'Sad What We Are Doing': Global CO2 Increase Sets New All-Time Record

The average monthly concentration of carbon dioxide in the atmosphere jumped by a record 4.7 parts per million between March 2023 and March 2024, according to new data from NOAA's Mauna Loa Observatory in Hawaii.

The spike, reported by the University of California, San Diego's Scripps Institution of Oceanography on Wednesday, reveals "the increasing pace of CO2 addition to the atmosphere by human activities," the university said.

"I'd make this the lead story in every paper and newscast on the planet," author and long-time climate activist Bill McKibbenwrote on social media in response to the news. "If we don't understand the depth of the climate crisis, we will not act in time."

"Human activity has caused CO2 to rocket upwards. It makes me sad more than anything. It's sad what we are doing."

Scientists have been tracking rising CO2 concentrations from Mauna Loa since 1958, and their upward trajectory has come to be known as the "Keeling Curve," named for Charles Keeling, who began the measurements. The curve has become an important symbol of the climate crisis—making visible how the burning of fossil fuels and the clearing of vegetation has released more and more CO2 into the atmosphere, where it traps heat from escaping into space and raises global temperatures.

For most of human history, concentrations have hovered around 280ppm, and the curve's first measurement put them at 313. Sixty-five years later, C02 concentrations averaged 419.3 ppm in 2023, a level not seen since 4.3 million years ago when sea levels were around 75 feet higher and parts of today's Arctic tundra were forests. As of Wednesday, the Keeling Curve reported a daily concentration of 426.72 ppm.

The record jump from March 2023 to March 2024 surpasses the last record jump of 4.1 ppm from June 2015 to June 2016.

"We sadly continue to break records in the CO2 rise rate," Ralph Keeling, Charles' son who now directs the Scripps CO2 Program, said. "The ultimate reason is continued global growth in the consumption of fossil fuels."

The record leaps from both 2015-2016 and 2023-2024 were also influenced by active El Niño events. The El Niño phenomenon increases atmospheric carbon dioxide because it leads to warmer, drier temperatures in the tropics, which decrease vegetation and encourage fires. Atmospheric CO2 levels tend to rise especially quickly toward the end of an El Niño cycle, and last March's CO2 levels were unusually low, leading to a larger gap in the 12-month period.

This year's rate of increase during the current El Niño is significantly larger than the one that took place in 2016. As Scripps explained:

The increase from February 2023 to February of this year was 4.0 ppm, compared to 3.7 for the 2016 El Niño. The increase from January 2023 to January of this year was 3.4 ppm, compared to 2.6 for the 2016 El Niño.

The growth rate from April 2023 to April 2024 dropped to 3.6 ppm, but taking into account the first four months of 2024, the growth rate is well above that for 2016. If this El Niño follows the pattern of the last El Niño, the world might experience a very high growth rate for several more months, Keeling said.

However, any regular climate variations such as El Niño events occur over the longer-term rise in both fossil fuel emissions and greenhouse gas levels.

"The rate of rise will almost certainly come down, but it is still rising and in order to stabilize the climate, you need CO2 level to be falling," Keeling toldThe Guardian. "Clearly, that isn't happening. Human activity has caused CO2 to rocket upwards. It makes me sad more than anything. It's sad what we are doing."

Jeff Goodell, author of The Heat Will Kill You First, wrote in response, "We're riding the Venus Express."

The record jump in CO2 concentrations comes as 2023 was the hottest year both on record and in around 100,000 years. Of the 12 months covered by the March 2023 to March 2024 period, 10 of them (June through March) were the hottest of that month on record.