Back in December of 2013, a little less than three years ago, Earth Wise reported that the observatory on Mauna Loa in Hawaii had briefly measured carbon dioxide levels greater than 400 parts per million for the first time ever. During the following year, readings above the 400 level started to pop up occasionally elsewhere as well.
But this year, for the first time since before the last Ice Age, CO2 levels will not fall below the 400 ppm level at all. Measurements at atmospheric observatories on Mauna Loa and at the South Pole both indicate that CO2 has passed the 400 ppm level for good.
According to Pieter Tans, lead scientist of the NOAA Global Greenhouse Gas Reference Network, it is unlikely that we will ever see CO2 levels below 400 for the remainder of our lifetimes and probably much longer.
For most of human history, CO2 levels hovered around 278 ppm. This all changed during the 1850s as a result of massive deforestation around the world. Then in the 1950s, the dramatic increase in the burning of fossil fuels vastly accelerated the rate of CO2 being pumped into the atmosphere. About 85% of all the fossil fuel consumption since the start of the industrial revolution has taken place during our lifetimes. As a result, the rate of CO2 increase is more than 100 times faster than anything observed in the ice core record that goes back 800,000 years.
We may not be able to get the atmosphere back to where we would like it to be, but we are well on the way to making things far worse unless we can dramatically change what we are doing.
Photo, posted September 29, 2010, courtesy of NOAA via Flickr.