CO2.Earth mainly features CO2 data from measurements made by two scientific institutions at the Mauna Loa Observatory (MLO) on the Big Island of Hawaii USA: the National Atmospheric and Oceanic Administration (NOAA) and Scripps Institution of Oceanography (SIO). This is the site of the world's longest, continuous CO2 record of direct atmospheric measurements using high-precision instruments. The location is near the middle of the world's largest ocean, and near the top of the world's tallest mountain, from its base (McGee, 2017, p. 99). The Mauna Loa Observatory may be considered one of the best locations on earth for making these measurements. NOAA notes the following locational advantages:
"The undisturbed air, remote location, and minimal influence of vegetation and human activity at MLO are ideal for monitoring constituents in the atmosphere that can cause climate change."
Planetary Significance of the MLO Trend
At present, atmospheric CO2 is rising twice as fast as it was in the 1960s. You can see the difference in data from the Mauna Loa Observatory. But the rate of change is essentially the same at every CO2 monitoring station. In the book CO2 Rising, author Tyler Volk writes:
"Data from Alaska and Samoa fit right in with the trend from Mauna Loa and the South Pole, where monitoring was begun nearly 20 years earlier. We are witnessing a global phenomenon. CO2 is rising everywhere, and at about the same rate."
~ Tyler Volk (2008, pp. 40-41)
For stations at different latitudes, you will find differences in amplitude—much smaller near the South Pole and much larger near the North Pole.
Mauna Loa Links
Scripps Keeling Curve & lesson for long term earth observations
NOAA Mauna Loa CO2 record
See the "MLO" tab for more links about the Mauna Loa Observatory and other earth monitoring stations.
McGee, M. (2017). Learning for Planetary Habitability: A Lived Experience Study With Senior Earth System Scientists. (Master's thesis). Royal Roads University, Victoria, Canada. https://doi.org/10.13140/RG.2.2.11160.90882.
Volk, T. (2008). CO₂ rising: The world's greatest environmental challenge (2010 paperback ed.). Cambridge, MA: MIT Press. [MIT Press]
Scripps CO2 Monitoring at MLO
Charles David Keeling of the Scripps Institution of Oceanography started high-precision CO2 measurements at the Mauna Loa Observatory in March 1958. He directed the Scripps CO2 program, including CO2 monitoring at MLO, until he died in 2005. Keeling's son. Ralph F. Keeling. is now the senior scientist and principal investigator who oversees the Scripps CO2 monitoring program, as well as the the Scripps O2 Program that measures atmospheric oxygen and argon. Both programs are based at the Scripps Institution of Oceanography, University of California San Diego (UCSD) in La Jolla, California.
Scripps CO2 UCSD Home page
Scripps CO2 UCSD Keeling Curve website
Scripps CO2 UCSD Twitter (@Keeling_curve)
Scripps CO2 UCSD CO2 Data at MLO and other stations
NOAA CO2 Monitoring at MLO
Starting May 1974, the National Oceanic and Atmospheric Administration (NOAA). started a second, indepement CO2 monitoring program at the Mauna Loa Observatory. NOAA datasets for Mauna Loa CO2 that start in 1958 incorproate Scripps CO2 data from March 1958 to April 1974. NOAA now monitors observatory facilities at Mauna Loa. Pieter Tans is the senior scientist and principal investigator who oversees the NOAA CO2 monitoring program.
NOAA Mauna Loa Observatory webcam (facing west)
NOAA More webcams at MLO
Calculation of CO2 Mean Values
Monthly and weekly mean CO2 concentrations are determined from daily averages for the number of CO2 molecules in every one million molecules of dried air (water vapor removed). Annual mean CO2 concentrations are the arithmetic mean of the monthly averages for the year.
Atmospheric CO2 concentrations are expressed as parts per million (ppm). This is a shortened and common abbreviation for parts per million by volume (ppmv) as opposed to mass. The UAR Center for Science Education provides a helpful illustration of carbon dioxide concentrations in parts per million.
NOAA NOAA-ESRL calculation of global means
NOAA How CO2 levels are measured at Mauna Loa
Time Zones of Mauna Loa Data
Scripps CO2 data is based on local time in Hawaii, USA, where the observatory is located. NOAA CO2 data is based on local time in Boulder, Colorado, USA, from where scientists coordinate the activites of its global monitoring network.
Preliminary Publication of Data
Data published within the past year should be considered preliminary and subject to change by scientists based on recalibrations of reference gas mixtures or other quality control procedures. Adjustments may be made to earlier years for the same reasons. In the past, changes have been minor.
NOAA started publishing change log and notes in 2008 that provides a record of adjustments and reasons for them.
Mauna Loa Observatory
Mauna Loa Data & The Keeling Curve
NOAA MLO Monitoring & Research Programs
NOAA MLO Frequently Asked Questions (FAQs)
NOAA How CO2 levels are measured at Mauna Loa
Scripps CO2 Keeling Curve Lessons
U of Hawai'i Press BOOK | Hawaii's MLO: 50 Years of Monitoring the Atmosphere
CO2.Earth Data sources used at CO2.Earth
San Diego UT Keelings' CO2 measurements as global warming's longest yardstick
CDIAC Atmospheric CO2 from continuous air samples at MLO, Hawaii
Mauna Loa Visits & Photos
NOAA Tour information for the general public
NOAA MLO photo gallery
Nebraska Weather Photos A visit to the Mauna Loa Observatory, 2008
Worldview of Global Warming CO2 reaches 400 ppm (2011 photos)
Trip Advisor Mauna Loa Observatory (Things to do in Hilo, Hawaii)