Data
Carbon dioxide, global annual mean
Annual mean carbon dioxide in dry air averaged over NOAA's global network of marine surface sites, since 1979.
Latest value
425.62ppm
Global mean of marine surface sites, 2025 (preliminary). Version 2026-09.
Carbon dioxide, global annual mean (parts per million)
Show as a table
| Period | Value (ppm) | Range | Status |
|---|---|---|---|
| 1979 | 336.85 | 336.75 to 336.95 | final |
| 1980 | 338.91 | 338.84 to 338.98 | final |
| 1981 | 340.11 | 340.03 to 340.19 | final |
| 1982 | 340.85 | 340.82 to 340.88 | final |
| 1983 | 342.53 | 342.47 to 342.59 | final |
| 1984 | 344.07 | 344.00 to 344.14 | final |
| 1985 | 345.54 | 345.47 to 345.61 | final |
| 1986 | 346.97 | 346.90 to 347.04 | final |
| 1987 | 348.68 | 348.58 to 348.78 | final |
| 1988 | 351.16 | 351.09 to 351.23 | final |
| 1989 | 352.79 | 352.73 to 352.85 | final |
| 1990 | 354.06 | 353.99 to 354.13 | final |
| 1991 | 355.40 | 355.34 to 355.46 | final |
| 1992 | 356.09 | 356.03 to 356.15 | final |
| 1993 | 356.83 | 356.76 to 356.90 | final |
| 1994 | 358.33 | 358.24 to 358.42 | final |
| 1995 | 360.18 | 360.14 to 360.22 | final |
| 1996 | 361.93 | 361.89 to 361.97 | final |
| 1997 | 363.04 | 362.99 to 363.09 | final |
| 1998 | 365.70 | 365.65 to 365.75 | final |
| 1999 | 367.79 | 367.73 to 367.85 | final |
| 2000 | 368.96 | 368.90 to 369.02 | final |
| 2001 | 370.56 | 370.51 to 370.61 | final |
| 2002 | 372.58 | 372.54 to 372.62 | final |
| 2003 | 375.14 | 375.10 to 375.18 | final |
| 2004 | 376.94 | 376.89 to 376.99 | final |
| 2005 | 378.98 | 378.93 to 379.03 | final |
| 2006 | 381.15 | 381.10 to 381.20 | final |
| 2007 | 382.90 | 382.85 to 382.95 | final |
| 2008 | 385.02 | 384.98 to 385.06 | final |
| 2009 | 386.50 | 386.46 to 386.54 | final |
| 2010 | 388.75 | 388.69 to 388.81 | final |
| 2011 | 390.62 | 390.56 to 390.68 | final |
| 2012 | 392.65 | 392.58 to 392.72 | final |
| 2013 | 395.40 | 395.34 to 395.46 | final |
| 2014 | 397.34 | 397.28 to 397.40 | final |
| 2015 | 399.65 | 399.60 to 399.70 | final |
| 2016 | 403.07 | 403.00 to 403.14 | final |
| 2017 | 405.22 | 405.15 to 405.29 | final |
| 2018 | 407.61 | 407.54 to 407.68 | final |
| 2019 | 410.07 | 409.99 to 410.15 | final |
| 2020 | 412.44 | 412.37 to 412.51 | final |
| 2021 | 414.70 | 414.64 to 414.76 | final |
| 2022 | 417.08 | 416.99 to 417.17 | final |
| 2023 | 419.35 | 419.25 to 419.45 | final |
| 2024 | 422.79 | 422.70 to 422.88 | final |
| 2025 | 425.62 | 425.57 to 425.67 | preliminary |
Where it comes from
- Producer
- NOAA Global Monitoring Laboratory · Trends in atmospheric carbon dioxide
- Version
- 2026-09
- Fetched
- 2026-10-04 (automatically), 2,513 bytes
- Fingerprint
- sha256 36d6a6dd6bb5db53100d300b35fc6cb5ea6ad8756dd93326f847e4251c70bd14ETag "9d1-65af9c4f70378" · Last-Modified Tue, 08 Sep 2026 14:44:18 GMT
- Copies
- No Wayback copy recorded yet.Our copy of the exact file
- Cite the producer
- Lan, X., Tans, P. and K.W. Thoning: Trends in globally-averaged CO2 determined from NOAA Global Monitoring Laboratory measurements. Version 2026-09 https://doi.org/10.15138/9N0H-ZH07
What was done to it
Read co2_annmean_gl.csv, created by NOAA on 5 September 2026. The vintage is the year and month of that creation date, which is how NOAA labels its versions.
Code: pipeline/src/envdash/transforms/air/noaa_co2.py · code sha256 251a10a6dfe1ae29… · inputs 36d6a6dd6bb5…
Lower and upper are the mean minus and plus NOAA's stated uncertainty, which the file defines as the mean of the standard deviations of 200 Monte Carlo global averages (one standard deviation).
Code: pipeline/src/envdash/transforms/air/noaa_co2.py · code sha256 251a10a6dfe1ae29… · inputs 36d6a6dd6bb5…
The last year is marked preliminary because the file states that the data for the last year are subject to change.
Code: pipeline/src/envdash/transforms/air/noaa_co2.py · code sha256 251a10a6dfe1ae29… · inputs 36d6a6dd6bb5…
What it covers
- Geography
- Global mean of marine surface sites
- Basis
- Dry-air mole fraction; NOAA's global marine boundary layer average.
- Unit
- parts per million (ppm)