Standardizing losses in Sheldus

Yet another reason that a comprehensive standardized database of hazard events and losses at the national scale is needed can be seen in the way historical loss data are reported. SHELDUS reports losses by using a conservative ''yardstick,'' meaning that all losses based on SHELDUS should be considered as minimum estimates. This conservative approach is required because the input data, which are derived from different federal agencies, report losses in diverse metrics. Some entities give loss...

Sea level and coral growth

Sea level is predicted to rise over the next 100 years from the thermal expansion of seawater and the melting of continental ice (Intergovernmental Panel on Climate Change IPCC , 2001,2007). This rise will increase the depth of the water column above a coral reef, and as the depth is related to the level of irradiance by the Beer-Lambert law, the intensity of irradiance will decrease. The stability of sea level for the past few thousand years has led to reefs growing up to a point where they...

The origin of extreme events

Understanding the processes that lead to the creation of extreme events and how they might change in the future is a key goal of climate science. To help tackle the problem of the origin of extremes, I propose two guiding principles. * The evolutionary principle. Extreme events do not arise spontaneously instead, they evolve continuously from less extreme events and they stop evolving to become even more extreme events. * The stationary principle. Extremes such as local maxima and minima are...

Foreword

The Intergovernmental Panel on Climate Change (IPCC, 2007) definition of climate change refers to any change in climate over time, whether it is due to natural variability or is a result of human activity. Climate and non-climatic factors interact to produce both opportunities and disasters. It is the goal of good adaptation practices to take advantage of such opportunities and to reduce associated risks. There are substantial vulnerabilities to hurricanes along the Atlantic seaboard of the...

Hurricane activity rates

Since the first generation of models, one of the basic principles of hurricane catastrophe loss modeling had been that activity rates should be based on the average of history (over the maximum time period for which historical observations could be considered complete). For landfalling storms in the United States, this has generally been taken to be the period since 1900. However, hurricane activity in the Atlantic basin had remained persistently high (in all but El Nino years) since 1995, and...

Flooding of New Orleans

In the 2005 RMS US Hurricane model (as available in RiskLink 5.0), extreme storm surges were modeled as extending into New Orleans (for hurricanes of category 3 and above), but it had been assumed that there would not be significant breaching of levees and that deep flooding would be prevented by the pumping capacity in the city. These widely shared assumptions had proved highly unconservative (Independent Levee Investigation Team ILIT , 2006). With respect to the potential for levee breaching,...

Changes in temperature extremes

On a regional basis, a number of studies of extremes have been completed as a part of a series of regional workshops coordinated by the joint World Meteorological Organization WMO Climate Variability and Predictability Climate Change Indices CLIVAR CCI Expert Team on Climate Change Detection, Monitoring and Indices ETCCDMI . Each of these workshops used a set software that calculated extremes defined in Frich et al. 2002 . These workshops included the Caribbean Peterson et al., 2002 , southern...

Introduction

Outbreaks of anomalous summer heat occur each year somewhere on Earth. Typically associated with persistent blocking anticyclones, summertime heat waves in the mid-latitudes have a coherent spatial structure that is characterized by lack of rainfall, dry air and soil, and increased fire risk. Disastrous consequences Macfarlane and Waller, 1976 Sheridan and Kalkstein, 2004 can result from hot spells that are extreme in their duration and spatial extent. The summer of 2003, very likely the...

Illustrative reinsurance example

Reinsurers tend to work on very focused risk portfolios, because they are dealing with risks that are unacceptable to primary insurers. The example below illustrates how such risks could escalate in the future and become unacceptable, even to reinsurers. Suppose that in 2000 the reinsurer assessed there were three possible event outcomes normality, an extreme event defined as a 1-in-100-year probability , and a catastrophe defined as having a 1,000-year return period . Swiss Re's current...

Tropical Atlantic Main Development Region temperature trends

The region of the tropical North Atlantic and Caribbean extending from 10 N to 20 N is often referred to as the Main Development Region MDR for Atlantic hurricane activity, owing to the large portion of major hurricanes that can be traced to disturbances originating there e.g., Goldenberg et al., 2001 Bell and Chelliah, 2006 . Here we explore possible causes for a warming of this region during the twentieth century. Shown in Figure 7.1 are 10-year running mean surface temperature indices for...

Climate Variability United States Hail

Convective storms play a vital role in weather and climate. They act to redistribute heat, moisture, and trace gases in the vertical and in the horizontal. In the tropics and in the warm season in the mid-latitudes, they provide a significant part of the precipitation. Therefore, they are beneficial to society, Climate Extremes and Society, ed. H. F. Diaz and R. J. Murnane. Published by Cambridge University Press. Cambridge University Press 2008. particularly in agriculture. When convection is...

Underlying problems and approaches

Part of the problem in defining severe convection is the susceptibility of different parts of society to effects of the same weather event. For example, a large amount of small hail less than 2 cm in diameter may have little impact on urban areas, but could be devastating to agricultural interests at certain times of the year and for certain crops. Similarly, strong winds may have minimal impact in an area of grassland used for cattle ranching, whereas the same winds may be damaging in a...

References

A. 2002 . Mortality, growth and reproduction in Scleractinian corals following bleaching on the Great Barrier Reef. Marine Ecology Progress Series, 237, 133-41. Bak, R. P. M. 1976 . The growth of coral colonies and the importance of crustose coralline algae and burrowing sponges in relation with carbonate accumulation. Netherlands Journal of Sea Research, 10, 285-337. Baker, A. C., Stargert, C. J., McClanahan, T. R., and Glynn, P. W. 2004 . Corals' adaptive...

Munich Re estimates of climaterelated losses

Munich Re has been compiling statistics on natural disasters for many years because they illustrate the need for risk management. Their definition of what are ''major natural catastrophes'' follows the criteria laid down by the United Nations the affected region's ability to help itself is distinctly overtaxed, interregional or international assistance is necessary, thousands are killed, hundreds ofthousands are made homeless, and there are substantial economic losses and or considerable...

European storms

This author reported a striking correlation between winter temperatures and the occurrence and strength of great European storms, using the Central England Temperature CET, as measured by the Hadley Centre as a proxy for temperature, and Lamb's Lamb, 1991 record of great storms Chartered Insurance Institute CII , 1994 . The data in Table 13.8 show that storms are twice as frequent in warm months as in medium months, and 150 more common than Table 13.8. Great European storms and winter...

Definition of extreme events

Extreme events are generally easy to recognize but difficult to define. This is due to several reasons. First, there is no unique definition for what is meant by the word extreme several definitions are in common use. Second, the concept of extremeness is relative and so strongly depends on context. Third, the words severe, ''rare,'' ''extreme,'' and high-impact are often used interchangeably. 1.2.1 Severe, rare, extreme, or high-impact In an attempt to alleviate some of the confusion, here are...

Modeling coral growth in Curacao

Curacao is completely surrounded by fringing reefs, which provide protection, food, and income to the island population of approximately 150,000. There are several documented natural and anthropogenic threats to the Curacao reefs. Massive coral bleaching impacted the Curacao coral reef in 1987, 1990, and 1995 hurricanes and disease have caused considerable damage and massive coastal development has led to increased sedimentation and sewage, which are also harmful to the reefs Burke and Maidens,...

Extreme precipitation

Increased temperatures lead to an increase in the water-holding capacity of the atmosphere, such that with each 1 C increase we have an increase of about 7 in the water-holding capacity Trenberth et al., 2003 . Furthermore, observations suggest that as this capacity increases with increased temperatures, relative humidity remains more or less constant, resulting in an increase in water vapor in the atmosphere owing to enhanced drying of the surface. Figure 2.5 shows 10 20 30 40 50 60 70 80 90...

Acknowledgments

We are grateful for the help provided by Irene Fischer-Bruns, Iris Grabemann, and Beate Gardeike. Alexandersson, H., Schmith, T., Iden, K., and Tuomenvirta, H. 1998 . Long-term trend variations of the storm climate over northwest Europe. Global Atmosphere-Ocean System, 6, 97-120. Alexandersson, H., Schmith, T., Iden, K., and Tuomenvirta, H. 2000 . Trends of storms in northwest Europe derived from an updated pressure data set. Climate Research, 14, 71-3. Aspelien, T. 2006 . The use of long-term...

Genesis of the Risk Prediction Initiative

The large losses resulting from Hurricane Andrew put many insurance companies out of business or in difficult straits, and a significant fraction of capital available for use by the insurance industry was used to pay claims. The resultant depleted pool of capital available for insurance drove up reinsurance prices and increased the potential returns for companies offering reinsurance.1 A number of new property catastrophe reinsurers were formed in Bermuda to take advantage of this business...

Irradiance and coral growth rate

Schematic Diagram Coral

The abundance of corals in the tropics compared with the extratropics poleward of latitudes 23 , which is apparent from Figure 9.1, is caused by differences in seasonal temperatures and the levels of annual solar irradiance, or insolation. The photosynthetic rates of zooxanthellae are dependent on both light and temperature Muller-Parker and D'Elia, 1997 . As a result, corals are found in warm, clear, shallow waters that have sufficient irradiance necessary for photosynthesis. Reef corals can...

Evidence Of Trends In Daily Climate Extremes Over Southern And West Africa

Changes in precipitation and temperature extremes in Central America and northern South America, 1961-2003. Journal of Geophysical Research, 110, D23107, doi 10.1029 2005JD006119. Akinremi, O. O., McGinn, S. M., and Cutforth, H. W. 1999 . Precipitation trends on the Canadian prairies. Journal of Climate, 12, 2996-3003. Alexander, L., et al. 2006 . Global observed changes in daily climate extremes of temperature and precipitation. Journal of Geophysical Research, 111,...

Loss amplification

The traditional approach in catastrophe loss modeling has been to employ an engineering definition of damage as the basis from which to determine insured losses. In both the two major catastrophe losses of the 1990s - Hurricane Andrew in 1992 and the 1994 Northridge earthquake - it had been recognized that an additional factor termed ''demand surge'' was required to reflect all elements of the increase in losses, beyond the expectations of the predicted costs to repair the damages. In the...

Multidimensional nature of extreme events

In addition to this potential source of confusion, extreme events have a variety of different attributes and so cannot be completely described by a single number. The multidimensional nature of extreme events is often overlooked in rankings of the events based on only one of the attributes e.g., the category numbers for hurricanes based solely on maximum surface wind speed . Extreme events have attributes such as rate probability per unit time of occurrence For example, a major hurricane is...

Statistical diagnosis of extreme events

This section will briefly describe some statistical approaches for interpreting extreme events. A more comprehensive discussion is given in the excellent book by Coles 2001 . 1.3.1 Point process modeling of simple extreme events In order to make the analysis more amenable to mathematical modeling, it is useful to neglect important attributes such as temporal duration, spatial scale, and multivariate dependencies. The IPCC 2001 defined ''simple extreme'' events to be ''individual local weather...