California’s Historical Fire Activity Before Modern Fire Suppression Report,
as prepared by CARB (November 2021)
Senate Bill 901 (2018) directed the California Air Resources Board (CARB) to develop a baseline estimate of greenhouse gas (GHG) emissions from California’s natural fire regime that reflects conditions before modern fire suppression (i.e., before 1910). In response, CARB has prepared a draft report, titled California’s Historical Fire Activity Before Modern Fire Suppression, dated November 2021, which is available for public comment until January 31, 2022. The draft report addresses the current understanding of historical fire GHG emissions, California’s fire history, and the dynamic relationship that exists between fire and climate, environmental, and human factors.
With respect to recent wildfire GHG emissions, the draft report states wildfires that occurred between 2000 and 2020 emitted – on average – 19 million metric tons of carbon dioxide per year. This equates to an average of 24 metric tons of carbon dioxide per acre burned. For historical emissions, though, the draft report concludes there is not enough available data to make an educated estimate of the GHG emissions that occurred from historical wildfires in California. That being said, studies indicate that fuel loads and vegetation biomass densities are generally larger today than they were historically, which leads to higher emissions per acre burned and more intense fires.
Overall, the report leaves readers with the following take-aways:
- Fire is a natural process that has played an integral role in California’s ecosystems for tens of thousands of years.
- Indigenous People used and continue to use fire to steward the land; their adaptive fire regime practices, such as cultural burning, have shaped large portions of California.
- In the early 20th century, large-scale fire-suppression tactics were implemented; this practice, combined with fire exclusion, climate change, an increasing human population, and an increasing need for natural resources have created the unprecedented fire conditions that currently exist in California. Fire suppression tactics also have caused California’s ecosystem to become less ecologically diverse and less adaptable to climate variability.
- Fires are expected to become more severe as the climate continues to warm.
- It is difficult to accurately estimate GHG emissions from California’s historical wildfire regime.
- Opportunities exist to reintegrate Indigenous People’s knowledge into prescribed burning and land management practices.
[This alert does not constitute legal advice and no attorney-client relationship is created by viewing or responding to this alert. Legal counsel should be sought for answers to specific legal questions.]