CO2 levels reach record high: UN

The World Meteorological Organization (WMO) says levels of carbon dioxide in the atmosphere reached a record high in 2013.

The UN weather agency said in an annual report on Tuesday that the volume carbon dioxide, the main greenhouse gas emitted by human activities, increased to 396 parts per million last year, which is the biggest year-to-year change in 30 years.

That is a rise of 2.9 ppm from 2012, which was itself up 2.2 ppm from 2011.

“We know without any doubt that our climate is changing and our weather is becoming more extreme due to human activities such as the burning of fossil fuels. Time is not on our side, for sure,” WMO Secretary General Michel Jarraud said.

Jarraud added at a press conference that the rise “may be due to the reduced uptake of CO2 by the biosphere. If that is confirmed, it is of significant concern.”

The UN agency report also said the rate of ocean acidification, which comes from added carbon absorbed by oceans, “appears unprecedented at least over the last 300 million years.”

“Past, present and future CO2 emissions will have a cumulative impact on both global warming and ocean acidification. The laws of physics are non-negotiable,” Jarraud noted.

The WMO report said carbon dioxide and other gas emissions caused a 34% rise in the warming effect on the climate between 1990 and 2013.

Methane has the second biggest effect on climate after carbon dioxide. Methane’s atmospheric concentrations reached a new high of 1,824 parts per billion last year.

Some 40% of the methane comes from natural sources but the rest is caused by rice agriculture, cattle breeding, landfills, fossil fuel burning and incineration.

SAB/SS