The amount of carbon dioxide in the earth’s atmosphere attained record rate in 2016 to a level that has not been witnessed for millions of years, this resulted to a 20-metre rise in sea levels and adding 3 degrees to temperatures, according to the United Nations.
The U.N. World Meteorological Organization, in its annual Greenhouse Gas Bulletin, said that the atmospheric concentrations of carbon dioxide (CO2) which is the main man-made greenhouse gas, hit 403.3 parts per million (ppm), up from 400.0 in 2015.
The growth rate was 50 percent quicker than the average over the past decade, causing CO2 levels to rise about 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 the WMO bulletin, “Today’s CO2 concentration of ~400 ppm exceeds the natural variability seen over hundreds of thousands of years.”
The latest data contributes to the reason why environment ministers from around the world will converge in Bonn to work on guidelines for the Paris climate accord signed by 195 countries in 2015.
However, the agreement is already threatened because U.S. President Donald Trump has said he plans to pull his the United States out of the deal, which seeks to limit the rise in temperatures to “well below” 2 degrees Celsius (3.6 Fahrenheit) above pre-industrial times.
CO2 emissions from sources such as coal, oil, cement and deforestation by human have reached a record in 2016, and the El Niño weather pattern gave CO2 levels a further boost, the WMO said.
According to scientists, the world has never experienced 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 (CO2) levels reached 400 ppm was 3-5 million years ago, in the mid-Pliocene era.
“During that period, global mean surface temperatures were 2–3°C warmer than today, ice sheets in Greenland and West Antarctica melted and even parts of East Antarctica’s ice retreated, causing the sea level to rise 10–20 m higher than that today,” according to the WMO bulleting.
The global warming effect of CO2 and other long-lived greenhouse gases has risen by 40 percent since 1990. The two other main gases – methane and nitrous oxide – also attained record concentrations last year, although at a slower rate of increase than carbon dioxide.