By the end of this century, the Greater Yellowstone region could endure great strains to its temperate ecosystems with warming trends bringing seasons up to 9.7 degrees higher.
These higher temperatures could turn Yellowstone National Park summers as hot as the Los Angeles suburb of Culver City, according to the first ever-comprehensive climate report for this area.
“What we humans are doing to the climate isn’t just melting polar ice caps, it’s disrupting the places that are nearest and dearest to us,” said Stephen Saunders, Rocky Mountain Climate Organization (RMCO) president and lead author of the report, a collaboration by RMCO and the Greater Yellowstone Coalition (GYC). “Already, threads are being pulled out of the tapestries of Yellowstone and other special places, and they are losing some of their luster.”
In the past decade Yellowstone temperatures have exceeded the worldwide rate of warming compared to the 20th-century average, and the effects are being felt now, said the report, which also showed the region is at its driest since 1985, when weather measurements began.
Two warming scenarios, developed by the Intergovernmental Panel on Climate Change, one based on a medium-to-high-range level of carbon emissions in the future and another one based on a lower set of carbon emissions – which shows averages projections for the summers at 5.6 degrees hotter – neither of which assumes new political strategies to reduce heat-trapping pollutants.
“With new policies it would be possible to hold future climate change to an even smaller degree,” said the report.
The groups compared data collected from five weather stations in the U.S. Historical Climatology Network (USHCN) in Greater Yellowstone that have extensive data records for the past 100 years to global temperature trends.
In the last decade (the hottest on record at 1 degree warmer than the 20th-century average), temperatures have averaged 1.4 degrees Fahrenheit higher than the century’s average for the region, which covers parts of Wyoming, Montana and Idaho. Summers are even hotter, averaging 2.3 degrees hotter than 20th-century summers.
The effect of even this relatively small amount of additional heat causes notable problems in many of the park’s most recognizable aspects. The reports shows the area’s forests being disrupted in ways that will fundamentally change them, such as substantial mortality of nearly half of whitebark pine trees, the dominant trees of Greater Yellowstone’s highest-elevation forests.
In July a decision by the U.S. Fish and Wildlife Service (FWS) declared the trees, which can live more than 1,000 years and provide food for grizzly bears and host of other wildlife, to be in “substantial and pervasive decline” – however, they have not yet been listed due to a backlog of uncompleted listing decisions for other species, said the report.
They are under assault in several ways, including temperature increase, a decrease of soil moisture and the non-native disease white pine blister rust, which has now infected essentially the tree’s entire range and kills and overwhelming majority of infected trees.
Another of its greatest and climate-induced effect has been the epidemic-sized infestations of tree-killing mountain pine beetle (MPB). While such episodes have occurred throughout recorded history, the high elevation’s prior cold and frost were “climactically inhospitable” to the MPB. Lower winter temperatures kept them at mostly two-year life cycles – not favorable to epidemic outbreaks – whereas warmer temperatures promote a one-year life cycle, leading to synchronize mass attacks that overcome host trees’ defenses.
The report also indicates that human suppression of wildfires has many whitebark pine areas undergoing succession to other conifers, due to fire’s regenerating effects. This and the other threats faced by the species are thought to interact and make regeneration after the fires, which are said to increase in severity and commonplace (the 1988 fires are projected to become more common) due to climate change, causing potential “danger of extinction.”
Other effects to the park include danger of elimination of aspens in the American West due to hotter and drier conditions the trees cannot withstand, a loss of wildflowers and increase in sagebrush, a reduction in key wetland areas and lower late-season water levels along with effects of reduced snow pack and hotter, drier summers on native species like the coldwater trout and a decline in food sources for animals like elk (whose birth rates have lowered in recent years), whose main food sources dry up too quickly.
Also cited are effects not only on the wildlife and ecosystems but also on the human beings who enjoy them. Floods, delayed openings of the north park’s winter over-snow season until as late as January, a drop in fishing permits and increase in restrictions and greater conflicts with pre-hibernation bears are just some consequences of the warming trends that are predicted will affect visits to the national park.
These outcomes as well as the melting of glaciers in the Wind River Range and the Greater Yellowstone area were discussed at the GYC’s annual meeting on Friday at Snow King Resort. Western Wyoming Community College professor of geology and anthropology Dr. Charlie Love came to share his findings and pictures of the receding glaciers in this area, comparing photos as far back as the 1920s and as recent as last year.
In comparing photos of the Wind River Range, he said that there is no ice left from 1922 and the timberline has climbed about 100 feet.
“Is that evidence of global warming?” he said, adding that the impact of the melting will affect water supplies by melting ice reservoirs and losing storage capacities. “That would be evidence to me.”
Healy Hamilton, biodiversity scientist at the California Academy of Sciences and adjunct professor at San Francisco State University, came to discuss some statistical data presented in the climate report that details temperature and precipitation levels from the 1900s to 1970s to create a baseline used to determine how they have changed in the past 30 years.
Using Parameter-elevation Regressions on Independent Slopes Model (PRISM) weather stations already in place and interpolation to evaluate areas in between, Healy found that the winters have warmed somewhat drastically, especially in the last 10 years.
“The coldest part of January has disappeared,” she said, adding that while there was no clear trend in precipitation, the temperature is likely to continue its cooling trend and that these January minimum temperatures are the “most pervasive evidence of climate change.”
Healy said this data, especially that which shows many of the same places staying resistant (like the Wind River Range and Bear Tooth Plateau) and many continually being effected by the climate’s change, can be used to start implementing climate adaptation planning.
Dr. Robert E. Gresswell, research biologist and assistant professor in the Department of Ecology at Montana State University, discussed continued suppression efforts of invasive lake trout on the native cutthroat trout population, which also faces projected declines from warming waters in Yellowstone Lake.
He said that this summer biologists will have collected up to 210,000 lake trout and spent $1 million trying to fix what has become “ a national park issue, not just a fisheries issue.”
Gresswell said that cutthroat trout are a food source for up to 42 other species in the area, for which the lake trout cannot substitute due to the depths they swim in and because they spawn in lakes, not tributaries.
Cutthroat preservation “may be one of the most significant resource issues in the Greater Yellowstone Ecosystem,” he said. He added that this issue must become a national one, and that the program cannot survive on its present budget.
Author and Cora resident Gretel Ehrlich gave a presentation on the future of ice, sharing experiences from her trips to northwestern Greenland where melting glaciers have drastically altered life for the native people. She stressed the need for immediate action and a new way of thinking about the Earth.
“It’s like falling in love right before you die,” she said of the realization by mankind that their most loved places might be drastically changing.
The conference concluded with GYC’s climate-change program director Scott Christensen saying the group had identified at least 40 projects that could start immediately if the funds were present.
For more information, visit www.greateryellowstone.org or www.rockymountainclimate.org.
For the complete article see the 10-04-2011 issue.
Click here to purchase an electronic version of the 10-04-2011 paper.
Share on Facebook