Atmospheric concentrations of GHGs reached a new high in 2014, with CO2 levels reaching 397.7 parts per million (ppm), according to a new report from the UN’s World Meteorological Organization. The annual Greenhouse Gas Bulletin shows a 36% rise in radiative forcing – the warming effect on earth’s climate – between 1990 and 2014. GHGs such as CO2, nitrous oxide and methane are noted as the main culprits and are attributed to industrial, agricultural and domestic activities.
The report also notes that carbon dioxide concentrations crossed the symbolic 400 ppm threshold, the level suggested by scientists as a “stabilization point” that shouldn’t be exceeded to prevent future climate issues, in spring of 2014 in the Northern hemisphere, while the global average concentration passed the border in spring 2015. The relationship and amplification effect between carbon dioxide and rising levels of water vapor is also highlighted, as the two gases work together to enhance the greenhouse effect, with the researchers predicting that increased CO2 concentrations will lead to high increases in thermal energy and warming from water vapor.
While many reports examine GHG emission levels, the study instead focuses on GHG concentrations, or what is left in the atmosphere after the oceans and biosphere take up some of the excess CO2. The WMO’s data highlights the need for GHG emission reduction and mitigation strategies, with many scientists predicting vast changes to the earth’s atmosphere that could be irreversible if GHG levels continue to rise.
“Every year we report a new record in greenhouse gas concentrations. Every year we say that time is running out. We have to act now to slash greenhouse gas emissions if we are to have a chance to keep the increase in temperatures to manageable levels,” says WMO Secretary-General Michel Jerraud.