A new report from the World Meteorological Organization (WMO) revealed that the global average concentration of carbon dioxide has reached 400 part per million (PPM) for the first in 2015 and will most likely to continue or even increase throughout 2016.

According to the WMO's annual Greenhouse Gas Bulletin, the levels of carbon dioxide in the atmosphere have reached the 400 ppm barrier for certain months in the year and in certain locations. However, it is the first time that the global average carbon dioxide atmosphere to reach the barrier for an entire year.

The recent increase in carbon dioxide concentration is attributed to the El Niño event, which started in 2015 and goes on in 2016. The drought condition brought by the El Niño event in some tropical regions has caused many plants and vegetation to wilt and die. Lesser vegetations mean lesser capacity of natural "sinks" to absorb carbon dioxide from the atmosphere. Furthermore, the warm and dry climate brought by the El Niño event is promoting more and more forest fires, which in turn more carbon dioxide in the atmosphere.

"The year 2015 ushered in a new era of optimism and climate action with the Paris climate change agreement," said Petteri Taalas, Secretary-General of WMO, in a press release. "But it will also make history as marking a new era of climate change reality with record high greenhouse gas concentrations."

Before the rise of the industrial revolution, the global average carbon dioxide in the atmosphere was about 278 ppm, which represented a balance between the atmosphere, the oceans and the biosphere. However, the increase use of fossil fuels has altered the natural balance, with the global average carbon dioxide levels 144 percent higher than pre-industrial levels.

Using the readings of the longest-established greenhouse gas monitoring station at Mauna Loa, Hawaii, WMO predicts that the global average concentration of carbon dioxide in the atmosphere will less likely to go back from pre-2015 levels for many generations.