The panel intends for this assessment report to guide international negotiators as they work, in the run-up to the big Paris climate summit in December 2015, to hammer out an agreement to reduce global greenhouse gas emissions. The U.N. hopes nations will find a way to squeeze through the ever-shrinking window of opportunity and cut a deal to keep the planet from exceeding 2 degrees Celsius of warming — the goal scientists have set to avoid the worst impacts of climate change — before we blow right past that target.
It is worth reminding yourself that everything you encounter in any media is biased somehow. We’re all human and we all have our own biases. Nothing is unbiased or objective because the act of putting words to concepts is derived from brains with preferred neural pathways. There is nothing inherently bad with the bolded language above. It comes from Grist, which many in the climate activist community view as a legitimate source of information (unlike say, Fox News). However, the 2 °C threshold was not originally scientific. That was one of the fundamental take home messages of my last post.
Negotiators in the early 1990s for the IPCC asked for some type of threshold that they might use in negotiations because, not being scientists, they didn’t know what threshold might be useful or appropriate. A German scientist offered up the 2 °C threshold as part of the UNFCCC process and because nobody else came up with a different threshold or challenged the temperature threshold, negotiators moved it through their process until politicians from countries around the world agreed to insert the language in a formal report. As is usually the case with these type of things, it has remained as the public threshold ever since. Climate scientists started using the threshold as part of their work in an attempt to maintain legitimacy in the funding process because politicians control research purse strings. Finally, as I wrote in my last post, the status quo is very hard to change. Witness the personalized (not science-based!) attacks on the authors of the Nature Comment that initiated the most recent version of the threshold discussion.
The language Grist uses plays into skeptics hands. “The goal scientists have set.” That implies that scientists have political power and have already exercised it at the expense of every other person. Unsurprisingly, most people aren’t fans of yielding power without a chance at involvement. Hence one very good reason to subvert those scientists. Grist is helping perpetrate the meme that there is a conspiracy against non-scientists – a meme that many climate scientist activists further inflame when they claim exclusive providence over anything climate related. If activists don’t view someone as a perfect example of their tribe, they attack the “other” without hesitation because they’re using the climate issue as a proxy for arguments they should have instead.
Politicians and diplomats set the 2 °C threshold. They were the only ones that had the power to do so. Scientists don’t approve the IPCC’s language. They write their own papers and contribute to the IPCC process, but politicians are responsible for approving every last word in IPCC reports. Grist writers and editors should know this. They’re all too willing to allow zombie myths to keep roaming the discussion space, it appears.
I’ve collected a number of interesting climate and energy related news releases, stories, and opinion pieces in the past couple of weeks. In no particular order:
The only way we will take large-scale climate action is if there are appropriate price signals in markets – signals that reach individual actors and influence their activities. One step in the right direction was phasing out federal subsidies for high-risk coastal properties’ flood insurance policies, as Congress did in 2012. This had the expected effect of increasing premiums for policy holders. Unsurprisingly, people don’t want to pay more to live in their high-risk homes. So they complained to their representatives, who responded by passing new legislation … reinstating government subsidies. Taxpayers across the country are shoveling good money after bad for a select handful of wealthy people to build without mitigating risk to their homes or paying the true economic costs of their lifestyle decisions. We will pay for them to rebuild again and again (remember: sea levels will rise for centuries) unless we as a society decide to stop.
Tesla is entering the energy industry. This could be a game changer in terms of home solar energy and electric vehicles, no matter how Tesla comes out in the long-term.
20 years of IPCC effort and “achievement”. With no robust international climate agreement after 20 years’ of work, I have a hard time accepting the claim the IPCC has achieved much of anything except an excessive bureaucracy and huge reports that few people read.
News that’s not really news: Asia will be among those hardest hit by climate change. This isn’t a new result, but something that the IPCC’s WGII report will report on with increased confidence in 2014 versus 2007 (see above statement). The number of people living close to coasts in Asia dwarf the total population of countries who historically emitted the most greenhouse gases. That was true in 2007 and will be true in the future. It will take a generation or more before effects on developed nations generate widespread action.
New research (subs. req’d) indicates ice gains in Antarctica’s Ross Sea will reverse by 2050. Recent temperature and wind current patterns will shift from their current state to one that encourages rapid ice melt, similar to what the Arctic experienced in the past 20 years or so.
An El Nino might be developing in the tropical Pacific. The anomalous heat content traveling east via an Equatorial Kelvin Wave rivals that of the 1997-1998 El Nino, which was the strongest in recorded history. Earlier this month, NOAA’s Climate Prediction Center issued an El Nino Watch, citing a 50% probability that an El Nino would develop in summer or fall 2014, based in part on projections such as Columbia University’s. El Nino is the warm phase of the ENSO phenomenon. Warm ocean waters move from the western to eastern Pacific, affecting global atmospheric circulations. Related to science policy, one result of Congress’ austerity approach to the economy is monitoring buoys’ degradation in the Pacific Ocean. NOAA helped deploy a widespread network of buoys following the 1982-1983 El Nino which helped track the progress of the 1997-1998 El Nino with greatly improved fidelity. That network is operating at less than 75% of its designed capacity, hampering observations. If we can’t observe these impactful events, we can’t forecast their effects. This negatively impacts business’ and peoples’ bottom line.
Finally, I want to make some observations regarding goings-on within the climate activist community. Vocal critics recently spent a lot of energy on hit pieces, this being only one example (poorly written with little on science, heavy on “he-saids”, with an overdose of personal insults and vindictive responses to anyone who didn’t agree with the piece, including my comments). These writings demonstrate something rather simple to me: if you do not agree with 100% of what the activist consensus is, you’re no better than people the activists label ‘deniers’. Additionally, the their argument is absurd: social scientists have no business analyzing climate data or commenting on activist’s claims. Why is this absurd? Because they simultaneously hold the contradictory belief that physical scientists should have exclusive input and decision-making power over climate policy (a social creation). Furthermore, implicit in their messaging is social scientists don’t have the right kind of expertise to participate in “serious” discussions. These efforts to deligitimize someone they don’t believe should participate (how very elitist of them) is reminiscent of efforts by many in the Republican party to deligitimize Barack Obama’s presidency simply because of his race. Nothing is gained and much is lost by these efforts. How does this advance the climate discussion to people not currently involved, which will need to happen if we are to ever take any kind of large-scale climate action?
Additional lack of critical thought is found in this post, mostly in this penultimate paragraph:
I’ve said before that I think people can believe what they want, as long as they don’t try to act on those beliefs in a way that interferes with others’ lives. When they deny the reality of global warming, and preach it to their flock, that’s exactly what they’re doing (incidentally, a large fraction of Americans believe to some extent the Bible is literally true).
The very same complaint is made by the people the author derides in this paragraph and post but in reverse and it’s one of the biggest reasons why we’ve taken so little climate action. The author’s condescension is plainly evident for those who don’t believe exactly as he does. Instead of trying to reach out to people with different beliefs (and underlying value systems), he takes the lazy route and spends time insulting them. Have you ever believed in something you didn’t previously after someone insulted you? No, it’s an absurd and self-defeating strategy. These basic problems underlie most climate change discussions and people retrench their positions instead of trying to step into other’s shoes. I’m not sure how much this has to change before we undertake more widespread and effective climate mitigation strategies.
Ask and ye shall receive. I recently wrote about what future GHG emissions scenarios included in terms of emission reduction requirements. I have maintained for some time now that most of the IPCC’s emission and concentration scenarios are essentially useless for practical planning purposes. Sure, they’re interesting academically, but we climate scientists can’t just study something for the sake of studying it in today’s tight federal budget environment.
Well, a new Nature Climate Change paper (26Feb2014) updates the 2013 graph I showed, with some small changes:
Figure 1. Historical (black dots) and projected CO2 emissions from a Nature Climate Change article (subs. req’d). Bold colored lines (red (RCP8.5), yellow (RCP4.5), green (RCP6), and blue (RCP2.6)) represent IPCC AR5 RCP-related emission scenarios.
Note that this figure shows exactly what I wrote about in my earlier post: historical emissions are tracking at or above the RCP8.5 scenario. They also exceed the other three scenarios so far in the early 21st century. These differences are relatively small so far (they will grow with time), but the trend difference between historical and RCP2.6 is already important. As the figure shows, if we wanted to match RCP2.6 (and keep 2100 global mean annual temperatures near 2C above pre-industrial), emissions would have to be declining for multiple years already. They aren’t. Our actual annual emissions already exceed the annual maximum assumed by RCP2.6. If we were to match RCP2.6 at some time in the future, emission reductions would have to be larger than RCP2.6 assumes, which is currently technologically impossible.
The figure also shows that if we continue at or along the RCP8.5 pathway, we will exceed the 2°C policy target by approximately 2046. The paper begins with this short and sweet abstract:
It is time to acknowledge that global average temperatures are likely to rise above the 2 °C policy target and consider how that deeply troubling prospect should affect priorities for communicating and managing the risks of a dangerously warming climate.
And it includes this well-written paragraph:
This global temperature target has brought a valuable focus to international climate negotiations, motivating commitment to emissions reductions from several nations. But a policy narrative that continues to frame this target as the sole metric of success or failure to constrain climate change risk is now itself becoming dangerous, because it ill-prepares society to confront and manage the risks of a world that is increasingly likely to experience warming well in excess of 2°C this century.
I wouldn’t have used the term `dangerous` because it conveys a judgmental aspect to an objective statement. But that’s personal style. I agree completely with the underlying message. If we have a small (I would say nearly zero) chance of keeping warming below 2°C this century, then 2°C shouldn’t be the target. We can make an infinite number of possible targets, but most of them will be unachievable. How much effort should we put into such targets? How supportive of additional climate policies will the public be if initial targets fail early? These aren’t simply academic questions. Many climate activists think they’re convinced of how important action is, but their rhetoric doesn’t support that conviction. They’re more ideological than they’d care to admit.
I met someone at a talk at the University of Colorado on Monday and ended up having lunch with them to exchange economic information for climate information. I tried to convince them of the need to switch targets now, to no avail. I ran into a basic problem of climate communication. This person has a worldview and I was in the unenviable position of trying to modify that worldview. Just as many climate communicators try to do with climate skeptics. It’s incredibly difficult to do this because you’re dealing with a lifetime of information and experience overlaying a biology that is predisposed to that very worldview.
I will continue to post about historical versus projected emission/concentration pathways. If activists really are supportive of the objective science as they claim, I think they will eventually shift their target. They will of course have to come to terms with what they will initially perceive as a failure. But the faster they can do that, the sooner we can set more reasonable and achievable targets and start making headway towards mitigation.
A recent research article didn’t generate anything terribly earth-shattering, but I wanted to write about some writing on it because it deals with a recurring theme on this blog. For context, I’ll start with the news release and article (article subs. req’d). In a nutshell,
Climate model projections show an Arctic-wide end-of-century temperature increase of +13∘ Celsius in late fall and +5∘ Celsius in late spring if the status quo continues and current emissions increase without a mitigation scenario. In contrast, the mean temperature projection would be +7∘ Celsius in late fall and +3∘ Celsius in late spring by the end of the century if a mitigation scenario to reduce emissions is followed, concludes the paper titled, “Future Arctic Climate Changes: Adaptation and Mitigation Timescales.”
Again, there is nothing terribly shocking there. If we do nothing, the Arctic will likely warm a whole lot more than if we implement mitigation policies.
But that paragraph could use some additional context. What do the greenhouse gas emissions scenarios look like to generate those varying warming projections? To get a little technical (stay with me), the authors compared two out of four of the Intergovernmental Panel on Climate Change’s (IPCC) Representative Concentration Pathways (RCPs): RCP8.5 and RCP4.5. These pathways represent an additional 8.5 W/m^2 and +4.5 W/m^2 radiative forcing at the year 2100 relative to pre-industrial values.
But even though I’ve taken a graduate level radiation course and I’m using these same pathways in my own research, I don’t really know what +8.5 W/m^2 radiative forcing is, and neither do most people. It’s a number with units that is not intuitively obvious. This is where climate scientists underperform in communicating with the public and where I come in.
So instead of losing ourselves in the technical details, how can we understand what these two pathways represent? Qualitatively, RCP8.5 represents a scenario in which we do not enact GHG mitigation policies until after the year 2100. Economic growth and GHG emissions continue to grow throughout the rest of this century due to 4x 2000’s global energy use. The radiative forcing is induced by 1370 ppm CO2-eq (CO2 and other GHGs).
By comparison, RCP4.5 represents a scenario that stabilizes forcing at 4.5 W/m^2 without overshooting it and has 650 ppm CO2-eq by 2100 (583 ppm CO2; 2013 mean CO2 concentration: 397 ppm). Global energy use is just over 2x 2000 levels. RCP4.5 achieves relatively lower CO2 concentrations by steadily decreasing the amount of carbon per energy unit supplied from 2000 to 2050, then decreasing the carbon/energy ratio very rapidly between 2050 and 2075, then leveling off from 2075-2100. It does this via wider renewable energy deployment, but predominantly fossil fuel use with carbon capture and sequestration deployment.
In other words, RCP4.5 chiefly relies on slower CO2 concentration growth by assuming widespread and rapid deployment of technologies that do not exist today. This point is very important to understand.
This study essentially writes off the possibility of humanity doing any better:
The RCP2.6 scenario requires a 70% reduction of emissions relative to present levels by 2050, a scenario that is highly unlikely in view of the current trajectory of emissions and the absence of progress toward mitigation measures. We refer to the RCP8.5 and RCP4.5 future scenarios as business-as-usual and mitigation.
But the fact is that RCP2.6 — which is about 421 ppm CO2 — is entirely feasible from both a technical and economic perspective. It is only the irrationality, myopia, and, it would seem, self-destructiveness of Homo sapiens that make it “highly unlikely.”
No, it’s not. RCP2.6 makes many more assumptions about technological capabilities and deployment than does RCP4.5. It does this more quickly than RCP4.5 by modeling declining carbon per energy unit between 2010 and 2025 (which hasn’t happened yet), then declining much more rapidly starting in 2025 (only 10 years away) until 2050, then slowing down in 2050 and again in 2075. But here is the kicker: it assumes negative carbon per energy unit after 2075! How does it do this? By assuming more carbon will be removed from the atmosphere than emitted into it starting in 2075 and continuing thereafter. Do we have carbon capture and sequestration (CCS) technologies ready for rapid global deployment? No, there is to my knowledge only a couple of utility-scale projects currently operating and they haven’t achieved the level of capture and sequestration this pathway assumes.
In order for CCS to operate at the level RCP2.6 assumes, global investment in the technology would have to increase by many factors for years. Is there any discussion of this occurring in any government? Will we price carbon-based fuels without interference (i.e., an end to market manipulation by fossil fuel entities and governments)? No and these things aren’t likely to begin any time soon.
Simply put, RCP2.6 is a fantasy scenario [see update below]. Absent global economic collapse that dwarfs the Great Depression, CO2 emissions and concentrations will continue to increase as economies continue to rely on relatively cheap dirty fossil fuels with manipulated prices. At this point, I think RCP4.5 is to a lesser extent another fantasy scenario. That’s neither irrational nor myopic, but realistic based on historical climate policy and my own reading of where international climate policy is likely to exist in the next 35 years. We are currently on the RCP8.5 pathway. Researchers use RCP4.5 because it is illustratively different from RCP8.5. They think it is technically feasible simply because they understand the likely science ramifications of RCP8.5 and misunderstand the public’s desire for continued increasing quality of life that comes with fossil fuel use. Case in point: researchers have shown the difference between “worst-case” and “best-case” climate scenarios for 30+ years. Nobody enacted robust climate policy in response to these comparisons. To continue to do so moving forward is a waste of resources.
[Update]
I wanted to share some updated data demonstrating my statement that RCP2.6 and RCP4.5 are “fantasy scenarios”. Here are two plots I used in a related post in last 2012:
Figure 1. Historical (black dots) and projected (out to 2050 only) CO2 emissions from a Nature Climate Change article (subs. req’d). Bold colored lines (red, yellow, gray, and blue) represent IPCC AR5 RCP-related emission scenarios. Thick green dashed lines and thin green solid lines represent SRES emission scenarios used in IPCC AR4. Light blue dashed lines represent IS92 scenarios. Different generation scenarios are presented together for inter-report comparison purposes.
Figure 2. As in Figure 1 except projections shown to year 2100 and RCP scenarios highlighted.
Figures 1 and 2 show historical and projected annual CO2 emissions in Pg/year from 1980 until 2050 and 2100, respectively. Historical data end in 2011 because the paper was published in 2012. So there are two more year’s data available to us now. How do you think global CO2 emissions changed since 2011? Did they decrease, stay the same, or increase?
It’s more challenging than it should be to find similar graphics, but I found this update:
Figure 3. Historical (1990-2012; 2013 projection) global CO2 emissions in GtC/year (1 PgC = 1 GtC).
As Figure 3 shows, global CO2 emissions rose in 2012 compared to 2011, and emissions likely rose further in 2013 compared to 2012. It further shows that emission rates increased only by 1.0%/year in the 1990s and accelerated to 2.7%/year in the 2000s. While recent year-0ver-year increases aren’t at 2000 mean levels, they are at least twice that of 1990 levels. In other words, there has been no stabilization of CO2 emissions, let alone a decrease, as RCP2.6 and RCP4.5 assume.
A fair counterpoint can be made that RCP2.6 assumes a decline starting in 2020, while RCP4.5’s decline starts in 2040. Sure enough, Figure 1 and 2 demonstrate those assumptions. To that, I say Figure 1 and 2 also shows RCP2.6’s maximum annual emissions peak at 2010 levels. Emissions have already increased at 2%+/year since then historically. For argument sake, let’s say emissions will peak in 2020. Historical emissions will then be higher than RCP2.6 assumed, which would require even more CO2 removal to achieve <2C stabilization by 2100. More CO2 removal means more efficient and widespread deployment than RCP2.6 already assumes, which makes it less likely to occur.
RCP4.5 assumes peak annual emissions in 2040 of approximately 11 PgC/year. If annual growth rates continue near 2.1%, we’ll actually reach that level in 2018 – 22 years ahead of RCP4.5’s assumption. What emissions growth rate is required to hit 11 PgC/year in 2040? See the chart below:
Figure 4. Historical (1959-2012) and projected (2013-2040) global annual CO2 emissions using mean 2000’s emissions growth (blue) and calculated emissions required to achieve 11 GtC/year in 2040 (red). [Historical data: 2013 Global Carbon Project.]
Note that the RCP4.5 scenario has declining emissions growth rate between 2030 and 2040 while my computations uses constant growth rate assumption. Still, this calculation sheds some light on required changes to achieve RCP4.5 scenario assumptions. Figure 4 shows that if future emissions grow at constant rate of 2.1%/year (less than the mean 2000’s rate; more than the mean 1990’s rate), 2040 emissions will total >17 GtC/year (remember RCP4.5’s maximum of 11 GtC/year could be achieved as early as 2018). To max out at 11 GtC/year, emissions would either have to grow at no more than 0.475%/year – less than half the 1990’s mean value – or grow more quickly in the near future, stabilize quickly, and decrease every year following 2030.
RCP2.6 and RCP4.5 demand that countries begin to change their entire energy production fleet from fossil fuels to renewables – either immediately (RCP2.6) or within the next 10-15 years (RCP4.5). What costs are associated with this conversion? How many people without energy access today are denied energy access in the future? That is something that Romm doesn’t address in his talking point that “the fact is that RCP2.6 — which is about 421 ppm CO2 — is entirely feasible from both a technical and economic perspective.” 421 ppm CO2 means no higher concentration than what will occur by 2025.
A permanent emissions decline has obviously never happened historically. What basis allows for the assumption that it will occur starting in 2030? More sweeping and effective policies than have ever been implemented are required. The point to this exercise is to demonstrate that we can play games with numbers all day, but the real world is quite different from economic and climate models as well as Excel spreadsheets. Unless and until we see real world evidence that emissions stabilization occurs, I see little reason to discuss what RCP2.6 or RCP4.5 shows beyond what “could be” as a rhetorical exercise.
I have waited since 2007 (when they released AR4) for this report’s issuance. I read most of the AR4’s WGI report (1000 pages long). Since it’s release, I have read hundreds of climate-related journal articles so I could stay current on the latest research. I have also read some of AR4’s WGII report, dozens of social science journal papers and books because it became clear to me after the AR4 WGI report that there was no significant problem with the science. As a scientist, I realized that the state of climate science hasn’t changed appreciably for decades. The same top-level messages of the First Assessment Report remain in place today. The AR5 WGI report primarily provides more confidence in the reported numbers. Detail changes are relatively minor compared to the knowledge body that existed in 1990. Scientists will continue to work on important items such as mechanisms behind deep ocean heat uptake and cryosphere dynamics. They need to better model Important feedback processes because of their nonlinearities. But the science, by and large, settled long ago.
What remains is our handling of that science, which is where social science knowledge comes in. The difference between acting today to provide cheap, reliable energy to the 1 billion people on Earth who currently have no such access with clean energy versus dirty energy is monumental. Prior to that, we need a reconciliation between believers and skeptics. Nobody should browbeat anyone else in a conversion effort. Instead, we need to identify solution pathways which acknowledge multiple worldviews. Those pathways exist but the status quo is awfully powerful within today’s systems. Changing from the status quo will not be easy, but it will be fruitful. Unfortunately, that very same Twitter feed puts that status quo on display daily; the more so when the IPCC issues a comprehensive science report. Why do the same climate scientists that demand others believe a particular stance from peer-reviewed physical science articles discount a particular stance from peer-reviewed social science articles? Should we trust experts, or not? The reason is tribalism. Tribalism runs rampant on Twitter and too many people think if they shout a little louder every day that eventually everyone will hear and agree with them, despite years of evidence to the contrary.
There is plenty to write about and discuss within the IPCC AR5 summary. I will do so as time permits. I do want to pass along a good article written by Andrew Revkin (the most salient part is at the end). My own research is climate science-based, but I am also working on a social science aspect in order to make the physical science results meaningful to policymakers.
The Scripps Institution of Oceanography measured an average of 391.03ppm CO2 concentration at their Mauna Loa, Hawai’i’s Observatory during October 2012.
391.03ppm is the highest value for October concentrations in recorded history. Last year’s 388.92ppm was the previous highest value ever recorded. This October’s reading is 2.11ppm higher than last year’s. 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, as seen in the graphs below.
The yearly maximum monthly value normally occurs during May. This year was no different: the 396.78ppm concentration in May 2012 was the highest value reported this year and in recorded history (I’m neglecting proxy data). If we extrapolate this year’s value out in time, it will only be 2 years until Scripps reports 400ppm average concentration for a singular month (likely May 2014). Note that I previously wrote that this wouldn’t occur until 2015. I’ve seen comments on other posts that CO2 measured at Mauna Loa should be higher than anywhere else because of its elevation and specific location. It is important to understand that this statement exists somewhere between correct to purposefully confusing to outright deceitful. CO2 is a well-mixed constituent of the atmosphere. That means that emissions of new CO2 are quickly and pretty evenly distributed in space. While point locations might vary between each other (differences between polar and tropical CO2 concentrations at the same point in time vary the most, for example), the observations at Mauna Loa are very representative of those found across the set of observation stations on the globe. In addition, as the graphs below will help demonstrate, the historical record is very clear: concentrations have done only one thing in the past 50+ years at Mauna Loa (or any other station, for that matter): increased. There has been no plateauing or decrease in that time period. Moreover, concentrations at all the individual recording sites show the same long-term trend: an increase.
Judging by the year-over-year increases seen per month in the past 10 years, I predict 2012 will not see an average monthly concentration below 390ppm. Last year, I 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. So far into 2012, my prediction is holding up. October’s concentration is typically the smallest of any individual month’s. We will know for certain next month whether October’s 391.0ppm is the minimum this year or not.
Figure 1 – Time series of CO2 concentrations measured at Scripp’s Mauna Loa Observatory in October: from 1957 through 2012.
This time series chart shows concentrations for the month of October in the Scripps dataset going back to 1957. As I wrote above, concentrations are persistently and inexorably moving upward. Alternatively, we could take a 10,000 year view of CO2 concentrations from ice cores and compare that to the recent Mauna Loa observations:
Figure 2 – Historical (10,000 year) CO2 concentrations from ice core proxies (blue and green curves) and direct observations made at Mauna Loa, Hawai’i (red curve).
Or we could take a really, really long view into the past:
Figure 3 – Historical record of CO2 concentrations from ice core proxy data, 2008 observed CO2 concentration value, and 2 potential future concentration values resulting from lower and higher emissions scenarios used in the IPCC’s AR4.
Note that this graph includes values from the past 800,000 years, 2008 observed values (~6-8ppm less than this year’s average value will be) as well as the projected concentrations for 2100 derived from a lower emissions and higher emissions scenarios used by the IPCC. Has CO2 varied naturally in this time period? Of course it has. But you can easily see that previous variations were between 180 and 280ppm. In contrast, the concentration has, at no time during the past 800,000 years, risen to the level at which it currently exists.
Moreover, if our current emissions rate continues unabated, it looks like a tripling of average pre-industrial concentrations will be our reality by 2100 (278 *3 = 834). This graph clearly demonstrates how anomalous today’s CO2 concentration values are (much higher than the average recorded over the past 800,000 years). It further shows how significant projected emission pathways are. I will point out that our actual emissions to date are greater than the higher emissions pathway shown above. This reality will be partially addressed in the upcoming 5th Assessment Report, currently scheduled for public release in 2013-14.
Given our historical emissions to date and the likelihood that they will continue to grow at an increasing rate for at least 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 or any other knowledgeable body has done this to date. To remain relevant, I think institutions who want a credible seat at the climate science-policy table will have to do so moving forward. The AR5 might possibly fill in some of this knowledge gap. I expect most of that work has recently started and will be available to the public around the same time as the AR5 release, which is likely to cause some confusion in the public.
As the second and third graphs imply, efforts to pin any future concentration goal to a number like 350ppm or even 450ppm will be incredibly difficult – 350ppm more so than 450ppm, obviously. 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 in the near future (as President Obama himself stated recently). That is not to say that we should abandon hope or efforts to do something. On the contrary, this post series informs those who are most interested in doing something. With a solid basis in the science, we become well equipped to discuss policy options. I join those who encourage efforts to tie emissions reductions to economic growth through scientific and technological research and innovation. I am convinced that path is the only credible one moving forward.
Climate change is a monumental problem. I characterize it by saying that it is our species’ greatest confirmed threat. Nuclear war? Possible but unlikely in any given decade. An asteroid/comet collision with Earth resulting in an extinction level event? Possible but unlikely in any given decade. I would, however, rate the asteroid/comet threat above nuclear war. One day, the former will happen, we just don’t know when; the latter can be held off and eliminated based on our own decision making. In a way, climate change combines aspects of both of these threats. Climate change (at a level that will challenge our civilizations) is both possible and likely in a given decade; it is currently happening and its magnitude will only increase each decade during the rest of this century unless and until we decide to do something about it.
It should not be surprising then that, given the sheer magnitude of catastrophic climate change, solutions addressing it are also monumental in scale. That’s the root of why so many climate change activists have been calling for a “climate-Manhattan Project” or a “climate Apollo Project”. My view on climate change actions has shifted somewhat from thinking a bunch of personal actions will eventually accumulate enough inertia to reduce our climate forcing to recognizing that the number of actions will require large-scale policy shifts – something that requires governments to act. That’s why the U.S. Senate’s recent failure to seriously address this developing crisis is so maddening. The status quo approach to policy will not work with climate change, mostly because we’re dealing with physical systems that respond to forcing, not people’s tender egos and greed.
There was nothing inherently bad about the IPCC’s 4AR; I and others simply feel that their final report had to include more conservative estimates and projections in order for world governments to sign off on its language. That does the world’s citizens an injustice, however. In order to correctly assess risk, people need best- and worst-case scenarios available to them. The most likely amount of sea-level rise by 2100 provided by the 4AR came out to between 0.2m and 0.6m. Those estimates have implications to world societies, conservative though they were. Additional implications will enter into our lives if there is 0.4-0.8m additional rise.
I want to stay on the IPCC projections for another moment. The 2007 estimates included rates of sea level rise between 1980 to 1999 and 2090 to 2099 in metes and mm/yr. The mm/yr rates in particular interest me because they allow for both the IPCC projections and the updated projections from the Vermeer and Rahmstorf paper to be placed in context with actual observations. The six emissions scenarios examined by the IPCC had rates of 1.5, 2.1, 2.1, 1.7, 3.0 and 3.0mm/yr. Satellite observations indicate that there has been approximately a +3.2mm/yr change in sea level (linear fit since 1993). Only two IPCC emissions scenarios are close to the observed rate, and both of them underestimate them, albeit very slightly. It is worth pointing out that the IPCC wrote:
The global average sea level rose at an average rate of 1.8 [1.3 to 2.3] mm per year over 1961-2003.
Averages over longer periods of time like this will, by nature of the averaging, tend to reduce extreme values that are small in number, as in the case of sea-level rise in the past 10 years or so.
Onto the new research findings. Vermeer and Rahmstorf developed and tested an updated methodology to project future sea levels based on projected changes in temperature that was originally presented by Rahmstorf in a separate paper. The original technique was based on the assumption that the sea level response time scale was long compared to the time scale of interest. The updated technique allows for some sea level components to change quickly to a given temperature change. The updated technique is shown to agree very well with historical data (82% of sea-level rate variance from the year 1000 to 2000).
Applying the technique to future conditions provides another potential case against which real-world observations can be compared. By the year 2100, three different IPCC emissions scenarios generate a range of sea level projections: 1.0m, 1.2m and 1.4m, as the figure below (from the paper) shows. That’s a big difference between the AR4 projections, using the same emissions scenarios, of 0.2-0.4m. That extra potential meter of sea level rise will indeed have large implications across the world.
The figure shows the possible range of sea level rise values for 3 emissions scenarios considered by the IPCC: B1 in green, A2 in blue and A1F1 in yellow. The observed emissions to date is represented by the red curve. One important detail to note is our actual emissions rate is currently at the high end of all those considered by the IPCC (Copenhagen Diagnosis Figure 1, after Le Quere et al. 2009).
The IPCC projected a higher future rate of sea-level rise than was observed from 1961-2003. 1.8mm/yr equals 0.18m after a century (by linear extrapolation), slightly below the 0.2 minimum projected by all emissions scenarios. Recent observations of 3.2mm/yr equals 0.32m after a century – well within the IPCC range, but well below the Vermeer and Rahmstorf range. So what will it take to get 1.0-1.4m of sea level rise by 2100? 10mm-14mm/yr or 3-4X as much per year as is currently being observed. There are some important details involved with that projection. First of all, sea level change is not linear. It varies year to year and decade to decade. There has to be a transition from today’s 3.2mm/yr to the 10mm/yr necessary to achieve 1m sea level rise by 2100. The rate of sea level rise would therefore have to increase over time.
Given the state of today’s atmosphere, oceans and cryosphere, a drastic change would have to occur for sea levels to rise by 10mm+ per year by the end of this century. It is widely known that the IPCC’s science basis did not include a number of processes and feedbacks to the globes’ continental ice sheets, glaciers and sea ice (cryosphere). Again, that wasn’t their fault – it just happens to be a weak link in the climate community’s research. Work has been conducted since the IPCC 4AR to rectify those shortcomings. Much more work will have to be done in the future. Once that area is fleshed out further, I expect the IPCC’s projections to be more closely aligned with the leading research of today.
Word came yesterday of an island in the Bay of Bengal that has quietly slipped beneath rising seas. New Moore Island was a rocky island that was 2 miles long and 1.5 miles wide. This isn’t the first island to succumb to rising sea levels, nor will it be the last, especially since we continue to belch greenhouse gas pollution into the atmosphere. Indeed, 10 additional islands in the same area continue to face submersion in the near future. This news isn’t a surprise to any reputable scientist who has studied climate change, nor to any activist who has followed the state of the science.
Also unsurprisingly, Sen. James Inhofe’s family was not photographed on New Moore Island constructing a building in further efforts to misinform the fringe anti-science crowd. I’m sure the lunatic Senator would cite his favorite conspiracy of global economic domination as the real topic to be discussed. It wasn’t his island that disappeared, after all. You’ll also note that the disappearing islands don’t garner much corporate media attention. Since the stenographers look for controversy, there must be a lack of dimwits who are willing to go record disputing these events.
I wanted to collect some information I’ve seen about climate change action costs. Some of it is right-wing propaganda, some of it is reality-based facts from large-scale studies that have been done. The short answer is what I’ve been writing for a while: it is far cheaper to act than not to act.
Beginning with the right-wing, extremist, denier propaganda:
On the subject of a still-in-the-works cap-and-trade plan, Con-servatives are running around screaming about a $3,128 tax that would befall the American people. As usual, they’re trying to work up their base over … nothing. As usual, they’re misquoting a scientific study by MIT that examined what a potential cap-and-trade plan would do to the “average American”. As usual, they’re promoting a three-word catch-phrase designed to fool people into buying into their b.s. They’re calling the cap-and-trade plan a light-switch tax. What is the true number from the MIT study? $79 per family (based on 2.56 people, just as the Con-servatives did) in 2015. The long-term cost to a household? $215.05. That’s 6.9% of what the Cons are talking about. They’ve boosted the number over 14 times its true cost – purposefully lying to generate fear and anger. As usual, that’s disgusting behavior from the “family-values” crowd.
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