Note on recent increased day-to-day variability

Robert MonroeDaily Measurements, Measurement Notes

Photo: Erik Jepsen/UC San Diego

An observer of Keeling Curve data queried last week why there’s such a spread in atmospheric CO2 measurements this year. In response, Scripps CO2 Program Director Ralph Keeling offered the following: “It’s true the Mauna Loa Observatory (MLO) record typically has considerable day-to-day variability in the first half of the calendar year.  It’s also true that this type of variability … Read More

During Year of Extremes, Carbon Dioxide Levels Surge Faster than Ever

Robert MonroeDaily Measurements, Keeling Curve History

Rainbow frames NOAA’s Mauna Loa Observatory. Photo: Brian Vasel, NOAA Global Monitoring Laboratory

Carbon dioxide is accumulating in the atmosphere faster than ever — accelerating on a steep rise to levels far above any experienced during human existence, scientists from NOAA and Scripps Institution of Oceanography at the University of California San Diego announced today. Scientists at Scripps Oceanography, which initiated the CO2 monitoring program known as the Keeling Curve at Mauna Loa in 1958 and … Read More

Largest Year–Over-Year Gain in Keeling Curve Set in March

Robert MonroeAnnouncement, Measurement Notes

New record for largest 12-month gain in carbon dioxide concentration ever observed The monthly average concentration of carbon dioxide in the atmosphere measured at NOAA’s Mauna Loa Observatory in March 2024 was 4.7 parts per million (ppm) higher than that recorded in March 2023, setting a new record and revealing the increasing pace of CO2 addition to the atmosphere by … Read More

The Keeling Curve Hits 420 PPM

Robert MonroeMost Popular, Videos

Levels of the greenhouse gas carbon dioxide eclipsed 420 parts per million for the first time in human history in 2021. Scripps Institution of Oceanography updated this animation, which explains the rise of carbon dioxide concentration in the atmosphere over the past 300 years and the measurement our researchers collect at Hawaii’s Mauna Loa, known as the Keeling Curve. When … Read More

What Does This Number Mean?

Robert MonroeMeasurement Notes

Repost of April 2013 entry The Mauna Loa carbon dioxide (CO2) record, also known as the “Keeling Curve,” is the world’s longest unbroken record of atmospheric carbon dioxide concentrations.  

A Keeling Curve Funding Update – April 2015

Robert MonroeOutreach

The Scripps Institution of Oceanography, UC San Diego O2 and CO2 programs have received funding from multiple sources that put these operations on a relatively secure footing for the next few years.