The Earth hit a worrying climate change milestone this month, and it appears to be permanent. The concentration of carbon dioxide in the planet’s atmosphere has surpassed 400 parts per million during ...

Less than a year after scientists first warned that the amount of carbon dioxide in the atmosphere could rise above 400 parts per million and stay there, it has finally happened. For the first time in ...

Global CO2 levels rose above 400 parts per million for the first time ever in the modern era in March 2015, marking a significant milestone in the planet’s progression toward a warmer future. The ...

We have spent the entirety of calendar year 2016 above 400 ppm atmospheric carbon dioxide. If you aren't concerned, you aren't paying attention. Share on Facebook (opens in a new window) Share on X ...

April fell first. It lasted through May. Now June will be the third month in a row with average carbon dioxide levels above 400 parts per million. Atmospheric concentrations of the greenhouse gas, ...

Until very recently, atmospheric concentrations of carbon dioxide below 400 parts per million were all you had ever known. They were all this planet had known for millions of years. But those days are ...