Damaging storms are causing some to question how much climate change is costing Arizona. A look at insurance data suggests it could be more than a billion dollars a year and rising. Critics say it's impossible to prove climate change has caused any specific natural disaster, but Laurie Johnson of the Natural Resources Defense Council says a pattern is emerging.
"Basically when you're warming up the atmosphere you are turbo charging any natural weather events that happen," Johnson said. "You can't say any one event is due to climate change but you can look at an overall pattern."
Insurance data indicates bad weather cost Arizona $1.6 billion in 2012, making it the second most expensive year on record. It also shows 13 of the 20 worst United States natural disasters since 1950 have taken place since 2000.