June's global average concentration of atmospheric carbon dioxide (#CO₂) was about 419 parts per million (ppm), a roughly 50% increase since 1750 due to human activities, such as burning fossil fuels and
Global Monitoring Laboratory - Carbon Cycle Greenhouse Gases
Carbon Dioxide Through Time | EARTH 103: Earth in the Future
CO2 Levels: Current & Historic Atmospheric Carbon Dioxide / Global Temperature Graph & Widget
Earth's Atmosphere Passes Significant Carbon Milestone - Dan's Wild Wild Science Journal - AGU Blogosphere
CO2 on the atmosphere and annual emissions (1750-2019) | Real-World Economics Review Blog
Met Office: Atmospheric CO2 now hitting 50% higher than pre-industrial levels - Carbon Brief
A Graphical History of Atmospheric CO2 Levels Over Time | Earth.Org
Atmospheric concentrations - Our World in Data
File:Atmospheric carbon dioxide concentrations and global annual average temperatures over the years 1880 to 2009.png - Wikimedia Commons
Carbon Dioxide Through Time | EARTH 103: Earth in the Future
co2 levels in atmosphere at their highest in 800,000 years | World Economic Forum
Climate Change: Atmospheric Carbon Dioxide | NOAA Climate.gov
Chart of 420,000 year history: temperature, CO2, sea level - John Englander - Sea Level Rise Expert
CO2 Levels: Current & Historic Atmospheric Carbon Dioxide / Global Temperature Graph & Widget
Atmospheric concentrations - Our World in Data
How the World Passed a Carbon Threshold and Why It Matters - Yale E360
The History of Atmospheric Carbon Dioxide on Earth
Carbon dioxide now more than 50% higher than pre-industrial levels | National Oceanic and Atmospheric Administration
Climate Change: Atmospheric Carbon Dioxide | NOAA Climate.gov
Global CO2 levels reach highest levels in human history
A Graphical History of Atmospheric CO2 Levels Over Time | Earth.Org
Carbon dioxide in Earth's atmosphere - Wikipedia
Graphic: The relentless rise of carbon dioxide – Climate Change: Vital Signs of the Planet
Ancient Deepsea Shells Reveal 66 Million Years Of Carbon Dioxide Levels - Texas A&M Today
Carbon Dioxide Through Time | EARTH 103: Earth in the Future
Carbon dioxide in Earth's atmosphere - Wikipedia
