Thursday, December 27, 2012

Why uncertainty matters in global warming

On Christmas Eve, I had a delightful dinner with my extended family. My dad was present and we got into a discussion about global warming. He was convinced that the science is stronger than ever, and seemed to suggest that uncertainty was not a real issue. I disagreed. I do not believe the process is an assembly line where scientists make a discovery, obvious policy is drafted, and politicians choose whether to do the right thing. Instead, I believe that the scientific process is complicated by uncertainty and the drafting of policy necessarily must take into account people with diverse interests and opinions. His perspective helped me greatly, though. If I am going to successfully argue for a new approach to issues such as this one, I need to be able to convince smart and concerned people like him.

What’s your favorite explanation for why climate change is such a divisive subject? The corruptive influence of corporations on politics? The self-interest of scientists skewing the results to justify funding for their work? Al Gore? Fox News?

The same basic explanations (plus or minus one ex-VP) are thrown about in frustration during most environmental policy debates. I’ve been privy to many of these through my work in fisheries, marine protected areas, and for the federal government’s National Oceanic and Atmosphere Administration (NOAA). In addition to the Fisheries Service, NOAA runs the Weather Service; the National Ocean Service, which has diverse responsibilities ranging from National Marine Sanctuaries to maintaining and updating nautical charts; and the Office of Oceanic and Atmospheric Research, which develops weather forecasting technologies and is a major player in climate change science. It turns out that the same issues I’ve encountered in fisheries (including the relevance of rocket science) apply to subjects as diverse as managing a freshwater reservoir through unpredictable weather events to addressing climate change.

Recall from last week’s blog that our brains lead us to respond predictably to uncertainty in one of two ways: ignoring it or overreacting. Lo and behold, this may explain the polarization of environmental issues. In virtually every one, there is a side that dismisses the environmental threat and another side that portrays it as if the world will end unless we act decisively and immediately.

Let’s look at climate change through this lens. Isn’t it plausible that people who overreact might be frustrated with the speed of policy development and look for an explanation such as corrupt politics or Fox News? On the other side, might not the ignorers perceive scientists and Al Gore as overblown and look for any signs of bias to challenge their often haughtily emphasized credibility?

Inadvertently, the scientific community has fed the impression of bias. Climate scientists made a strategic choice to downplay uncertainty as a way of getting out of the media pattern of presenting dueling experts (i.e., regardless of his or her credentials, including the opinion of a scientist who argued against climate change). Reputable scientists have stressed that climate change is happening and is caused by humans, and deemphasized any disagreements among themselves about the details. This strategy, of putting up a united scientific front, has had interesting effects. It stopped most of the news media from reporting climate change with dueling experts; but it also made it easier for skeptics to attack the credibility of scientists.

Michael Crichton, author of the blockbuster Jurassic Park and a medical doctor by training, wrote a novel that presented real data about climate change, raising doubts about the science. State of Fear is a poorly written story with a thin plot, but is interesting because of the political reaction it generated. The novel made a splash in conservative political circles and garnered Dr. Crichton an invitation to testify before the US Congress as an expert witness on climate change, despite criticism by trained scientists of the novel as distorted. Yet, a united front only passes muster if it is truly united. By presenting selected data and highlighting underlying real scientific disagreements to the public, Crichton and others have been able to challenge the united front and damage the credibility of climate scientists in the process.

Let’s look at more examples that highlight the fragility of scientific credibility. There was a huge uproar about a 2007 report by the Intergovernmental Panel on Climate Change. The report included a misstatement that the Himalayas could lose their glaciers by 2035. That assertion came from a media interview with a scientist rather than a scientific journal (which peer reviews scientific claims prior to publication), and is most likely false. However, this misstep was the exception rather than the norm in the report, which was literally thousands of pages long. Nevertheless, it generated a huge amount of media coverage and no doubt fueled skepticism. In similar fashion, one of Al Gore’s claims of the evidence of global warming was receding glaciers on Mount Kilimanjaro. While it’s true that the glaciers are melting, recent studies have shown that the cause is more likely deforestation than global warming. As expected, skeptics are having a field day and presenting this new information as if it disproves global warming entirely.

What an unfortunate mess given the state of the science. Scientists collect new data and learn more about climate change every year. If you are interested in a good review of the current evidence, albeit one designed to make a global warming believer of you, check out the website Skeptical Science. Of particular relevance to this blog is a discussion of climate change models. As the author points out, there are uncertainties in predicting the future. However, among the many potential climate change scenarios that have been predicted, data from the past 20 years have generally been on the warm side of things. Despite the growing strength of evidence, though, the US public has remained wary. Opinion is gradually shifting towards seeing climate change as a real concern but as recently as 2010, a major poll indicated that nearly half of all Americans thought the threat was exaggerated. I am convinced the skepticism comes from the strategy of emphasizing scientific consensus. In fact, I will go so far as to claim that, in doing so, scientists have failed to give the public and politicians the information that could actually be useful in choosing how to move forward.

What is it that we need? We need a better sense of what risks we are facing and how much sacrifice will be necessary to reduce them. This theme is one I’ve addressed in an earlier blog about the US cod fishery. The key from scientists is a clearer picture of the uncertainty surrounding climate change. Even if scientists generally agree that climate change is occurring and is influenced by human activities, they do not agree on what the world will look like in 50 or 100 years. Under a scenario with no new policies, estimates of temperatures in 2100 range from mild to catastrophic. If the Earth warms only a couple of degrees, the costs will be fairly benign. Some people, particularly in low lying areas, will suffer. However, the benefits of reversing those changes may not be worth the immediate costs that would be associated with cutting our carbon emissions. If the Earth warms 20 degrees, though, we could easily be looking at an apocalyptic future. In that case, which is a realistic possibility, the future benefits would almost surely be worth even major costs of acting today. The actual outcome could be anything between these extremes. Thus, we are in a situation where we have to choose among gambles, but we don’t get useful information because the debate is about whether global warming is real rather than the odds we face.

Yet there is progress, albeit work that does not often get much publicity. Robert Lempert, a senior scientist at the RAND Corporation, has been exploring robust policy strategies—ones that will work across a range of possible warming scenarios. These have commonalities with the fisheries lessons I learned by working with a rocket scientist. More directly related to the strategy I suggested above, economist William Nordhaus has worked extensively on models that allow the analysis of policy options by pairing climate science, including its uncertainty, with economics. The uncertainty matters a lot: the prudence of immediate and decisive action depends greatly on how much weight is given to the potential for catastrophic outcomes. Educated people may disagree about the details of such analyses but at least this approach moves us in the right direction.

Climate change is a serious issue. When the media begins presenting stories that talk about risks and the costs of reducing them, we will be on track for global solutions. Until then, scientists can do their part by emphasizing uncertainty in a constructive manner, and non-scientists can help by demanding this sort of information.

Please share your thoughts in the comments section. I invite you to respond to this post, propose subjects for future posts, or just say hi. I’d love to have this blog evolve into a dialog.

Best regards,

Thursday, December 20, 2012

It’s the uncertainty, stupid

Bill Clinton won his first campaign to become President of the US by focusing on what would really influence voters—the economy. Concerned about the fate of an environmental issue? Don’t follow a standard tactic of sensationalizing the problem or calling for patience and further study, it’s the uncertainty, stupid! (please know that the “stupid” is rhetorical)

In an earlier blog, I described my experience learning lessons for fisheries management from rocket science. During that time, I stumbled across a paper in the field of behavioral economics. This field focuses on how people perceive and respond to uncertainty and has inspired my studies, research, and work ever since. Historically, economic models assumed people maximize their profits (or utilities in more general models). Daniel Kahneman and Amos Tversky, both research psychologists, began a Nobel Prize-garnering revolution by showing that that people often act in predictably irrational ways, particularly when facing uncertain consequences. You see, we tend to think differently when choosing between future A and future B than when choosing between options that will influence the probabilities that we get future A or B. Drs. Kahneman and Tversky referred to these choices as gambles, and it doesn’t take a cognitive psychologist to know that people are irrational gamblers.

Along with Dan Lovallo, Dr. Kahneman wrote a paper about the implications of these behaviors for organizational decision making. It turns out that corporate managers, like other people, are prone to be overly conservative when they fully recognize an outcome is uncertain, but more often ignore or downplay uncertainty altogether. When I first read their paper, I found it hard to remember that the subject was corporations. Fisheries managers and interest groups lobbying them were behaving in the same way. Before the article, I tended to blame dirty politics, self-serving scientists and managers, and even the media for fisheries problems. This article showed me that normal functioning of the human brain just might be responsible for fisheries failures. It makes perfect sense that some of us ignore environmental concerns while others portray these concerns as if the world is about to end. It’s the way our brains are wired. The key question, and my biggest professional passion, is how to get people to recognize and respond to uncertainty in a more thoughtful way. In order to make good policy, it would seem we need a rocket scientist but also a psychologist.

Encouragingly, people do not always fail when it comes to recognizing and responding to uncertainty. Daniel Kahneman’s most recent work is Thinking, Fast and Slow, a book in which he suggests we have two modes of thinking. Fast thinking is reflexive, emotional, and prone to biases, while slow thinking is more logical and deliberative. When you really look, signs of slow thinking are common. I’ve found them in cases ranging from the obvious, for example investment banking and bridge design; to the unexpected, for example indigenous natural resource management practices and even survival stories. To quote Rosie the Riveter, “We can do it!” The question is, how?

I’ve already shared some thoughts on this topic, but next week I will give an extended example. Rather than focus on my own work, or even on the world of fisheries, I will demonstrate the generality of my approach by discussing climate change/global warming. In anticipation, I ask you this: What’s your favorite explanation for why climate change is such a divisive subject?

Please share your thoughts in the comments section. I invite you to answer the question, propose subjects for future blogs, or just say hi. I’d love to have this blog evolve into a dialog.

Happy holidays,

Thursday, December 13, 2012

Fishing, a window into marine ecology

Many of us look at nature, particularly at a healthy ecosystem, and see chaotic color, a messy morass, a lawless lot of life forms. The science of ecology shows us otherwise. We find collections of animals and plants within specific ecosystems, which themselves are subdivided into habitats with distinctive characteristics.

One of the things I like about fishing is that it’s a chance to witness the local ecology. I started fishing as a little kid, mostly with my maternal grandfather. Ben Harris was a third-generation San Franciscan, born in 1898 and witness to massive environmental and economic change in the areas surrounding his and my hometown. He used to take me fishing for sunfish in man-made lakes, which was mostly what was left of fishing opportunities in the area by my lifetime. In high school, I had a serious love interest whose parents owned land in the Trinity Alps of northern California. She, her dad (named Sherwood, who better to explore a forest with?), and I used to go fly fishing for trout on the stream that flowed through that small plot of land. This was a vastly different experience than catching sunfish in a man-made lake: the fish were big enough to eat (and tasty at that) and the fishing technique required hiking and casting skills. The biggest difference, though, was the omnipresence of ecology in our fishing strategy. We chose flies to match naturally occurring insects in that place and season so that they would be recognizable by the trout as common food. We identified likely trout pools based on their suitability to shelter and feed a big fish. We aimed our casts upstream from these pools, choosing a placement that would allow the fly to drift naturally into them. To catch our trout, we had to be in tune with their ecology.

Bolivar Cay in the Seaflower Biosphere Reserve, Colombia
As one of my favorite research projects, my colleagues and I advised managers based on similar ecological patterns. In 2000, I had the great luck to lead two expeditions to the future Seaflower Biosphere Reserve in the Caribbean waters of Colombia. The local government agency wanted advice on how to design the Reserve, including no-fishing and other restricted access zones, and relied on me because of my expertise in marine protected area design. They already had some sophisticated maps of coral reef distributions, but wanted to consider fish communities for the sake of healthy fisheries and vibrant diving sites. Our expeditions consisted of collecting information on benthic communities, including coral, sponges, algae, and other bottom dwellers; and fishing assemblages. We then used statistics to categorize sites, grouping ones with similar species assemblages and separating those with differences.

Not surprisingly, we found that the benthic communities fell into categories that varied depending on depth, proximity to land, and whether the reef was on the exposed or protected side of the island. These categories matched what my team had expected prior to the surveys, based on our understanding of Caribbean coral reef ecology. What was more surprising were the fish assemblages. Despite the mobility of fish and the potentially disruptive effects of fishing, the fish assemblages grouped exactly the way the benthic communities had. You can read more about our work here. Our work confirmed the ecological basis of our definitions of habitat types, and suggested that the Colombian government could protect a representative portion of their coral reef ecosystems if they included similar percentages of each habitat type in their protected areas. We were also able to reassure the government that sites of the same habitat type would have similar value, allowing them to work flexibly with the local fishing community to devise the most acceptable version of fishery closures.

Dolphinfish, Coryphaena hippurus
These patterns can also be viewed through fishing activity itself. I worked with a graduate student, Kristin Kleisner, on a project to look at the ecology of pelagic fishes—those that live up in the water column. We examined oceanographic conditions using satellite data and fish abundance using catches as recorded by observers, who took down details of fishing strategies and catches (including discards). With these two data sets, we found that dolphinfish (Coryphaena hippurus) showed distinct patterns. Inshore, they were more likely to be caught in shallower water and near fronts—places where warm and cold water come into contact. Offshore, they were more likely to be caught in deep water and farther from fronts. Once again, ecology shined through in patterns of fish catches, and such patterns are integral to the strategies of fishing captains who target pelagic fishes.

These patterns play an important role in the management of fisheries through the challenge of estimating fish abundance. Ideally we would have regular, independent, scientific surveys for this purpose that sampled a wide variety of conditions in a controlled fashion. However, most often we rely on catch per unit effort (CPUE) from the fishing industry. If a fish stock is abundant, we can assume a fishing operation will catch more fish per unit effort (e.g., hook-hour, trap-day). We regularly assume that CPUE is a good, linear indicator of abundance. In other words, if CPUE doubles, we assume the fish stock has become twice as abundant. If it drops to half its original value, we assume the same of the stock abundance. We have major challenges with using CPUE as an indicator of fish abundance. Fishing activity is not random or consistent. In fact, we expect smart fishermen and women to adapt their strategies to maintain high CPUE, even if fish abundance drops. In order to see through these changing strategies, we need information about fishing behavior so we can account for changes, a process known as standardization by tracking different fishing strategies and looking for changing CPUE within each strategy. Often we lack sufficient information to do so. This problem becomes even more complex in fisheries that target multiple species. In these fisheries, which are the norm rather than the exception, changes in effort can also involve a shift in the target species. When this happens, we may see dramatic drops in the CPUE for one species simply because another becomes a more profitable target. If we have a better understanding of the underlying ecology and how it gets represented in catches, we can do a better job of standardizing effort and understanding and accounting for targeting.

Recently, I tried out a new idea for handling fishing effort. When I was in Colombia a month ago, we examined data from many fishing trips that all used hooks on fishing line. Some of these were used at the surface, others in midwater, and still others deep down. Trips were categorized as surface, midwater, deep, or some combination thereof. We had a hard time standardizing effort based on these reports because most trips were a mix of strategies without any indication of which were the main emphasis. We did have records of fish caught on the trip, and I thought it might be interesting to see if we could see some ecology reflected in the data. Even with messy data from fishing trips that ranged across a large area and varied in time from hours to days, the ecology did shine through. Certain trips tended to catch deep-dwelling species while others tended to catch certain species of shallower water fish. We are now working on an index of how heavily each trip should be weighed when calculating CPUE, with heavier weights for trips that caught a collection of species that were ecologically similar to the one of interest. Fishing does indeed offer a window into marine ecology, and we can do a better job of understanding fisheries by paying attention to the view in that window.

All my best,

Thursday, December 6, 2012

A lesson in environmental policy from a small island fishery

I was extremely fortunate early on in my career. I guess I can be credited with bucking my educational system and insisting on doing research that had application to real-world environmental issues. Upon choosing this path, I recall advice from faculty that included such colorful phrases as “no funding,” “unemployable,” and “throwing your career away.” Thankfully, I was even more stubborn back then than I am now and so I did it anyway.

Red hind
It wasn’t an easy path. Despite a new Ph.D. from Cornell University, a world powerhouse in ecology, and a publication in Ecology, the top ecological journal in the world, my job search was brutal. Maybe those faculty were right after all! I applied for about 60 positions, and only one of them resulted in any follow up. Fortunately, it was a great opportunity.

Shortly after finishing up my dissertation, I moved to St. Thomas, U.S. Virgin Islands, to do research with Callum Roberts, a leader in applied marine environmental research. I came in to help with a project to rezone a marine park on St. Lucia. Callum left in my first year to return to his native England, and I was chosen to replace him as a professor at the University of the Virgin Islands. Not bad for a 27 year old! My job included advisory responsibilities to the government on environmental issues. Through those responsibilities, I got to know the fishing community.

Near the end of my three year stint on the island, a major issue resurfaced. The Caribbean Fisheries Management Council, which helps to set fishing policy for the waters around Puerto Rico and the U.S. Virgin Islands, wanted a no-fishing zone as a way of helping to protect coral and coral reef ecosystems. Such closures have many names, from marine protected areas to marine reserves to, most recently, marine spatial planning. The Council’s scientific advisory panel had their heart set on an area that was south of St. John (a close neighbor to St. Thomas and home to  the Virgin Islands National Park, which covers a large section of the island due to the foresight and generosity of the Rockefeller family). The proposed area was close to, but not actually bordering, the waters of the British Virgin Islands (part of the same island chain but a British territory with independent environmental management).

The fishermen of St. Thomas and St. John were not pleased. These were productive fishing grounds and, more importantly, closing them would also isolate a further area between the proposed closure and the British Virgin Islands border. Traveling a fair distance to that remote corner would not have been worthwhile. The fishing community had responded to the threat of the closed area by stalling. Their primary technique was to propose the closure of a small area bordering the British Virgin Islands, suggesting that authorities on the other side of the border could reciprocate and, together, the two areas would be suitable. The likelihood of this sort of international cooperation was slim, and so the fishermen’s proposal slowed progress.

When the issue resurfaced, I had an opportunity to meet with the local fisheries advisory board, made up mostly of fishermen. I was invited to present my research on the design of fisheries closures because I was a world expert in the subject. Instead of preaching, though, I talked to the fishermen and women in attendance, asking them about the quality of fishing, how it had changed over the years, and what they wanted out of their fisheries in the future. What was supposed to be a half-hour scientific presentation turned into a three hour heart-to-heart on fisheries management. I encouraged the fishing community to embrace the change suggested by the Council, but to use the process to create management measures that would serve their purposes instead of thwarting them. Over subsequent weeks, leaders of the fishing community floated several proposals by me, eventually coming up with one that, in my expert opinion, matched the conservation value of the Council’s proposed area.

The fishermen’s proposal was an interesting one. Due to earlier good work by some responsible fishermen and two marine biologist friends of mine, Jim Beets and Alan Friedlander, the Council had identified a spawning aggregation site for red hind, a medium-sized member of the Serranid (grouper) family. From 1990, the Council closed the Red Hind Bank during spawning season. You see, some of the tastiest and most sought-after fish in tropical waters gather together in large numbers once or more per year to reproduce. When discovered, these large aggregations of prized fish can be subject to intense fishing pressure, which can deplete that species across a broad area. For this reason, protecting spawning aggregations is generally a good idea.

Red Hind Bank Marine Conservation District (blue border), and
areas to which red hind migrated after spawning (red border).
But the seasonal closure complicated fishing efforts in that area during the open season. One of the preferred methods of fishing in the tropics is the use of fish traps, cages with funnels that fish swim into but are less likely to swim out of. Traps are typically strung together on lines, and moving a line of traps is an undertaking. Fishermen prefer to pull up traps, empty them, and return them immediately to continue fishing. Because of the productivity of the Red Hind Bank even outside of spawning season, fishermen still brought traps in, but either had to leave them there (illegally) or move them back and forth. When they proposed a year-round closure of the area, it fit with the mandate to protect corals and coral reef ecosystems. With the support of the fishing community and the scientific stamp of approval by a world expert in marine protected area design, the fishermen’s proposal sailed through the Council process. In 1999, the Red Hind Bank Marine Conservation District was created and closed year-round the area around the spawning aggregation.

On my visit to St. Thomas last week, I heard welcome news about the closure. Red hind were extremely plentiful in the catches of St. Thomas fishermen, and it was common to catch very large individuals, larger than fishermen used to think was possible. The fishermen I spoke to continue to support the closure and seem more open to protection of other spawning aggregations, more of which have now been identified in the U.S. Virgin Islands. Efforts to create fishery closures do not always go this smoothly or result in such vivid benefits. However, they often have the capacity for success if we use science more effectively and inspire fishing communities to develop management measures that meet their objectives while satisfying broader sustainability and conservation mandates. We did that in creating the Red Hind Bank Marine Conservation District, and both fish and fishermen are better off as a result.

Warm regards,

PS Próxiamente, una version en español de este blog. ¡Estén pendientes!