The amount of greenhouse gases in the world’s atmosphere reached a new record high in 2011, according to the World Meteorological Organisation.
The Swiss-based research group said between 1990 and 2011 there was a 30% increase in ‘radiative forcing’ – the warming effect on our climate – because of carbon dioxide (CO2) and other heat-trapping gases like methane (CH4) and nitrous oxide (N2O).
The WMO’s 2011 Greenhouse Gas Bulletin reports on atmospheric concentrations, rather than emissions – of greenhouse gases. The WMO says emissions represent what goes into the atmosphere whereas concentrations count for what remains in the atmosphere “after the complex system of interactions between the atmosphere, biosphere and the oceans.”
The report says since the start of the industrial era in 1750 roughly 375 billion tonnes of carbon have been released into the atmosphere as CO2, mainly from fossil fuel combustion. About half of this carbon dioxide remains in the atmosphere, with the rest being absorbed by the oceans and terrestrial biosphere.
WMO Secretary-General Michel Jarraud said: “These billions of tonnes of additional carbon dioxide in our atmosphere will remain there for centuries, causing our planet to warm further and impacting on all aspects of life on earth. Future emissions will only compound the situation.”
He warned the so-called ‘carbon sinks’ such as deep oceans, which have absorbed nearly half the CO2 humans emitted in the atmosphere, may not continue to do so in the future.
He went on: “We have already seen that the oceans are becoming more acidic as a result of the carbon dioxide uptake, with potential repercussions for the underwater food chain and coral reefs. There are many additional interactions between greenhouse gases, Earth’s biosphere and oceans, and we need to boost our monitoring capability and scientific knowledge in order to better understand these.”