Risk Communication on Climate

John Sterman’s new Policy Forum in Science should be required reading. An excerpt:

The strong scientific consensus on the causes and risks of climate change stands in stark contrast to widespread confusion and complacency among the public. Why does this gulf exist, and why does it matter? Policies to manage complex natural and technical systems should be based on the best available scientific knowledge, and the Intergovernmental Panel on Climate Change (IPCC) provides rigorously vetted information to policy-makers. In democracies, however, the beliefs of the public, not only those of experts, affect government policy.

Effective risk communication is grounded in deep understanding of the mental models of policy-makers and citizens. What, then, are the principal mental models shaping people’s beliefs about climate change? Studies show an apparent contradiction: Majorities in the United States and other nations have heard of climate change and say they support action to address it, yet climate change ranks far behind the economy, war, and terrorism among people’s greatest concerns, and large majorities oppose policies that would cut greenhouse gas (GHG) emissions by raising fossil fuel prices.

More telling, a 2007 survey found a majority of U.S. respondents (54%) advocated a “wait-and-see” or “go slow” approach to emissions reductions. Larger majorities favored wait-and-see or go slow in Russia, China, and India. For most people, uncertainty about the risks of climate change means costly actions to reduce emissions should be deferred; if climate change begins to harm the economy, mitigation policies can then be implemented. However, long delays in the climate’s response to anthropogenic forcing mean such reasoning is erroneous.

Wait-and-see works well in simple systems with short lags. We can wait until the teakettle whistles before removing it from the flame because there is little lag between the boil, the whistle, and our response. Similarly, wait-and-see would be a prudent response to climate change if there were short delays in the response of the climate system to intervention. However, there are substantial delays in every link of a long causal chain stretching from the implementation of emissions abatement policies to emissions reductions to changes in atmospheric GHG concentrations to surface warming to changes in ice sheets, sea level, agricultural productivity, extinction rates, and other impacts. Mitigating the risks therefore requires emissions reductions long before additional harm is evident. Wait-and-see policies implicitly presume the climate is roughly a first-order linear system with a short time constant, rather than a complex dynamical system with long delays, multiple positive feedbacks, and nonlinearities that may cause abrupt, costly, and irreversible regime changes.

The problem is not purely technical, but basic comprehension of the problem requires science:

It is tempting to respond to these discouraging results by arguing that poor public understanding of climate change is unimportant because policy should be informed by scientific expertise. Many call for a new Manhattan Project to address the challenge. The desire for such technical solutions is understandable. In 1939, scientists directly alerted the nation’s leaders to developments in atomic physics, then, by focusing enough money and genius in the deserts of New Mexico, created nuclear weapons in just 6 years. Science has arguably never affected geopolitical outcomes more decisively.

But a Manhattan Project cannot solve the climate problem. The bomb was developed in secret, with no role for the public. In contrast, reducing GHG emissions requires billions of individuals to cut their carbon footprints by, e.g., buying efficient vehicles, insulating their homes, using public transit, and, crucially, supporting legislation implementing emissions abatement policies. Changes in people’s views and votes create the political support elected leaders require to act on the science. Changes in buying behavior create incentives for businesses to transform their products and operations. The public cannot be ignored.

The civil rights movement provides a better analogy for the climate challenge. Then, as now, entrenched interests vigorously opposed change. Political leadership and legislation often lagged public opinion and grass-roots action. Success required dramatic changes in people’s beliefs and behavior, changes both causing and caused by the courageous actions of those who spoke out, registered voters, and marched in Washington and Selma.

Building public support for action on climate change is in many ways more challenging than the struggle for civil rights. Science is not needed to recognize the immorality of racism but is critical in understanding how GHG emissions can harm future generations. The damage caused by segregation was apparent to anyone who looked, but the damage caused by GHG emissions manifests only after long delays.

And the bottom line:

The scientific community has a vital role to play in building public understanding. First, the SPM is far too technical to change people’s mental models. The IPCC should issue its findings in plain language. Second, clarity, while necessary, is not sufficient. When “common sense” and science conflict, people often reject the science. Even if people sincerely wish to mitigate the risks of climate change, wait-and-see will seem prudent if they misunderstand basic concepts of accumulation and erroneously believe that stopping the growth of emissions will quickly stabilize the climate. The implications go beyond the failure to understand accumulation. People’s intuitive understanding of dynamics, including stocks and flows, time delays, and feedbacks, is poor. Analogous to common biases and errors in probabilistic reasoning, these errors are unlikely to be corrected merely by providing more information. We need new methods for people to develop their intuitive systems thinking capabilities. Bathtub analogies and interactive “management flight simulators” through which people can discover, for themselves, the dynamics of accumulation and impact of policies have proven effective in other settings and may help here. Third, climate scientists should partner with psychologists, sociologists, and other social scientists to communicate the science in ways that foster hope and action rather than denial and despair. Doing so does not require scientists to abandon rigor or objectivity. People of good faith can debate the costs and benefits of policies to mitigate the risks of climate change, but policy should not be based on mental models that violate fundamental physical principles.

Of course, we need more research and technical innovation–money and genius are always in short supply. But there is no purely technical solution for climate change. For public policy to be grounded in the hard-won results of climate science, we must now turn our attention to the dynamics of social and political change.

Climate Interactive has more on Sterman’s work, with a link to the GHG Emissions Simulator.


Climate Interactive has another article.

Climate Feedback doesn’t get it.

A related earlier paper by John Sterman and Linda Booth Sweeney is here.

2 thoughts on “Risk Communication on Climate”

  1. Here’s an argument for why simulators, or other communication tools to demonstrate to laypersons the long lag time between intervention and climate change amelioration, might not increase climate change reducing behavior: A combination of status quo bias and time discounting means that future (and perhaps uncertain) improvements in climate appear small and current sacrifices in comfort and money loom large, so that increasing appreciation of long lags may seem to justify inaction rather than action.

  2. If I understand you correctly, this could be summarized as
    behavior = min( stock-flow understanding
    , discounted benefit perception)
    Thus increasing understanding would not necessarily change behavior. To the extent that either input involves misperceptions, it would seem to me to be beneficial to address those, because any progress on one would at least increase the possibility of progress.

    As I understand the literature, expressed preferences (in experiments and surveys) do not generally involve high discount rates over the very long term (hence one rationale for hyperbolic discounting). Revealed preferences (e.g., high apparent discount rates on energy efficiency investments) contradict that, but this would seem to be a case where people are being asked to change the rules in order to tilt the playing field in favor of stable climate, rather than to purchase something tomorrow. Then the question is, will they vote on the basis of their aspirations for endowment to their grandchildren, or vote the way they install lightbulbs and buy cars?

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