Tuesday, March 9, 2010

Why is Global Warming so hard to understand and respond to?

I attended a professional dinner on the weekend where one of the speakers was a University Executive who was formerly an engineering professor working on biofuels. As you might expect, he brought up the concept of global warming in his talk, but the way in which he explained it made it sound like the burning of fossil fuels raised the average global temperature through the heat generated by combustion and not through the increase in GHGs (greenhouse gasses). As a result, in the Q&A he had to fend off a number of comments that nuclear power was terrible from the point of view of global warming due to the enormous quantities of waste heat released.

While the speaker could obviously have expressed himself better, his talk got me wondering about why global warming due to the emission of GHGs is such a difficult concept to communicate to professionals and to the public. There has been no shortage of press on the topic over the last 20+ years. And while a majority of americans now believe that the earth is warming, the message about why isn’t really getting across. A recent poll found that 65% of people did not feel that human activity was to blame or weren’t sure. Worse, when John Keller, a colleague of mine at the University of Arizona, asked a group of undergraduates the best way to combat global warming in a multiple-choice survey, the top answer was by picking up beach trash. This does not bode well for the future.

Obviously, part of the problem is that many environmental causes, from pollution to overfishing to the ozone layer to global warming, have become conflated in the public’s mind. However, this hasn’t stopped concerted action in the past. For instance, the Montreal protocols of the 1980s that sought to curb the emission of CFCs and preserve the ozone layer was passed easily and by any standard has been wildly successful. So what is it that makes global warming different? Here are a few possible reasons which together suggest a “perfect storm” of confusion and inaction of sorts. I’ll cover reasons both why it is complicated to convince people and why it is difficult to spur them to action:

1) Complexity. The concept of a heat-trapping gas producing an effect similar to that inside your car on a hot summer’s day isn’t a difficult one. It’s when you get to projected effects that the mind starts to boggle; stronger hurricanes, less rain in some places, more rain in others, warmer climate in some places, colder in others, to say nothing of the biological effects real and claimed. As such, it’s very difficult to say with precision what the effect will be on a person living in a particular place and to measure that effect. This contrasts with ozone degradation where you can take someone out in the sun in a well-mapped area of depletion and show them that they burn more easily.

2) Size of the effect and Natural Cycles. Catastrophic increase in temperatures from today’s levels could be as little as a few °C. That’s less than the difference between night and day, less than the difference between yesterday and today, and much less than the difference between summer and winter. I’m sure that you could get almost anyone to agree that an increase in temperatures of 30°C would be bad, but getting people to believe that such a small change could be devastating is difficult. Worse, the increase is not monotonic; it’s not as if global warming will add 2°C to the daily high every day. Instead some years will be colder, in fact some decades will be colder than the decade before, even though the trend is towards higher temperatures. Thus, some preferentially use the moniker “climate change” since any change in the climate, heating or cooling, can then be attributed to the effect without confusion.

3) The challenge of thinking Long-term. By and large human beings are not used to thinking long term, especially not in terms of hundreds of years, our brains just aren’t built that way. This means that it is very difficult to avoid processes which are slow to build, even if we suspect that there could be a runaway or tipping-point effect out there. The same is true of hundred-year floods and storms. Eventually, the cultural memory of the event recedes.

4) Global Reach. If you put together a group of friends to clean up trash in the local park, you see immediate benefits in your life and the lives of those around you. However, global warming can only be combatted on a global scale, and we naturally feel less kinship the farther we go from our own community. Furthermore, there is the spectre that actions you take may in fact cause detriment to your own personal quality of life, even though they will benefit the planet overall.

5) Cost. Unlike CFC reduction, which was a relatively small change, economically, reducing the world’s carbon footprint is a monumental task. It will cost trillions to implement and change our daily lives. Potentially, it will change the job market and sap the economies of those countries that make it a priority, versus those who do not. This is true even though we will all rise or fail collectively. Since the cost to change is so high, the standard of proof demanded is thus correspondingly higher than for any other scientific issue.

6) Politics. Not surprisingly, the issue has also become a political one in which parties exploit public sentiment for and against global warming as a wedge issue. In December there was an entire episode of the McLaughlin group dedicated to the topic which discussed only the horse-trading around the issue and nothing of substance. You’re more likely to hear about global warming as a positive for energy security then for environmental reasons in the political sphere these days.

All of this makes global warming a hard nut to crack. I certainly don’t have all the answers. As a scientist I will continue to do my best to educate wherever possible. But things are starting to look a bit better. Attitudes towards wasteful behavior are changing and more technologies are coming online that can get us through. For instance, the world’s largest emitter of GHGs, China, is also the world’s largest investor in photovoltaics. That bodes well.

But I do not wish to encourage those who would try to convince by false claims or facile arguments. In particular, one famous youtube video shows a man making the following argument (“never refuted!”) which I have paraphrased: that because the possible consequences of global warming are so dire, it behoves us to spend mightily to prevent it whether or not we know if or why it will happen, or how bad it will be. How much should we spend? He doesn’t elaborate.

Unfortunately, governments and citizens are in the business of managing finite resources. Thus, money supplied to one cause has to come from somewhere else. Bjorn Lomborg, derided in many circles as “one of the greatest opponents of global warming,” does in fact list it as one of the most serious problems facing the planet today. However, as he says, there are many better ways to spend that capital that could have a larger impact on alleviating human suffering; a few hundred million to provide access to fresh water for everyone, even less to provide vaccinations, just to name a few. That’s the kind of calculated, sober and rational thinking the gravity of this topic deserves.

As a side note, why does a planetary scientist care? Because understanding the climate of the earth, how it works and what it has done in the past, may be the key to unlocking the past history of the climates of the terrestrial planets in general. For Mars this is an important problem. Did the faint young sun permit liquid water, and perhaps life to exist? The sinuous channels, deltas, and chemical/morphological evidence from the MER rovers say yes. But we don't know how long those conditions persisted. As well, we do not know if the large swings we predict in climate today could make it clement again for life on 100,000-year timescales. If so, then our chances for finding life on Mars are much better!

As well, if we wish to live on the surface of Mars one day, we will need to artificially induce global warming there. By knowing exactly what portion of the current trend on the Earth is explained by anthropological activities, we can more effectively warm Mars or determine if it is even possible (One study by Chris MacKay suggests that it would be quite difficult). This concept is known as Terraforming.

No comments:

Post a Comment