Group.