Understanding complacency about climate change

Bathtub jpeg
Professor Sterman of the MIT Sloan School of Management took a closer look at why climate change is so much easier for people to ignore than other disasters.  He says that a lot of the problem is due to the fact that people don't really understand climate change and the factors that relate to it and its solutions.

Posted Oct. 30, 2008
By MIT Sloan School of Management

Professor Sterman and colleague find flawed reasoning at the root of complacency

Sterman likens climate change to an overflowing bathtub. Even if the
drain is open, when the inflow of water exceeds the outflow, the water
level will rise over time — and eventually the tub will overflow.

Why is the general public not more concerned about the potential
consequences of climate change? On many risk assessment issues, such as
the risk of a plane crash, the public is far more fearful than
scientists, observed John Sterman, the Jay W. Forrester Professor of
Management at the MIT Sloan School of Management. But he noted, on the
issue of climate, the situation is just the opposite.

“The science is unequivocal now, and the scientists are telling us
that it's urgent that we reduce emissions,” he said. “That debate is
basically done.” However, Sterman added, the public at large doesn't
understand that.

What's behind this puzzling complacency? Sterman's research suggests
some clues. In some important research conducted with Linda Booth
Sweeney of the Harvard Graduate School of Education, Sterman, who is
director of the Systems Dynamics Group at MIT Sloan, has found that
even highly educated people have a poor understanding of some of the
dynamics that affect climate change.

And if people don't have good mental models for understanding
climate change, they may come to faulty conclusions about policy. For
example, if people erroneously think that climate change is easily
reversible, they may support waiting to see what the effects of climate
change will be before taking substantial actions to reduce emissions of
greenhouse gases like carbon dioxide.

More on systems with long time delays >>

The bathtub metaphor

To help people better understand climate change, Sterman uses the
metaphor of a bathtub filling with water. Suppose you are adding water
to a bathtub that has a drain that is open, and you keep adding water
to the tub at a rate twice as fast as the water flows out through the
drain. Even though water is constantly flowing out through the drain,
the inflow of water into the tub exceeds the outflow, and the water
level in the tub will rise over time. Eventually, the tub will

A similar dynamic, according to Sterman, is found in climate change.
Carbon dioxide is removed from the atmosphere by natural processes —
much the way the bathtub has a drain. The problem is that human
activity now adds carbon dioxide to the atmosphere at roughly twice the
natural removal rate — much as the spigot in the bathtub example adds
water faster than the water flows out through the drain.

As a result, to halt greenhouse gas-induced climate change, it's not
enough to stabilize carbon dioxide emissions at their current level or
cut them slightly; to start to reduce the carbon dioxide concentration
in the atmosphere, current carbon dioxide emissions would have to be
cut by more than half, so that they would fall below the natural rate
of carbon dioxide removal.

More on climate change dynamics >>

To test the hypothesis that people have poor mental models for
understanding climate change, Sterman and Booth Sweeney conducted a
study in which highly educated university students were given a short,
nontechnical summary of information about climate change — including
information about the fact that carbon dioxide emissions are currently
twice the rate of natural carbon dioxide removal.

The study participants were then asked to draw a simple graph of
what would have to happen to carbon dioxide emissions and removal rates
in order for carbon dioxide concentrations in the atmosphere to
stabilize or fall some over time.

The study participants had much stronger technical backgrounds than
the average person: 98 percent of them were graduate students, and 60
percent had training in science, math or engineering. Most of the rest
were trained in social sciences, particularly economics. But even among
a group of graduate students with strong technical backgrounds, the
researchers found, most people answered incorrectly.

For example, a substantial majority — 63 percent — thought that
concentrations of carbon dioxide in the atmosphere could be stabilized
even if emissions levels remained above the natural carbon dioxide
removal rate. They apparently did not realize that the system would
still be out of balance, with carbon dioxide continuing to be added at
a faster rate than it is being removed.

More on mental models >>

Flawed reasoning not unique to climate change

The kind of flawed reasoning that the study revealed is not specific to
climate change; in other, related research, Sterman and Booth Sweeney
found that people generally don't have good mental models for
understanding systems that involve inflows, outflows, and accumulation
— whether those systems are bathtubs, business inventories or the
concentrations of greenhouse gases in the earth's atmosphere.

Unfortunately, on the question of climate change, the stakes are
extremely high. “To make a difference in the climate change challenge,
we have to change the way everybody thinks about their personal energy
choices,” Sterman observed.

“The good news,” says Sterman, “is that you don't need to know any math
to understand that the level of water in a tub rises as long as you
pour water in faster than it drains out. Once people understand that
we're pouring greenhouse gases into the atmosphere far faster than they
are removed, they understand why we can't wait and see — why we have to
reduce our emissions today to protect the world we will pass on to our
children, and their children.”

Want to test your own understanding of climate change dynamics? Try the System Dynamics Group's online Greenhouse Gas Emissions Simulator. You can also read a paper describing this research; the paper was published in the journal Climatic Change.

No Responses to “Understanding complacency about climate change”

  1. I like the bathtub image. Great metaphor. Most people see climate change as being inconvenient, at worst. Summers are getting hotter – big deal. There is still a lot of work to do in helping people really understand the problem and buy into becoming part of the solution.
    Andy Greene
    Green Living Tips for Rednecks

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