During June 2013, the Scripps Institution of Oceanography measured an average of 398.58 ppm CO2 concentration at their Mauna Loa, Hawai’i Observatory.
This value is important because 398.58 ppm the largest CO2 concentration value for any June in recorded history. This year’s June value is 2.81 ppm higher than June 2012′s! Month-to-month differences typically range between 1 and 2 ppm. This year-to-year jump is clearly well outside of that range. This is more in line with February’s year-over-year change of 3.37 ppm and May’s change of 3.02 ppm. Of course, the unending trend toward higher concentrations with time, no matter the month or specific year-over-year value, as seen in the graphs below, is more significant.
The yearly maximum monthly value normally occurs during May. This year was no different: the 399.89ppm concentration in May 2013 was the highest value reported this year and, prior to the last five months, in recorded history (neglecting proxy data). I expected May of this year to produce another all-time record value and it clearly did that. May 2013′s value will hold onto first place all-time until February 2014.
Figure 1 – Time series of CO2 concentrations measured at Scripp’s Mauna Loa Observatory in June from 1958 through 2013.
CO2Now.org added the `350s` and `400s` to the past few month’s graphics. I suppose they’re meant to imply concentrations shattered 350 ppm back in the 1980s and are pushing up against 400 ppm now in the 2010s. I’m not sure that they add much value to this graph, but perhaps they make an impact on most people’s perception of milestones within the trend.
How do concentration measurements change in calendar years? The following two graphs demonstrate this.
Figure 2 – Monthly CO2 concentration values (red) from 2009 through 2013 (NOAA). Monthly CO2 concentration values with seasonal cycle removed (black). Note the yearly minimum observation occurred eight months ago and the yearly maximum value occurred last month. CO2 concentrations will decrease through October 2013, as they do every year after May.
Figure 3 – 50 year time series of CO2 concentrations at Mauna Loa Observatory (NOAA). The red curve represents the seasonal cycle based on monthly average values. The black curve represents the data with the seasonal cycle removed to show the long-term trend. This graph shows the recent and ongoing increase in CO2 concentrations. Remember that as a greenhouse gas, CO2 increases the radiative forcing of the Earth, which increases the amount of energy in our climate system.
CO2 concentrations are increasing at an increasing rate – not a good trend with respect to minimizing future warming. Natural systems are not equipped to remove CO2 emissions quickly from the atmosphere. Indeed, natural systems will take tens of thousands of years to remove the CO2 we emitted in the course of a couple short centuries. Human systems do not yet exist that remove CO2 from any medium (air or water). They are not likely to exist for some time. So NOAA will extend the right side of the above graphs for years and decades to come.
This month, I want to spend some more time on this focus: CO2 concentration values. Given our species’ penchant for round numbers, it came as little surprise that the corporate media placed an uncommon amount of attention on a value that really has relatively low meaning: daily CO2 concentrations at Mauna Loa surpassed 400 ppm for a day during the month of May. In fact, both the media and many climate activists made a very big deal about this development (news articles and my twitter feed “blew up” with this news). I think that was largely a waste of time. Again, the daily value itself didn’t represent any large difference once reached. The climate system did not automatically kick into a different setting once concentrations passed 400 ppm for a day. Nothing substantially new occurred that didn’t when concentration were “only” 399 ppm (or 390 ppm or 380 ppm for that matter). Indeed, where are the articles this month with daily values in the 398-399 ppm range? They’re nonexistent. So what is important: psychologically significant thresholds or the unending acceleration of concentrations across years and decades?
As I state in this series every month, the trend makes much more of a difference than any daily, monthly, or even yearly average value. And that trend is accelerating upwards at a rate that many experts didn’t think was possible even 10 years ago. The effects from last year’s average CO2 concentrations won’t manifest in real-world terms until 30-50 years from now. I didn’t see anybody else in May pointing out that important detail. Similarly, I didn’t see any explanation that today’s mean temperatures are largely a result of CO2 concentrations from 30+ years ago. Perhaps most importantly, climate activists didn’t mention that CO2 concentrations are rising at a rising rate despite decades of their “activism”. That fact creates a rather uncomfortable situation because most activists are proponents of doing tomorrow what they did yesterday. If those actions haven’t had any effect up until now, why the advocacy for the status quo when those same activists try to claim that the status quo is untenable. If they really believed in their catastrophic climate change claims, shouldn’t they honestly evaluate the effects their actions have had? And if those actions produced far less meaningful progress than they state is absolutely required for the survival of our species and the planet (grandiose language, I know), why do their strategies and tactics remain largely unchanged?
I write these posts for people who are curious or interested in the state of a key climate variable. Almost two years ago now, I realized that doomsday language turns a significant portion of my potential audience off from the get-go. If we are to do something meaningful about climate change, we cannot afford the disengagement and hostility of one-third or more of our fellow global citizens towards climate activism. I don’t want to simply treat people as empty vessels into which I can pour knowledge. I want to engage them on ground that is similar between us precisely because I want to do something. Screaming about a 400 ppm mean CO2 concentration for one day and then walking away from the variable until we pass the next perceived meaningful threshold doesn’t strike me as engagement.
The rise in CO2 concentrations will slow down, stop, and reverse when we decide it will. It depends primarily on the rate at which we emit CO2 into the atmosphere. We can choose 400 ppm or 450 ppm or almost any other target (realistically, 350 ppm seems out of reach within the next couple hundred years). That choice is dependent on the type of policies we decide to implement. It is our current policy to burn fossil fuels because we think doing so is cheap, although current practices are massively inefficient and done without proper market signals. We will widely deploy clean sources of energy when they are cheap; we control that timing. We will remove CO2 from the atmosphere if we have cheap and effective technologies and mechanisms to do so, which we also control to some degree. These future trends depend on today’s innovation and investment in research, development, and deployment. Today’s carbon markets are not the correct mechanism, as they are aptly demonstrating. But the bottom line remains: We will limit future warming and climate effects when we choose to do so.