The “Keeling curve” derives its name from Charles Keeling who showed, from even his earliest measurements, that there is a continuous, unabated increase of CO2 in the atmosphere. This results from the forcing tied to the Greenhouse effect. Few Americans knew of the graph, before it was made famous by Al Gore in his documentary "Inconvenient Truth". But it is the longest continuous record of CO2 in the world, starting from 316 ppm in March 1958.
When I first saw the "Keeling Curve" (see attached image superimposed on the Earth in a satellite view) it shook me to my core. It also sent me into despair realizing that nothing would halt the ominous rise of CO2 in the Earth's atmosphere. To put it bluntly, in the image of the Keeling Curve I beheld the future of our planet: as a hothouse wasteland with little water, barely thousands of people able to survive and with no hope ever for a green or plentiful future.
Now, according to the Scripps Institute of Oceanography at the University of California- San Diego, the ratio of carbon dioxide in Earth’s atmosphere is flirting with 400 parts per million, a level last seen about 2.5 million to 5 million years ago. Isolated measurements have already peaked at above 400 parts per million in the Arctic, but climate scientists have been more alarmed at steady readings from Mauna Loa, Hawaii, far from major pollution sources. Those measurements, considered to be the most reliable indicators of Earth's atmospheric content, could breach the 400 level this month, according to Scripps.
Climate scientists aren't sure of the exact threshold at which the nonstop Runaway greenhouse effect kicks in, but most put it at someplace between 450 ppm and 550 ppm. Since we're now increasing CO2 concentration at roughly 2 ppm, that gives us about 25 years before the lowest threshold is met. Of course, if the Keystone pipeline is put through the annual increase in CO2 would be significantly higher, perhaps bringing the year of reckoning closer by 5 or even 10 years.
This is why the speed at which Earth’s atmosphere has reached that density of carbon dioxide, a known greenhouse gas, has scientists alarmed. While climate change-global warming deniers and naysayers (amazingly, still around - skulking behind the cover of assorted think tanks) have often attempted to obfuscate issues by referring to "natural cycles" (such as the Middle Ages 'warming' period), this new data stuffs even their fat, bloviating mouths.
This is because for the previous 800,000 years, CO2 levels never exceeded 300 parts per million, and there is no known geologic period in which rates of increase have been so sharp. The level was about 280 parts per million at the advent of the Industrial Revolution in the 18th Century, when the burning of fossil fuels began to soar.
Scientists estimate that average temperatures during the Pliocene rose as much as 18 degrees Fahrenheit. Sea levels during that 2.8-million-year epoch ranged between 16-131 feet higher than current levels, according to Richard Norris, a Scripps geologist. Norris added:
"I think it is likely that all these ecosystem changes could recur, even though the time scales for the Pliocene warmth are different than the present”
He also warned that heating the oceans probably will cause sea level rises and change the pH balance, affecting a wide array of marine life. We ought to note that already the pH of the oceans is 30% more acidic than at the start of the Industrial Revolution on average. Another 30% increase could wipe out more than alf of all sea life including the phyto-plankton.
Norris added, reinforcing the point:
“Our dumping of heat and CO2 into the ocean is like making investments in a pollution bank,”
Scripps geochemist Ralph Keeling, who has taken over the Keeling curve measurement from his late father, added: "At this pace we'll hit 450 ppm within a few decades."
Or more likely less!
Tim Lueker, an oceanographer and carbon cycle researcher who is a longtime member of the Scripps CO2 Group, provides the most somber note:
"The 400-ppm threshold is a sobering milestone, and should serve as a wake-up call for all of us to support clean-energy technology and reduce emissions of greenhouse gases, before it's too late for our children and grandchildren,"