The Scripps Institution of Oceanography measured an average of 393.65ppm CO2 concentration at their Mauna Loa, Hawai’i’s Observatory during February 2012. These readings are from the Scripps’ dataset, not NOAA’s, which was my original data source when this series began.
393.65ppm is the highest value for February concentrations in recorded history. Last year’s 391.76 was the previous highest value ever recorded. This February’s reading is 1.89ppm higher than last year’s. As I’ve written before, this increase is significant. Of course, more significant is the unending trend toward higher concentrations with time, no matter the month or specific year-over-year value.
The yearly maximum monthly value normally occurs during May. Last year was no different: the 394.34 concentration is the highest value reported both last year and all time. If we extrapolate last year’s value out in time, it will only be 3 years until Scripp’s reports 400ppm average concentration for a singular month (likely May 2015).
Judging by the year-over-year increases seen per month in the past 10 years, I predict 2012 will not see a monthly concentration below 390ppm. I had earlier predicted that 2011′s minimum would be ~388ppm. I overestimated the minimum somewhat since both September’s and October’s measured concentrations were just under 389ppm. One month into 2012 and so far I’m spot on.
CO2Now has the following graph on their front page:
It shows concentrations in the Scripps dataset going back to 1958. As I wrote above, concentrations are persistently and inexorably moving upward.
Given our historical emissions to date and the likelihood that they will continue to grow at an increasing rate in the next 25 years, we will pass a number of “safe” thresholds – for all intents and purposes permanently as far as concerns our species. It is time to start seriously investigating and discussing what kind of world will exist after CO2 concentrations peak at 850 and 1100ppm. I don’t believe the IPCC has done this to date. To remain relevant, I think it will have to do so moving forward.
Additionally, efforts to pin any future concentration goal to a number like 350ppm or even 450ppm will be insanely difficult: 350ppm more so than 450ppm. Beyond an education tool, I don’t see the utility in using 350ppm – we simply will not achieve it, or anything close to it, given our history and likelihood that economic growth goals will trump any effort to address CO2 concentrations.