University of Wyoming scientists say average temperatures in the state have risen three degrees over the last 30 years. And that could be attributed to greenhouses gasses caused by the burning of fossil fuels and the clearing of forests.
Bryan Shuman teaches geology and geophysics at U-W. He says decades ago, nighttime January temperatures in Cheyenne would drop to negative 20 degrees or lower. But in the last three decades, there have been only a handful of times were temperatures dropped to below negative-five. Shuman says nighttime January temperatures in Laramie are as warm as they used to be in Cheyenne.
"And of course Laramie is quite a bit higher in elevation than Cheyenne, says Shuman. "So if our temperatures have warmed up to be like what it was like at lower elevation, then it’s not surprising that things, like up in the mountains, that you see things like tree lines starting to move up the mountain because those cold temperatures have moved up in elevation as well."
Shuman says the increase in winter temperatures is an important sign of global warming caused by greenhouse gasses, because nighttime, winter temperatures are not readily explained by solar energy influencing the states climate, ocean variability, or other natural cycles in the Earth’s system.