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Atmospheric Carbon Dioxide (CO2) levels, 1800–present



(hover mouse over options for detailed explanations)

To see precise values, hover your mouse cursor over the red graph trace. (However, the ice core values are less accurate than the Mauna Loa measurements.)

Click here for a downloadable, bookmarkable image (except in Internet Explorer or Microsoft Edge, use PrtScn).

We also have a similar graph for methane (CH4), and a combined graph with both CO2 and CH4.

Direct measurements of CO2 at Mauna Loa Observatory, in Hawaii began in March, 1958. This is the annual average data we've graphed: (1959–2017)
For monthly data see: 
1850-1958 data is from (ice cores). 
1800-1850 CO2 data is from (Law Dome ice cores, 75 year smoothed).