California has a long history of fighting fires, but as climate change brings longer, drier fire seasons, the threat has grown. In the past decade, California has set new records for the largest, costliest, deadliest, and most destructive fires. Last year’s most severe fires, the Camp Fire in northern California and the Woolsey Fire near Los Angeles, burned simultaneously and caused the loss of dozens of lives, as well as unprecedented evacuations and smoke-related public health concerns. According to Bloomberg, the two fires resulted in around $19 billion in damages. Such devastating fires raise questions concerning climate change and forest management, both in California and other western states.


Carbon: From Sink to Source?


Healthy forests sequester carbon, keeping it out of the atmosphere by storing it in plant tissues or in the soil. In fact, between 1990 and 2015, American forests stored around 742 million metric tons of CO2 each year—more than one-tenth of total annual emissions. But if forests face drought, pests, or poor management, trees die and decompose, becoming sources of atmospheric carbon dioxide (CO2)—especially if they go up in flames. According to the federal government’s Fourth National Climate Assessment, tree growth and carbon storage capacity will decline as hotter temperatures, drought, and forest fires become more frequent. Over the past decade, the state of California has faced its worst drought in recorded history. Since 2010, dry conditions, combined with an infestation of bark beetles, have killed 129 million trees, primarily in the Sierra Nevada, the state’s largest mountain range. It’s estimated that roughly 15 million acres need to be reforested to restore these forests’ capacity to sequester carbon.

Despite widespread tree deaths, forests are too dense in many parts of California, which can allow fires to spread and intensify. While nine out of ten wildfires are caused directly by humans, climate conditions and forest management shape how they evolve and grow, and current trends suggest larger, more frequent fires lie ahead. California’s Fourth Climate Change Assessment, prepared by a number of state agencies, reports that the frequency of wildfires burning over 25,000 acres could increase by nearly 50 percent by the end of the century, and owners could see an increase in wildfire insurance costs of 18 percent by midcentury. These trends hinder forest growth and regeneration, and threaten to convert California’s forests from carbon sinks into sources of atmospheric CO2.


Restoring California’s Forests


Seeking to reverse these trends and promote healthy, resilient forests, as well as protect its residents and advance its climate goals, California’s fiscal year 2017-2018 budget includes $220 million for programs supporting forest health and fire prevention. The Forest Climate Action Team, created under Gov. Jerry Brown, released an action plan in May 2018 that evaluates the challenges the state faces and outlines objectives for short- and long-term forest management. The Forest Climate Action Plan prescribes increasing the rate of reforestation, protecting forested lands, monitoring and collecting data, and investing in durable wood products like lumber and mass timber products that can store carbon long-term in the building sector. In addition to reducing the dangers of large forest fires and climate change, restoring California’s forests will enhance the state’s water security by reducing erosion and surface water ash contamination.

A study in the journal Frontiers in Ecology and the Environment, funded by the U.S. Department of Agriculture, suggests that changes to forest management can reduce risks from large fires and ensure that forests act as a carbon sink. Using model simulations to examine how different restoration efforts in California’s Sierra Nevada mountains may interact with future climatic changes, the study found that fire hazards can be mitigated and the carbon storage potential of forests can be preserved. It also found that the rapid implementation of restoration efforts could enable the forests to trap more carbon.

In March 2018, an omnibus spending package provided $20 billion over the next decade to address the rising costs of wildfires for the U.S. Forest Service. In recent years, the Forest Service, responsible for managing National Forest lands, has been forced to allocate more than half of its total budget to fighting fires, pulling funds from other programs midyear in a practice known as ‘fire borrowing.’ This funding fix will become active in FY2020, hopefully enabling the Forest Service to renew its focus on forest management and promoting healthy forests.


Mass Timber and the Farm Bill


California is not alone in its struggles with wildfires. Throughout the western United States, a century of suppressing forest fires has left many areas too densely forested, especially with small-diameter trees. This creates conditions that fuel intense wildfires. While wide-scale thinning of small diameter trees is costly, an innovative class of structural wood building materials, known as mass timber, may be part of the solution. The mass timber industry is more developed in Europe, but it is taking root in North America as well. If new technologies make ecologically wise, restorative forest thinning economically feasible, that will ease pressure on state and federal budgets while improving the health and safety of people living in and near federal forests. In many cases, mass timber also provides a lower-carbon alternative to traditional building materials like steel and concrete.

The 2018 Farm Bill included provisions that support mass timber, including cross-laminated timber (CLT). This type of mass timber is made by layering wood from small-diameter trees to create a strong, lightweight building material. The bill also encourages the development of tall wood buildings. These tall wood buildings, constructed with mass timber and standing over 85 feet in height, have been tested extensively for strength, durability, and fire safety. Blast testing on CLT was performed at Tyndall Air Force Base in Florida, and the material is now being used in a handful of military construction projects. Additionally, the U.S. Forest Service’s Wood Innovations Grants program, which supports new and traditional uses for wood, is continued under the Farm Bill. Each year, the program provides funding to a handful of projects with the goal of expanding wood markets and promoting wood as a building material.


While these mass timber provisions have implications for climate change, wildfires, and sustainable use of forest resources, solutions will certainly involve innovation in the private sector and proactive efforts by all levels of government.


For more on mass timber, check out EESI’s briefing "Wood: The Building Material of the Future?"


Author: Clayton Coleman