One of the main indicators of climate change hit a new high this month. Carbon dioxide levels in the atmosphere are, on average, higher now than they have been in all of recorded human history, according to readings from research facilities around the world. And many leading scientists believe that the number will only continue to go up in the future.
Recently, a reading taken at Hawaii’s Mauna Loa observatory reached over 401 parts per million on the Keeling Curve. The Keeling Curve plots the measure of CO2 in the atmosphere and has been tracking those changes since when it was first created by geochemist Charles Keeling in 1958. When Keeling first started taking measurements, the average amount of CO2 in the atmosphere was closer to 320 parts per million. The 401 reading that was taken this week marked the first time in human history that CO2 levels had reached that level. Levels have probably not been that high since the Pliocene epoch, which was over 3 million years ago and when the earth was several degrees warmer on average than it is now.
Earlier this month, Ralph Keeling, from the Scripps Institution of Oceanography in San Diego, took the measure which broke the 401ppm level. Ralph is the son of Charles Keeling and took over updating the Curve from his father when he passed away several years ago. Keeling does not believe that this trend will stop, but will only go higher.
On March 19, Keeling announced another high for carbon dioxide readings: the first week in history which averaged above the 400ppm mark. According to Keeling, not only is the amount of CO2 going higher, it is rising at an ever faster rate. Some think that as soon as this year, we could see month-long averages above the 400ppm mark.
Other climate scientists, taking measures at other points on the globe, have confirmed Keeling’s readings that the indicators hit a new high. The director of the greenhouse gas measurement program at the National Oceanic and Atmospheric Administration (where??), Pieter Tans, said their readings were similar to those in Hawaii and San Diego.
For the most part, the earth’s atmosphere is made up of two gases, nitrogen which makes up 78 percent of the atmosphere, and oxygen, at 21 percent. Parts per million is a way to measure how much of one substance is in another. In this case, for every million molecules in the atmosphere, there are 401 molecules of carbon dioxide.
For many years now, scientists have considered 400 parts per million to be a very important, symbolic, benchmark. As the CO2 in the atmosphere approached 400, Keeling posted the latest reading on Twitter, which was followed by over 5,000 people.
While the numbers themselves may seem small, their impact on the planet are potentially huge. More carbon dioxide in the atmosphere means that more light and heat from the sun gets trapped than normal. The extra heat increases the overall temperature of the planet.
One repercussion of the extra heat is that areas of the planet that have long been ice-bound, begin to melt. Scientists have been measuring the melting of the polar ice-caps for decades now. As the ice begins to melt, sea levels begin to rise and places that have low coastlines are the first to be impacted as carbon dioxide, one of the main indicators of climate change, reaches new highs.
By Dan Reyes