Is Munich Re really suggesting that CO2 has caused "extreme natural catastrophes" to increase fivefold in North America over the last 30 years?

Twitter / billmckibben: Munich Re, world's largest ...

Munich Re, world's largest insurance company, says number of severe storms in the U.S.has doubled http://www.dw.de/dw/article/0,,16199514,00.html …

As weather conditions worsen, damage costs soar | Americas | DW.DE | 28.08.2012

...Experts at Munich Re have studied weather risks in North America since 1980. Their analysis shows a significant increase of severe storms in recent years. If in the 1980s there were about 50 severe storms per year, that number has risen to between 100 and 150 in recent years...Over the past 30 years, the number of extreme natural catastrophes has increased fivefold. "There is no other continent that shows such an upward trend," said Peter Hoeppe, head of global risk at Munich Re in an interview with the German business newspaper Handelsblatt.