Near the top of the results of Google new search of the phrase climate change today is a post from KPTM Fox 42 in Omaha, Nebraska claiming climate change is contributing to an increase in extreme weather events. This is false. Real-world data and the most recent report from the U.N. Intergovernmental Panel on Climate Change (IPCC) indicate the incidences of extreme weather events are not increasing, nor are the duration or severity of such events worsening.
For the article, titled “State Climatologist says climate change is contributing to severe weather,” KPTM Omaha interviews Martha Shulski, Nebraska’s state climatologist concerning recent severe weather events which hit the state.
Shulski linked these events to climate change.
“‘Climate change is something that it is real and here now,’” Shulski told KPTM, continuing, “‘It really impacts everything, the question is not did climate change cause it, the question is more how much worse was it made with climate change. There is a climate change signature on all of these events we experience, its really just a matter of how strong of a signature.’”
Nobody disputes climate change is occurring. Climate has changed on local, regional, continental, and global scales across the course of history. However, available data does not show ongoing climate change is making instances of extreme weather more common or more severe.
The KPTM article discusses a recent spate of tornadoes which struck Iowa and Nebraska in mid-December. Concerning tornadoes, the IPCC states, “There is low confidence in observed trends in small spatial-scale phenomena such as tornadoes.”
As discussed in Climate at a Glance: Tornadoes, data conclusively shows the number of tornadoes has been declining for the past 50 years, and, as shown in the figure below, the number of strong tornadoes, F3 or higher, has been dramatically declining for the past 50 years.
From 2017 through 2018, the U.S. set a record for the longest period in history without a tornado death. Also in 2017 and 2018, the U.S. set a record for the longest period in history without an F3 or stronger tornado. The two record-low years for number of tornadoes both occurred this past decade, in 2014 and 2018, a decade which climate alarmists have regularly described as the warmest on record. Even counting the recent December tornadoes, the number of tornados recorded in 2021 has been below average.
Concerning flooding, another extreme weather event Shulski links to climate change in the KPTM story, there has been no increase flooding frequency or severity as the climate modestly warms. The IPCC admits having “low confidence” in any climate change impact regarding the frequency or severity of floods. Although the IPCC states in its recent 6th Assessment Report, “the frequency and intensity of heavy precipitation have likely increased at the global scale over a majority of land regions with good observational coverage,” it explicitly states “heavier rainfall does not always lead to greater flooding.”
In addition, the IPCC writes, “Confidence about peak flow trends over past decades on the global scale is low, … [and] there is low confidence in the human influence on the changes in high river flows on the global scale.”
The best available evidence shows extreme weather is neither more frequent, nor more severe than it has been historically. Shulski was wrong to say otherwise, and KPTM was wrong to report her claims without checking the facts.