427.4 ppm
2025 (latest)
Every value on this page is read from the publisher below. Current and historical source documents:
| Year | Mauna Loa atmospheric CO2 | Change |
|---|---|---|
| 2025 | 427.4 ppm | +1% |
| 2024 | 424.6 ppm | +1% |
| 2023 | 421.1 ppm | +1% |
| 2022 | 418.5 ppm | +1% |
| 2021 | 416.4 ppm | +1% |
| 2020 | 414.2 ppm | +1% |
| 2019 | 411.6 ppm | +1% |
| 2018 | 408.7 ppm | +0% |
| 2017 | 406.8 ppm | +1% |
| 2016 | 404.4 ppm | +1% |
| 2015 | 401.0 ppm | +1% |
| 2014 | 398.8 ppm | +1% |
| 2013 | 396.7 ppm | +1% |
| 2012 | 394.1 ppm | +1% |
| 2011 | 391.9 ppm | +0% |
| 2010 | 390.1 ppm | +1% |
| 2009 | 387.6 ppm | +0% |
| 2008 | 385.8 ppm | +0% |
| 2007 | 384.0 ppm | +1% |
| 2006 | 382.1 ppm | +1% |
| 2005 | 380.0 ppm | +1% |
| 2004 | 377.7 ppm | +0% |
| 2003 | 376.0 ppm | +1% |
| 2002 | 373.4 ppm | +1% |
| 2001 | 371.3 ppm | +0% |
| 2000 | 369.7 ppm | +0% |
| 1999 | 368.5 ppm | +0% |
| 1998 | 366.8 ppm | +1% |
| 1997 | 363.9 ppm | +0% |
| 1996 | 362.7 ppm | +0% |
| 1995 | 361.0 ppm | +1% |
| 1994 | 359.0 ppm | +0% |
| 1993 | 357.2 ppm | +0% |
| 1992 | 356.5 ppm | +0% |
| 1991 | 355.7 ppm | +0% |
| 1990 | 354.4 ppm | +0% |
| 1989 | 353.2 ppm | +0% |
| 1988 | 351.7 ppm | +1% |
| 1987 | 349.3 ppm | +0% |
| 1986 | 347.6 ppm | +0% |
| 1985 | 346.4 ppm | +0% |
| 1984 | 344.9 ppm | +1% |
| 1983 | 343.1 ppm | +0% |
| 1982 | 341.5 ppm | +0% |
| 1981 | 340.1 ppm | +0% |
| 1980 | 338.8 ppm | +1% |
| 1979 | 336.8 ppm | +0% |
| 1978 | 335.4 ppm | +0% |
| 1977 | 333.8 ppm | +1% |
| 1976 | 332.0 ppm | +0% |
| 1975 | 331.1 ppm | +0% |
| 1974 | 330.2 ppm | +0% |
| 1973 | 329.7 ppm | +1% |
| 1972 | 327.5 ppm | +0% |
| 1971 | 326.3 ppm | +0% |
| 1970 | 325.7 ppm | +0% |
| 1969 | 324.6 ppm | +0% |
| 1968 | 323.1 ppm | +0% |
| 1967 | 322.2 ppm | +0% |
| 1966 | 321.4 ppm | +0% |
| 1965 | 320.0 ppm | +0% |
| 1964 | 319.6 ppm | +0% |
| 1963 | 319.0 ppm | +0% |
| 1962 | 318.4 ppm | +0% |
| 1961 | 317.6 ppm | +0% |
| 1960 | 316.9 ppm | +0% |
| 1959 | 316.0 ppm | — |