In 2017, following one of the wettest winters in decades, California burned. Last November, far beyond fire season’s typical boundaries, it burned again in the Camp Fire and we watched as tens of thousands of structures were lost and lives irreparably changed. After the tragedy, fingers were pointed — PG&E, inadequate fire funding, poor forest management … but during California’s most destructive summer of wildfire, the state released its Fourth Climate Change Assessment, which named another cause. The study indicated that roughly half of the wildfire danger we are currently facing can be attributed to climate change.
Wildfire is the most recognizable climate-related threat the region is facing, but it’s not the only one. Rising snow levels have far-reaching consequences, including the risk of major flooding. Paradoxically, in spite of the added moisture, drought remains an ever-present danger. This community is one of many on the front lines of climate change, and one thing is certain — life in the mountains is set to change. Here, we look at some of the direct effects of climate change on the region thus far and what is in store for the future.
Has the train left the station?
By the end of the century, the state climate assessment warns, snowpack will “likely be eradicated” below 6,000 feet, and reduced by about 60 percent across much of the range. “Climate change is already underway in the Sierra Nevada region,” the study says, “affecting heat and precipitation extremes, with long-term warming trends, declining snowpacks, and changes in streamflow timing.” All changes occur, the study says, even if greenhouse gas (GHG) emissions are curbed early.
“It’s the extremes and the variability,” said Andy Rost, associate professor and chairman of the Department of Science and Technology at Sierra Nevada College. “We’re getting wetter winters and hotter summers and they’re happening closer and closer to each other. And with that we’re also getting more extreme [weather] events as the climate system destabilizes.”
Rost clarified that while temperature increases in the region have been expected and recorded, it is uncertain what kind of moisture trend will occur in the Tahoe region. It rests in a transition zone between the Southwest, which is predicted to become drier over time, and the Northwest, which is becoming wetter. According to Rost, it looks like we are trending toward the latter for the time being — but the jury is out on how long that trend holds.
Drought on one hand, flood on the other
There’s a catch-22 associated with wetter winters: Although we may trend toward more precipitation, it’s not equating to drought resilience. Due to the rising snow levels, much of the spring runoff happens earlier in the year, and for less overall time.
Steph McAfee, associate professor at University Nevada Reno and deputy state climatologist, equates the snowpack in the Sierra Nevada to a massive reservoir — a frozen water source with a relatively predictable runoff that we’ve designed much of our water supply infrastructure around — but it’s shrinking.
“If not as much of the precipitation is coming as snow, if we’re getting rain instead or if it’s melting earlier, we don’t have that stored as long into the summer,” McAfee said. “We’re basically losing a reservoir. It’s not one we had to build but we’re losing it all the same.”
Has this begun to happen already? According to the North American Freezing Tracker, an online resource used to track snow levels around the world, the average snow level in Truckee for the month of March has risen more than 1,000 feet since 1950. The 10-year average was consistently around 7,000 feet over 60 years ago, but it began to rise in the 1980s and now sits near 8,250 feet.
While snow levels are quantifiably rising, how much precipitation we receive is still very much up in the air. The Sierra Nevada has always been an unpredictable region in terms of precipitation, with most years varying from 50 to 200 percent of “normal,” according to the state climate assessment.
Ironically, the same factors that increase our susceptibility to drought in any given year — the loss of water stored in the snowpack due to rising snow levels — can also lead to flooding, according to both Rost and McAfee. Rising temperatures increase the amount of moisture the atmosphere can hold, thus these hotter years have the potential to equal more precipitation and extreme storms, McAfee said. Combine this with increased likelihood of rain due to rising snow levels and we have possible massive rain-on-snow events, and therefore potential flooding.
“Both with the increased potential for rain-on-snow events, and the possibility to have perhaps more intense precipitation at any time of year, flooding could be a concern,” McAfee said. “We’re in this kind of interesting position where we might see increases in both drought and flooding.”
Fire — The hairy, smoldering elephant in the room
Between 2012 and 2016, California experienced one of the most intense droughts in at least 1,000 years. According to environmental scientist and climate journalist Dana Nuccitelli, the drought was so destructive not simply due to low precipitation levels — they were low, but not record low — but due to record high temperatures.
“[A UC Berkeley study] estimated that the high temperatures caused by global warming amplified the natural drought by about 25 percent,” Nuccitelli said. “So it took a bad drought and made it a record-breaking drought.”
The effects of this record-breaking dry spell will stretch on through the years, and have likely contributed to some of the catastrophic wildfires that have plagued the state since. According to the Sierra Nevada Conservancy, drought-related mortality has killed almost 110 million trees in the Sierra Nevada region as of 2017, each one more likely to burn.
“Certainly since 2007, and more specifically in the last five years, we have seen increases in the length of fire season; how severe fire season is,” said North Tahoe Fire Protection District Chief Michael Schwartz. “With that the number of homes lost, the amount of acreage burned, and the amount of fatalities has been on a real rise.” Schwartz says the increased tree mortality is definitely a factor in increased wildfire danger in the Truckee/Tahoe region, as well as other factors such as temperature increases and the wind that comes with it. Decades of fire suppression also play a significant factor, see Fighting Fire with Fire, online.
As to whether this region is at risk of wildfire, Schwartz echoes the common statement that it’s not a matter of if, but when. He said you can take what happened in Paradise last year and Napa the year before and “overlay that on most of our communities and get a pretty good picture of what the effects here would be.”
Mitigation and adaptation
“There is already a certain amount of climate change baked in to what has already happened that we are not going to be able to reverse,” said Deirdre Henderson, lead for the Citizens Climate Lobby — North Tahoe Chapter. “There are lots of people who are now looking at climate adaptation, but we are working on climate mitigation.”
One of the primary goals of the Climate Lobby, of which the Tahoe chapter is one of 513 active chapters around the world, now includes supporting legislation that puts a price on carbon — CO2 emissions being one of the leading causes of global warming. This includes finding support for HR 763, or the Energy Innovation and Climate Dividends Act, a bipartisan bill that Climate Lobby economist Jerry Hinkle says would place a price on carbon which would then be transferred directly to the fund for the American people to help incentivize clean energy technologies and market efficiencies.
“Generally speaking we know what to do: charge for polluting and return all the funds, and that bill is before Congress now on a bipartisan basis,” Hinkle said. “It’s not just a good thing to do, it’s not just for tree huggers, now it pays.” The act was introduced to the House of Representatives in January.
Back at the local level, there are myriad green initiatives taking place at many levels — far too many to name here, but look out for a few included throughout this edition. Ski resorts Squaw Alpine and Northstar have both committed to 100 percent renewable electricity among other sustainable initiatives, see p. 33, and the Town of Truckee has also signed off on a 100 percent renewable electricity by 2030 goal, which we covered in-depth last March, see All Roads (hopefully) Lead to Renewable online.
An important caveat here is that even if we curb emissions it is not looking likely to reverse or even halt the changes taking place. The Truckee/Tahoe region will most likely need to practice both climate mitigation and adaptation looking forward.
“Climate change action has got to be at every level,” said Erin DeLafontaine, a local activist who was instrumental in Truckee’s renewable energy pledge. DeLafontaine currently sits on Truckee’s General Plan Advisory Committee, where she hopes a climate action plan will take on a bigger role in the process, potentially even as its own document.
“Time is short, as you know from the fourth climate assessment we have a very small window here,” she said.