Current carbon dioxide levels in the atmosphere

Real-time and Historical data

CO2 levels are updated daily with data directly from NOAA's science lab on the slopes of Moana Loa volcano on the Big Island of Hawaii. Atmospheric carbon dioxide measurements have been collected here daily since 1959. Pre-1959 data comes from ice core data taken from Antarctica. Historical and current atmospheric temperature can be overlayed on the graph. Learn more about the data sources.

Free CO2 Levels Graph

This interactive graph is free to use on your website. Simply choose your color theme and then copy and paste 2 lines of code. Data and source code is hosted on our servers so you do not have to worry about using up your server's bandwidth. New CO2 measurement data is updated automatically every day and temperature data is updated monthly.

Zoomable and Printable

View atmospheric CO2 levels and/or temperature over a span of thousands of years or zoom to specific time periods. Use your fingers to pinch and zoom on a handheld device or use a mouse with a computer. Export the chart to PNG, JPG, PDF or SVG format with the click of a button or print the chart directly from the web page.

Customizable and Responsive

Choose from 4 color themes to match your website's look and feel. Customize the width and height of your graph or have it fill your entire screen. The carbon dioxide levels graph is responsive and can automatically resize to fit whatever device or screen size it is being viewed on.

explorations now is the free award-winning digital science magazine from Scripps Institution of Oceanography. Join subscribers from around the world and keep up on our cutting-edge research.

Email (required) *

First Name

Last Name

Constant Contact Use. Please leave this field blank.

By submitting this form, you are consenting to receive marketing emails from: Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, 92093-0210, https://scripps.ucsd.edu/. You can revoke your consent to receive emails at any time by using the SafeUnsubscribe® link, found at the bottom of every email. Emails are serviced by Constant Contact

The present level of atmospheric CO2 concentration is almost certainly unprecedented in the past million years, during which time modern humans evolved and societies developed. The atmospheric CO2 concentration was however higher in Earth’s more distant past (many millions of years ago), at which time palaeoclimatic and geological data indicate that temperatures and sea levels were also higher than they are today.

Figure 3. Data from ice cores have been used to reconstruct Antarctic temperatures and atmospheric CO2 concentrations over the past 800,000 years. Temperature is based on measurements of the isotopic content of water in the Dome C ice core. CO2 is measured in air trapped in ice, and is a composite of the Dome C and Vostok ice core. The current CO2 concentration (blue dot) is from atmospheric measurements. The cyclical pattern of temperature variations constitutes the ice age/ interglacial cycles. During these cycles, changes in CO2 concentrations (in blue) track closely with changes in temperature (in orange). As the record shows, the recent increase in atmospheric CO2 concentration is unprecedented in the past 800,000 years. Atmospheric CO2 concentration surpassed 400 ppm in 2016, and the average concentration in 2019 was more than 411 ppm. Source: Based on figure by Jeremy Shakun, data from Lüthi et al., 2008 and Jouzel et al., 2007. ( larger version)

Measurements of air in ice cores show that for the past 800,000 years up until the 20th century, the atmospheric CO2 concentration stayed within the range 170 to 300 parts per million (ppm), making the recent rapid rise to more than 400 ppm over 200 years particularly remarkable [figure 3]. During the glacial cycles of the past 800,000 years both CO2 and methane have acted as important amplifiers of the climate changes triggered by variations in Earth’s orbit around the Sun. As Earth warmed from the last ice age, temperature and CO2 started to rise at approximately the same time and continued to rise in tandem from about 18,000 to 11,000 years ago. Changes in ocean temperature, circulation, chemistry, and biology caused CO2 to be released to the atmosphere, which combined with other feedbacks to push Earth into an even warmer state.

For earlier geological times, CO2 concentrations and temperatures have been inferred from less direct methods. Those suggest that the concentration of CO2 last approached 400 ppm about 3 to 5 million years ago, a period when global average surface temperature is estimated to have been about 2 to 3.5°C higher than in the pre-industrial period. At 50 million years ago, CO2 may have reached 1000 ppm, and global average temperature was probably about 10°C warmer than today. Under those conditions, Earth had little ice, and sea level was at least 60 metres higher than current levels.

Page last updated: March 2020

Find out about the Royal Society's latest work on energy, environment and climate

Was this page useful?

Thank you for your feedback

Thank you for your feedback. Please help us improve this page by taking our short survey.