  Ask Tom Why  September 18, 2004|By Tom Skilling  Dear Tom,
Your answer to a question of what causes global warming was
evasive and misleading. Your answer made it sound like the
recent dramatic warming is just part of the natural order, which
it certainly is not.  Dr. Michael Savina, Argonne National
Laboratory  Dear Dr. Savina,  I believe you misunderstood my
answer, because we are in agreement. Climatologists generally
agree that Earth's temperature has risen about 11(degrees)F
since the peak of the last ice age 12 thousand years ago. At
least 9(degrees) of that warming, roughly at an average rate of
1(degrees) per thousand years, occurred before man's presence
became a factor. However, 1.5(degrees) of warming has occurred
in just the last 150 years--an alarming increase in the rate of
warming--and there is growing consensus that man's addition of
"greenhouse gases" to the atmosphere is the root cause of that
accelerated warming.