Showing papers by "Stanley A. Changnon published in 1999"

Temporal Fluctuations in Weather and Climate Extremes That Cause Economic and Human Health Impacts: A Review

Abstract: This paper reviews recent work on trends during this century in societal impacts (direct economic losses and fatalities) in the United States from extreme weather conditions and compares those with trends of associated atmospheric phenomena. Most measures of the economic impacts of weather and climate extremes over the past several decades reveal increasing losses. But trends in most related weather and climate extremes do not show comparable increases with time. This suggests that increasing losses are primarily due to increasing vulnerability arising from a variety of societal changes, including a growing population in higher risk coastal areas and large cities, more property subject to damage, and lifestyle and demographic changes subjecting lives and property to greater exposure. Flood damages and fatalities have generally increased in the last 25 years. While some have speculated that this may be due in part to a corresponding increase in the frequency of heavy rain events, the climate contr...

Impacts of 1997-98 El Niño Generated Weather in the United States.

Abstract: This paper assesses the major impacts on human lives and the economy of the United States resulting from weather events attributed to El Nino 1997-98. Southern states and California were plagued by storms, whereas the northern half of the nation experienced much above normal cold season temperatures and below normal precipitation and snowfall. Losses included 189 lives, many due to tornadoes, and the major economic losses were property and crop damages from storms, loss of business by the recreation industry and by snow removal equipment/supplies manufacturers and sales firms, and government relief costs. Benefits included an estimated saving of 850 lives because of the lack of bad winter weather. Areas of major economic benefits (primarily in the nation's northern sections) included major reductions in expenditures (and costs) for natural gas and heating oil, record seasonal sales of retail products and homes, lack of spring flood damages, record construction levels, and savings in highway-based...

Data and Approaches for Determining Hail Risk in the Contiguous United States

Abstract: Rapidly increasing hail damages to property have brought average annual losses to $1.2 billion (in 1997-adjusted dollars) during the 1990s; this rise in loss exposure has created great concern in the insurance industry and has led to efforts to define the hail risk across the nation. Since the property industry has not kept hail loss records, it must rely on available climatological data supplemented by data from field studies to assess hail risk. Hail risk at a point or over an area is a function of the target at risk (property or crop) and the hail frequency and intensity. Newly available climatological data based on historical hail records collected by the National Weather Service since 1900 have enhanced the ability to assess point risk. Some spatial risk assessments have combined point averages of hail-day frequencies with hailstone sizes to define risk, and others also employed hailstone volume (mass of ice) and wind associated with hail, based on data from field projects. Those seeking to ...

Rapidly Expanding Uses of Climate Data and Information in Agriculture and Water Resources: Causes and Characteristics of New Applications

Abstract: During the last 20 years the use of climate data and information in agriculture and water resources has increased dramatically. This has resulted from vastly improved access to comprehensive datasets and climate information made available by wide use of personal computers, as well as ease of access due to Internet connections to computer systems containing specially developed climate databases and information packages. Furthermore, the recent development of better, more sophisticated information about how climate conditions affect various physical conditions and economic outcomes has enabled more informed decisions by managers, who, in turn, developed a greater awareness of how to utilize climate information. The demand for information has grown as a result of increasing economic pressures and because certain agricultural and water management activities and their infrastructure have become more sensitive to certain climate aberrations. These factors have led to the development of new suppliers of...

A Rare Long Record of Deep Soil Temperatures Defines Temporal Temperature Changes and an Urban Heat Island

Abstract: A long-term set of deep soil temperature data collected over a 64-year period beginning in 1889 in a rural Illinois area provide a rare opportunity to assess the natural shifts in temperatures in a pristine environment without any urban or instrument bias. Temperatures from 1901 to 1951 increased 0.4 °C, and this was 0.2 °C less than nearby values from two high quality surface temperature data sets that supposedly are without any influence of urban heat islands, shifts in station locations or instrumentation, or other changes with time. Comparison of the soil values with surface air temperatures from a nearby weather station in a growing university community revealed a heat island effect of 0.6 °C. This value is larger than the adjustment based on population that has been recommended to eliminate the urban bias in long-term temperature trends in the U.S. Collectively, the results suggest that additional efforts may be needed to eliminate the urban influence on air temperatures, beyond techniques that simply use population as the basis. Population is only an approximation of urban factors affecting surface temperatures, and the heat island influences inherent in the values from weather stations in smaller communities which have been used as control, or data assumed to be unaffected by their urban environment in the adjustment procedures, have not been adequately accounted for.

Factors affecting temporal fluctuations in damaging storm activity in the United States based on insurance loss data

Abstract: Insured weather losses in the US reached record highs in the early 1990s, leading to major concerns in the insurance industry about the causes, including the possibility of climate change due to global warming. Several studies addressing the interpretation of the record high losses used historical insurance data sets, those for crop-hail losses and others based on the catastrophic events to the property insurance industry, both covering the 1949–1995 period. The past loss values were adjusted by insurance experts for shifting coverage, inflation, and evolving construction practices. The resulting adjusted values of crop loss and costly catastrophes to property both showed similar distributions for 1949–1995, with losses being high in the 1950s and again in the early 1990s. This distribution was found to have a weak relationship with extra-tropical cyclone activity in the US, but most of the recent increase in weather losses to insured property was found to be related to shifting societal factors that have put ever more property at risk in storm-prone areas, including coastal areas and large metropolitan areas. The low property and crop storm losses of the 1966–1985 period had created an incorrect perception of the weather risk in the insurance industry, which did not understand nor appreciate the existence of the decadal-scale fluctuations that exist in climate conditions. Copyright © 1999 Royal Meteorological Society

Interactions Between the Atmospheric Sciences and Insurers in the United States

Abstract: Insurance and insurers are directly affected and concerned about climate fluctuations in the United States. Growing losses in the 1990s awakened many in the insurance business to the enormity of weather-related problems they faced and a need for better information about climate and its fluctuations including a new potential problem, climate change. This paper presents the views of experts from the crop insurance sector, the property-casualty insurance sector, and from the atmospheric sciences sector based on atmospheric research accomplished for the insurance industry for decades. The paper addresses how climatologists and insurers can and need to work together to effectively bring understanding and wise consideration of climate conditions and their future fluctuations and extremes to insurers. Considerable climatological analyses have been employed in the past by the crop insurance industry, but less by property insurers. Insurers can adjust to a change in climate but to do so will require clear evidence, which does not exist now for the United States, and an understanding as well as wide acceptance of the on-going change by regulators and the buying public. Atmospheric scientists can help insurers to mitigate weather losses, to assess risks, to measure critical perils, to educate about risks, and to learn about critical issues like climate change and long-range forecasts.

Record Flood-Producing Rainstorms of 17–18 July 1996 in the Chicago Metropolitan Area. Part III: Impacts and Responses to the Flash Flooding

Abstract: A record-breaking 24-h rainstorm on 17–18 July 1996 was centered on south Chicago and its southern and western suburbs, areas with a population of 3.4 million. The resulting flash flooding in Chicago and 21 suburbs broke all-time records in the region and brought the Illinois and Mississippi Rivers above flood stage. More than 4300 persons were evacuated from the flooded zones and 35 000 homes experienced flood damage. Six persons were killed and the total estimated cost of the flood (losses and recovery actions) was $645 million, ranking as Illinois’ second most costly weather disaster on record after the 1993 flood. Extensive damages and travel delays occurred on metropolitan transportation systems (highways and railroads). Commuters were unable to reach Chicago for up to three days and more than 300 freight trains were delayed or rerouted. Communities dealt with removal of flood-damaged materials, as well as damage to streets, bridges, and sewage treatment and water treatment plants. Reduced c...

Record Flood-Producing Rainstorms of 17–18 July 1996 in the Chicago Metropolitan Area. Part I: Synoptic and Mesoscale Features

Abstract: A unique rainstorm in northern Illinois produced 43 cm of precipitation in mid-July 1996, the highest 24-h precipitation amount ever recorded officially in the upper Midwest. Rains exceeding 20 cm fell over an area of 4400 km2, creating extremely damaging flash floods in portions of Chicago and its suburbs. Measurements from 496 rain gauges, including 80 recording gauges in the heavy rain area, made it possible to accurately define this storm. The heavy rains were the result of two massive mesoscale convective systems, one in the afternoon and one at night. These systems formed to the north of a nearby stationary warm front. Several factors contributed to the excessive rainfall. Excessive moisture was present to the southwest of the warm front over Iowa and western Illinois; atmospheric moisture content was enhanced by surface evaporation from a very wet surface created by heavy rains the previous day, creating a conditionally unstable atmosphere. A cool air mass transported by easterly winds off...

Long-term variations in seasonal weather conditions important to water resources in illinois

Abstract: An analysis of historical relationships between seasonal weather conditions and water resource conditions in Illinois provides insights to the challenges of projecting such relationships under conditions of climate change. In Illinois for 1901–1997 there were major temporal shifts in types of seasonal conditions that have positive and negative effects on surface water and ground water supplies and their quality. Major seasonal effects came in the spring and summer seasons and when either wet-and-warm or dry-and-warm weather conditions prevailed in either season. Sixty percent of the summer seasons creating negative impacts occurred during only 40 years: 1911–1940 and 1951–1960. Seasons creating impacts relate well to the frequency of cyclone passages and to the incidence of El Nino or La Nina conditions. This reveals that future climate fluctuations that shift the frequency of cyclones and/or ENSO events will have profound effects on Midwestern seasonal conditions that affect water resources. Projecting future effects of climate change on water resources will need to consider how shifts in water use and water management technologies act to re-define the seasonal weather conditions that are critical.