Published on:

CO2 Levels Reach 400 PPM

For the first time in what is believed to be 3 million years, carbon dioxide levels were recorded this week at 400 ppm on top of the 11,000 foot Mauna Loa mountain in Hawaii. As noted by National Geographic, the last time CO2 was at those levels:

” the Earth then was in the final stage of a prolonged greenhouse epoch, and CO2 concentrations were on their way down. This time, 400 ppm is a milepost on a far more rapid uphill climb toward an uncertain climate future.”

-Steven Silverberg