Greenhouse Gases Reach Record Highs in 2023: UN Report

AFP/APP

Geneva: Greenhouse gas levels reached unprecedented highs in 2023, reinforcing concerns over escalating global temperatures, the United Nations reported on Monday. 

The World Meteorological Organization (WMO) revealed that concentrations of carbon dioxide, methane, and nitrous oxide—the three primary greenhouse gases—continued to climb last year, locking in future temperature rises.

Carbon dioxide levels are accumulating at an alarming rate, with concentrations now up over 10 percent in the past two decades, according to the WMO’s Greenhouse Gas Bulletin. 

The report was released ahead of the COP29 UN climate summit scheduled for November 11-22 in Baku, where global leaders will face growing pressures to address climate goals.

“Another year. Another record,” said WMO chief Celeste Saulo. “This should set alarm bells ringing among decision-makers. 

We are clearly off track to meet the Paris Agreement goal.” The 2015 Paris Agreement set an ambitious target to cap global warming well below two degrees Celsius, ideally limiting it to 1.5 degrees Celsius above pre-industrial levels. 

But greenhouse gases will continue to accumulate and warm the Earth as long as emissions persist, the WMO warned.

Global temperatures on land and sea reached their highest levels since records began in 1850, the report added. Even with rapid reductions to net-zero emissions, current temperature levels are expected to persist for decades due to CO2’s prolonged presence in the atmosphere.

In 2023, the concentration of carbon dioxide hit 420 parts per million (ppm), methane reached 1,934 parts per billion, and nitrous oxide stood at 336 parts per billion—marking increases of 151 percent, 265 percent, and 125 percent, respectively, compared to pre-industrial levels. “Every fraction of a degree increase has a real impact on our lives and our planet,” noted Saulo.

Carbon dioxide alone is responsible for approximately 64 percent of climate warming. The year 2023 marked the twelfth consecutive year with a CO2 increase of over two ppm, largely due to fossil fuel emissions from the 2010s and 2020s.

 “CO2 is accumulating in the atmosphere faster than at any time during human existence,” the WMO report highlighted, with levels now 51 percent higher than pre-industrial times.

Comparable CO2 concentrations were last seen three to five million years ago, when global temperatures were 2-3 degrees Celsius warmer, and sea levels were 10-20 meters higher.

Nearly half of CO2 emissions remain in the atmosphere, while oceans and land ecosystems absorb the rest. However, WMO deputy chief Ko Barret cautioned that climate change itself could transform these ecosystems into greenhouse gas sources.

 “Wildfires could release more carbon emissions, and warmer oceans might absorb less CO2, allowing more of it to remain in the atmosphere and intensify global warming,” she warned, underscoring the potential for a dangerous feedback loop.

With climate feedbacks posing critical risks to society, the report signals an urgent call for action as global leaders prepare for discussions at COP29.