In December of 2007, a newly created California State Agency, the Sierra Nevada Conservancy presented a Climate Change Symposium in Nevada City. Dan Cayan, of Scripps Institute of Oceanography/US Geological Survey, set the tone for the day with his keynote presentation of charts showing climate change impacts on various regions in the U.S. In a stunning series of graphs, Cayan illustrated to what degree different regions will be impacted by variations in climate. Both coasts had patches of green, indicating moderate effect, most of the middle U.S. was blue, indicating comparatively less effect: but when you hit the Sierra Nevada, a bright orange band, indicating severe effect by climate change, painted a stark picture: according to these graphs, the Sierra Nevada is very vulnerable: more so than much of the United States. Cayan said the Sierra Nevada is a bellwether for climate change.

“The Sierra is exquisitely sensitive to change, not only hydrologically, but biologically,” Cayan said. The Sierra, perhaps more than most of America, have reason to care about climate change: they will feel these changes profoundly. This is now self-evident as the Sierra Nevada, along with much of the West, is facing mega-fires of previously unrecorded proportions.

Prof. Kolden

UC Merced Assistant Professor Crystal Kolden has spent years researching possible solutions to wildfire, including a diverse array of surprising mitigation practices. Kolden is a Pyrogeographer and fire scientist with over 20 years of experience implementing GIS, remote sensing, and spatial analysis in fire ecology and management, including fire science research, education, and outreach. She is a Certified Fire Ecologist by the Association of Fire Ecology. Kolden holds a Ph.D. in geography. Her extensive career includes work as a firefighter, fire ecologist and researcher. Kolden is uniquely qualified to comment on issues relating to fire ecology and fire mitigation.

I recently interviewed Kolden who provided in-depth solutions to some of the most troublesome wildfire issues in this time of increasing climate-change impacts. These solutions are presented in four articles, each presenting mitigation solutions from personal options to broad-ranging policies for social good. These interviews were facilitated by


PB: California now has 147 million dead or dying trees. We are still facing a drought, with 2021 being the 8th driest year to date over the past 127 years. Roughly 40% of Californians live in Wildland Urban Interface zones. As of October 27, 2021, a total of 8,239 fires have been recorded, burning 2,495,889 acres across the state. This is a serious threat on many levels. Let’s talk about solutions.

CK: There is no silver bullet single, simple solution that we can follow. Complex problems require complex solutions. The first stage is to accept that the solutions will be complex and diverse—they will look different in different regions. Secondly, this landscape is a landscape that historically was shaped by fire and that fire was not just lighting fires, but that there was extensive indigenous burning across California prior to European colonization. One of the fruits fire science has finally come to realize is that we need to listen better and follow the lead of our indigenous colleagues who have retained a lot of knowledge about how we can actually return some of this landscape, not to what it looked like 500 years ago, minus 40 million people, but that we can return a lot of the natural processes and the natural resilience of this landscape if we incorporate this historical knowledge that we still have and that tribes have passed down over generations because this knowledge is really comprehensive and reflects how complex this ecosystem is and how complex fire is in this landscape.

Many of the solutions to our fire problem actually lie in looking at the natural world. As someone who has studied this for a long period of time, it does not exclude humans, it includes humans managing this landscape in a very specific way. So, when we talk about how we can learn from nature how to restore these landscapes to health, returning to natural solutions means including humans and very much following the lead of indigenous peoples who have been here for millennia.

So how does this translate into solutions? There are so many, but the biggest solution of all is returning fire to these natural landscapes and so one of the things I advocate for is that we have to scale up the amount of fire. In thinking about this, we have to put this in perspective. People are rarely scared of a campfire, right, let’s roast marshmallows or enjoy a celebratory bonfire. That’s not terribly scary. It’s when these fires scale up and become these raging infernos, that’s what’s scary and that is also what also does the most destruction. If you take a campfire and replicate this practice millions of times across the landscape, it’s still just a little campfire, it’s just happening in many places all at once. That’s not actually terribly scary and what it is doing is restoring and rejuvenating that ecosystem—it is removing the dead material and the build-up on top of the soil and the fire is converting that into nutrients that then go back into the soil. The soil is then able to be replenished through receiving these nutrients and is then able to absorb and return moisture. This is where we talk about having a lot more area burning and not in infernos, but in a whole lot more campfires, and not just in California, but across the West much more broadly because that is what was here and what happened prior to European colonization. Small-scale controlled fire is one of the major solutions that we look at. We need more fire.

This raises many questions, for instance, what to do about the smoke? Well, the thing about campfires is that it is a small amount of smoke that dissipates quickly, so when we are favoring prescribed fire, what we are saying is that we (scientists) understand that we can mitigate smoke impacts with a relatively contained set of solutions, rather than with wildfire fire, which is much denser and has a much higher density of particulates, which are the source of many issues. There are some negative impacts from prescribed fire, but the impacts from a prescribed fire are far preferable to the side effects of wildfire.

Prescribed fire is a vaccination for the land. It is not perfect, but overall, it greatly provides benefits, especially reducing the risk of catastrophic and fatal wildfires. This is the argument that comes from many scientists, myself included. We are not looking at a risk-free future. We are going to have some kind of risk and that risk is increasing with climate change. The question is how much of that risk can we control. With prescribed fire, we can control and manage the risk. In California, prescribed fire is one of the most looked to potential solutions.

Yuhan Fire, courtesy
Yuhan Fire, courtesy

We can live with fire. Indigenous people not only lived with fire, they thrived with fire. It is a core tenant of tribal culture. We can do this if we increase prescribed burns in a responsible way. We do have to deal with the tremendous amount of dead material in the forest. We do have to thin trees. We are resistant to thinning because that is the same language that loggers use. Anyone who has spent time in the forest realizes that when a logging company says thinning the forest, they mean something very different than when a fire scientist says thinning the forest. Scientists are talking about taking small trees without any merchandisable timber and the understory brush that fuel the big fires.

There is a range of anecdotal evidence where we see wind-driven mega-fires burns through cleared areas and other sites where the fire passes through and the forest survives and is actually healthier. Most notably, South Lake Tahoe is an area where past prescribed burns allowed the fire to go from a crown fire to drop to the forest floor where the flame lengths were only 3-4 feet high and firefighters were able to knock these flames down and this effectively saved South Lake Tahoe from burning. So, we have this collection of data and can start to aggregate all this data into big databases which allow us to then create statistical evidence.

The SQF Complex Fire killed hundreds, if not thousands, of old-growth Giant Sequoias that had survived countless smaller, less severe fires.
The SQF Complex Fire killed hundreds, if not thousands, of old-growth Giant Sequoias that had survived countless smaller, less severe fires. Photos: Curtis Kvamme, U.S. Forest Service

All of the analogies that we use in a fire have been really exemplified in the vaccines for COVID. If we look at single instances, we have different takeaways than if we look at millions and millions of instances. Epidemiological evidence means looking at hundreds of millions of doses, then the probability becomes very low for hospitalization. Data collection provides us with the probabilities that are needed to make safe choices. This is the same thing we ask with fuel treatments for prescribed fire. Yes, this is sometimes ineffective, but overall, we see critical resources saved, such as South Lake Tahoe and the Sequoia National Forest, where the fires were stopped from many even greater forms of catastrophic damages than occurred.

Next, we’ll look at ways to harden homes.