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Last CO2 Earth update: loading... on loading..., Hawaii local time (UTC -10)
Data source: NOAA GML (Mauna Loa Observatory)
Units: parts per million (ppm)
This table presents the latest, daily average reading for atmospheric CO2 on the planet. Updates happen once a day with few exceptions.
CO2 Is The Number to Watch
When the trend for atmospheric CO2 trend begins to falter and fall, we can expect global average temperature to follow. For those who care about the sustainability of the planet, and who want it to remain a place where people can flourish, the measured CO2 levels in the atmosphere serve as the single best, real-time signal of whether the world as a whole is on track to a safe future, or needing to do more to get on track.
Explore the info under the tabs below for more info and daily CO2 readings.
Daily CO2 Comparisons
NOAA Daily CO2
Recent Daily Average CO2 at Mauna Loa
(last 31 days)
Source Graphic: NOAA Daily Average MLO CO2
More NOAA CO2: Daily / Weekly / Monthly
Source Graphic: NOAA Weekly Mauna Loa Web Page
The NOAA CO2 averages use colour codes as follows:
- daily CO2 = black dots
- weekly CO2 = red lines (Sunday to Saturday)
- monthly CO2 = blue lines.
CO2 Earth Weekly CO2
Scripps Hourly & Daily CO2
Source Graphics: Scripps Keeling Curve Website
Scripps reports daily averages based on Mauna Loa local time.
The Scripps graph shows hourly CO2 averages with small grey dots, and daily averages with larger black dots.
Scripps UCSD Keeling Curve website
Scripps CO2 Program MLO Datasets
Daily Global CO2Trend
NOAA's Daily Global CO2 chart averages seasonally-adjusted data from four core observatories at different latitudes from the South Pole to Alaska. Recent values are estimates, not current observations.
Source Graphic: NOAA Global CO2 Trend webpage
NOAA states that lines in the graphic "are a very good estimate of the global average levels of CO2."
Why does the graph show us?
NOAA's Daily Global CO2 table shows us atmospheric CO2 phenomena that Charles David Keeling discovered with the high-precesion CO2 measuring instruments and programs he created in the 1950s. These phenomna include:
- seasonal fluctuations of CO2 levels in well-mixed background air that is free of local influence such as plant respiration and industry
- large difference in seasonable fluctuations betwen the South Pole (least fluctuation) to near the North Pole (highest fluctuation) which shows that seasonal fluctuations are driven mainly by vegetation cycles in the Northern Hemisphere where most land is located.
- year-over-year increases in carbon dioxide--increases that have continued and accelerated since Keeling's discovery and which scientists attribute primarily to emissions caused by human activities (roughly 90% fossil fuel combustion and most of the remainder due to land use changes)
Why does CO2 Earth focus on Mauna Loa CO2 readings?
Maybe you are wondering why CO2 Earth features daily readings from the Mauna Loa Observatory (MLO) alone and not a seasonally adjusted estimate? If you are, there are many reasons.
First, CO2 readings from Mauna Loa are direct observations of the Earth system. They are precise measurements of the air made at one location in the Earth's atmosphere. They are not projections, estimates or averages that use advanced mathematics to generate a daily number. CO2 Earth was created to make it easy for non-scientists to see changes of consequence to the planet as they happen. Whether the CO2 problem is getting worse or getting resolved, people deserve to have access to objective informaiton without filters and delays. For this reason, CO2 Earth use data from direct observations when it reports the latest available CO2 levels.
This brings us to another reason. Unlike CO2 readings from other observing stations in the world, CO2 readings from Mauna Loa are practically real time.
A third reason relates to reliability. CO2 readings are available from not one, but two scientific institutions: NOAA ESRL (Global Monitoring Division) and the Scripps Institution of Oceanography at UCSD (Scripps CO2 Program). Each institution measures CO2 readings with separate instruments and reports their readings indepndently of the other. Scripps started continuous measurements at Mauna Loa in 1958. The NOAA-ESRL program started in 1974.
Fourth, the Mauna Loa CO2 record is the the world's longest, continuous record of observations using high precision instruments. Observations today can be compared against observations at the same location over a period of time that is longer than any other.
Fifth, year-over-year comparisons of Mauna Loa CO2 gives people a signal of planetary significance. It's true that Mauna Loa is just a spot on the map. But the year-over-year trend in the Mauna Loa CO2 is essentially the same as the trends at other observing stations. “CO2 is rising everywhere, and at about the same rate” (Volk, 2008, pp. 39-41). Further, the CO2 data presents a trend that is so clear that statistical analysis is not needed to detect it (Tans & Bolin, 2006, p. 329).
And then there is the Mauna Loa Observatory and its remote location in the middle of the largest and deepest ocean on the planet. It is 3,400 metres above sea level on a slope about 3/4 of a kilometre metres below the top of the tallest mountain on Earth. (McGee, 2017, p. 99) NOAA-ESRL states that "the undisturbed air, remote location, and minimal influences of vegetation and human activity at MLO are ideal for monitoring constituents in the atmosphere that can cause climate change (NOAA-ESRL, GMD, 2020)."
Mauna Loa CO2
CO2.Earth Daily CO2 Data
CO2.Earth Weekly CO2 Data
CO2.Earth Monthly CO2 Data
CO2.Earth Yearly CO2 Data
CO2.Earth CO2 Trend
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