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Stanley A. Changnon Jr.

The State of Illinois has just established a climate center addressing a wide variety of climate-related activities. This center has evolved after 25 years of services, research, and data management addressing the climatology of Illinois and the Midwest. The products of this effort reflect state-related interests in climate information and data. The Illinois program may also help serve as a model for some states who will evolve centers as part of the federal-state cooperative effort that is to be an integral part of the National Climate Program.

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Stanley A. Changnon Jr.

The winter of 1977–78 was the worst, on the basis of both low temperatures and snow, on record in Illinois and many other areas of the Midwest. Representatives of 70 households in central Illinois participated in a detailed study of how the extreme cold and snow affected individuals. The average added cost was $93 per individual, largely to residences and vehicles, and extrapolation of this to all Illinois citizens results in an estimated statewide cost in excess of $1 billion. This was compounded by a wide variety of personal inconveniences, worries, extra work, and injuries. There were no deaths in the sampled group but 52 Illinoisans were killed by the 18 winter storms. For those living in rural areas beyond the city of their employment, costs and inconveniences were greater. The average individual cost was $120, and rural dwellers experienced more travel problems, more delayed services, and more absences from school and work.

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Stanley A. Changnon Jr.

A review of recent research in the United States concerning urban effects on precipitation has revealed that relatively few studies have been performed. The lack of densely spaced precipitation stations with good historical records, inadequate instruments for airborne measurements of the mechanisms that affect precipitation systems, and the difficulties associated with separating orographic, maritime, and gage-exposure effects are the primary reasons for so little research.

However, certain climatological studies of four variously sized cities in the midwest and two large cities in the east have shown apparent urban-produced increases ranging from 5 to 16% in annual precipitation and rain days, with 7 to 20% increases in summer thunderstorm days. Substantially greater increases in precipitation, thunderstorms, and hailfalls, 31 to 246%, have been shown in a recent study of an area downwind from a major steel mill complex. The available results show little evidence of urban effects on the occurrence of excessive rainfall rates or on the amount of snowfall, although little study of these conditions has been performed.

The recent development of airborne nuclei measuring instruments has led to selected measurements of condensation and freezing nuclei over several urban areas. These furnish evidence that urban-induced nuclei concentrations are high and probably sufficient to produce the observed changes in precipitation, whereas other American studies have indirectly shown the importance of the urban thermal effects. The study of inadvertent precipitation increases from urban areas has particular significance for planned weather modification since the amounts of the inadvertent increases approximate those confirmed for planned experiments. The results of the urban studies may indicate the effectiveness of ground-based seeding, the possibility of successful increases in all seasons, the likelihood of thunderstorm and hailstorm increases with rainfall increases, and the need for dense raingage networks to adequately determine the area and amount of increase.

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Stanley A. Changnon Jr.

A notable increase in precipitation, moderate rain days, thunderstorm days, and hail days has been occurring since 1925 at La Porte, Ind. Since La Porte is 30 miles east of the large complex of heavy industries at Chicago, there is a strong suggestion that the increases in precipitation conditions are due to inadvertent man-made modification.

If these increases are real, they serve as a good measure of the increase in convective precipitation that man could attain, at the same time pinpointing an excellent site for future meteorological studies of the exact causes of the increases. If the increases are fictional and result from exposure changes and observer error, they serve as an indication of the sizeable errors that may exist in some of our long-term climatological records.

The increase at La Porte is sizeable: during the 1951–1965 period La Porte had 31% more precipitation, 38% more thunderstorms, and 246% more hail days than did surrounding stations. Since 1925 the year-to-year fluctuations in the annual and warm season precipitation at La Porte show agreement with the temporal distribution of steel production in the Chicago area. After a careful assessment of all available climatological data, it was concluded that these sizeable increases were real and not fictional.

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Stanley A. Changnon Jr.

A midwestern group of 46 scientists and 16 nonscientists were polled at a recent AMS meeting about their beliefs on climate change, the CO2 issue, and the overall importance of these issues. Most indicated a belief in a trend to a climate that is colder, wetter, and has more weather variability. The group also indicated that the reports on CO2 were confusing to them and especially to the public. Finally, they indicated that the ongoing climate shift has been important to their lives.

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Stanley A. Changnon Jr.
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Stanley A. Changnon Jr.
and
Richard G. Semonin

Illinois is completing a comprehensive statewide water plan. The plan selects three atmospheric issues, among the 11 identified as key issues facing the state's water resources. The issues selected include climate change and prediction, inadvertent weather and climate modification, and planned weather modification. Each atmospheric issue presents major resource or policy problems, with capabilities needed to enhance the quality and/or quantity of the state's waters. The identification of these atmospheric issues reveals awareness at the policy level of their importance. Policy and programmatic needs found to be common to each issue include 1) collection of more data and continued research (with an increasing state role); 2) coordinated policy development around atmospheric expertise from several agencies and universities; and 3) an expanded public information program. A Climate Detection and Assistance Board is to be established in Illinois to provide the planning, coordination, and assistance needed to address atmospheric issues.

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Stanley A. Changnon Jr.
and
Richard G. Semonin

A series of mesoscale meteorological research projects have developed since 1975 in the area over and around the south end of Lake Michigan. These regionally focused projects, under the label of the Chicago Area Program (CAP), are being performed by scientists from 12 research groups or universities using funds from a variety of state and federal agencies. Efforts to date have led to the installation and operation of a major rain gage network, other weather networks and sondes, several weather radars, meteorological aircraft, and a ship. This sizeable program is addressing five major study areas including lake meteorology, water resources and hydrometeorology, inadvertent weather modification, air pollution and its impacts, and severe weather. Multigroup field experiments and the exchange of data are coordinated at the scientist level.

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Stanley A. Changnon Jr.
and
J. Loreena Ivens

A major weather modification effort at the turn of the century went unnoticed by the “pioneers” of 1950–70. There are several amazing similarities between the two periods that point to two key truths, the need for scientific resolution of weather modification questions, and for awareness by all scientists that events of the past are often relevant to new research considered to be of a pioneering nature.

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Kenneth E. Kunkel
,
Roger A. Pielke Jr.
, and
Stanley A. Changnon

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 contribution to the observed impacts trends remains to be quantified. There has been a steady increase in hurricane losses. However, when changes in population, inflation, and wealth are considered, there is instead a downward trend. This is consistent with observations of trends in hurricane frequency and intensity. Increasing property losses due to thunderstorm-related phenomena (winds, hail, tornadoes) are explained entirely by changes in societal factors, consistent with the observed trends in the thunderstorm phenomena. Winter storm damages have increased in the last 10–15 years and this appears to be partially due to increases in the frequency of intense nor'easters. There is no evidence of changes in drought-related losses (although data are poor) and no apparent trend in climatic drought frequency. There is also no evidence of changes in the frequency of intense heat or cold waves.

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