SEVENTH ANNUAL ROGER REVELLE COMMEMORATIVE LECTURE Disasters, Death, and Destruction Making Sense of Recent Calamities

INTRODUCTION A disaster happens when an extreme event occurs in the context of societal vulnerability. Nowhere is the meeting of vulnerability and extreme more tangible than where the land meets the sea. This was horrifi cally apparent on 26 December 2004 when a powerful earthquake under the eastern Indian Ocean caused a massive tsunami that killed more than 280,000 people and caused billions of dollars (all dollars in this article refer to U.S. dollars) in damage. Other disasters at the ocean-land boundary are similarly fresh in our minds—the U.S. hurricane seasons of 2004 and 2005 resulted in hundreds of billions of dollars in damage and more deaths than in the previous 35 years combined. We do not have to look too far back in time to recall other tragedies, such as Hurricane Jeanne, which killed several thousand people in Haiti in 2004; the Venezuelan coastal landslides in 1999, which killed upwards of 30,000 people; and Hurricane Mitch in 1998, which killed more than 10,000 people, mainly in Nicaragua and Honduras (Taft, 2004; Pielke et al., 2003). In 1991, perhaps 150,000 people died in Bangladesh as the result of storm surge and fl ooding from a tropical cyclone (Pielke and Pielke, 1997). The recent spate of disasters has created two common perceptions among decision-makers and the general public. First, there is a sense that the economic impacts associated with extreme events have increased in recent years. Second, given that a human infl uence on the climate system has been well established, a perception exists that the recent increase in weather-related disasters like fl oods and hurricanes is in some way related to changes in climate. These perceptions beg two questions: • Have loss of life and damages associated with extreme weather events actually increased in recent years? • What factors account for observed trends in the impacts of weather on society? The answers to these questions are more than simply idle speculations—they help shape how we think about policy options with important social, economic, and political ramifi cations (such as disaster preparation, insurance, international climate-change negotiations) and how we set priorities for the funding of scientifi c research. Because policy is based in part on the perceptions that policy-makers hold about weather and climate, it is worth determining the answers to the two questions in a scientifi cally rigorous manner. This lecture discusses trends B Y R O G E R A . P I E L K E , J R . S E V E N T H A N N U A L R O G E R R E V E L L E C O M M E M O R AT I V E L E C T U R E


INTRODUCTION
A disaster happens when an extreme event occurs in the context of societal vulnerability.Nowhere is the meeting of vulnerability and extreme more tangible than where the land meets the sea.This was horrifi cally apparent on 26 December 2004 when a powerful earthquake under the eastern Indian Ocean caused a massive tsunami that killed more than 280,000 people and caused billions of dollars (all dollars in this article refer to U.S. dollars) in damage.Other disasters at the ocean-land boundary are similarly fresh in our minds-the U.S. hurricane seasons of 2004 and 2005 resulted in hundreds of billions of dollars in damage and more deaths than in the previous 35 years combined.We do not have to look too far back in time to recall other tragedies, such as Hurricane Jeanne, which killed several thousand people in Haiti in 2004; the Venezuelan coastal landslides in 1999, which killed upwards of 30,000 people; and Hurricane Mitch in 1998, which killed more than 10,000 people, mainly in Nicaragua and Honduras (Taft, 2004;Pielke et al., 2003).In 1991, perhaps 150,000 people died in Bangladesh as the result of storm surge and fl ooding from a tropical cyclone (Pielke and Pielke, 1997).
The recent spate of disasters has created two common perceptions among decision-makers and the general public.
First, there is a sense that the economic impacts associated with extreme events have increased in recent years.Second, given that a human infl uence on the climate system has been well established, a perception exists that the recent increase in weather-related disasters like fl oods and hurricanes is in some way related to changes in climate.
These perceptions beg two questions: • Have loss of life and damages associated with extreme weather events actually increased in recent years?
• What factors account for observed trends in the impacts of weather on society?The answers to these questions are more than simply idle speculations-they help shape how we think about policy options with important social, economic, and political ramifi cations (such as disaster preparation, insurance, international climate-change negotiations) and how we set priorities for the funding of scientifi c research.Because policy is based in part on the perceptions that policy-makers hold about weather and climate, it is worth determining the answers to the two questions in a scientifi cally rigorous manner.This lecture discusses trends

UNDERSTANDING DISASTER TRENDS
The fi rst thing to understand about disasters is that they have indeed been rapidly increasing worldwide over the past century, in both number and severity, and that the causes of this increase  The economic losses from disasters are increasingly concentrated in the affl uent world.But, as a percentage of GNP, the economic effects of natural disasters on poor countries can be hundreds of times greater.For example, Hurricane Mitch, which devastated Central America in 1998, caused damages estimated as much as $8.5 billion or about the annual combined total economic activity of the two hardest-hit nations, Honduras and Nicaragua (Pielke et al., 2003).Their economies still have not recovered.By comparison, the magnitude 6.

SOME DETAILS AND DATA
If we hypothesize that changes in weather patterns are responsible for some part of the trend of increasing disaster losses, then it is logical that the fi rst place we might look for changes is in the behavior of weather extremes.The most recent IPCC report took a close look at research on extreme weather events and found little evidence for changes over time (IPCC, 2001a).
Consider that over recent decades, the IPCC found no long-term global trends in extra-tropical cyclones (i.e., winter storms), in "droughts or wet spells," or in "tornados, hail, and other severe weather."In the absence of trends in these weather events, they cannot be identifi ed as being responsible for any part of the growing economic toll.
More recently, Massachusetts Institute of Technology's Kerry Emanuel published a study in the journal Nature that described an increase in the intensity of hurricanes in the North Atlantic and North Pacifi c, but this trend is not related to increasing damage (Emanuel, 2005).Emanuel writes on his web site (http://wind.mit.edu/%7Eemanuel/an-thro2.htm), "There is a huge upward trend in hurricane damage in the U.S., but all or almost all of this is due to increasing coastal population and building in hurricane-prone areas.When this increase in population and wealth is accounted for, there is no discernible trend left in the hurricane damage data."Indeed, a comment I wrote in response to Emanuel's paper (2005), also published in Nature, provided evidence that indicated that once U.S. hurricane damage was adjusted to refl ect societal changes, there was no trend of increasing damages over the twentieth century or an increase in damages per storm But as logical and enticing as it may seem to connect the ever-growing toll of disasters with global warming, the current state of science simply does not support making such a connection.(Pielke, 2005).Another prominent study has found an increase in the proportion of the strongest storms (Webster et al., 2005), and scientists have differing expectations about the cause of this trend, but no one has connected such trends to increasing disasters.
The IPCC did fi nd "a widespread increase in heavy and extreme precipitation events in regions where total precip-itation has increased, e.g., the mid-and high latitudes of the Northern Hemisphere" (IPCC, 2001a).But, at the same time, the IPCC warned that "an increase (or decrease) in heavy precipitation events may not necessarily translate into annual peak (or low) river levels" (IPCC, 2001a).Indeed, while the IPCC found some changes in streamfl ow, it did not identify changes in streamfl ow extremes To explain the increase in damage, it

CLARITY FROM CONFUSION
While it is understandable why some advocacy groups might stretch the bounds Group admits that data on changes in wealth are not available around the world and changes in GDP are not always a good proxy for data on wealth.
Third, Munich Re Group's data apparently includes weather and non-weather events (e.g., it appears to also include earthquake damages).
But let's assume that all of the issues raised above can be overcome, and in the end there remains a 2-to-1 ratio.The fact is that the large decadal variability in disaster losses makes it quite dodgy to assert a trend by comparing two different ten-year periods over a period of 30 years.This can be illustrated with an example from our database of hurricane in damages associated with disasters with a focus on extreme weather events, fl oods, and hurricanes.It also discusses factors that account for the observed trends and the state of our knowledge in this area.It concludes with a discussion of implications for policy and research related to natural hazards and global climate change.CONTEXT: DISASTERS AND GLOBAL WARMING Today one cannot engage in a discussion of the global trend in disasters without also discussing global warming.The increasing threat of natural disasters has long been cited as one of many reasons why society should reduce greenhouse gas emissions, and the disasters of 2004 and 2005 have only made those calls louder.For example, a day after the Indian Ocean tsunami, Sir David King, Britain's chief science adviser, said in a BBC (British Broadcasting Company) interview, "What is happening in the Indian Ocean underlines the importance of the Earth's system to our ability to live safely.And what we are talking about in terms of climate change is something that is really driven by our own use of fossil fuels" (The Guardian, 2004).Disasters are a powerful symbol in the highly politicized climate debate; consequently, the climate debate shapes how we think about disasters and what policies make sense in response.Linkages between climate change and disasters have a rich pedigree.Environmental groups use the threat of increasing disasters to advocate decisive action to reduce the emission of greenhouse gases and to implement the Kyoto Protocol on climate change.The advo-cacy group Scientists and Engineers for Change supported John Kerry in the 2004 U.S. Presidential election by posting billboards in storm-ravaged Florida with the message, "Global Warming = Worse Hurricanes.George Bush just doesn't get it" (Figure 1).But as logical and enticing as it may seem to connect the ever-growing toll of disasters with global warming, the current state of science simply does not support making such a connection.While politicians and political advocates might sometimes be expected to stretch the bounds of scientifi c accuracy, it is particularly troubling to see leading scientists join them.For instance, the former head of the United Nation's Intergovernmental Panel on Climate Change (IPCC), Sir John Houghton, testifi ed before the U.S. Senate last July that increasing disaster losses could be attributed to increased storminess (Houghton, 2005).And Rajendra Pachuri, the current head of the IPCC, suggested in February 2004 that the escalating costs of disasters could be attributed in part to climate change (Pachuri, 2005).Yet such claims are simply not supported by existing scientifi c research, and thus have the potential to mislead both thinking and advocacy on policy options related to climate.It is crucial to observe that humancaused global climate change is, of course, underway and well-documented by the scientifi c community.Further, developing alternative energy sources and reducing global carbon-dioxide emissions are essential.But the claim that action to slow climate change is justifi ed by the rising toll of natural disastersand, by extension, that reducing emissions can help to signifi cantly address these rising losses-is both scientifi cally and morally insupportable.To address ever-escalating damage from hurricanes, fl oods, and other extreme events, we need to expand our focus on climate policy beyond simply reducing emissions to reducing our vulnerability to disasters.Reducing vulnerability requires an understanding of why it is that disasters have been increasing.

Figure 1 .
Figure 1.Billboard put up along highways in Florida during the 2004 presidential election by the groups Environment 2004, and Scientists and Engineers for Change.Photo from Environment 2004.Available online at: http://www.environment2004.org/global_warming.php.

Figure 2 .
Figure 2. Th e growing global toll of disasters, according to data collected by Munich Re Group.Source: Munich Re Group (2005).
7 earthquake that struck California in 1994, one of the costliest disasters in U.S. history, caused an estimated $20 to $40 billion in losses, but this amounted to only 2 to 4 percent of California's economic activity (Sarewitz and Pielke, 2005).Disasters disproportionately harm poor people in poor countries because those countries typically have densely populated coastal regions, shoddily constructed buildings, sparse infrastructure, and grossly inadequate public health capabilities.Poor land use leads to widespread environmental degradation, such as deforestation and wetlands destruction, which in turn exacerbates fl ooding and landslides.Emergency preparation and response capabilities are often inadequate and hazard insurance is usually unavailable, further slowing recovery.Thus, while the world's poorest 35 countries make up only about 10 percent of the world's population, they suffered more than half of the disaster-related deaths between 1992 and 2001 (Jones, 1997).Disparities in disaster vulnerability between rich and poor will continue to grow.About 97 percent of population growth is occurring in the developing world.This growth, in turn, drives urbanization and coastal migration.The result is that the population of urban areas in the developing world will likely increase by two billion people in the next two decades.And this population is being added to cities that are mostly located on coastal or fl ood plains-or in earthquake zones-and are unable to provide the quality of housing, services, infrastructure, and environmental protection that can help reduce vulnerability.Uncontrolled urban growth exacerbates exposure to extreme events.
(i.e., fl oods), and concluded on a regional basis that, "Even if a trend is identifi ed, it may be diffi cult to attribute it to global warming because of other changes that are continuing in a catchment."A recent study by the International Ad Hoc Detection and Attribution Group (2005), published in the Journal of Climate, was unable to detect a greenhouse gas signal in global precipitation.These fi ndings are consistent with research seeking to document a climate signal in a long-term record of fl ood damage, which has concluded that an increase in precipitation does indeed contribute to increasing fl ood damage, but the precise amount of this increase is small and diffi cult to identify in the context of the much larger effects of policy and the ever-growing societal vulnerability to fl ood damage.Figure 3a shows how fl ood damage has increased dramatically in the United States, but Figure 3b shows that it has stayed almost constant when growing national wealth is considered.The case of hurricane impacts in the United States is similarly instructive.Consider economic damage (adjusted for infl ation) related to hurricane landfalls in the United States, 1900-2005, as shown in Figure 4.Although damage is growing in both frequency and intensity, this trend does not refl ect increased frequency or strength of hurricanes.In fact, while hurricane frequencies have varied a great deal over the past 100+ years, they have not increased in recent decades in parallel with increasing damages.To the contrary, although damage increased during the 1970s and 1980s, hurricane activity was considerably lower than in previous decades.
, 2001b) attributing some part of the trend of increasing disaster losses to changes in climate.However, upon closer look, the claim seems unfounded.The IPCC relied on a report published in 2000 by Munich Re that found that global disasters resulted in $636 billion in losses in the 1990s compared with $315 billion in the 1970s, after adjusting for changes in population and wealth.The Munich Re report concludes that disaster costs have increased by a factor of two (i.e., 636/315) (Munich Re Group, 2000), independent of societal changes; the IPCC suggests that climate change is responsible for the difference.Methodologically, the calculation is suspect for a number of reasons.First, Munich Re Group provides neither their methods nor data.Second, Munich Re

Figure 5 .
Figure 5.Estimated hurricane damages 1900-2005 if storms of the past made landfall with coastal development of 2005.Th e black line is the 11-year centered moving average of estimated hurricane damage.Source: Roger A. Pielke, Jr.