Our first example of the near-universal lack of CO2-damning evidence comes from long-term sea level records of several coastal stations in northwest Europe.  When analyzed for trends and variations related to storminess over the past century, Bijl et al. (1999) report that "although [the] results show considerable natural variability on relatively short (decadal) time scales," there is "no sign of a significant increase in storminess … over the complete time period of the data sets."  In the southern portion of the North Sea, however, where natural variability was more moderate, they found "a tendency towards a weakening [our italics] of the storm activity over the past 100 years."

Much the same results were obtained by Pirazzoli (2000), who analyzed tide-gauge, wind and atmospheric pressure data over the period 1951-1997 for the northern portion of the Atlantic coast of France.  In that study, the number of atmospheric depressions (storms) and strong surge winds were found to be decreasing in frequency.  In addition, it was reported that "ongoing trends of climate variability show a decrease in the frequency and hence the gravity of coastal flooding."

Also in Europe, Bielec (2001) analyzed thunderstorm data from Cracow, Poland for the period 1896-1995, finding an average of 25 days of such activity per year, with a non-significant linear-regression-derived increase of 1.6 storm days from the beginning to the end of the record.  From 1930 onward, however, the trend was negative, revealing a similarly-derived decrease of 1.1 storm days.  It was also determined there was a decrease in the annual number of thunderstorms with hail over the entire period and a decrease in the frequency of storms producing precipitation in excess of 20 mm.

Moving across the Atlantic Ocean to the east coast of the United States, Zhang et al. (2000) utilized ten long-term records of storm surges derived from hourly tide gauge measurements to calculate annual values of the number, duration and integrated intensity of storms in this region.  Their analysis did not show any trends in storm activity during the twentieth century, which, in their words, "suggests a lack of response of storminess to minor global warming along the U.S. Atlantic coast during the last 100 yr."

Boose et al. (2001) used historical records to push the time frame of such studies all the way back to 1620 for the six New England states and adjoining New York City and Long Island, finding "no clear century-scale trend in the number of major hurricanes."  For the most recent and reliable 200-year portion of this record, the cooler 19th century had five of the highest-damage F3 category storms, while the warmer 20th century had only one such storm.  Hence, as the earth experienced modest global warming in recovering from the worldwide chill of the Little Ice Age, it would appear that this part of the planet (New England, USA) experienced, if anything, a decline in the intensity of severe hurricanes.

In the interior of the United States, Changnon and Changnon (2000) examined hail-day and thunder-day occurrences over the 100-year period 1896-1995 in terms of 20-year averages obtained from records of 66 first-order weather stations distributed across the country.  They found that the frequency of thunder-days peaked in the second of the five 20-year intervals, while hail-day frequency peaked in the third or middle interval.  Thereafter, both parameters declined to their lowest values of the century in the final 20-year period.  Hail-day occurrence, in fact, decreased to only 65% of what it was at mid-century, accompanied by a drop in national hail insurance losses over the same period.

After completing this large regional study, Changnon (2001) turned his attention to an urban and a more rural site in Chicago in an attempt to determine if there might be an urban influence on thunderstorm activity.  Over the 40-year period investigated (1959-1998), he found the urban station to have experienced an average of 4.5 (12%) more thunderstorm days per year than the more rural station; and statistical tests revealed this difference to be significant at the 99% level in all four seasons of the year.  In view of ongoing population growth over this period, the results of Changnon and Changnon (2000) would thus be considered, if anything, to be conservative, suggesting that the decreases in hail- and thunder-days they found for the interior of the United States over the last half of the 20th century may well have been even greater than what they determined them to be.

Moving south, Liu and Fearn (1993) studied sediment cores taken from the center of Lake Shelby in Alabama to determine the history of intense hurricane activity there over the past 3500 years, finding that "major hurricanes of category 4 or 5 intensity directly struck the Alabama coast ... with an average recurrence interval of ~600 years," the last of which super-storms occurred around 700 years ago.  They further note that "climate modeling results based on scenarios of greenhouse warming predict a 40% - 50% increase in hurricane intensities in response to warmer tropical oceans," suggestive of the likelihood that if one of these severe storms (which is now about a century overdue) were to hit the Alabama coast again, climate alarmists would be citing its occurrence as vindication of their doomsday predictions.  In reality, however, it would be nothing more than an illustration of the age-old adage that history repeats itself.

Examining a larger geographical area was Hayden (1999), who investigated storm frequencies over North America between 25° and 55°N latitude and 60° and 125°W longitude from 1885 to 1996.  Over this 112-year period, large regional changes in storm occurrences were observed; but when integrated over the entire geographic area, no net change in storminess was evident.

Out over the open sea, Graham and Diaz (2001) developed a climatology of North Pacific Ocean (30°N-50°N, 150°E-130°W) cyclones having a sea level pressure of 975 mb or less, based on sea level pressure obtained from NCEP/NCAR reanalysis data for the period 1948-1998, finding the frequency of such cyclones to be increasing at a linear rate of 0.2 per year, or by an average of 10 cyclones per half century.  In a study of the entire Northern Hemisphere, however, Gulev et al. (2001) developed a winter climatology of cyclones that reached a sea level pressure of 1000 mb or lower, also based on sea level pressure obtained from NCEP/NCAR reanalysis data, for the period 1958-1999, deriving a linear trend over time (significant at the 95% level) indicative of a decline in cyclone numbers of 1.2 per year, which indicates there are now, on average, 50 fewer winter cyclones in the entire Northern Hemisphere than there were only 42 years ago, once again revealing an overall trend that is just the opposite of what climate alarmists continue to predict.

Results of research conducted in the Southern Hemisphere are also at odds with the predictions of those who are attempting to scare the world into embracing the Kyoto Protocol.  De Lange and Gibb (2000), for example, analyzed trends in sea level data over the period 1960-1998 - which they obtained from tide gauges located within Tauranga Harbor, New Zealand - finding that (1) there was a considerable decline in the annual number of storm surge events in the latter half of the nearly four-decade-long record, (2) there was a similar trend in the magnitude of storm surges, and (3) maximum water levels, including tides, also declined over the past two decades, which, of course, is the period of time the climate alarmists associate with unprecedented global warming.

On a much longer time scale, Hayne and Chappell (2001) tested the hypothesis that "global warming leads to an increase of cyclone frequency or intensity" in a study of a series of storm ridges at Curaco Island on the central Queensland shelf of Australia that were deposited there over the past five millennia.  Their primary finding, in their own words, was that "cyclone frequency was statistically constant over the last 5,000 years," with "no indication that cyclones have changed in intensity."

Additional evidence that storminess will not increase as a result of global warming - due to any factor - is to be found in an analysis of the frequencies of Southern Hemispheric extratropical cyclones of more recent occurrence.  Using a new cyclone finding and tracking scheme to conduct what Simmonds and Keay (2000) refer to as "arguably the most reliable analysis of Southern Hemisphere cyclone variability undertaken to date," these researchers found that the annual number of cyclones experienced a steady increase from 1958 to 1972, whereupon a decline began that culminated in the counts in the 1990s being "particularly low."  This oscillation was essentially out-of-phase with the region's temperature history, suggesting to the authors that the downward trend in cyclone numbers over the last quarter of the 20th century was "associated with a warming Southern Hemisphere."

Lastly, Key and Chan (1999) analyzed trends in seasonal and annual frequencies of low-pressure centers (cyclones) at 1000- and 500-mb heights for six latitude regions (0-30°N, 0-30°S, 30-60°N, 30-60°S, 60-90°N and 60-90°S) over the four-decade period 1958-1997.  When considering the results for all latitudes at both heights, trends in cyclone frequencies turned out to be pretty much of a wash, with both positive and negative trends occurring.  When the data were stratified according to warmer El Niño versus cooler La Niña years, however, cyclone frequencies were found to be lower at all latitude regions except two (30-60°S and 60-90°S) during warmer El Niño years.

In conclusion, it is abundantly clear from the real-world observations reviewed in this Summary, as well as our Summary on Hurricanes, that as the earth has warmed over the past hundred or so years (during its recovery from the global chill of the Little Ice Age), there has been no significant increase in either the frequency or intensity of stormy weather over the globe.  This fact, coupled with the fact that storminess in many regions of the world has actually decreased as local or regional temperatures have risen, suggests there is little reason to believe that storms will suddenly get worse if the world were to warm somewhat more in the future.

It is thus becoming ever more difficult for the prosecutors of the case against anthropogenic CO2 emissions to maintain there is a "discernible human influence" on global climate, since the alleged crime scene is almost totally devoid of human fingerprints.  Nevertheless, they continue to do so, hoping you won't take the time to share the information on our website with any of your friends or associates, including your elected representatives.  Why not prove them wrong on this point too!

References
Bielec, Z.  2001.  Long-term variability of thunderstorms and thunderstorm precipitation occurrence in Cracow, Poland, in the period 1896-1995.  Atmospheric Research 56: 161-170.

Bijl, W., Flather, R., de Ronde, J.G. and Schmith, T.  1999.  Changing storminess?  An analysis of long-term sea level data sets.  Climate Research 11: 161-172.

Boose, E.R., Chamberlin, K.E. and Foster, D.R.  2001.  Landscape and regional impacts of hurricanes in New England.  Ecological Monographs 71: 27-48.

Changnon, S.A.  2001.  Assessment of historical thunderstorm data for urban effects: the Chicago case.  Climatic Change 49: 161-169.

Changnon, S.A. and Changnon, D.  2000.  Long-term fluctuations in hail incidences in the United States.  Journal of Climate 13: 658-664.

De Lange, W.P. and Gibb, J.G.  2000.  Seasonal, interannual, and decadal variability of storm surges at Tauranga, New Zealand.  New Zealand Journal of Marine and Freshwater Research 34: 419-434.

Graham, N.E. and Diaz, H.F.  2001.  Evidence for intensification of North Pacific winter cyclones since 1948.  Bulletin of the American Meteorological Society 82: 1869-1893.

Gulev, S.K., Zolina, O. and Grigoriev, S.  2001.  Extratropical cyclone variability in the Northern Hemisphere winter from the NCEP/NCAR reanalysis data.  Climate Dynamics 17: 795-809.

Hayden, B.P.  1999.  Climate change and extratropical storminess in the United States: An assessment.  Journal of the American Water Resources Association 35: 1387-1397.

Hayne, M. and Chappell, J.  2001.  Cyclone frequency during the last 5000 years at Curacoa Island, north Queensland, Australia.  Palaeogeography, Palaeoclimatology, Palaeoecology 168: 207-219.

Key, J.R. and Chan, A.C.K.  1999.  Multidecadal global and regional trends in 1000 mb and 500 mb cyclone frequencies.  Geophysical Research Letters 26: 2053-2056.

Liu, K.-b. and Fearn, M.L.  1993.  Lake-sediment record of late Holocene hurricane activities from coastal Alabama.  Geology 21: 793-796.

Pirazzoli, P.A.  2000.  Surges, atmospheric pressure and wind change and flooding probability on the Atlantic coast of France.  Oceanologica Acta 23: 643-661.

Simmonds, I. and Keay, K.  2000.  Variability of Southern Hemisphere extratropical cyclone behavior, 1958-97.  Journal of Climate 13: 550-561.

Zhang, K., Douglas, B.C. and Leatherman, S.P.  2000.  Twentieth-Century storm activity along the U.S. East Coast.  Journal of Climate 13: 1748-1761.