No evidence exists that climate change has led to more tornadoes or stronger ones, experts said Wednesday at a House hearing exploring the links between global warming and severe weather events.

“Tornadoes in the United States have not increased in frequency, intensity or normalized damage since 1950,” said Roger Pielke Jr., the director of the Center of Science and Technology Policy Research at the University of Colorado.

“And based on research we've done, there's some evidence in fact that they've actually declined — the strongest tornadoes.”

Pielke was one of three researchers from U.S. universities who testified before a House Science, Space and Technology subcommittee about severe weather and climate change. The Republican-controlled subcommittee sought to debunk oft-cited claims that climate change has contributed to severe droughts and storms in recent years.