Scientists have found links between a warming planet and hurricanes, heat waves, and droughts, suggesting that climate change may have played a role in these events. However, connecting tornadoes to climate change has proven to be more challenging. Despite ongoing research on tornado trends and behavior, the extent to which climate change impacts tornadoes remains uncertain. Many questions regarding the relationship between climate change and tornadoes still lack definitive answers, according to experts in the field. Tornadoes are created within large rotating thunderstorms as a result of a combination of temperature, moisture profile, and wind profile. They form when unstable air causes cold air to move over warmer humid air, creating an updraft as the warm air rises. If wind speed or direction changes abruptly over a short distance, the air inside the clouds can begin to spin. Tornadoes, like hurricanes and earthquakes, are classified on a scale called the Enhanced Fujita, or EF, scale, which ranges from 0 to 5. The tornado that swept through northeast Arkansas, Tennessee, and western Kentucky recently was approximately three-quarters of a mile wide and had wind speeds reaching between 158 and 206 mph, earning it a minimum EF rating of 3. Because it is difficult to directly measure the winds within a tornado, experts typically assess tornadoes based on the extent of damage to various structures. This may involve determining whether only roof shingles are missing or if entire sections of roofs or walls have been destroyed. By analyzing the damage, researchers can estimate the wind speeds and assign a rating to the tornado. There is evidence to suggest that tornado patterns have changed in recent years, with tornadoes occurring in more concentrated "clusters" and the traditional tornado alley in the Great Plains shifting eastward. The total amount of tornadoes each year remains consistent at approximately 1,200. Tornadoes in the US during December are uncommon, as they usually happen in the spring. The tornadoes on Friday may have been caused by high wind shear, which is typically at its highest during the winter, and warmer than usual weather. The text raises the question of whether climate change is the reason for these occurrences. The elements that contribute to tornado formation are warm, moist air near the ground, cool dry air at higher altitudes, and wind shear, which refers to changes in wind speed or direction. These factors may be impacted differently by climate change. According to Brooks from NOAA, as the planet heats up and the climate shifts, these factors may not all change in the same way. While temperature and humidity may increase, providing more energy in the atmosphere, wind shear may not. Without sufficient wind shear to create rotation, the strength of the energy does not matter. The small size of tornadoes makes it difficult to model them accurately for attributing extreme weather events to climate change. The tornado record is limited compared to other types of events, possibly because tornadoes are localized weather events and are typically reported by individuals who witness them. This indicates that smaller or unnoticed tornadoes may go unreported. ©2021 The New York Times Company.