CO2 levels are the highest since humanity began
The last time Earth hit 415 ppm, sea levels were 82 feet higher.
In May of 2013 Marc Lallanilla, of Life’s Little Mysteries Assistant Editor wrote:
“In 1953, a young scientist named Charles David Keeling began to measure the amount of carbon dioxide (CO2) in the atmosphere around Pasadena, Calif.
Soon, Keeling expanded his CO2 research to areas as diverse as Big Sur, near Monterey, Calif.; the Olympic Peninsula in Washington; and the mountains of Arizona.
But everywhere he went, an interesting pattern emerged: CO2 levels increased at night, and leveled off at about 310 parts per million (ppm) in the afternoon.
Keeling soon realized that the nightly increase was largely due to localized respiration from plants. After word of Keeling’s research spread, he was invited to expand his network of CO2 monitoring stations to places like the Mauna Loa Observatory in Hawaii, and Antarctica.
As his monitoring stations gathered data, Keeling once again discovered something that had eluded scientists: the seasonal rhythm of CO2 levels.
In 1958 at Mauna Loa, Keeling observed that CO2 levels peaked in May, and then dropped to a low in October; the May/October pattern was repeated in 1959.
“We were witnessing for the first time nature’s withdrawing CO2 from the air for plant growth during summer and returning it each succeeding winter,” Keeling was quoted as saying by the Scripps Institution of Oceanography.
But Keeling also discovered something more profound: Year after year, the amount of CO2 in the atmosphere was gradually increasing due to the combustion of fossil fuels.
Of even greater concern to Keeling was his discovery that the rate of increase was sharper each successive year, giving Keeling’s CO2 chart a distinctive upward curve, now called the “Keeling Curve.”
Keeling’s record of data from Mauna Loa is considered one of the best and most consistent climate records anywhere, though scientists also use other sources for atmospheric data, including samples of air trapped in polar ice, to analyze CO2 levels in past millennia.
And when the Keeling Curve is added to atmospheric research from the past, it shows a trend that has alarmed scientists worldwide: CO2 levels are rising at a dramatic pitch, one unseen in the entire geologic record.
Levels of CO2 will soon reach heights of 400 ppm and higher — levels not seen in millions of years, with unknown consequences for the planet.
According to the CO2 Program at the Scripps Institution, “Unless serious efforts are made to reduce the dependence on fossil fuels, it is clear that we are on a threshold of a new era of geologic history — one with climate very different from that of our ancestors.”
Though David Keeling passed away in 2005, his son Ralph continues his father’s CO2 research efforts at the Scripps Institution.”
So here we are in 2019 and we have passed the 400 mark, something never seen in earth’s history. What does this mean for us?
The last time carbon dioxide (CO2) levels hit such a high was around 3 million years ago, when the average temperature in the Arctic as 15 degrees Celcius (60F). At that point, the north was covered by trees, not ice, and mean sea levels were believed to be at least 25 meters (82 feet) higher.
CO2 emissions, largely caused by humans burning fossil fuels, keep heat trapped on Earth that would normally disperse into space. They have already led to a 1 degree C rise in global temperatures, with further increases expected unless action is taken by world governments. That could cause sea level rises, flooding, severe storms, droughts and forest fires, among other problems. The UN estimated that climate change and human activity could result in the disappearance of over a million plant and animal species.
Apart from being the highest level in human history, the 415 ppm figure shows CO2 levels to be rising unabated, despite the Paris climate accord. To reach those goals, nations already had to dramatically increase the pace of change toward clean energy, and the latest CO2 figures highlight the urgency of that task.