Page 8 - GEL 1103 เอกสารประกอบการเรียนบทที่ 2

English for Communication and Study Skills

Floods, Heat Waves, and droughts
Global warming has changed the pattern of precipitation
worldwide. Flooding in the northern half of the eastern United States, the
Great Plains, and over much of the Midwest has been increasing,
especially over the past several decades. These regional flooding trends in
the Northeast and upper Midwest are linked to increases in extreme
precipitation and are consistent with the global trends driven by climate
change. At the same time, areas such as the U.S. Southwest are
witnessing more droughts, and these too are consistent with global
climate change patterns projected by climate models as a consequence of
rising CO levels.
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Since 1950, heat waves worldwide have become longer and more

frequent. One study indicates that the global area hit by extremely hot
summertime temperatures has increased fifty-fold, and the fingerprint of
global warming has been firmly in these trends. In the United States, new
record high temperature more regularly out number new record lows by a
ratio of 2:1.

Wilde fires
Climates change has amplified the threat of wildfires in many
places. In the western United States, both the area burned by wildfires and
the length of the fire season have increased substantially in recent
decades. Earlier spring snowmelt and higher spring and summer
temperatures contribute to this change. Climate change has increased the
thread of “mega-fires”—large fires that burn proportionately greater
areas. Warming has also led to wildfires encroaching on some regions
where have been absent in recent history.

Smog
Smog is a type of air pollutant. The word “smog” was coined in the
th
early 20 century as a portmanteau of the words smoke and fog to refer to
smoky fog. The word was then intended to refer to what was sometimes
known as pea soup fog, a familiar and serious problem in London from
th
th
the 19 century to the mid 20 century. This kind of visible air pollution
is composed of nitrogen oxides, sulfur oxides, ozone, smoke or
particulates among other (less visible pollutants include carbon monoxide,
CFCs and radioactive sources). Man-made smog is derived from coal
emissions, vehicular emissions, industrial emissions, forest and
agricultural fires and photochemical reactions of these emissions.
Modern smog, as found for example in Los Angeles, is a type of air
pollution derived from vehicular emission from internal combustion
engines and industrial fumes that react in the atmosphere with sunlight to

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