National Policy Analysis

 August 1998

Don't Like the Weather? Don't Blame it on Global Warming

by David Ridenour

In recent years, advocates of the global warming theory have convinced many Americans that virtually any weather-related calamity is evidence that human-induced global warming is underway.

One has only to look at the Second Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) - the United Nations body tasked with coordinating a world response to the threat of global warming - to understand why global warming theory advocates have been so successful. Among the many gems in the report is this one: "Warmer temperatures will lead to prospects for more severe droughts and/or floods in some places and less severe droughts and/or floods in others."

The University of Virginia's Dr. Patrick Michaels has taken the time to translate this sentence for us. It means that global warming will be characterized by "more intense wet periods, more intense dry periods, more intense wet and dry periods, less intense wet periods, less intense dry periods, and less intense wet and dry periods." i Precisely how this is different than a world without human-enhanced global warming is unclear. From year to year, some areas of the world have always experienced more severe droughts and floods than others. Likewise, some areas of the world have always experienced less severe droughts and floods than others. With or without global warming, this process will continue in the future.

But because the symptoms of global warming as identified by advocates of the global warming theory are so ambiguous, so subject to change, virtually any weather event - at least any bad weather event - can be attributed to global warming. And therein lies the brilliance of the global warming theory and its advocates. Whether the weather is too hot, too cold, too dry, too wet or perhaps even too normal, global warming is always the convenient culprit.

The Clinton Administration knows this all too well. The Florida fires, the northeastern blizzard in 1996, the hurricanes of 1995, floods in South Dakota in 1997 and the heat waves in the South and West this year have all been cited by the Clinton Administration as evidence that global warming is occurring and that we need to act immediately to stop it.

Close examination of the scientific data and historical record, however, suggests far more plausible explanations for these weather events - they have nothing to do with global warming.


Where There's Fuel There's Bound to be Wildfire

"There's only a one in one-thousandth chance that this is normal without the effects of global warming factored in."

-Vice President Albert Gore commenting on the Florida fires, June 30, 1998ii

When Vice President Albert Gore claimed that there was only one-thousandth of a chance that the fires that burned nearly a half million acres in Florida during June and July 1998 would have occurred without global warming, he actually overstated the odds. Without global warming, there would have been zero chance of such fires as there would have been no life in Florida or anywhere else to burn. It's sometimes easy for us to forget - amid all the rhetoric on this highly politicized issue - that global warming is a natural process that keeps the planet warm enough to sustain life.

As for where the Vice President came up with "one in one-thousandth chance," it's anyone's guess. An inquiry to his office on this matter yielded no reply.

What the Vice President appears to have been attempting to say was that anthropogenic global warming - global warming caused by humans - was somehow to blame for the Florida fires.

The Vice President's reasoning goes something like this: Human beings, through their burning of fossil fuels, are accelerating global warming. This increased global warming, in turn, is inducing more frequent and more powerful El Niños. In Central Florida's case, El Niño produced heavier rains in the spring, which increased vegetation, and a drought in the summer creating the ideal conditions for wildfires.

The problem with Vice President Gore's logic is that it is not supported by the historical record.

Fires in Florida are certainly nothing new and, in any event, are unlikely to be related to such recent phenomena as global warming or global warming-enhanced El Niños (allowing, for the moment, that either process is underway). Explorers Sir Francis Drake and Giovanni da Verrazano, for instance, reported seeing fires in Florida during the 1500s. The planet was in the midst of the Little Ice Age at the time. Shortly after the turn of the last century, 105% of Florida reportedly burned in a single year (reflecting the fact that some areas burned more than once). That was well before widespread use of fossil fuels - which the Vice President blames for accelerated global warming.iii

The last time Florida experienced fires of the same magnitude as the 1998 fires was 1932- 1933. But El Niño was not a factor then.iv In fact, the incidence of drought in Florida appears to be no more common during El Niño years than non-El Niño years. The most severe droughts this century occurred during 1907-1908, 1932-1933, 1963-1964, and 1980-81, not the strong El Niño years 1904-1905, 1917-1918, 1940-1941, 1957-1958, 1965-1966, 1972-1973, 1982-1983 and 1991-1992.

Dr. Patrick Michaels of the University of Virginia examined 100 years of Florida drought history and found that El Niños have not led to droughts in Florida. Using the Palmer Drought Severity Index (a common drought indicator in which dry conditions are expressed in negative values while wet conditions are expressed in positive values), Michaels found that wet conditions prevailed in Central Florida more often than dry conditions during El Niño years (see Chart 1). v


Chart 1


The Florida fires are only the most recent example used by global warming theory proponents to suggest a link between global warming and fire. In its 1997 State of the Climate report, for example, the World Wildlife Fund warned that fires in the United Kingdom, Australia and Borneo and drought conditions in Yellowstone that threaten future fires are indications that global warming is beginning to have a profound influence not only on our climate, but our

But the existence of fires neither proves that global warming exists nor that global warming increases the risk of forest fires. Prior to settlement of North America - again, when the planet was still in the grips of the Little Ice Age - an estimated four to eleven percent of the land mass that is now the United States burned each year. For the lower 48 states this represents 75 to 206 million acres.vii

More recently, in 1924, 28.8 million acres of land burned in the United States, not including fires in national parks and Indian reservations. To put this figure in perspective, the amount of acreage burned in 1924 was roughly 58 times the acreage claimed by the fires in Central Florida in June-July 1998. And 1924 wasn't an aberration. Fires in 1923 and 1925 claimed 26.1 and 26.5 million acres, respectively.

Since the 1920s, however, wildfires have been on a more or less steady decline. The average number of acres burned have fallen from 12.4 million per year during the 1920s, to 3.9 million in the 1930s, 2.6 million acres in the 1960s and just 2 million acres during the 1980s (see Chart 2).viii Improved fire suppression capabilities, better forestry management techniques, forest fire prevention education programs such as "Smokey Bear" and the "Dixie Rangers" (which were effective in convincing Americans that fire prevention was a civic duty) all played a part in the success.


Chart 2

But this success hasn't come without a price. Since the beginning of this decade, there has been an uptick in the number of fires nationwide. Neil Sampson, a senior fellow with the Forest Policy Center who served as the chairman of the National Commission on Wildfire Disasters (established by Congress), explains why: "We've been living through a period when fire suppression capability grew faster than the fire hazard... In the late 1970s, something different started to happen. Any dry weather period began to be accompanied by a greatly increased amount of wildfire... [T]he natural resource conditions in wildland ecosystems had been made more fire-prone and dangerous, at least in part by our past success at stopping the fires that would have reduced fuel buildups."ix In other words, the increased risk of fire is the result of excess timber and vegetation that provides fuel for fires. While advancements in fire suppression were able to keep pace with the increased fire risks of ever-increasing fuel loads for a while, they are no longer able to do so. Complicating matters further is the fact that environmentalists frequently stand in the way of forest management policies that could help reduce these fuel loads. It's now no longer a question of "whether" more fires like those in Florida are going to occur, but "when." It is therefore absurd to blame global warming for such phenomena.


If Hot Periods Are Something New, How Do We Know to Call Them Heat Waves?

"As you can see from this sweltering heat... the Vice President is right: The climate of our country and our globe is changing. The globe is warming."

-President Clinton at a speech before the American Federation of Teachers in New Orleans, July 21, 1998x

There are two major problems with the President's assertion that the heat waves in the South and West are indications that global warming is underway. For one thing, local weather events tell us little about global climate. Because it is unusually warm in one area of the world does not mean the entire planet is warming. Indeed, data from NASA's TIROs series of weather satellites indicate that there has been a slight cooling trend of .04 degrees Celsius since 1979.xi And there may be no way to know how a particular weather event is affected by global warming. As the Intergovernmental Panel on Climate Change (IPCC) noted in its 1995 summary report: "...[Q]uantitative projections of the impacts of climate change on any particular system at any particular location are difficult because regional-scale climate change predictions are uncertain; our current understanding of many critical processes is limited; and systems are subject to multiple climatic and non-climatic stresses, the interactions of which are not always linear or additive."xii

The second, more obvious problem with the President's assertion is that the heat waves in the South and West are neither very unusual nor record-breaking. Through July 21, 1998, the news media reported high temperatures of 98º Fahrenheit in Los Angeles, 102º F in Salt Lake City, 129º F in Death Valley and 101º F in Little Rock.xiii But none of these were records: Los Angeles hit a record high of 109º F on July 12, 1891 to cap off an extended heat wave, Death Valley hit a record-setting 134º F on July 10, 1913, Salt Lake City broke 107º F on July 26, 1960 and Little Rock established a record of 112º F on July 31, 1986.xiv If any period of American history can be considered its hottest, it would have to be the 1930s. During that decade, 25 states established their record highs - 15 of them established their record highs in 1936 alone (see Table 1).xv


Table 1






September 5, 1925



June 27, 1915



June 29, 1994



August 10, 1936



July 10, 1913



July 11, 1888



July 21, 1991



July 21, 1930



June 29, 1931



July 24, 1952



April 27, 1931



July 28, 1934



July 14, 1954



July 14, 1936



July 20, 1934



July 24, 1936



July 28, 1930



August 10, 1936



July 10, 1911



July 10, 1936



August 2, 1975



July 13, 1936



July 6, 1936



July 29, 1930



July 14, 1954



July 5, 1937



July 24, 1936



June 29, 1994

New Hampshire


July 4, 1911

New Jersey


July 10, 1936

New Mexico


June 27, 1994

New York


July 22, 1926

North Carolina


August 21, 1983

North Dakota


July 6, 1936



July 21, 1934



June 27, 1994



August 10, 1898



July 10, 1936

Rhode Island


August 2, 1975

South Carolina


June 28, 1954

South Dakota


July 5, 1936



August 9, 1930



August 12, 1936



July 5, 1985



July 4, 1911



July 15, 1954



August 5, 1961

West Virginia


July 10, 1936



July 13, 1936



July 12, 1900

Nonetheless, the national news has been filled with reports that 1998 has seen the warmest summer in history. One such report claimed that June 1998 was the warmest June on record for Huntsville, Alabama, at an average daily temperature of 80.5º F. But Dr. John Christy, associate professor of atmospheric science at the University of Alabama at Huntsville, takes issue with this claim. After reviewing over 100 years worth of records in the Alabama office of the state climatologist - including handwritten forms - Christy found that while June 1998 was indeed hot, it was not as hot as June 1943, 1952 or 1953, when the average temperatures at the Huntsville airport were 80.8º F, 83.0 º F and 81.7º F, respectively. It was also not as hot as June 1914 when the average temperature at Valley Head (elevation 1,031 feet) soared to 81.3º F - well above Huntsville's June 1998 reading, despite its higher elevation. Christy concluded that the report of record temperatures in Huntsville must have been based on digitized records of the National Weather Service (NWS) which are incomplete.xvi The Birmingham office of the NWS, for example, reports that NWS temperature records for Huntsville only go back to 1958.xvii One can only wonder if this same kind of error has been repeated elsewhere.

Unfortunately, President Clinton saw the 1998 heat wave as an opportunity to generate fear and play on the American people's emotions to promote his global warming policies. The loss of 130 people's lives is a very real tragedy and should not have been used to promote a political agenda.

As tragic as that death toll is, however, it is important to remember that even greater losses of life have resulted from heat waves during times in which the globe was presumably much cooler than today: A heat wave in Chicago in 1915, for example, claimed 535 lives.xviii Heat waves in Los Angeles in 1939, 1955 and 1963 claimed 546 lives, 946 lives and 580 lives, respectively. During the 40 year period 1936-1975, an estimated 20,000 people died from heat-related causes - equal to 500 people per year.xix

What makes 1998 different than other years is not that there is an unprecedented heat wave, but that a President of the United States is using the human suffering resulting from a heat wave to promote his own political agenda.


Trail Linking Blizzards to Global Warming is Cold

"I know there is a pattern of more intense rainfall and snowfall."

-President Bill Clinton responding to a question about global warming and the 1996 northeastern blizzard, February 16, 1996xx

On February 16, 1996, less than a month after a crippling blizzard hit the northeastern United States and just as a second major storm was bearing down, President Clinton blamed the blizzards and the unusually cold weather on global warming. That's right. Not only does the President believe global warming is responsible for heat waves and fires, but blizzards as well.

If anything, increased snowfall and colder weather is an indication that global warming is not occurring. A review of how polar and Arctic air masses (which make extreme cold and snow possible) form is instructive.

The coldest air masses in winter form over the frozen Arctic Ocean. These air masses cool by emitting heat both toward the ground and into space as they move over the snow and ice-covered surfaces. At the same time, both the snow and ice lose heat to both the atmosphere and to space. So long as such air masses are warmer than the surface, they continue to cool. But in order for an air mass to become cold enough to create the kind of conditions that chilled the eastern two-thirds of the country in 1996, two things must occur. First, there must be a high pressure system - a condition characterized by clear skies and calm winds. Second, the air mass must remain over the snowpack long enough - perhaps a week or more - to ensure it becomes cold enough. The longer the cold air mass stays in place, the colder it becomes.

But if the planet were truly warming, one could expect fewer cold air masses of this type, not more. The reason? Less heat would escape into space, leading to warmer surface temperatures and thus warmer air masses.xxi

But one doesn't necessarily need such technical explanations to understand that global warming isn't necessary for cold weather and heavy snows. History is replete with examples of blizzards, including during periods when the planet was in the midst of the Little Ice Age. A storm on January 16, 1831, for example, blanketed states from Georgia to Maine in up to 30 inches of snow.xxii A storm on February 27, 1717, which still holds the record as the greatest snowstorm in New England history, dumped more than three feet of snow in Boston and up to six feet of snow further north.xxiii In 1899, just after the conclusion of the Little Ice Age when the planet was still cooler than it is today, the "Great Eastern Blizzard" left snow from Georgia to New Hampshire. The average snowfall totals in Virginia were between 30 and 40 inches.xxiv

The trail linking blizzards to global warming is thus very, very cold.


Hurricanes, Cyclones and Typhoons on the Decline, Not Increase

"...[T]he overwhelming balance of evidence and scientific opinion is that it is no longer a theory, but now a fact that global warming is for real. The world's scientists believe that if we don't cut our emissions of greenhouse gases, we will disrupt the global climate. In fact, there is ample evidence that human activities are already disrupting the global climate..."

-President Bill Clinton, meeting with scientists, July 24, 1997xxv

Some of the "evidence" that human activities are already changing the climate of the planet includes reports that the incidence of hurricanes, cyclones and other tropical storms are on the rise. Recent analyses of tropical storm records, however, indicate that precisely the opposite is occurring.

A study conducted by Christopher W. Landsea, a scientist with the National Oceanic and Atmospheric Administration's Atlantic Oceanographic and Meteorological Lab, for example, found that the number of intense hurricanes (those hurricanes reaching Saffir-Simpson scale ratings of 3, 4 or 5) actually declined in the Atlantic basin during the 1970s and 1980s. That trend continued into the 1990s: According to Landsea, the period 1991-1994 was the "quietest" four years on record in terms of hurricane activity - even taking into account 1992's Hurricane Andrew. Among Landseas' other findings:

* There was no significant change in the frequency of hurricanes and tropical storms in the Atlantic basin between 1944 and 1995.

* There were no hurricanes in the Caribbean Sea between 1990 and 1994, the longest period of such calm weather for the region since 1899.

* There was a moderate decrease in the per season maximum intensity reached by all storms between 1944 and 1995.xxvi

Other studies, including one by noted hurricane expert William Gray and published in Science magazine, produced similar results.

According to Gray, between 1970 and 1987, Atlantic hurricane activity was less than half the hurricane activity observed between 1947 and 1969. By global warming theory proponents' projections, this should not have been the case as greenhouse gas concentrations rose at a much faster pace from 1970 to 1987 than from 1947 to 1969.xxvii

The absence of increased tropical storm activity suggests that proponents of the global warming theory are either wrong when they say a planetary warming trend is underway, wrong when they suggest that human-induced global warming is leading to increased tropical storm activity or wrong on both counts. Available evidence suggests they are wrong on both counts.

In a 1990 study, Drs. Robert Balling, Sherwood Idso and Randall Cerveny found that warmer global temperatures actually lead to fewer hurricanes, not more. Their analysis - which assessed data for 1947 through 1987 - found that the warmest years over the 41-year period produced the fewest number of hurricane days, on average. Conversely, the coldest years, on average, produced a greater number of hurricane days.xxviii

These findings are certainly consistent with the historical record. According to the George C. Marshall Institute, the most severe storms in the North Sea occurred during the 15th and 16th centuries, after the onset of the Little Ice Age. Storms in 1421 and 1446 claimed 100,000 lives each while a storm in 1570 claimed over 400,000 lives.xxix

Global warming theory proponents are also wrong when they say the planet is warming. NASA's TIROs series of weather satellite as well as weather balloons have both confirmed that the planet has been cooling since

Hurricanes, cyclones and typhoons are clearly not on the rise nor is the temperature of the planet. But by claiming otherwise, President Clinton may be generating a few gale-force winds of his own.


Contrary to statements by President Clinton and Vice President Albert Gore and others, extreme weather events - floods, blizzards, tropical storms, wildfires and heat waves - are nothing new nor are they on the increase. The President and Vice President have simply been playing upon the fears and emotions of the American people to advance a political agenda which includes sharp restrictions on U.S. greenhouse gas emissions. Such exploitation represents not only the worst of American politics, but the worst of all environmental policies. Environmental policy based on fear rather than science can only place the planet at greater risk.



David Ridenour is vice president of The National Center for Public Policy Research. Comments may be sent to [email protected]



i Patrick Michaels, Speech before Competitive Enterprise Institute's "Costs of Kyoto Conference," National Press Club, July 15, 1997.

ii Reuters, June 30, 1998.

iii Alston Chase, "Seared by Amnesia," The Washington Times, July 16, 1998.

iv Patrick Michaels, "Gore Fans Rhetorical Flames in Florida," World Climate Report, July 13, 1998.

v Patrick Michaels, "It's Wildfire!" World Climate Report, July 13, 1998.

vi State of the Climate: A Time for Action, The World Wildlife Fund, 1997.

vii R. Neil Sampson, "Living With Nature: Are We Willing to Pay the Price?" Wildfire News and Notes, February 1996.

viii National Inter-Agency Fire Center figures.

ix R. Neil Sampson, "Living With Nature: Are We Willing to Pay the Price?" Wildfire News and Notes, February 1996.

x The Washington Times, July 21, 1998.

xi "Is Earth's Temperature Up or Down or Both?" and "Global Climate Monitoring: The Accuracy of Satellite Data," NASA's Marshall Space Flight Center, 1997.

xii Intergovernmental Panel on Climate Change Second Assessment Report Summary, 1995.

xiii "Deputies Look for Victims as Texas Keeps Sweltering," The Washington Times, July 21, 1998.

xiv "July Weather Facts," National Oceanic and Atmospheric Administration.

xv "Highest Temperatures by State Through 1996," National Climate Data Center (National Oceanic and Atmospheric Administration).

xvi "June 1998 Hot, But Not Hottest," Press Release Issued by Dr. John Christy, July 14, 1998.

xvii S. Fred Singer, "NWS Weather 'Records' Likely False," July 14, 1998.

xviii "1915, 1916, 1955, 1995: Heat Waves," Chicago Historical Information, City of Chicago.

xix Randolph E. Scmid, "Study Finds That Heat Wave is the Deadliest Type of Weather," Associated Press, July 27, 1998.

xx United Press International, February 16, 1996.

xxi Patrick Michaels, "Record Cold Caused by Global Warming?" World Climate Report, March 4, 1996.

xxii "January Weather Facts," National Oceanic and Atmospheric Administration.

xxiii "February Weather Facts," National Oceanic and Atmospheric Administration.

xxiv Ibid.

xxv United States Information Service - Israel.

xxvi Christopher Landsea,"FAQ: Hurricanes, Typhoons, and Tropical Cyclones," Atlantic Oceanographic and Meteorological Lab (National Oceanic and Atmospheric Administration), January 13, 1998.

xxvii Robert C. Balling, "Calmer Weather: The Spin on Greenhouse Hurricanes," The Competitive Enterprise Institute (Washington, D.C.), May 1997.

xxviii Ibid.

xxix "Are Human Activities Causing Global Warming?" George C. Marshall Institute, 1996.

xxx "Is Earth's Temperature Up or Down or Both?" and "Global Climate Monitoring: The Accuracy of Satellite Data," NASA's Marshall Space Flight Center, 1997.


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