Modeling: worst-case scenarios

OSU professor Beverly Law and her researchers have published another paper on a topic we’ve discussed before, such as here — that it would be better, carbon-wise, to preserve forests rather than harvest timber. This new paper builds on that theme

Carbon sequestration and biodiversity co-benefits of preserving forests in the western USA

Authors: Polly C. Buotte1, Beverly E. Law, William J. Ripple, Logan T. Berner

Abstract and conclusions below. The paper is behind a pay wall.

I noted in the abstract that the authors based their modeling on “two high-carbon emission scenario (RCP 8.5) climate models.” RCP 8.5 was the subject of a recent article in Forbes by Roger Pilke Jr., “It’s Time To Get Real About The Extreme Scenario Used To Generate Climate Porn,” in which he says RCP 8.5 is a “worst-case scenario” and that “it may not even be a plausible worst-case scenario, because it requires improbable changes to our global energy policies, such as a wholesale return to coal throughout the 21st century and the abandonment of natural gas and renewables.”

So I hope any discussion here the Buotte/Law article will focus on climate modeling and scenarios, rather than the proposal to preserve much of the west-side forests and reduce harvesting (though that certainly is a topic of interest).


Forest carbon sequestration via forest preservation can be a viable climate change mitigation strategy. Here we identify forests in the western conterminous United States with high potential carbon sequestration and low vulnerability to future drought and fire, as simulated using the Community Land Model and two high-carbon emission scenario (RCP 8.5) climate models. High-productivity, low-vulnerability forests have the potential to sequester up to 5,450 TgCO2 equivalent (1,485 Tg C) by 2099, which is up to 20% of the global mitigation potential previously identified for all temperate and boreal forests, or up to ~6 years of current regional fossil fuel emissions. Additionally, these forests currently have high above- and belowground carbon density, high tree species richness, and a high proportion of critical habitat for endangered vertebrate species, indicating a strong potential to support biodiversity into the future and promote ecosystem resilience to climate change. We stress that some forest lands have low carbon sequestration potential but high biodiversity, underscoring the need to consider multiple criteria when designing a land preservation portfolio. Our work demonstrates how process models and ecological criteria can be used to prioritize landscape preservation for mitigating greenhouse gas emissions and preserving biodiversity in a rapidly changing climate.


If we are to avert our current trajectory towards massive global change, we need to make land stewardship a higher societal priority (Chan et al. 2016). Preserving temperate forests in the western US that have medium to high potential carbon sequestration and low future climate vulnerability could account for approximately eight years of regional fossil fuel emissions, or 27-32% of the global mitigation potential previously identified for temperate and boreal forests, while also promoting ecosystem resilience and the maintenance of biodiversity. Biodiversity metrics also need to be included when selecting preserves to ensure species-rich habitats that result from frequent disturbance regimes are not overlooked. The future impacts of climate change, and related pressures as human population exponentially expands, make it essential to evaluate conservation and management options on multi-decadal timescales, with the shared goals of mitigating committed CO2 emissions, reducing future emissions, and preserving plant and animal diversity to limit ecosystem transformation and permanent losses of species



25 thoughts on “Modeling: worst-case scenarios”

  1. As with all conjecture, always pay attention to the “If’s … and’s … but’s …” as well as any use of the hypotheticals like “might, maybe, could, possibly, etc.”

    • (Steve, thanks for this thought experiment throwing red meat to Smokey’s professional rationalizers, while invoking Pilke’s “Porn” to get the juices flowing.)

      Gil, (thanks for not disappointing)

      What aspect of applied science isn’t conjecture (that is, if one possesses common decency, professional integrity and personal honesty?)

      To be willing to admit as scientists, they cannot “know” and predict anything conclusively around behaviors of complex systems is an essential ethic of science. You seem to reject such conclusions based upon the practical application of professional ethics.

      Nonetheless we can attempt to understand how to avoid known high risk behaviors in forest mismanagement.

      (Just as importantly, if not more so, the elevation of consumerism “demand” for timber and elevation of market fundamentalism over the interest of avoiding collective self annihilation during a climate emergency is readily apparent in Sharon’s thesis below.)

      Taking cheap shots at applied climate science suggests Gil, you must possess then an exceptional level of certainty (and just as with referring to Matthew below as “Saint Matthew”) I see how your point of view gets fully rationalized and justified.

      (How sad.)

      On the other hand, I thought The Smokey Wire was discussing the publicly owned National Forest System which contributes a mere 6% or less to our national timber demand.

      Given the other ~94% is derived from private foresters and imported timber, it is reasonable to suggest Buotte, Law, Ripple and Berner’s conclusions should be discussed in context to that which ‘we the people’ have control over. That is, our NFS and its highest and best uses in the midst of a climate emergency.

      So, as a dependent resident of one of the NFS’ highest carbon volume forests in North America, (the Tongass) I would hope Smokey sticks to that picnic basket.

      I would also hope that Sharon’s elevation of market “demand” over scientifically reasonable mitigations of NFS management not conflate and confuse its tiny basket (as its proportion of national timber products supply) with all the other private picnic baskets (which we the people have no control over.)

      Also, however, invoking those actual market realities as sacrosanct and elevating the necessity of feeding consumer culture ‘demand’ — regardless of consequences — needs to be carefully reconsidered in the context of the precautionary principle and ethics.

      As the worst offenders of GHG emissions per capita, the US is presently the worst offender of destroying international collaboration efforts in addressing our climate emergency.

      The real question for discussion here is why has Smokey been exploited to advance Pilke’s Porn at the pleasure of climate emergency denialists?

      • David, Pilke has a valid point — regardless of the topic of a paper, he suggests that scientists do science and the public a disservice by failing to evaluate only worst-case scenarios.

        To its credit, the IPCC evaluates low, moderate, and high-emissions scenarios. It explains in “The Ocean and Cryosphere in a Changing Climate,” Summary for Policymakers, September 2019:

        “This report uses mainly RCP2.6 and RCP8.5 in its assessment, reflecting the available literature. RCP2.6 represents a low greenhouse gas emission, high mitigation future, that in CMIP5 simulations gives a two in three chance of limiting global warming to below 2°C by 2100 15. By contrast, RCP8.5 is a high greenhouse gas emission scenario in the absence of policies to combat climate change, leading to continued and sustained growth in atmospheric greenhouse gas concentrations. Compared to the total set of RCPs, RCP8.5 corresponds to the pathway with the highest greenhouse gas emissions. The underlying chapters also reference other scenarios, including RCP4.5 and RCP6.0 that have intermediate levels of greenhouse gas emissions and result in intermediate levels of warming. {Annex I: Glossary, Cross-Chapter Box 1 in Chapter 1}.”

        • Thanks Steve,
          I too, appreciate the importance of a spread of scenarios to consider– when appropriate.

          The international news outlets document consequences of climate catastrophe occurring on the planet daily. Millions of documented climate refugees and billions of dollars in destruction with each event are occurring on an increasingly frequent basis. If these events are not indicative of a “worst case scenario” to you and Sharon, it is perhaps because either, you have not been tracking the news, nor science or if so, you both possess no capacity for an empathic response.

          (Perhaps if either of you and other agency apologists here personally lost everything as millions of other innocent victims have as a consequence of our accelerating climate emergency, you’d “get” the fact we already exist within a worst case scenario?)

          The full force of what is to come has yet to be unleashed.

          Ethicists point out the richest country in the world (we are citizens of) bears the lion’s share burden of responsibility for this suffering.

          My personal reaction to the twisted ethics of delay, denial and obfuscation of established facts by international consensus on Smokey Wire is to struggle to contain my revulsion and contempt.

          As in NEPA, I’d appreciate the spread of scenarios in a choice of alternatives which include “No Action” as a meaningful alternative. (It is, of course NOT a meaningful alternative.) In my 30 year history of NEPA commenting on the deconstruction of the last of what remains of our largest coastal temperate rainforest, in Southeast Alaska, I’ve been seeking a deeper understanding of process through FOIAs.

          I know too well from that history, derived from emails and personal communications, the culture of denial in the USFS is a career imperative. Consequently, there is rarely a meaningful “spread of scenarios” allowed to occur when timber targets get imposed.

          This happens even while the agency is openly admitting to “irretrievable and irreversible consequences” to our commonwealth, and Buotte et al conclude — with globally-significant implications in those actions.

          Given the USFS pattern of failures to act in the face of what has devolved into our current Climate Emergency, and Mass Extinction Event, it is clear by the “seek to meet market demand” (TTRA language) and the primacy of politically-determined timber targets, that the agency and its apologist enablers have some serious ‘mansplainin’ to do.

          The USFS culture has always been a politically-driven market fundamentalism to be executed at ALL costs. THAT is as “sacrosanct” (def. “regarded as too important or valuable to be interfered with”), as it gets.

          The problem of course, is when it comes to elevating politically determined timber targets known to exacerbate our now internationally-recognized Climate Emergency and its concurrent Mass Extinction events, the other side of the USFS ”No Action” coin must now be examined for what it actually is.

          The USFS No Action Alternative is a con man’s coin toss citing the classic, “Heads, you lose — tails, I win!” declaration of market fundamentalism at ALL costs. It is Margaret Thatcher’s, “There IS NO alternative!”

          Smokey’s “No Action Alternative” to our present Climate Emergency must now be examined for what the “No Action” gets used for: to deny reality itself.

          To repudiate, obfuscate, and delay meaningful alternatives in the midst of an internationally recognized climate emergency is to discover in the mirror the ugly the face of denial with massive ethical consequences.

          To accomplish this, invoking (if not usurping) “Smokey’s” name beside Pielke’s Porn however, introduces an entirely different set of historical, ethical and legal dimensions.

          It is now time to talk about the well-known “Smokey Bear effect,” in the context of Smokey Wire’s penchant for climate emergency denialism and obfuscation. The original context of the effect is best described by a former USFS Fire manager:

          “For a hundred years, we’ve been very good at suppressing [forest fires]. And now, we’re reaping that fiery maelstrom — we have fires now we can’t stop! And they’re going to continue to burn…until there isn’t a whole lot left to burn.” -William Armstrong, Fire Manager, U.S. Forest Service. ”

          Here’s NPR’s coverage

          And here’s my observation of the tragic irony of a public agency and its apologist co-dependent enablers, employing what has been determined, the second most recognizable icon in the advertising industry, (yup, “Smokey”, with an “e” added for brand identification).

          That icon was originally misused for the purposes of ingratiating the timber industry and business as usual in the service of the “market.” Now, having learned nothing, those usurping the Smokey brand perpetuate the misuse at the risk of exacerbating our present worst case scenario–

          So, to invoke an updated version of Smokey,:
          “Remember, only YOU can prevent NFS and planetary conflagrations stemming in part from national forest mismanagement in the face of a climate emergency.” (and this is done by NOT blowing smoke in the public’s eyes vaping Pielke’s Porn.)

          Under the present climate chaos regimes of globally and nationally-observed acceleration of climate forcing feedbacks, a fully justified emphasis on understanding worst case scenarios is indicated — including the extraction of fossil fuels from federal lands —

          — unless of course, those invoking “Smokey” himself (an icon protected by an act of Congress) choose to blow their private climate denialist’s outliers’ smoke around an internationally recognized scientific consensus during an internationally-declared “climate emergency.”

          That’s a worst scenario Steve, and I’d like to think you possess the capacity to recogonize this.

      • His name is Pielke as in Roger Pielke, Jr.
        I didn’t say that market demand was “sacrosanct” I just said it exists. If you can reduce consumer demand for wood products, without substituting material with worse carbon impacts, it seems like that would be good.

        David, how exactly would you go about doing that?

        • Sharon,
          You stated,
          “If we were to try to splice in social sciences to this biological analysis, we would add
          a) but we still have a demand for wood products…” and ,”“not cutting forests” is a useful climate intervention (social decision, compared with other interventions), ”

          THAT is as “sacrosanct” (def. “regarded as too important or valuable to be interfered with”), as it gets.

          (I’d love to bring in the social sciences on this matter of rural poverty as a direct consequence of NFS plantation management. But in this case, you’d best include discussions of political economy to be fair.)

          … however, I stated, this discussion should more correctly be in the context of the 6% or less supplied by the NFS, rather than the entire national timber demand.

          If you are questioning what the consequences of 6% or less of the actual supply to meet our national market demand for timber products, rather the consequences of NOT doing that which is documented as an important paradigm shift in NFS management during a climate emergency of grave proportions, it is reasonable to conclude you are elevating the importance of the tiny over the risk of unleashing the terrible.

          In my view, this would be an unconscionable disservice to the stated intent, “to protect and obtain the greatest benefit from all forest resources” of our NFS and a disservice to all extant and future generations of life.

          Finally, I need to know: Do you have permission to use “Smokey” the brand? If so, please provide the evidence.

          PLEASE RESPOND to this request Sharon,
          Thank you.

      • David

        The answers to your questions / Concerns are found as follows:

        Re your concern: “To be willing to admit as scientists, they cannot “know” and predict anything conclusively around behaviors of complex systems”
        You read my comment in opposition to this statement of your’s but you seem to have ignored it. Plz see:

        Re your concern: “Taking cheap shots at applied climate science suggests Gil, you must possess then an exceptional level of certainty” and your twice mentioned “climate emergency”
        Plz see: It should show you that you too have an “exceptional level of certainty” in spite of the unsettled science.

  2. Thanks for bringing up the RCP 8.5 work, Steve! We will talk about that more on the Climate Science Voyage of Discovery series.

    But what I see in this is an argument that I can understand and at least in part agree with.
    (1) If we decide that “not cutting forests” is a useful climate intervention (social decision, compared with other interventions), then
    **(2) we should pick areas where a) trees and forests are sequestering more than average and b) will continue to, for say, the next 50 years (we could discuss this timeframe) and have a relatively low chance of burning up.** I totally agree with this with the caveat “all other things being equal” which of course they are not- you have to agree with 1 first. I don’t actually need emissions scenario modeling to arrive at the idea that this makes sense, because of observations of current conditions of relative drought and fires.

    (3) If we were to try to splice in social sciences to this biological analysis, we would add
    a) but we still have a demand for wood products and what are the carbon implications of producing them elsewhere and transporting them?
    b) the yellow areas on the map in general do not have production facilities (anymore) or few. They also have plenty of people who don’t want to get commercial production back in those areas, plus difficulties producing from public lands. Note that the Sierras are yellow. We have covered quite a bit about the difficulty of selling trees in California, let alone Utah.

    It seems to me that the only thing modeling really helps with in this analysis is quantifying the carbon, and to make a good policy decision you would have to weigh that against all the other potential interventions and their social and economic costs and benefits.

    • A agree, Sharon, that modeling is useful. But as Pilke says, too many scientists opt for the worst-case scenario — perhaps to call more attention to sensational findings.

      I wouldn’t object if Buotte et al modeled other scenarios — best case, likely case, and worst case. That would offer important perspective. But Buotte et al did not mention any models but RCP 8.5.


      “But the result of the disproportionate emphasis on RCP 8.5 combined with its mischaracterization as the “business as usual” scenario has been an avalanche of studies and corresponding media coverage that presents a worst-case scenario as the most likely future. At best, this represents a form of cherry picking. Imagine if studies instead focused solely on RCP 4.5 as “business as usual” and concluded that climate change would really not be that big a deal. Such selectivity would be highly misleading.”

      • I agree with Roger about RCP 8.5 – my point was that I wouldn’t have framed the question
        “where is the best place to do carbon sequestration by not cutting forests?”
        “how does carbon sequestration by not cutting forests stack up carbon-wise, socially and economically, with other potential interventions?”
        Then, if “not cutting forests” stacks up (so to speak) as an intervention, the next question would be “where is the best place to do it?”

        • Ah, I get you. How does carbon sequestration by not cutting forests stack up carbon-wise, socially and economically, with other potential interventions? That would be of much more value.

          • My point is that if academia provides us with an intervention at a time “don’t do x because of y” we can never get to what are the best options. It’s kind of the broader scale variant of the Carolyn Daly point “why are scientists always telling us what we can’t do?”

            For me that’s a structural flaw of some investigator-initiated research that claims to address policy problems. IMHO it requires something much more multi-disciplinary and multi-institutional with participation by practitioners and affected communities of place and interest.

  3. It’s cool to see how a five year long study supported by the U.S. Department of Agriculture, and conducted by top PhD scientists and researchers at the Oregon State University’s College of Forestry, can be picked apart on this blog in a matter of minutes…and apparently without anyone having actually read the actual study. Some of y’all got some mad skills!

      • Thanks Steve. Good to know. Maybe you’re the only person commenting here who has read the actual study. I did look over Pilke’s point. I admit to not knowing enough about climate modeling to know if he’s making a good point, or not. Seems to me that there are plenty of signs of various stages of climate change, a human-caused extinction crisis and ecosystem collapse.

        I also think that there are many great reasons to preserve and protect native forests in addition to any carbon sequestration benefits, whatever those may be. Other benefits to preserving and protecting native forests include benefits to clean water, wildlife habitat, biodiversity and natural processes.

        P.S. What if….

    • Saint Matthew, in these blog pages, over the years, you’ve found fault with plenty of long term validated research performed by those at least equally qualified to your researchers. You have rejected studies which had been replicated both in statistically sound research and in operational trials both performed over a wide range of spatial and temporally disparate circumstances. On multiple occasions you have denied one of the principle tenets of the science of plant physiology in terms of the importance of stand density in regards to the probability of the incidence and spread of insects, disease and wildfire. Me thinks that the pot is calling the kettle black.

    • Matthew, (1) how do you know who has read it and who has not? e.g “anyone”? Just curious.

      (2) I may well be the only person regularly on TSW who has sat in a grants department at USDA. Many of them simply need to sound plausible to other scientists. Otherwise we wouldn’t have spent so much $ on engineered trees.

      (3) I don’t have “mad skills,” but almost 45 years of experience reading papers on forest science, running research panels for grants, attending presentations and so on. If you don’t think the materials and methods can tell you what’s in the conclusions because they didn’t frame the question in a useful way, then that’s fairly easy to tell.

      Here’s a possible U of Colorado study:

      “we measured the number of cars on I70 on winter weekends and through a survey found that many were going to ski areas. Based on the number of non-electric cars, and the proportion of coal and natural gas in the Colorado electricity supply, we calculated that this used x units of carbon. Y number of skiers come via airplanes, on the average using z amounts of carbon.

      To reduce carbon impacts, the best thing we can do is close ski areas on National Forests for climate change reasons. We looked at substitution via surveys and many people from Colorado would just not ski. The richer ones would go to BC or Europe, but we calculated that those substitutions would lead to a much reduced amount based on …..”
      (note that this paper actively addresses substitutions)(I would be curious as to what they found out about substitutions and whether that matched what people I know think about it)
      Conclusions: ski areas should be closed on all National Forest lands.

  4. We have set aside most of our Western federal forests already, but now let them burn for resource benefit.( I wonder how that works for carbon sequestration?) Most of the lost of forests on federal land now comes from disease and fire, not timber harvesting.

  5. More on the use of RCP8.5 in climate modeling, from Judith Curry’s blog. An excerpt from a long post, “The toxic rhetoric of climate change.”…

    The most alarming scenarios of 21st century climate change are associated with the RCP8.5 greenhouse gas concentration scenario. Often erroneously described as a ‘business as usual’ scenario, RCP8.5 assumes unrealistic long-term trends for population and a slowing of technological innovation. Even more unlikely is the assumption that the world will largely be powered by coal.

    In spite of the implausibility of this scenario, RCP8.5 is the favored scenario for publications based on climate model simulations. In short, RCP8.5 is a very useful recipe for cooking up scenarios of alarming impacts from manmade climate change. Which are of course highlighted and then exaggerated by press releases and media reports.

    Apart from the issue of how much greenhouse gases might increase, there is a great deal of uncertainty about much the planet will warm in response to a doubling of atmospheric carbon dioxide – referred to as ‘equilibrium climate sensitivity’ (ECS). The IPCC 5th Assessment Report (2013) provided a range between 1 and 6oC, with a ‘likely’ range between 1.5 and 4.5oC.

    In the years since the 5th Assessment Report, the uncertainty has grown. The latest climate model results – prepared for the forthcoming IPCC 6th Assessment Report – shows that a majority of the climate models are producing values of ECS exceeding 5oC. The addition of poorly understood additional processes into the models has increased confusion and uncertainty. At the same time, refined efforts to determine values of the equilibrium climate sensitivity from the historical data record obtain values of ECS about 1.6oC, with a range from 1.05 to 2.7oC.

    With this massive range of uncertainty in the values of equilibrium climate sensitivity, the lowest value among the climate models is 2.3oC, with few models having values below 3oC. Hence the lower end of the range of ECS is not covered by the climate models, resulting in temperature projections for the 21st century that are biased high, with a smaller range relative to the range of uncertainty in ECS.

    • So let’s keep pretending the failures of consensus to date around underestimation in scale and timing never happened?

      Mea Culpas given recently at COP 25 in Madrid are unwarranted?

      The abandonment of the precautionary principle was appropriate in order to protect shareholders?

      Now that shareholders are in court class action suits, arguing over evidence that they’ve been lied to for decades by CEOs and been made Fossil Fools– it’s a race then, between judges and scientists as to which group will take over the helm to avert irreversible climate catastrophe?

      I want no part of this irrationality.

      True justice in parallel universes will be conferred to those who deny, delay, and obfuscate these uncertainties as if there weren’t a planet at stake They get to come back in their next life to the planet they helped destroy.

      And their innocent victims get to come back to the planet they deserve to enjoy.

      • The planet is not “at stake.” The planet will not be destroyed. Climate change is a serious issue, but it isn’t an existential crisis. Those who say that it is an existential crisis aren’t furthering the cause they profess to support. As Paul Homewood writes in Forbes,

        “There is good evidence that the catastrophist framing of climate change is self-defeating because it alienates and polarizes many people. And exaggerating climate change risks distracting us from other important issues including ones we might have more near-term control over.”

        • Forbes?
          Paul Homewood?
          I tried Steve… it’s not there.
          What IS there is excruciatingly familiar though.

          The actual author is a well-known nuclear industry corporate shill who also predicted the “Death of Environmentalism.” (This of course, is at odds with the millions of people across the globe protesting in the streets.)

          Shellenberger’s free market fundamentalist worldview parallels nuclear, oil, coal, gas, and other mining CEOs, Steve.

          I recommend you find more credible sources with regards to our Climate Emergency as national security and existential threats such as, the Department of Defense

          “The effects of a changing climate are a national security issue with potential impacts to Department of Defense (DoD or the Department) missions, operational plans, and installations.”

          (and speaking of the exalted “high priest” and “nuclear humanist” Shellenberger);

          The Bulletin of Atomic Scientists’ Doomsday Clock:
          “The Doomsday Clock conveys how close humanity is to catastrophic destruction–the figurative midnight–and monitors the means humankind could use to obliterate itself. First and foremost, these include nuclear weapons, but they also encompass climate-changing technologies and new developments in the life sciences that could inflict irrevocable harm.”

          I agree, the planet is not at stake, just our biosphere and its ecosystems which are in chaos and experiencing mass extinction rates on orders of magnitude greater than natural background rates.

          Parroting clever naysaying psy-op strategies used by the heavily invested multi-millionaire and billionaire classes who own MSM and their “market based solutions” doesn’t win much street cred around the world these days.


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