Atmospheric carbon dioxide levels for the last 500 million years | PNAS
Scientists reveal the history of Earth's CO2 since the dinosaurs died | Mashable
Doesn't carbon dioxide in the atmosphere come from natural sources? | NOAA Climate.gov
Earth's Atmosphere Passes Significant Carbon Milestone - Dan's Wild Wild Science Journal - AGU Blogosphere
CO2 Past
Carbon Dioxide Through Time | EARTH 103: Earth in the Future
CO2 levels and mass extinction events - John Englander - Sea Level Rise Expert
A Graphical History of Atmospheric CO2 Levels Over Time | Earth.Org
A Graphical History of Atmospheric CO2 Levels Over Time | Earth.Org
Global CO2 levels reach highest levels in human history
CO2 levels higher than any point since the evolution of humans | CNN
CO2 Past
Earth's atmosphere has changed profoundly since the first Earth Day | Mashable
Graphic: The relentless rise of carbon dioxide – Climate Change: Vital Signs of the Planet
![OC] CO2 concentration in atmosphere over last 800,000 years : r/dataisbeautiful](https://preview.redd.it/f0pwsd5hcph31.png?auto=webp&s=43942d6171830c150bd04846f4755f16609ea9f7 "OC] CO2 concentration in atmosphere over last 800,000 years : r/dataisbeautiful")
OC] CO2 concentration in atmosphere over last 800,000 years : r/dataisbeautiful
The Carbon Cycle
Ancient Deepsea Shells Reveal 66 Million Years Of Carbon Dioxide Levels - Texas A&M Today
CO2: Past, Present, & Future – Time Scavengers
7. Is the current level of atmospheric CO2 concentration unprecedented in Earth's history? Answer | Royal Society
New Clue to Past CO2 Levels?? - Dan's Wild Wild Science Journal - AGU Blogosphere
Do high levels of CO2 in the past contradict the warming effect of CO2?
Climate during the Carboniferous Period
Carbon Dioxide Levels over Time | Biological Principles
