News Briefs

CO2 Levels in Atmosphere Rise for Seventh Consecutive Year

Jun. 20, 2019
By Isabel Putinja

Recent News

New data reveals that the con­cen­tra­tion of carbon diox­ide in the atmos­phere rose to record levels during the month of May.

According to read­ings released on June 4, 2019 by the Mauna Loa Observatory in Hawaii, the U.S. National Oceanic and Atmospheric Administration (NOAA) and Scripps Institution of Oceanography at the University of California, San Diego, carbon diox­ide levels aver­aged 414.7 parts per mil­lion (ppm) in May 2019. This is 3.5 ppm higher than the amount mea­sured at the same time last year.

This is the sev­enth con­sec­u­tive year that carbon diox­ide levels have increased. This year’s levels also rep­re­sent the high­est sea­sonal peak recorded and the second high­est annual rise in the past 60 years.

In the past decade, rising carbon diox­ide levels have been reach­ing an aver­age annual growth rate of 2.2 ppm com­pared to 1.5 ppm in the 1990s. More recently, this figure has climbed even higher and faster.

See more: Climate Change News

Carbon diox­ide levels have been mon­i­tored since 1958 at the Mauna Loa Observatory, located in the Pacific Ocean on top of Hawaii’s biggest vol­cano.


“It is crit­i­cally impor­tant to have these accu­rate long-term mea­sure­ments of CO2 in order to under­stand how quickly fossil fuels are chang­ing our cli­mate,” said Pieter Tans, a senior sci­en­tist at NOAA’s Global Monitoring Division. “These are mea­sure­ments of the real atmos­phere, and do not depend on any models, but they help us verify cli­mate model pro­jec­tions, which if any­thing have under­es­ti­mated the rapid pace of cli­mate change being observed.”

Increasing con­cen­tra­tions of carbon diox­ide in the atmos­phere are an indi­ca­tion of an increase in the burn­ing of fossil fuels.

“There is abun­dant and con­clu­sive evi­dence that the accel­er­a­tion is caused by increased emis­sions,” Tans said.


Global carbon diox­ide con­cen­tra­tions are mea­sured in the month of May because this is when they peak, just before the start of spring in the north­ern hemi­sphere and the growth of carbon diox­ide-absorb­ing veg­e­ta­tion.

Carbon diox­ide is a green­house gas that causes global warm­ing and is largely man-made through the burn­ing of fossil fuels such as coal, oil and gas.


“Many pro­pos­als have been made to mit­i­gate global warm­ing, but with­out a rapid decrease of CO2 emis­sions from fossil fuels, they are pretty much futile,” Tans added.

The increase of green­house gases in the atmos­phere has been linked to sea levels rising faster than expected as well as pre­dic­tions that droughts may become more preva­lent in North America and Europe.

“CO2 growth rate is still very high,” Ralph Keeling, of the Scripps Institution of Oceanography, said. “The increase from last May was 3.5 ppm, which is well above the aver­age for the past decade. We’re likely seeing the effect of mild El Niño con­di­tions on top of record fossil fuel use.”

In 2014, read­ings at the Mauna Loa Observatory revealed the carbon diox­ide levels had passed the 400 ppm thresh­old. Scientists warn that con­cen­tra­tions of more than 450 ppm can trig­ger tem­per­a­ture rises and extreme weather events.