Earth's carbon cycle transfers carbon between land, oceans, and the atmosphere, and in turn, facilitates the life cycle of all life forms globally. Fire is a part of Earth's terrestrial carbon cycle that is balanced by vegetation recovery and growth. By contrast, fossil fuels consist of ancient carbon that has been stored underground for millions of years. Fossil fuel combustion contributes to climate change by releasing fossil carbon that the Earth's atmosphere has not seen for millions of years.
For millennia, fire has served ecological functions in California's diverse ecosystems, including facilitating germination of seeds for certain tree species, replenishing soil nutrients, maintaining diverse ecosystems, and reducing the accumulation of fuels that otherwise sustain high-severity wildfires. From time immemorial to the present, Indigenous People have been stewards of the land and have used fire to shape and maintain California's diverse ecosystems. Since the late 19th Century, California's forests have come under various forms of public and private control with corresponding management activities.
In addition to the natural world, fire and forest management activities intersect with public safety, natural resources management, the built environment, air quality, and climate change. Trends brought about by climate change and legacies of California's historical development, together with society's efforts to address them, amplify the standing of forests in California.
To better understand the quantity of carbon exchange in the California forest and rangeland system, an assessment of greenhouse gas (GHG) emissions and carbon impacts of wildfire and forest management activities was performed by the California Air Resources Control Board, The study helps California better understand the effects of current forest management practices and prioritize efforts to leverage natural and working lands for addressing climate change.
California's forests and other natural lands contain large quantities of carbon in the forms of plant biomass, dead organic matter, and soil organic matter. The current carbon stores represent slow accumulation over long periods of time. The annual amounts of carbon transferred from the atmosphere to biomass and the transfers of carbon out of the land base represent a small portion of the land carbon reservoir. Figure 8 summarizes CARB staff's estimates of carbon stock and GHG emissions from wildfire, prescribed fire, and forest management activities. These estimation results are shown along with carbon sequestration and other processes to provide broader context to the estimated emissions.
Figure 8: Flows of carbon and CO2 between the atmosphere and California's forests and other natural lands The upper portion of this diagram represents the reservoir of carbon in the atmosphere. The lower portion of this diagram represents reservoir of carbon within California's land base and extracted biomass. The exchanges of carbon and CO2 between the land and atmosphere are shown by arrows, and the boxes attached to each arrow indicate the type and quantity of the exchange. Arrows and boxes that have dashed outlines represent reservoirs and transfers of carbon or CO2 that have not yet been quantified due to limitation in existing
Read the whole study here: https://ww3.arb.ca.gov/cc/inventory/pubs/ca_ghg_wildfire_forestmanagement.pdf
