More bad news from the global warming front. It seems that there is never any good news to report from this front.
Scientists report that this week, for the first time, their sensors have measured a daily average of more than 400 parts per million of carbon dioxide in the atmosphere. Carbon dioxide is the primary fuel that is heating up the planet.
Now, if you are like me, that figure by itself may mean nothing to you. But prior to the industrial revolution, the proportion of carbon dioxide in Earth’s atmosphere hovered around 280 parts per million. As late as 1958, when scientists began measuring average carbon dioxide levels at an observatory on Mauna Loa in Hawaii, the figure was around 320 ppm. This means that in the last 50 years we have added more carbon dioxide to the atmosphere than in all the 100 years prior.
Scientists say that the last time carbon dioxide levels were this high was about 4 million years ago while Australopithecus still walked the Earth. We are well on our way from the pre-industrial carbon-dioxide levels toward an upper limit of 450 ppm that the Intergovernmental Panel on Climate Change has warned is necessary to have any significant hope of limiting global warming to 2 degrees Celsius. If we continue to heat up as fast as we have over the last fifty years, we will blow right past that dangerous limit within the next fifty and may reach the point of no return for the human race.
This chart from Slate.com today shows our progress toward the limit that climate scientists warn against.
At some point, it seems likely that Mother Nature will correct this problem if we fail to, at which time, as George Carlin used to say, she may "shrug us off like a bad case of fleas." There are limits beyond which the human race will not be able to survive, but the planet will go on and perhaps life in another more benevolent - dare we hope wiser? - form will continue.