Greenhouse Gas Concentrations Highest in 800,000 Years

Ethiopia drought
Woman uses a rope attached to a jerry can to pull water from a borehole in drought-stricken Hadhawe village, Somali regional state, Ethiopia, February 2017 (Photo by Mulugeta Ayene, UNICEF)


GENEVA, Switzerland, October 30, 2017 (ENS) – Concentrations of carbon dioxide (CO2) in the atmosphere surged at record-breaking speed in 2016 to the highest level in 800,000 years, the World Meteorological Organization says in its latest annual Greenhouse Gas Bulletin, issued today.

The abrupt changes in the atmosphere seen in the past 70 years are “without precedent,” said the UN’s agency on the state and behavior of the Earth’s atmosphere, its interaction with the oceans and the climate it produces.

Ethiopia drought
Woman uses a rope attached to a jerry can to pull water from a borehole in drought-stricken Hadhawe village, Somali regional state, Ethiopia, February 2017 (Photo by Mulugeta Ayene, UNICEF Ethiopia)

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 that warmed the Eastern tropical Pacific Ocean.

Concentrations of CO2 are now 145 percent of pre-industrial levels, before the year 1750, according to the WMO’s 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,” says the report.

The last time the Earth experienced a comparable concentration of carbon dioxide was three to five million years ago, the temperature was 2-3°C warmer and sea level was 10 to 20 meters higher than it is now.

“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 warned.

“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.

Graphs of carbon dioxide concentrations in Earth’s atmosphere from the WMO’s latest Greenhouse Gas Bulletin (Graphs courtesy WMO)

The WMO Greenhouse Gas Bulletin reports on atmospheric concentrations of greenhouse gases.

Emissions represent what goes into the atmosphere. Concentrations represent what remains in the atmosphere after the complex system of interactions between the atmosphere, biosphere, cryosphere and the oceans.

About a quarter of the total emissions is taken up by the oceans and another quarter by the biosphere, reducing the amount of CO2 in the atmosphere.

The annual Greenhouse Gas Bulletin is based on observations from the WMO Global Atmosphere Watch, GAW, Programme. More than 100 countries have registered more than 800 observation stations with the GAW Station Information System. Their 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, says the WMO.

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. There has been 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.

A separate Emissions Gap Report by the UN Environment agency, to be released on October 31, tracks the policy commitments made by countries to reduce greenhouse gas emissions and analyzes how these policies will translate into emissions reductions through 2030, clearly outlining the emissions gap and what it would take to bridge it.

“The numbers don’t lie. We are still emitting far too much and this needs to be reversed. The last few years have seen enormous uptake of renewable energy, but we must now redouble our efforts to ensure these new low-carbon technologies are able to thrive,” said Erik Solheim, head of UN Environment.

“We have many of the solutions already to address this challenge. What we need now is global political will and a new sense of urgency,” Solheim said.

Desert lands in Inyo County, California, which contains Death Valley, May 2017 (Photo by CEBImagery)

Together, the Greenhouse Gas Bulletin and Emissions Gap Report provide a scientific base for decision-making at this year’s UN climate change negotiations, which will be held from November 7-17 in Bonn, Germany, hosted by the government of Fiji.

WMO, UN Environment and other partners are working towards an Integrated Global Greenhouse Gas Information System to provide information that can help nations to track the progress toward implementation of their national emission pledges, improve national emission reporting and inform mitigation actions.

This system builds on the long-term experience of WMO in greenhouse gas instrumental measurements and atmospheric modelling.

WMO is also striving to improve weather and climate services for the renewable energy sector and to support the green economy and sustainable development.

To optimize the use of solar, wind and hydropower production, new types of weather, climate and hydrological services are needed.

Key findings of the Greenhouse Gas Bulletin

Carbon dioxide

CO2 is by far the most important human-emitted, long-lived greenhouse gas. Globally averaged concentrations for CO2 reached 403.3 parts per million in 2016, up from 400.00 ppm in 2015. This record annual increase of 3.3 ppm was partly due to the strong 2015/2016 El Niño, which triggered droughts in tropical regions and reduced the capacity of carbon sinks like forests, vegetation and the oceans to absorb CO2.

Concentrations of CO2 are now 145 percent of pre-industrial (before 1750) levels.

The rate of increase of atmospheric CO2 over the past 70 years is nearly 100 times larger than that at the end of the last Ice Age. As far as observations can tell, such abrupt changes in the atmospheric levels of CO2 have never before been seen.

Over the last 800,000 years, pre-industrial atmospheric CO2 content remained below 280 ppm, but it has now risen to the 2016 global average of 403.3 ppm.

From the most-recent high-resolution reconstructions from ice cores, it is possible to observe that changes in CO2 have never been as fast as in the past 150 years.


Methane (CH4) is the second most important long-lived greenhouse gas and contributes about 17 percent of radiative forcing. About 40 percent of methane is emitted into the atmosphere by natural sources such as wetlands and termites, and about 60 percent comes from human activities like cattle breeding, rice agriculture, fossil fuel exploitation, landfills and biomass burning.

Atmospheric methane reached a new high of about 1,853 parts per billion in 2016 and is now 257 percent of the pre-industrial level.

Nitrous Oxide

Nitrous oxide (N2O) is emitted into the atmosphere from both natural sources (about 60 percent)  and human sources (about 40 percent), including oceans, soil, biomass burning, fertilizer use, and industrial processes.

The N2O atmospheric concentration in 2016 was 328.9 parts per billion. This is 122 percent of pre-industrial levels.

This greenhouse gas also plays an important role in the destruction of the stratospheric ozone layer which protects us from the harmful ultraviolet rays of the sun. It accounts for about six percent of radiative forcing by long-lived greenhouse gases.

Copyright Environment News Service (ENS) 2017. All rights reserved.


Continue Reading