Atmospheric CO2 ppm by year 1959-2025| ��ƽ��

Average carbon dioxide (CO₂) levels in the atmosphere worldwide from 1959 to 2025 (in parts per million)

Characteristic	Concentration in parts per million
2025	427.49
2024	425.4
2023	421.86
2022	418.99
2021	416.67
2020	414.23
2019	411.97
2018	409.99
2017	407
2016	404.64
2015	402.06
2014	399.08
2013	397.03
2012	394.57
2011	392.06
2010	389.99
2009	387.63
2008	385.79
2007	384.19
2006	382.02
2005	380.31
2004	377.68
2003	376.17
2002	373.98
2001	371.42
2000	369.83
1999	368.26
1998	367.3
1997	364.51
1996	362.39
1995	360.82
1994	359.1
1993	357.03
1992	355.68
1991	355.21
1990	354.41
1989	352.91
1988	351.62
1987	349.28
1986	347.48
1985	346.12
1984	345
1983	343.2
1982	340.78
1981	339.91
1980	338.29
1979	336.81
1978	334.91
1977	333.6
1976	331.62
1975	330.77
1974	329.58
1973	328.65
1972	327.55
1971	326.01
1970	325.13
1969	324.11
1968	322.89
1967	321.96
1966	321.02
1965	319.42
1964	318.71
1963	318.35
1962	317.7
1961	317.01
1960	316.19
1959	315.58

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Release date

January 2026

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Region

Worldwide

Survey time period

1959 to 2025; as of December every year

Supplementary notes

* Observations starting in December 2022 are from a site at Maunakea Observatories, 21 miles north of the prior location at Mauna Loa Observatory.
Data from March 1958 through April 1974 have been obtained by C. David Keeling.
Data has been measured at Mauna Loa Observatory, Hawaii as it constitutes the longest record of direct carbon dioxide measurements in the atmosphere.
CO₂ expressed as a mole fraction in dry air, micromol/mol, abbreviated as ppm.

Citation formats

Average annual atmospheric levels of carbon dioxide (CO₂) reached a record high of 427.49 parts per million (ppm) in 2025. Monthly atmospheric CO₂ concentrations peaked that year in June, at 426.91 ppm.

Human activities have caused CO₂ concentrations to soar

Annual CO₂ concentrations consistently averaged around 280 ppm before the industrial revolution began, according to the National Oceanic and Atmospheric Administration (NOAA). However, the mass burning of fossil fuels, and deforestation over the past two centuries has released trillions of tons of CO₂ into the atmosphere. This has caused atmospheric CO₂ levels to climb more than 50 percent above pre-industrial levels.

Impacts of high atmospheric greenhouse gas levels

The rapidly rising concentrations of greenhouse gases (GHGs) are worrying news for the planet, as they contribute to the climate crisis. GHGs like CO₂, methane, and nitrous oxide trap heat radiating from the planet’s surface, preventing it from escaping into space. This causes Earth’s atmosphere to heat and increases land and sea surface temperatures. Higher surface temperatures can unleash severe weather conditions such as extreme heat, droughts, and a higher frequency of high-intensity tropical storms.