A Graphical History of Atmospheric CO2 Levels Over Time | Earth.Org
Atmospheric Carbon Dioxide Levels | GlobalChange.gov
Swinging CO2 Levels Show The Earth Is 'Breathing' More Deeply : NPR
CO2 Levels: Current & Historic Atmospheric Carbon Dioxide / Global Temperature Graph & Widget
Yes, more carbon dioxide in the atmosphere helps plants grow, but it's no excuse to downplay climate change
A Graphical History of Atmospheric CO2 Levels Over Time | Earth.Org
Atmospheric carbon dioxide passing 'gloomy' milestone | Official blog of the Met Office news team
CO2 levels and mass extinction events - John Englander - Sea Level Rise Expert
Carbon Dioxide Levels Reach Unprecedented Highs: But Catastrophic Climate Change Can Still be Avoided
Climate Change: Atmospheric Carbon Dioxide | NOAA Climate.gov
How Exactly Does Carbon Dioxide Cause Global Warming? - You Asked
Global Monitoring Laboratory - Carbon Cycle Greenhouse Gases
Graphic: The relentless rise of carbon dioxide – Climate Change: Vital Signs of the Planet
Climate change: Carbon dioxide levels are higher than they've been at any point in the last 3.6 million years - CBS News
Carbon dioxide now more than 50% higher than pre-industrial levels | National Oceanic and Atmospheric Administration
Do high levels of CO2 in the past contradict the warming effect of CO2?
The Keeling Curve
Our current geologic period (Quaternary) has the lowest average CO2 levels in the last 600 million years - CO2 Coalition
File:Phanerozoic Carbon Dioxide.png - Wikimedia Commons
Climate Change: Atmospheric Carbon Dioxide | NOAA Climate.gov
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
The Atmosphere: Getting a Handle on Carbon Dioxide – Climate Change: Vital Signs of the Planet
Carbon dioxide in Earth's atmosphere - Wikipedia
USGCRP Indicator Details | GlobalChange.gov
