Could global warming change tornado season, too?  Published:
Friday, March 15, 2013 at 4:38 p.m. Last Modified: Friday, March
15, 2013 at 4:38 p.m.  OKLAHOMA CITY (AP) — With the planet
heating up, many scientists seem fairly certain some weather
elements like hurricanes and droughts will worsen. But tornadoes
have them stumped.  These unpredictable, sometimes deadly storms
plague the United States more than any other country. Here in
tornado alley, Oklahoma City has been hit with at least 147
tornadoes since 1890.  But as the traditional tornado season
nears, scientists have been pondering a simple question: Will
there be more or fewer twisters as global warming increases?
There is no easy answer. Lately, tornado activity in America has
been Jekyll-and-Hyde weird, and scientists are unsure if climate
change has played a role in recent erratic patterns.  In 2011,
the United States saw its second-deadliest tornado season in
history: Nearly 1,700 tornadoes killed 553 people. The Joplin,
Mo., twister was the si