August 03, 2006
Who Believes that GHG Mitigation Can Affect Tomorrow’s Climate?
Posted to Author: Pielke Jr., R. | Climate Change
The almost daily use of current weather and climate events to argue for action on greenhouse gases by the media and political advocates is among the most egregious misuses of science in the climate debate. Not only does it redirect attention away from those actions most likely to have an effect on the impacts of weather and climate, but it creates disincentives for action on the longer-term problem of human-caused climate change.
The use of current weather and climate events as a promotional symbol in the climate debate exploits a cognitive heuristic called pattern matching. One reason why there is so little mention of the long time lag between action on energy policies and a perceptible influence on climate is that it would work against exploitation of this cognitive heuristic.
These dynamics are well explained in research conducted by John Sterman of MIT and Linda Booth Sweeny at Harvard (PDF) which concludes that just about everyone – including management, math, and science graduate students at MIT (no slouches there) - believes that changes in energy policies can have an immediate and discernible influence on the climate system. Here is an excerpt from their paper:
We carried out experiments to assess public understanding of basic processes affecting the climate, specifically, whether adults understand the relationships between atmospheric GHG concentrations and flows of greenhouse gases into and out of the atmosphere. Though the subjects, graduate students at MIT, were highly educated, particularly in mathematics and the sciences, results showed widespread misunderstanding of mass balance principles and the concept of accumulation. Instead, most subjects relied on pattern matching to judge climate dynamics. The belief that emissions, atmospheric CO2, and temperature are correlated leads to the erroneous conclusion that a drop in emissions would soon cause a drop in CO2 concentrations and mean global temperature.
Sterman and Booth Sweeney explain why it is that many people think this way:
Why do people underestimate the time delays in the response of climate to GHG emissions? Obviously the average person is not trained in climatology. We hypothesize, however, that widespread underestimation of climate inertia arises from a more fundamental limitation of people’s mental models: weak intuitive understanding of stocks and flows—the concept of accumulation in general, including principles of mass and energy balance. Prior work shows people have difficulty relating the flows into and out of a stock to the trajectory of the stock (Booth Sweeney and Sterman, 2000). Instead, people often assess system dynamics using a pattern matching heuristic (Sterman and Booth Sweeney, 2002), concluding that system outputs (e.g., global mean temperature) are positively correlated with inputs (e.g., emissions). Pattern matching can work well in simple systems but fails in systems with significant stock and flow structures: a stock can rise even as its net inflow falls, as long as the net inflow is positive. For example, a nation’s debt rises as long as its fiscal deficit is positive, even as the deficit falls; debt falls only when the government runs a surplus. Since anthropogenic GHG emissions are now roughly double net removal, atmospheric GHGs would continue to accumulate, increasing net radiative forcing, even if emissions drop, until emissions fall to net removal (of course, removal is not constant; we consider the dynamics of removal below). In contrast, pattern matching incorrectly predicts mean temperature and atmospheric GHGs closely track emissions; hence stabilizing emissions would rapidly stabilize climate, and emissions cuts would quickly reverse warming and limit damage from climate change. People who assess the dynamics of the climate using a pattern matching heuristic will significantly underestimate the lags in the response of the climate to changes in emissions and the magnitude of emissions reductions needed to stabilize atmospheric GHG concentrations.
Stocks and flows may be stunningly obvious to a climate scientist, but it is difficult to comprehend for most people, and it made even more difficult to understand when the point is willfully ignored ot obfuscated by many advocates for energy policy action on climate change. Those who use current climate events like hurricanes or heat waves to justify action on mitigation are thus exploiting pattern matching for a short-term political gain. But my sense is that such exploitation will backfire.
People of good faith can debate the costs and benefits of policies to mitigate climate change, but policy should not be based on mental models that violate the most fundamental physical principles.
Sterman and Booth Sweeney argue that pattern matching is to be expected in how people think,
The difficulties people experience in our experiments should perhaps be expected. It is not necessary to understand stocks and flows to fill a bathtub. It is far more efficient to watch the water in the tub and shut off the tap when it reaches the desired level—a simple, effectively first-order negative feedback process. For a wide range of everyday tasks, people have no need to infer how the flows relate to the stocks—it is better to simply wait and see how the state of the system changes, and then take corrective action.
Sterman and Booth Sweeney suggest that this heuristic lends support to "wait-and-see" policies. This may be the case, but I think it also creates a sense of control over the climate system that simply doesn’t exist. If we can control the climate system, and correspondingly climate impacts, simply by changing our energy policies, then it would be logical to think - "Hey! Drive a Prius and no more heat waves or hurricanes!" The explotation of pattern matching also creates incentives for small, meaningless actions. The poverty of the current policy debate on climate change would be far more apparent if advocates more openly described the time lag between action on energy policies and perceptible influences of the climate system. This also would help to make advocacy for action on energy policies more honest and properly justified.
The hard reality is that the only justifiable use of current weather and climate events as a tool of promotion for action on climate change is in support of improving adaptive responses and reducing vulnerability.Posted on August 3, 2006 10:20 AM
Professor Pielke. Have you seen estimates for the time scales needed for implementation of 'corrective actions'. It seems that dependence on individual action is not at all effective. Look at high-efficiency energy appliances, alternative-fuel transportation, solar power, individual conservation, etc. Then also consider national-level actions. Fission power boomed early and then crashed and burned, MHD never made it out of the labs, fusion is still in the labs, wind, wave, and biomass do not have the capability to make truly significant contributions. Fission is a little over 50 years out and while it makes some contributions, it remains far from saturation.
I think we talking at least 100 years for implementation and significant contributions to CO2 reductions, after an approach to solutions are decided, researched, and developed.
These time scales alone, if they are in the ballpark, seem to indicate that 'let's do something today' is not at all realistic.
Posted by: Dan Hughes at August 3, 2006 11:07 AM
From Hank Roberts:
Dr. Pielke, you've stripped the context and stated your conclusions, which are quite the opposite of the authors'. In fairness you should offer them at least a chance to respond.
They invite comment where they posted the discussion, here:
"... US policymakers, too, argue that it is prudent to “wait and see” whether climate change will cause substantial economic harm before undertaking policies to substantially reduce emissions.
"This wait-and-see attitude is based on simple but serious misconceptions. It grossly underestimates the substantial delays in the climate’s response to the consequences of human emissions (“anthropogenic forcing” – that is, generated by, or the result of, human activity). And it presumes that climate change can be reversed quickly when harm becomes evident."
"We found a widespread misunderstanding of climate change dynamics. Two-thirds of the subjects believed global temperature responds immediately to slight or dramatic changes in CO2 emissions. Still more believed that reducing emissions near current rates would stabilise the climate, when in fact emissions would continue to exceed removal, increasing greenhouse gas concentrations and radiative forcing.
"Such beliefs make current wait-and-see policies seem entirely logical, but violate basic scientific principles of conservation of matter.
"Low public support for policies to reduce emissions may be based more on misconceptions of climate dynamics than high discount rates (that is, putting a low value on the future) or uncertainty about the risks of harmful climate change."
See: "Understanding Public Complacency About Climate Change" http://web.mit.edu/jsterman/www/StermanSweeney.pdf
I posted this a few days ago at Stoat and at RealClimate, after finding it here:
Posted by: Hank Roberts at August 3, 2006 04:55 PM
"Physics is a tricky subject to teach. Like math, it can be very abstract while describing some very concrete things. We expect students to master physics in a year, but the truth is few students really understand the subject well enough after one course to discuss it authoritatively. They remember bits and pieces, and in time the bits and pieces get jumbled up with ideas pulled from other sources of information. We can well imagine how blissfully entirely unaware of physics concepts that other 80% is...."
Posted by: hank at August 3, 2006 05:28 PM
Hank- Thanks for your comments. However, I accurately described the findings of the study. The study was focused on what people believe about stocks and flows as related to the climate issue. Their research was not about how such misunderstandings shape the political debate, and I do write in my post that "Sterman and Booth Sweeney suggest that this heuristic lends support to "wait-and-see" policies."
I am not sure about this assertion, as I wrote, but it is not implausible. My point was to point out that I can see another interpretation of their research.
My interpretation is not at all inconsistent with that of Sterman and Booth Sweeney. In no way is it opposite as you suggest.
Thanks for the additional links.
Posted by: Roger Pielke, Jr. at August 3, 2006 06:21 PM
Ok, so when you say:
"Sterman and Booth Sweeney suggest that this heuristic lends support to "wait-and-see" policies"
and they write:
"Such beliefs make current wait-and-see policies seem entirely logical, but violate basic scientific principles of conservation of matter."
You're both talking about the same thing?
Your words "this heuristic" refers to people's beliefs that "violate basic scientific principles" -- these lend support to the "wait and see" policies. Right?
Posted by: ankhatmac at August 3, 2006 07:07 PM
Sterman and Booth Sweeney argue that this heuristic -- i.e., these believes about stocks and flows that violate basic physical principles -- lend support to the notion of "wait and see" policies. As I said, this is possible. but there are other, perhaps more legitimate, reasons why one might support wait-and-see policies, such as the work of Wigley, Richels, and Edmonds:
Wigley, T.M.L., Richels, R., & Edmonds, J. (1996) Economic and environmental choices in the
So given these complexities I am not completely sold on the Sterman and Booth Sweeney interpretation of the significance of their work. It is at best a partial explanation for wait-and-see. I offered a complementary interpretation. You can take it or leave it, but be clear that there is no contradiction with what Sterman and Booth Sweeney have presented.
Posted by: Roger Pielke, Jr. at August 3, 2006 09:03 PM
You write, "I am not sure about this assertion, as I wrote, but it is not implausible. My point was to point out that I can see another interpretation of their research.
My interpretation is not at all inconsistent with that of Sterman and Booth Sweeney. In no way is it opposite as you suggest."
I agree that your interpretation is consistent with the *evidence* provided by Sterman and Booth Sweeney. But isn't your interpretation the opposite *conclusion* of that made by Sterman and Booth Sweeney?
They conclude that improper understanding may lead to delay, but you are suggesting that improper understanding may lead to support of actions that have no practical effect.
Aren't those essentially opposite interpretations of the evidence?
P.S. I notice that they propose this as a possible alternative to people using "high discount rates"...but they provide no evidence that the discount rates are improperly high. In fact, one of the few ways to justify immediate and substantial action to reduce CO2 emissions is to assume a ZERO discount rate.
Posted by: Mark Bahner at August 3, 2006 09:13 PM
I don't find much practical difference in "actions that have no practical effect" and "delay" [of actions that have a practical effect].
Posted by: Roger Pielke, Jr. at August 3, 2006 09:52 PM
You write, "I don't find much practical difference in "actions that have no practical effect" and "delay" [of actions that have a practical effect]."
Oh! Well, I think there's a huge difference.
Let's say I want to build a desk, and:
1) I decide to delay until I can buy the wood to do so, or
2) I have a bunch of toothpicks, and I try to make the desk out of the toothpicks.
In the case of path #1, I have free time to do other things, while I'm delaying until I can buy the wood. In the case of path #2, I'm spending ***all my time*** with those darn toothpicks, and still not getting the desk built.
So I'd say path #1 is much to be preferred over path #2.
Posted by: Mark Bahner at August 3, 2006 10:15 PM
While your citations give an accurate account of Sterman & Booth Sweeney’s Cloudy Skies paper, I think you have misappropriated the results to support unrelated conclusions.
Pattern matching in the experiment refers to observation of similar time-series growth trends in emissions, atmospheric concentrations, and temperature, and as a result forming linear expectations that emissions reductions will cause immediate concentration reductions. A single weather event is not a pattern, and has no obvious time-series similarity with emissions events (to the extent that there are any), so it’s hard to see how promotion of climate policies with weather events is a related phenomenon.
The use of current weather events to promote climate policies may or may not be wrong, but that is a question of attribution. (Mis)attribution may in turn depend on pattern matching (e.g. between historic emissions and temperature), but that’s not what Katrina-climate linkers are doing. Their claims are independent of the dynamics of accumulation, because they are not made with any reference to whether extreme events are due to an particular pattern of current or past emissions.
The notion that there is little mention of the time lag between action on energy policies and influence on climate because it would work against exploitation of pattern matching is similarly unsupported (perhaps you could elaborate with an example). My personal observation is quite the opposite – many advocates are vocal about the need to initiate immediate action in order to anticipate energy-economy response lags.
While there may be legitimate reasons to wait-and-see (contested in the literature, see http://www.uni-hamburg.de/Wiss/FB/15/Sustainability/Paje-Tol-paper2.pdf) it would be an extraordinary coincidence if through misperceptions of the dynamics of climate we arrived at exactly the right amount. Many of the arguments for wait-and-see are founded on models that assume equilibrium and perfect foresight, so it’s likely that enriching the policy discussion with greater consideration of delays would weaken the argument for waiting.
Even if pattern matching creates incentives for small actions, there may be nothing wrong with that, especially if those actions are cheap. Even the most conservative models suggest that carbon emissions should have a value higher than the current $0/tonC. I think the real poverty of the current debate is that it neglects valuation and focuses on achieving arbitrary atmospheric concentrations with even more arbitrary restrictions on emissions paths, mainly due to the desire to buy participation of hostile interests through grandfathered tradable permits.
Your point about the consequences of linear thinking for policy survival is well taken. Will altruists maintain their appetite for individual action, and could the political system sustain collective action, in the face of temperatures that rise for decades in the face of significant emissions reductions?
Posted by: Tom Fiddaman at August 4, 2006 11:03 AM
Tom- Thanks for your comments. A few reactions:
1. You write: ". . . it’s hard to see how promotion of climate policies with weather events is a related phenomenon" and "Their claims are independent of the dynamics of accumulation, because they are not made with any reference to whether extreme events are due to an particular pattern of current or past emissions."
I disagree. Many, if not most, linkages of current weather events with the need for emissions reductions do indeed place the event in the context of a broader pattern, while sometimes acknowledge the lack of a link for that particualr event.
Here is an example of how individual weather events are framed as a pattern:
"This heat wave and other extreme events we've seen in recent years are completely consistent with what we expect to become more common as a result of global warming, even though we can't be definitive on any single event,"
Notice how advocacy for action on climate change has shifted from hurricanes (not really happening at the moment) last fall to heat waves now. The implication of such linkages is that such events will become more common unless we act on emissions reductions. Such advocacy is capitalizing on today's pain, even though the relief provided by emissions reductions is far in the future.
The reality is that (according to the IPCC) such weather events will become more common independent of short term action on emisisons, and only can be influenced in the far distant future. Given this reality images of today's hurricanes and heat waves should always be accompanied with discussion of adaptations, not simply discussions of energy policies. It is the rare article or advocate who includes adaptation.
It is for this reason that such advocacy capitalizes on people's typical cognitive illusions.
Can you point me to one advocacy group that openly discusses the long lag between emisisons reductions and tehir effects on climate? I can't, but perhaps there are some ...
We do agree on arbitrary concentration targets.
Posted by: Roger Pielke, Jr. at August 4, 2006 01:21 PM
[I didn't mean to come here wearing two different socks -- I had trouble with TypeKey's authentication yesterday -- "ankhank" and "hank" posts above are both mine -- Hank Roberts]
I think there's confusion here starting from the headline -- "tomorrow's" conditions are weather, not climate.
If that's your point, Dr. Pielke -- people think "tomorrow's climate" is a valid concept, for small values of "tomorrow" -- and they're wrong -- well, it's not clear.
If the point is that making small and personal efforts isn't going to reward people because the weather won't improve tomorrow -- well, that's two different things. Reward it does, simply in cost savings from conservation and energy efficiency.
If the point is that policy makers have to assume the voters are both ignorant and shortsighted, and make decisions that satisfy that population -- well, that's dismal.
As to the difference between building out of toothpicks and building out of lumber, I'd say the bad option is more analogous to building out of matchsticks -- the bad choices aren't just neutral and delaying, because rushing to build more old tech coal plants in the next decade will 'burn us' by pumping out CO2 and pollution for fifty year lifespans).
The only advantage to rushing to commit more old tech coal plants is -- guaranteeing the anticipated short term profits of the business as usual industry.
And I can't think of a better argument for taxing coal than committing to hundreds more old tech coal plants -- they guarantee longterm use of the cheap and dirty fuel, of course they'll be obvious tax targets.
If the coal generating industries committed to a decade of conservation and efficiency and design for the closed-combustion generation that's already being tested, they'd have a far better argument against taxation.
Yes, they have to get the governments to force them to do the right thing -- because otherwise they'd be in line for antitrust collaboration accusations.
It's like water law, at least in California, where if someone's been pumping longterm for an aquifer without damaging it, and someone else comes along and starts sucking it dry, the first user -- by some 1949 case law -- has to keep sucking water out too or lose the right to future use. The law forces businesses to do the stupid thing, the aquifer collapses and never holds anything like that amount of water again. Businesses keep a right, and lose a resource. The law insists.
Coal's in the same position. Yes, we need smart public policy. No, I don't know how to get it.
But short term thinking is just using up the resource without building the next step we need.
Posted by: hank at August 4, 2006 01:28 PM
Re Mark Bahner's
If you mean discount rate in the conventional sense, the risk-adjusted rate of return one would demand in order to undertake a project, no model uses zero. Most (e.g. Nordhaus, Cline) endogenously generate rates on the order of 5-8%, consistent with observed long run returns. They find optimal policies involving modest (>10%) to substantial emissions reductions, starting immediately.
If you mean the social rate of time preference, again most models do not use zero (3% per year is typical, e.g. in Nordhaus' work). But this is essentially an ethical choice: how much of your granchild's welfare are you willing to trade for your own? 3%/yr implies that we are 6x as important as our grandchildren, yet models employing that value still propose policies as above. Choosing an intergenerationally equitable rate, i.e. zero, leads to policies involving large emissions reductions, but does not imply a zero discount rate for investment selection.
Posted by: Tom Fiddaman at August 4, 2006 01:30 PM
Hank- Thanks, we figured out the typo issue on you name, no worries.
As far as the short/long term issues invovled with mitigation you won't get an arguyment from me. See my recent Congressional testimony on this point:
Posted by: Roger Pielke, Jr. at August 4, 2006 02:40 PM
I don't think that placing extreme events in the context of a pattern is sufficient to constitute pattern matching in the sense of the paper. It's a more general strategy of attribution without exploration of alternative hypotheses. It is dangerous in its own way (a few cool years and you lose your basis for action) but it doesn't seem to me that it specifically creates the impression of linear causality. The danger of misperceiving dynamics (waiting until the problem is acute before acting) strikes me as much greater.
Google doesn't really lend itself to an unbiased assessment of whether advocates do or don't 'get it', but here are some links that at least mention the long atmospheric lifetime of emissions:
I suspect that there are reasons that adaptation is the poor cousin of energy policy in public conversations, other than the classic (that advocates fear industry skeptics will use the potential for adaptation to escape action):
Personally I'd welcome more talk about adaptation, in spite of the Greening Earth angle, as it's probably a better way to get a handle on the magnitude of impacts, and thus the objective for mitigation, than talking about heat waves.
Posted by: Tom Fiddaman at August 4, 2006 05:16 PM
> (according to the IPCC) such weather events will
Even the almost-outdated IPCC shows several paths depending on how soon changes are made.
Hansen's 'Alternative' focuses on this decade, when conservation and efficiency have easy paybacks.
Money not invested in the last gasp of the old tech can be spent on the new and more efficient tech it'll take this decade to prove.
"We're all just going to have to conserve" came over the radio.
People talk about the heat wave exactly because they are imagining what their grandchildren will live with. Same as they steer the car.
Many of those grandchildren have already been born -- people can look at their spending, then look at the kids' faces.
Any parent who drives with kids knows it's safer to hit an occasional dumb rabbit than swerve trying to miss it, with kids in the car.
People take costs for their grandchildren's future all the time. It's evolution in action.
The push to devalue and dismiss the little things people can do now is good PR for the coal lobby.
There's always one last "old tech" episode -- look at the Spruce Goose, which never flew out of ground effect,
Look back at how quickly more efficient power plants replaced the Q2 engines, eh?
The coal industry's doing it again. This time, the costs include the commitment to five more decades burning coal in the old fashion -- air pollution and heavy metal pollution and nitrogen oxides and thorium and uranium, uncontrolled.
Compare this to the energy efficiency alone of a closed cycle plant -- available by choosing not to build more old tech -- and with time bought by cooperation between the industry doing the research and the customers doing those "little things" you think people won't care about if they understand the science.
All the policy people can affect is how much we spend on the last of the old tech -- and with a far better idea of the total costs.
Hansen suggested this a decade ago. Yes, we'd probably have the same heat wave even if we'd started then.
If we'd started then, we'd be closer to a lower heat peak -- it'd look easier to climb, and people's grandchildren more likely would grow up on the far side of the problem, instead of in a worse and longer lasting heatwave.
Posted by: hank at August 4, 2006 05:28 PM