Introduction - The Global Climate System: Patterns, Processes, and Teleconnections - page 15

witnessed than the ones they hear or read about. This tendency is reinforced
by the local media, when they report for specific geographic locations,
for example, that ''this is the worst drought in 8 years'' or ''the heaviest
flooding in 3 years'' or ''the hottest summer in 5 years.'' While these may be
interesting facts, they are not very useful when it comes to understanding the
behavior of the regional climate system. More serious are media reports of
extremes that are unusual occurrences on the multi-decade scale.
Most likely, people do not recall the societal inconveniences of the inten-
sity of the drought in the US northeast in the mid 1960s that prompted
President Johnson to create a drought task force to identify ways to mitigate
the severity of its impacts, if not to avoid future droughts in the urban centers.
Yet, when drought struck New York City in 2001, policy makers, the public,
and the media viewed the recent urban drought as an unprecedented event. As
another example, people believe that the winters were snowier or that snow-
drifts were higher in the past, when they were younger, than today. However,
such perceptions of reality need to be compared to the actual climate record.
Perceptions about what constitutes normal climate conditions can be
manipulated. For example, in the 1800s railroad companies sold land in the
US West advertising the land as fertile for agriculture, as they expanded their
rail lines westward into arid and semiarid areas. This could be called ''green-
washing'', where a government tried to convince people to settle in new areas
where the climate-related conditions might not be conducive to sustained
human activities such as agriculture.
Burroughs ( 2002 ) noted: ''This personalized outlook on climate tends also
to view any unpleasant event as being way outside past experience. Fanned in
part by media hype, every storm, flood, heat wave or snowstorm is seen as
having exceptional characteristics ...In many instances however, unpleasant
weather is nothing more than part of the normal fluctuations that make up
climate ...our memories are often of snowy winters, balmier springs, long
hot summers or sunlit autumns. Unfortunately, these recollections have much
more to do with how our memories embellish features of long ago and little to
do with real climate change.'' Thus, what people believe to be normal climate
in their area may not be normal at all. A sign captures what I think people
need to keep in mind when it comes to their regional climate: ''Don't believe
everything you think.''
Normal climates' extremes
Anomalies denote the departure of an element (rainfall, temperature, etc.)
from its long-period average value for the location concerned. For example, if
the maximum temperature for June in Melbourne was 18C higher than the
long-term average for this month, the anomaly would be þ 18C (http://
www.bom.gov.au/climate/glossary/anomaly.shtml). Anomalies are of concern