Climate Change

How the dismantling of NOAA threatens the Keeling Curve

By Eric Morgan, Ralph Keeling, May 5, 2025

There are trillions upon trillions of numbers in the world. We use numbers to describe almost every conceivable thing in the universe. But there is one number that surpasses all others for the enormous impact it will have on every living thing on Earth over the next few thousand years. We consider it so important that we’ve dedicated our lives to acquiring and understanding it. Today that number happens to be: 427.6.

This is a measure (known in scientific terms as the mole fraction) of atmospheric carbon dioxide at the Mauna Loa Observatory in Hawai’i, in parts per million. It’s part of a continuous chain of observations stretching back across two generations, to 1958, when Dave Keeling recorded the first measurement of 313 parts per million. Dave Keeling maintained this record, known as the Keeling Curve, using a running hodgepodge of short-term grants until 2005, at which point geochemist Ralph Keeling, a professor at UC San Diego’s Scripps Institution of Oceanography, co-author of this piece and Dave’s son, assumed its stewardship. But now, after 67 years of battling to keep the program funded and provide the data to other scientists around the world, the program faces its most dire threat ever.

Why? Endeavors of this nature—highly precise measurements of a trace gas over many decades—require three basic inputs: knowledge, people, and money. It’s the third one that’s at risk, thanks to the current administration’s attacks on NOAA, the National Oceanic and Atmospheric Administration. NOAA provides support for our program both through an annual grant and through invaluable “in-kind” support, such as staffers taking samples for us, maintaining buildings in remote areas where sampling occurs, and running the Mauna Loa Observatory.

Monthly average carbon dioxide concentration at Mauna Loa (top panel) and annual financial support for the Scripps CO2 program (bottom panel), adjusted for inflation to US dollars in 2007. Figure is adapted from Sundquist and Keeling, 2009, “The Mauna Loa Carbon Dioxide Record: Lessons for Long-Term Earth Observations”, In Carbon Sequestration and Its Role in the Global Carbon Cycle. Acronyms: USWB, United States Weather Bureau; IGY, United States National Committee for the International Geophysical Year; NSF, National Science Foundation; ESSA/NOAA, Environmental Science Services Administration / National Oceanic and Atmospheric Administration; DOE, Department of Energy; EPRI, Electric Power Research Institute; UNEP-WMO, United Nations Environment Programme World Meteorological Organization; NBS/NIST, National Bureau of Standards/National Institute of Standards and Technology; CA Space, California Space Institute; BP, BP p.l.c. (formerly The British Petroleum Company); Schmidt, Schmidt Sciences.

The Trump administration has made clear it wishes to gut NOAA’s research enterprise, which is at the center of climate research globally. Already, we’ve seen large-scale firings and rejections of research proposals. Recent guidance from the Office of Management and Budget shows the administration intends to assiduously follow the blueprint of the Heritage Foundation’s Project 2025 and shutter the Ocean and Atmospheric Research Line Office. This is not just a little haircut for a large federal agency—it’s grabbing the scissors and stabbing the agency through the heart. If successful, this loss will be a nightmare scenario for climate science, not just in the United States, but the world. It will also likely spell the end of our ability to continuously update the Keeling Curve.

Against this ominous backdrop, a small group of scientists is scrambling to preserve the ability to know how much carbon dioxide is in the atmosphere. NOAA maintains a global backbone of measurements of carbon dioxide and other gases, not just at Mauna Loa, but at more than 50 stations around the world. In parallel, our program at Scripps maintains records at a dozen stations. Other countries also contribute, but their efforts are almost all focused regionally, leaving the big picture to just a few programs that are global in scope. Climate change, however, is a global problem, and global networks address the really important questions. Such networks provide critical information on how fast carbon dioxide and other greenhouse gases are building up in the air from fossil-fuel burning and other processes. They provide information on how much carbon dioxide is being removed from the atmosphere by the oceans and by land plants. They provide information critical to independently verify emissions, to negotiate international treaties, to make decisions now about how much carbon dioxide the world can emit. These observational networks are the factual basis upon which all efforts to mitigate and adapt to climate change are based.

NOAA and Scripps play another key role in the atmospheric measurement community. How does the world know that the value of carbon dioxide in the atmosphere today is really 427.6 and not 427.7 parts per million? Such differences may seem small, but they are consequential in the realm climate research, and they can be calculated only because a lot of work has gone into calibration. Hundreds of groups can measure carbon dioxide using various off-the-shelf analyzers, but these analyzers first need to be calibrated using compressed air that has a known amount of carbon dioxide in it. Scripps assumed the lead role for preparing tanks filled with known amounts of carbon dioxide and dispensing them to the community until 1995, at which point NOAA took over.

The country and the world are now at risk of losing the only two programs that have played this central role. If the current administration has its way, the climate change research community could soon be fully adrift, unable to know with sufficient accuracy how quickly carbon dioxide levels are rising.

Even in the best of times, long-term observations can be very fragile. It is difficult to convince funding agencies to put money into long-term observations because, by definition, they are continuations; they have been done before. Most funding entities, from science agencies to philanthropic organizations, want to be associated with exciting, groundbreaking work, and sustained observations are too routine to scratch that itch. (Dave Keeling records in his autobiography, Rewards and Penalties of Monitoring the Earth, that at one point a National Science Foundation program manager demanded that, to maintain funding, he generate two discoveries per year from his record of carbon dioxide levels.)

Another vulnerability stems from the fact that the community of researchers making sustained measurements of atmospheric carbon dioxide probably numbers less than 30. Graduate students interested in learning to conduct this arcane work are a rare commodity.  Patience and attention to detail are required, and years may be needed to accumulate enough data to answer the key questions or make groundbreaking discoveries. Researchers have to be extremely diligent and exacting to ensure that measurements in 1958 are comparable to those today. Calibration is an endless chore. This scientific pursuit isn’t for everyone.

Perversely, while the Keeling Curve has attained iconic global importance, this actually can hinder, rather than help the funding situation. Environmental programs tend to be organized by geographic domain and discipline—the National Water Quality Program of the US Geological Survey, NSF’s Arctic Observing Network, and the US Forest Service, for instance. Amid these focused efforts, the big picture can be lost. As the climate change field has evolved, we have found it increasingly difficult to find sponsors who accept responsibility for measuring vital signs of the Earth as a whole.

The original Mauna Loa measurements were started during the International Geophysical Year in 1957/1958. This was a massive, remarkable effort, led by the United States and including 67 countries, with the goal (simply put) of measuring every physical attribute possible on the Earth in one year. It led to numerous, important scientific discoveries and the establishment of many measurement programs worldwide. It established the South Pole station, for instance, a home for vital climate research that is still going today. It was a time of enormous optimism, of international cooperation (even during the height of the Cold War), of vast dreams, of global cooperation. And the United States was proud to lead the way.

This sense of endeavor continued into the 1970s, when then-President Richard Nixon—a conservative Republican—established NOAA to better understand the world’s oceans and atmosphere. By the 1980s, the NOAA grew in scope, alongside the Scripps effort, to become the beating heart of global climate science. Now, after just three short months of the Trump administration, we are contemplating the abdication of US leadership in oceanic and atmospheric science and the loss of the largest and most critical observing network for carbon dioxide and other greenhouse gases and their calibration laboratories.

Our colleagues at NOAA are living day to day, not sure if tomorrow will be their last on the job. We pray that common sense will prevail and that NOAA will be spared the worse. Whatever its fate, we will remain in the fight to preserve the world’s ability to measure carbon dioxide levels with whatever support we can muster, a small bulwark against climate science’s new dark age.

As the coronavirus crisis shows, we need science now more than ever.

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