Climate Change

Highest carbon concentration in atmosphere in 3 million years: WMO

The new WMO Greenhouse Gas Bulletin says CO2 concentration in atmosphere has breached all recent records

By Richard Mahapatra
Published: Monday 25 November 2019
The new WMO Greenhouse Gas Bulletin says CO2 concentration in atmosphere has breached all recent records. Photo: Getty Images

The World Meteorological Organization (WMO) has said that the concentration of carbon dioxide (CO2) in the atmosphere has breached all records in 2018. This means the global warming will be further pronounced and climate change will be more evident, leading to rising temperatures, extreme weather events and sea level rising.

The WMO Greenhouse Gas Bulletin, released on November 25, said “globally averaged concentrations of carbon dioxide reached 407.8 parts per million in 2018, up from 405.5 parts per million (ppm) in 2017”.

“It is worth recalling that the last time the Earth experienced a comparable concentration of CO2 was 3-5 million years ago. Back then, the temperature was 2-3 degrees Celsius (°C) warmer, sea level was 10-20 metres higher than now,” Petteri Taalas, WMO secretary-general, said.

Source: WMO

In 2015, the CO2 concentration in the atmosphere crossed 400 PPM, considered a symbolicallydangerous breach. Since then, it has been rising.

CO2 is one of the greenhouse gases (GHGs) that trap heat and cause global warming. Carbon dioxide has a very long life. Once emitted, it continues to be present in the atmosphere and keeps on trapping heat, leading to global warming. CO2 accounts for about 80 per cent of all GHGs in the atmosphere causing warming.

Source: WMO

“There is no sign of a slowdown, let alone a decline, in greenhouse gas concentrations in the atmosphere despite all the commitments under the Paris Agreement on Climate Change,” Taalas said.

“We need to translate the commitments into action and increase the level of ambition for the sake of the future welfare of the mankind,” he said.

Source: WMOAccording to the WMO Bulletin, fossil fuel combustion is the causative factor for the rising atmospheric concentration of CO2. “Fossil fuels were formed from plant material millions of years ago and do not contain radiocarbon. Burning them will add to the atmosphere radiocarbon-free CO2, increasing CO2 levels and decreasing its radiocarbon content. And this is exactly what is demonstrated by the measurements,” the bulletin said.

The current level of CO2 concentration in the atmosphere is 147 per cent of pre-industrial levels in 1750. In the period 2017-18, the CO2 level increase was above the average growth rate of the last decade.

“The growth rate of CO2 averaged over three consecutive decades (1985–1995, 1995–2005 and 2005–2015) increased from 1.42 ppm/yr to 1.86 ppm/yr and to 2.06 ppm/yr with the highest annual growth rates observed during El Niño events,” it said.

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