Less snow forecast for Tahoe basin in coming decades
The snow season at Lake Tahoe, which famously draws millions of skiers to the area’s powdery slopes each year, is likely to shrink by at least a month, and perhaps three months, by the end of the century, according to a recent report on the impacts of climate change on the region.
Temperatures around the lake, projected to rise as much as 9 degrees Fahrenheit by 2100, will simply be too warm at the beginning and end of the traditional ski season for snow to fall, the report said. What’s already on the ground will also melt more quickly.
The decline in snow is expected to be most severe on the north and east sides of the Tahoe basin, notably around Kings Beach, Incline Village and points farther south along the Nevada shore, toward South Lake Tahoe.
The report, published earlier this year by the Desert Research Institute in Nevada, echoes much of what scientists have previously said — and warned — about the changing climate at the lake. However, the document offers greater detail on what could happen, notably drilling down on the impacts on specific parts of the region. The findings are based on simulations of the lake’s future hydrology.
“In order to make decisions about how to prepare for climate change, how to adapt to changes that are already happening or coming, you’re going to need more than just basin (wide) numbers,” said Mike Dettinger, research hydrologist at the Desert Research Institute, who co-authored the report with fellow hydrologist Seshadri Rajagopal. “It’s about getting numbers that are needed to mobilize action.”
The effort was commissioned by the California Tahoe Conservancy, a state agency established in 1985 to protect the basin. The conservancy’s work
has increasingly turned to preparing for the warming climate, and the agency is now leading a regional effort to help communities adapt.
As might be expected, some of the biggest changes cited in the report were dips in snow and snowmelt.
Peak snowpack for the region, as traditionally measured on April 1, is projected to drop 60% to 80% or 80% to 100% of the historical average by late century, depending on levels of carbon pollution going forward.
The researchers basically examined two future scenarios, one in which worldwide emissions are cut back and one in which emissions continue unabated.
Eight popular climate models were used to run the simulations.
Under the more extreme scenario, parts of the Tahoe basin’s northern and eastern sides would have little or no snow at the beginning of April by 2100.
“Obviously, it’s a tremendous concern for us,” said Mike Reitzell, president of Ski California, a trade association representing 35 ski resorts in California and Nevada, which is advocating for a stronger global response to climate change. “We hope that it doesn’t get that bad.”
The snowmelt, which is critical for maintaining stream flows and water supplies through California’s dry spring and summer months, would drop 10% to 20% basin-wide by late century if emissions are reduced and up to 50% if they’re not, according to the report.
The flow of rivers and creeks overall, however, would not decline. While the amount of snow is projected to plunge with rising temperatures, total precipitation is not expected to change — just more rain instead of snow — and, in fact, precipitation could increase up to 15% by 2100, the report said.
The rain also will likely come in more concentrated bouts, according to the report, doubling flood risk by the end of the century in parts of the basin. The biggest streamflow increases are projected on the east side of the lake.
The large streamflows are significant because they could carry dirt and debris, disturbing Lake Tahoe’s distinctively clear water.
Dettinger said he hopes the report will serve as a call to action for the communities involved in adapting to climate change, whether it’s by hardening infrastructure or making greener accommodations, such as restoring meadows or widening flood plains.
He noted that the region, with its wealth, its environmental ethic and its relatively large population, has what it needs to succeed.
“If we can’t figure out how to make preparations for climate change in the Tahoe basin,” Dettinger said, “I don’t know any place we can figure it out in the mountain West.”