Last year’s 2017 increase was 50% higher than the average of the past 10 years. The amount of carbon dioxide in the earth’s atmosphere grew at record rate in 2017 to a level not seen for millions of years. This is potentially fueling a 20 meter rise in sea levels and adding 3 degrees to temperatures.
Atmospheric concentrations of carbon dioxide (CO2). The main man made greenhouse gas, hit 403.3 parts per million (ppm), up from 400.0 in 2016. The UN World Meteorological Organization said in its annual Greenhouse Gas Bulletin.
That growth rate was 50 percent faster than the average over the past decade. This driving CO2 levels 45 percent above pre industrial levels. And further outside the range of 180-280 ppm seen in recent cycles of ice ages and warmer periods.
According to experts, the last time the Earth experience a comparable concentration of CO2 was three to five million years ago, in the mid-Pliocene era. The climate then was 2-3C warmer, and sea levels were 10-20m higher due to the melting of Greenland and the West Antarctic ice sheets.
“Today’s CO2 concentration of ~400 ppm exceeds the natural variability seen over hundreds of thousands of years.”
The latest data adds to the urgency of a meeting in Bonn next month, when environment ministers from around the world will work on guidelines for the Paris climate accord backed by 195 countries in 2015.
The agreement is already under pressure because U.S. President Donald Trump has said he plans to pull the United States out of the deal.
The deal seeks to limit the rise in temperatures to “well below” 2 degrees Celsius (3.6 Fahrenheit) above pre-industrial times.
“The rapid increase in methane since 2007, especially in 2014, 2015, and 2016, 2017 is different. This not expect in the Paris agreement. Methane growth is strongest in the tropics and sub-tropics. The carbon isotopes in the methane show that growth is not being driven by fossil fuels. We do not understand why methane is rising. It may be a climate change feedback. It is a subject of very worrying.”
Human CO2 emissions from sources such as coal, oil, cement. And deforestation reach a record in 2017 and the El Niño weather pattern gave CO2 levels a further boost.
As far as scientists can tell, the world has never experience a rise in carbon dioxide like that of recent decades, which has happened 100 times faster than when the world was emerging from the last ice age.
Scientists know prehistoric levels from tiny air bubbles found in ancient Antarctic ice cores, and they can derive even older data from fossils and chemicals trapped in sediment.
The last time carbon dioxide levels reached 400 ppm was 3-5 million years ago, in the mid-Pliocene era.
The global warming effect of CO2 and other long-lived greenhouse gases has risen by 40 percent.
The report issue just a week ahead of the next instalment of UN climate talks, in Bonn. Despite the declaration by President Trump that he intends to take the US out of the deal, negotiators meeting in Germany will be aiming to advance and clarify the rulebook of the Paris agreement.