Geoscience Reference
In-Depth Information
20 Extreme weather and global warming
Anthony Watts
Up until recently, the posited effects of an increased global average surface temperature
were mostly limited to the direct effects of temperature itself. These included sea level rise
(by thermal expansion of ocean water and ice-melt of the ice caps), shrinking glaciers, and
longer, more intense heat waves, to name a few.
Most of these are somewhat distant effects for the average person. The average person
living in the midwestern United States wouldn't be affected at all by sea level rise, or loss
of glaciers, or the shrinking of the ice caps. That person might be affected by increased
temperature and possibly an extended heat wave, but both of these are things that can be
adapted to. Low-cost air-conditioners are accessible to a vast majority of the population,
which wasn't the case during the dust bowl years and other heat waves of the past in
America.
Essentially, these posited effects of an increased global average surface temperature just
aren't much of a concern in the daily lives of many people. Even people who live in coastal
zones can't detect the slow pace of sea level rise within their lifetimes, which ranges from
observations. Assuming the rates hold, over a 70 year lifetime, such changes would amount
to 111mm (4.3inches) to 231mm (9.1inches). The rate ofchange is soslow as to be almost
undetectableinthehumanexperience.Likewise,therateofglobaltemperaturechangesince
the early twentieth century is generally agreed to be about 0.8°C (1.4°F), again so small
to be almost undetectable in the human experience. In fact, if the global average surface
temperature data is plotted in the same scale as a standard outdoor home thermometer, the
change of the last 130 years is hardly even visible, as this graph of NASA Goddard Institute
for Space Studies (GISS) data shows in Figure 1.
