Deadly Dozen Extreme Weather Events of 2011

2011 was a banner year for weather. It was cold, wet, dry and hot, depending what part of the country you inhabit. And according to new analysis by the National Oceanic and Atmospheric Administration there were 12 weather events that each cost over $1 billion, setting a new record.

Jack Hayes, head of the National Weather Service says in his 40-year weather career he’s never seen a year quite like 2011, where floods, wildfires, tornadoes and blizzards all set records.

Here are the disasters that we’ll be talking about for years.

Billion-dollar disasters of 2011 (as of Dec. 7, 2011), courtesy of NOAA

Groundhog Day blizzard » January 29-February 3, 2011

Midwest/Southeast tornadoes » April 4-5, 2011

Southeast/Midwest tornadoes » April 8-11, 2011

Midwest/Southeast tornadoes » April 14-16, 2011

Southeast/Ohio Valley/Midwest tornadoes » April 25-28, 2011

Midwest/Southeast tornadoes » May 22-27, 2011

Midwest/Southeast tornadoes and severe weather » June 18-22, 2011

Southern Plains/Southwest drought and heatwave » Spring-Fall, 2011

Mississippi River flooding » Spring-Summer, 2011

Upper Midwest flooding » Summer 2011

Hurricane Irene » August 20-29, 2011

Texas, New Mexico, Arizona wildfires » Spring-Fall 2011

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Wildfires in Texas, New Mexico and Arizona from spring to fall fueled by a drought in the southwest exacerbated the problem, costing at least $1 billion in damage and killing five people.

Hurricane Irene blew up the eastern seaboard in late August, causing at least $7.3 billion in damage and killing 45 people.

Flooding in the upper Midwest along the Missouri and Souris rivers during the summer caused more than $2 billion in damaged and left at least five people died.

Flooding along the Mississippi River in spring and summer brought losses there between $3 billion and $4 billion and killed at least two people .

Drought and heat wave in the southern plains and Southwest from spring to fall cost the region $10 billion.

Tornadoes and severe storms in June tore through the Midwest and Southeast, causing at least $1.3 billion in damage and killing at least three people.

A tornado outbreak in the Southeast and Ohio Valley in late April left 321 people dead and caused $10.2 billion in damage.

Another string of tornadoes in the Midwest and Southeast in mid April killed 38 people and left a $2.1 billion path of destruction.

The first tornado outbreak of 2011 hit the Midwest and Southeast in early April, causing more than $2.8 billion in damage and killing nine people.

Just days later another set of twisters flattened parts of the Southeast and Midwest, causing over $2.2 billion in damage.

Another tornado outbreak in the Midwest and Southeast in May killed 177 people and caused more than $9.1 billion in damage.

The first big weather event of 2011 was the Groundshog Day blizzard, also known as Snopocalypse. It killed 36 people and caused more than $1.8 billion in damage.

Then there was the pre-Halloween blizzard that paralyzed cities, killed 27 people and caused $3 billion in damage.

And there are still a few weeks to go in the year before all the totals can be calculated.

NOAA chief Jane Lubchenco told scientists at the American Geophysical Union meeting this week that despite being a record-breaking year for weather disasters, 2011 was not an aberration.

She says, “What we are seeing this year is not just an anomalous year, but a harbinger of things to come for at least a subset of those extreme events that we are tallying.”

Dr. Lubchenco believes that some of the increase in frequency appears to be driven by climate change.

One of the largest reinsurance companies, Munich Re, agrees. In a 2010 report the company said, “The only plausible explanation for the rise in weather-related catastrophes is climate change.”

But 2011 was also a La Nina year, which meant that weather patterns were cooler and wetter than average (except where La Nina made it hotter and drier.) That could explain it right? Not quite.

And, as for the high cost of damage. More people are living in populated areas so when a weather disaster hits it affects more people.

But that doesn’t explain away the appearance of more extreme weather events. But is climate change responsible for this extreme weather?

Prevailing scientific wisdom says that you can’t attribute a single event to climate change.

Kevin Trenberth, the head of the climate analysis division of the National Center for Atmospheric Research says, “But there is a systematic influence on all of these weather events now-a-days because of the fact that there is this extra water vapor lurking around in the atmosphere than there used to be say 30 years ago.

In the last 30 years the amount of water in the atmosphere has increased by about four percent. Dr. Trenberth says that seemingly small increase “invigorates the storms, it provides plenty of moisture for these storms and it’s unfortunate that the public is not associating these with the fact that this is one manifestation of climate change.”

Last year, he told the New York Times, “It’s not the right question to ask if this storm or that storm is due to global warming, or is it natural variability. Nowadays, there’s always an element of both.”