Next month will be the anniversary of the massive tornado outbreak that killed 26 people in Oklahoma. A quick drive through Moore and you will see the cleanup and rebuilding is still underway.
Last night tragedy struck Oklahoma again, as a tornado outbreak killed at least 16 people in Oklahoma, Arkansas, and Iowa. With the threat of tornadoes still looming in the southern states, people are asking what impact climate change has on these storms. This is not an easy question to answer.
Last year after the deadly tornadoes in Oklahoma, Scientific American asked climate scientist, Kevin Trenberth of the National Center for Atmospheric Research in Boulder, Colo., if climate change could be causing more tornadoes:
“The main climate change connection is via the basic instability of the low-level air that creates the convection and thunderstorms in the first place. Warmer and moister conditions are the key for unstable air. The oceans are warmer because of climate change.
The climate change effect is probably only a 5 to 10 percent effect in terms of the instability and subsequent rainfall, but it translates into up to a 33 percent effect in terms of damage. (It is highly nonlinear, for 10 percent it is 1.1 to the power of three = 1.33.) So there is a chain of events, and climate change mainly affects the first link: the basic buoyancy of the air is increased. Whether that translates into a supercell storm and one with a tornado is largely chance weather.”
Harold Brooks, research meteorologist at NOAA’s National Severe Storms Laboratory in Norman, Okla., talked to Accuweather about this issue.
“As the planet warms with more greenhouse gases, we really don’t have very strong evidence as to what will happen with severe thunderstorms…
As the planet warms, the moisture content of the atmosphere will also increase. And that’s the basic fuel that drives thunderstorms. It’s where the storms get their energy from… as we warm the planet that will increase the energy available for producing storms… The other primary ingredient, the shear that organizes the storm, is likely going to decrease.”
There is currently not enough evidence to prove a link between tornadoes and climate change. However, there are links between climate change and extreme weather.
“The rise in natural catastrophe losses is primarily due to socio-economic factors. In many countries, populations are rising, and more and more people moving into exposed areas. At the same time, greater prosperity is leading to higher property values. Nevertheless, it would seem that the only plausible explanation for the rise in weather-related catastrophes is climate change. The view that weather extremes are more frequent and intense due to global warming coincides with the current state of scientific knowledge as set out in the Fourth IPCC Assessment Report.” – read more
More research is being done all the time to look at how climate change is impacting our weather and one thing is clear, we are entering uncharted territory.