Climate threatsGreenhouse gas concentrations in the atmosphere surge to new record

Concentrations of carbon dioxide in the atmosphere surged at a record-breaking speed in 2016 to the highest level in 800,000 years, according to the World Meteorological Organization’s Greenhouse Gas Bulletin. The abrupt changes in the atmosphere witnessed in the past seventy years are without precedent.

Globally averaged concentrations of CO₂ reached 403.3 parts per million in 2016, up from 400.00 ppm in 2015 because of a combination of human activities and a strong El Niño event. Concentrations of CO₂ are now 145 percent of pre-industrial (before 1750) levels, according to the Greenhouse Gas Bulletin.

 Rapidly increasing atmospheric levels of CO₂ and other greenhouse gases have the potential to initiate unprecedented changes in climate systems, leading to “severe ecological and economic disruptions,” said the report.

WMO notes that the annual bulletin is based on observations from the WMO Global Atmosphere Watch Program. These observations help to track the changing levels of greenhouse gases and serve as an early warning system for changes in these key atmospheric drivers of climate change.

Population growth, intensified agricultural practices, increases in land use and deforestation, industrialization and associated energy use from fossil fuel sources have all contributed to increases in concentrations of greenhouse gases in the atmosphere since the industrial era, beginning in 1750.

Since 1990, there has been a 40 percent increase in total radiative forcing – the warming effect on our climate - by all long-lived greenhouse gases, and a 2.5 percent increase from 2015 to 2016 alone, according to figures from the U.S. National Oceanic and Atmospheric Administration quoted in the bulletin.

“Without rapid cuts in CO₂ and other greenhouse gas emissions, we will be heading for dangerous temperature increases by the end of this century, well above the target set by the Paris climate change agreement,” said WMO Secretary-General Petteri Taalas. “Future generations will inherit a much more inhospitable planet,” he said.

“CO₂ remains in the atmosphere for hundreds of years and in the oceans for even longer. The laws of physics mean that we face a much hotter, more extreme climate in the future. There is currently no magic wand to remove this CO₂ from the atmosphere,” said Taalas.

The last time the Earth experienced a comparable concentration of CO₂  was 3-5 million years ago, the temperature was 2-3°C warmer and sea level was 10-20 meters higher than now.