Climate1959–2025ppm (parts per million)

CO₂ in the atmosphere (Mauna Loa)

Name: CO₂ in the atmosphere (Mauna Loa)
Creator: NOAA Global Monitoring Laboratory
License: https://gml.noaa.gov/about/disclaimer.html

Annual mean concentration of carbon dioxide in the air measured at Mauna Loa, Hawaii, the longest continuous record, since 1959.

427.4 ppmWorld · 2025

NOAA Global Monitoring LaboratoryRetrieved: 2026-11-05

Saved data version: retrieved 2026-11-05, ID 815b4779ce1bWarehouse version at build: v45

Data coverage

World: 1959–2025; observations: 67; missing years: 0

Missing years are counted between the first and last observations. A missing value is not zero.

World

67 rows for World

Time range:

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Year

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World

Period statistics

Calculated from the values shown in this view for the selected period. Statistics follow the active display mode.

World

316.0→427.4

Total change: +35.2 %
Annual growth (CAGR): +0.5 %
Period: 1959–2025

World: 316.0 (1959) → 427.4 (2025). Change of +35.2 % over 66 years. Compound annual growth rate (CAGR) of +0.5 % per year.

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Format:

CO₂ in the atmosphere (Mauna Loa) — World
Year	Country	Value
2025	World	427.4 ppm
2024	World	424.6 ppm
2023	World	421.1 ppm
2022	World	418.5 ppm
2021	World	416.4 ppm
2020	World	414.2 ppm
2019	World	411.7 ppm
2018	World	408.7 ppm
2017	World	406.8 ppm
2016	World	404.4 ppm
2015	World	401 ppm
2014	World	398.8 ppm
2013	World	396.7 ppm
2012	World	394.1 ppm
2011	World	391.9 ppm
2010	World	390.1 ppm
2009	World	387.6 ppm
2008	World	385.8 ppm
2007	World	384 ppm
2006	World	382.1 ppm

Source: NOAA Global Monitoring Laboratory
Licence: Public domain (U.S. Government work)
Published by source: —
Retrieved: 2026-11-05
Indicator code in source: co2_annmean_mlo
Unit of measure: ppm (parts per million)
Data version: v45

Cite

Longseries, “CO₂ in the atmosphere (Mauna Loa)”. NOAA Global Monitoring Laboratory (co2_annmean_mlo), 1959–2025, World. Retrieved 2026-11-05. Public domain (U.S. Government work). Data version v45. Data SHA-256: 815b4779ce1bc3381332483f10d1dd5d929702a22fde989a40cb48df14d3c6b8. https://longseries.com/en/d/climate-co2-mauna-loa/

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Latest values

Comparison year

1 place — sorted by value, highest first
Country
World	2025	427.4 ppm427.4 ppm

About this series

Annual mean CO₂ mole fraction at Mauna Loa Observatory, Hawaii, NOAA Global Monitoring Laboratory (with Scripps), 1959–.

Indicator definition

Carbon dioxide in dry air, in parts per million (ppm). This is concentration in the atmosphere, not yearly emissions; for emissions see CO₂ emissions, total.

How to read the data

From 316 ppm in 1959 to 427 ppm in 2025. The yearly rise has sped up from under 1 ppm in the 1960s to 2–3.5 ppm in recent years. Pre-industrial air held about 280 ppm.

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