California Wildfires, Explained

The fires of 2020 highlight the dangerous state of many of California’s landscapes.  This problem is decades, and perhaps more than a century, in the making. The solution is extremely complex and the scope of what’s needed is enormous. However, in order to make progress on the issue, it is time for all of us to get a clear handle on the problem and what our goals should be.

This page is designed to outline the problem of wildfires, what some of the solutions could be, and what role public lands can play. Please let us know if you have any other questions or comments.

Why are fires so much scarier, bigger, and more destructive than they have ever been?

It is important to recognize that it isn’t attributable to one thing. At this point, there are a number of things that are cumulatively causing much worse wildfires.  The factors CalWild would highlight (not in a particular order):

  1. A century of fire suppression and poor ecosystem health
  2. Climate change
  3. Development leading to more people living in high fire prone areas

Fire suppression and poor ecosystem health

The Big Blowup (or Big Burn or Great Fire) of 1910 set off a series of policy decisions at the U.S. Forest Service that concluded with the adoption of a 100% fire suppression approach to wildfires. This established a precedent followed by other public lands or firefighting agencies to a greater or lesser degree including the National Park Service, the Bureau of Land Management, and CalFire. It also set the stage for viewing fire in a combative, almost war-like, manner. Over 100 years of 100% fire suppression policies have led to an enormous buildup of fuel on our landscape.

For millennia, California’s indigenous people have intentionally set fire to the land. This is known as cultural or prescribed burning. By setting these low intensity fires at times of the year when they are less-likely to burn out of control, forests and other landscapes reduce their fuel loads and often create a cycle of re-birth for many plants. This is a very different way of understanding and working with fire than what we have been doing for the past century.

It is important to note that indigenous people were persecuted for continuing to practice cultural burning during this period. Only now is their knowledge of the land and its relationship with fire, which was in large part shaped by centuries of cultural burning, is being appreciated.

Fire has been and will continue to be a part of California’s landscape. In fact, much of the state’s ecosystems have adapted to and are dependent on fire for their health. When you combine the removal of fire on the landscape with logging practices, we have a recipe for catastrophic fires. Poor historical and ongoing logging practices have resulted in the removal of the largest, most fire-resistant trees. These big trees have been replaced by carpets of young trees and shrubs that are ready to burn. Logging also produces “slash,” or piles of bark, limbs, and other waste material that helps kindle the flames of unnaturally hot fires. As the University of California’s Sierra Nevada Ecosystem Project found in 1997, logging has increased fire severity more than any other human activity. From the perspective of forest health and resilience, there are too few large trees, too many small trees, and an excess of surface and ladder fuels that significantly increase the risk of high-severity wildfire.

Reintroducing fire on the land with preferred methods at times that are mostly within our control is the only way to restore many of these ecosystems. Historian Stephen Pyne summarized it best, “we thought we were putting out fires, when in reality we were merely putting them off.”


Yosemite Valley Floor Comparison Then and Now.(Ahwahneechee land). Photo from NY Times.

Climate change

The science of climate change is settled. The world is getting warmer, humans are the cause, and we are going to see the impacts in changing weather patterns. California has already experienced significant warming across the state and temperatures have collectively risen about 1.8 degrees Fahrenheit since just 1980. California endured a serious drought from 2012-2017, which arguably has not ended to date. The changing climate may also change wind patterns known as the Diablo winds in Northern California and the Santa Ana winds in Southern California, which play an important role in the size of wildfires. Whether there will be an increase or a decrease in these winds is still to be determined. Finally, even in wet years, the snowpack of the Sierra Nevada which has historically been the greatest source of summer water, will increasing fall as rain, making dry seasons even drier.

Regional average temperature change in CA. Graphic by The Washington Post.

Each of these changes have increased the likelihood of megafires in California. Additional heat, particularly in the summer months, has increased the dry material on our natural landscapes and increased the length of the fire season. The most recent drought was also the major factor in the die off of millions of trees in the Sierra. Droughts stress landscapes and make them more vulnerable to other disturbances like the infestation of the bark beetle which added to the enormous die off. The significant winds across the state also contribute to the scary speed some of these fires have moved into communities. We repeatedly hear stories of communities having fire bearing down on them without any warning or emergency alert and residents scrambling to get out with their lives.

Ultimately, climate change is a multiplier and an accelerator of the other challenges we face. It makes the problem bigger, the solution harder to attain, and the consequences of inaction even greater.

Population growth in fire-prone landscapes

The California housing crisis has been crushing for most people, especially along socio-economic and racial lines. To find relief, many people are moving to areas with slightly more affordable housing. Those communities are by and large embracing that growth. While finding more affordable places to live is important, much of this development is happening in fire prone areas.

The wildland-urban interface or WUI (pronounce “woo-ee”) is a term that is now flying around news reports. This is the area where human structures are built in or adjacent to wild places. This reality is making our wildfires more common and more destructive.

With more buildings and people in high fire areas, the likelihood of greater damage and loss of life is higher. There simply are more people in areas that traditionally burned, but have not in decades, and are likely to burn again. In California, growth in the WUI has exploded and we now have about one in three houses in the WUI.

The reason why fire becomes more common with the growth of the WUI is that humans are the primary source of wildfire. Humans cause 80% of all wildfires.  That number increases to 97% when you look at wildfires that burns structures.

The development and protection of WUI communities are not CalWild’s policy focus. However, it is impossible to acknowledge the impact of wildfire in California without outlining the enormous growth of communities in the WUI.

What policies would help to mitigate future fires?

Fire is a natural and necessary process for many landscapes in California. The confluence of all the factors above is making wildfires much bigger and more destructive.

Unfortunately, the problem of widespread megafires is more than a century in the making and arrived more suddenly than almost anyone anticipated. We likely will not be able to change this reality in any meaningful way for a decade or more, even with historically dramatic action.

The most important policies and investments focus around getting fire back on the land when it is safe and ecologically advantageous to do so. For decades, land managers anticipated today’s reality, even as early as the beginning of the 20th century, understanding what 100 years of fire suppression would do to the forest. However, those 100 years make the actual restoration of our landscapes a long and intensive task. Despite that, we have few other options than to get to work.

Here are a few key policies that can help:

Cultural and prescribed burning

Prescribed burning is an intentionally lit fire managed under specific conditions or prescriptions for social and ecological benefits. These are designed to burn at a low intensity and under favorable conditions so as not to grow out of control. It helps to reduce the buildup of surface fuels that contribute to an increased risk of megafires during fire season.

Indigenous people have a knowledge of this work and have been engaging in cultural burning for millennia. It is only now that state and federal governments are broadly recognizing how wrong their fire suppression policy was and still is in many respects. Leaning heavily on indigenous people for both the work and the development of new policy will be an essential piece of getting good fire on the land, restoring healthy ecosystems, and reducing the risk of megafires in the future.

Here is a good video of a community fire burning example in Napa County.

Managed wildfire

Fire has always been an integral part of the ecosystem in California. Managed fire is another way of restoring fire on our landscape in a safe and efficient manner. A managed wildfire is a fire ignited by an unplanned ignition (e.g., lightning) managed for ecological and social benefits under optimum conditions that don’t threaten structures or people.

California encompasses about 100 million acres. 44 million of that are public lands. Wilderness, roadless areas, and other wilderness like areas are about 30 million acres. The two realities of fire are that we can’t stop fire everywhere and, in the short term, we aren’t going to be able to use prescribed fire at the scale we need given the current state of public land agencies’ budgets. Managed fire is a tool that is particularly helpful and applicable to California’s roadless areas. Multiple studies have shown that roadless area fires do not burn as hot and are not as destructive as other wildfires.

Ecological thinning

The size and scope of these wildfires are unprecedented. As conservationists, we have a natural aversion to logging of any kind given that these practices have been fraught with many abuses to the long term health of the land and is a significant contributor to our current wildfire challenge. This is one area where the details of a project really matter. The Nature Conservancy has done a lot of work on ecological forestry which includes some thinning. The thinning shouldn’t be done alone, but paired with prescribed burning.

 A graphic comparing ecologically managed forest and fire-suppressed forest from The Nature Conservancy.

The goal of ecologically-based thinning is to maintain or restore ecosystems emphasizing diversity and resiliency. The goal is to retain the oldest and largest trees because they are generally more fire resilient than small trees, provide important wildlife habitat, and are too often absent due to past logging practices.

One example of this approach is the South Fork Trinity River Restoration Area in Representative Jared Huffman’s Northwest California Wilderness, Recreation, and Working Forests Act. This is a 729,000-acre former tree farm that shows how logging practices have created a monoculture of very dense trees of all the same age. These are very unhealthy environments and ones that are ripe for burning in a megafire.

Wildfire fuels reduction may even occur in protected areas like national parks and wilderness areas. The National Park Service has successfully introduced prescribed burns and allowed low intensity natural fires in thousands of acres of protected park land. The Forest Service, which manages 20 million acres of California, has just recently started working on fuels reduction and prescribed burns in protected areas like wilderness. The Caples Ecological Restoration Project on the Eldorado National Forest reintroduced fire back into a landscape the Forest Service recommended for and manages as wilderness.

We should focus any thinning on areas around communities. This restoration work should NEVER justify the building of new roads into roadless areas or allow for any kind of mechanical thinning in roadless or wilderness areas. Ecological forestry is a framework to manage, but if we want to protect roadless areas into the future we have to be active participants in this discussion.

Other areas that will need to be addressed, but that CalWild doesn’t work on:

  • Home hardening – these are building requirements and retrofitting for homes in fire-prone regions that increase the likelihood that these homes can survive a wildfire. There is a real question as to what the actual requirements are and how low-income Californians afford them.
  • Defensible space – making sure homes have enough space from flammable vegetation that could catch a house on fire. There is a real challenge of enforcement here.
  • Workforce development – In order to scale prescribed burning, there needs to be a dramatic increase in the number of certified people capable of doing the work. Right now the expertise and labor force does not exist anywhere close to the scale we’ll need to address the problem.
  • Biomass utilization – right now most forest restoration or fuel reduction projects burn fuels in large open burn piles. Getting to a place that allows for the development of science-based restoration using biomass for the health of an ecosystem is extremely hard. It is a difficult tightrope to walk as we do not want to incentivize taking more trees and material from landscapes than necessary to restore an ecosystem’s health, but the fuel build up is that large that addition incentives including economic may be needed.

California has all different kinds of ecosystems. Is the solution similar for all of them?

No. Prescribed burning is appropriate for many forests and oak woodlands. Fire suppression and logging practices have created unhealthy landscapes .

Contrary to that approach, chaparral has the opposite problem. The expansion of humans into that ecosystem has actually increased the amount of fire in chaparral. Chaparral can recover from high severity fire, which is how it normally burns, but only if the fire comes through periodically every 30 to 100 years.  The California Chaparral Institute has a great explanation about fires’ role in chaparral.

Surprisingly, a major desert fire in the Mojave desert was a part of the recent spate of megafires in California. That is an ecosystem not adapted to wildfire that is only vulnerable as a result of climate change and expansion of invasive grasses.

The variation experienced on the landscape even between similar ecosystems points to why environmental review is important. The appropriateness of any measure we’ve outline will depend entirely on the local conditions.

Is there any truth that logging could be a solution? 

The persistent argument that the commercial logging of forests to save them from wildfire is one simplistic “solution” pushed by many that fails to provide real relief. Several recent wildfires that threatened urban areas in California were largely in oak woodlands, grasslands, and chaparral. It is simply false that industrial logging can be used to reduce the fire danger in these ecosystems. Even when used in forest ecosystems as noted above, industrial logging (particularly clear cutting) creates even-aged forests that burn more readily than some non-managed wildlands. Ultimately, logging as traditionally practiced is more of a contributor to the problem of wildfires than any kind of solution.

What is the role that public lands play as it relates to fire?

Dealing with the challenge of megafires will have to include all land managers and create comprehensive plans and prioritize (or de-prioritize) areas. Public lands encompass 44% of the state. The federal government manages 57% of our forested area. This means public lands are going to have a huge role in managing wildfire.

It is important to re-iterate how the Forest Service’s fateful decision to promote a 100% fire suppression policy had a lasting impact. California’s own fire agencies followed that mantra for years. That attitude created a public perception of fire and its role in our lives that we continue to live with.

Therefore, there are two public lands issues that CalWild can help with. First, is to actively engage in the process of reforming public land agencies’ approach to fire. Given the enormous scale of the lands managed by the agency, the Forest Service can work without crossing jurisdictions and we should be looking to them to both reform their policy and actually implement reforms on the ground. We will also be working to get all public lands agencies more money to properly do the work that they are tasked and scale up for the enormity of the problem.

The second area is to push the Forest Service to change the narrative around fire. We must view fire as inevitable. If we try to exercise control on fire it should be when it is put on the land. For too long the federal government’s attitudes and public messages have focused entirely on the destructive nature of fire. As they work to reform land management policy and practice to include more fire and manage for greater ecological diversity and health, they should communicate effectively to the public the need for a change.

The issue of wildfire is going to be with us forever. The issue of megafires will be with us for years. We must start the transition to a more complicated relationship with fire now. Public lands can play an important role in that evolution. CalWild will be pushing for that.

Other explainers for further reading

ProPublica – overview preventing megafires and the frustration of many who have been add

Vox – a good general overview that outlines key issues including forest management, climate change and population growth in the WUI

PBS Newshour – Video that explains similar elements to the Vox piece, which has more depth

Yale 360 – Outlines why megafires aren’t only a California problem

Mother Jones – Article outlines how the WUI came to be a significant driver of housing grow

Center for Western Priorities Podcast – An interview with the researcher who discovered that 97% of fires that destroy human structures were started by humans.

California Sunday Magazine – Article by Mark Arax in 2019 recapping what happened during the Camp Fire that destroyed Paradise and why it is going to continue to happen.