The summers in the country’s first and oldest national park are heating up quickly, new research results. Over the past two decades, Yellowstone National Park has warmed at the fastest rate in at least 1,250 years.
2016 was the warmest the region had seen since 770.
The study published in the journal Geophysical research lettersused data from tree rings to reconstruct more than a millennium of summer temperatures in the Yellowstone region. Tree rings can provide a lot of information about a tree’s climate and weather conditions over the course of its life.
Led by Karen Heeter at the University of Idaho in Moscow, the researchers collected samples from live and fossilized Engelmann spruce in northwest Wyoming, including trees in Yellowstone National Park and the nearby Shoshone National Forest. Some samples were more than a thousand years old.
The samples helped scientists create a timeline of Yellowstone’s climate that focuses on August temperatures – the hottest time of the year.
They used a special type of analysis known as “blue intensity,” a relatively new method that measures the amount of blue light reflected from tree rings. This method helps scientists determine the density of tree rings, a property that is closely related to the summer temperatures experienced by the tree during its lifetime.
It’s one of the few tree ring records in North America that dates back to this day, scientists say. Most of the others go back only a few hundred years.
They found that Yellowstone had ups and downs over the past millennium, including periods of warming and cooling. However, recent human-made climate change has taken an unprecedented toll. The region’s strongest warming has occurred since 2000.
However, there are lessons to be learned from the past. The researchers found that other significant warm periods in Yellowstone’s history coincided with major climate-related disasters.
For example, 1988 was the fourth warmest year on record. It was also unusually dry. That year, a series of catastrophic forest fires swept the park, burning nearly 800,000 acres of land.
The fifth warmest period on the record, extending from 1931 to 1940, coincides with the extreme drought of the Dust Bowl era.
Scientists have warned that continued climate change in the Yellowstone region and the western United States could increase the likelihood of severe droughts and the risk of large forest fires. The current rate of warming gives cause for concern that the park could be on the way to dramatic changes in the coming decades, the researchers note.
“The rate of heat over a relatively short period of time is alarming and has important implications for ecosystem health and function,” Heeter said in a statement.
Reprinted from E&E News with permission from POLITICO, LLC. Copyright 2021. E&E News provides important news for energy and environmental professionals.