Are Wildfires and CO2 Really Linked?

The Myths of CO2 and Fire Intensity

Are Wildfires and CO2 Really Linked?

The mainstream climate discourse often insists that the increase in atmospheric CO2 is almost entirely driven by human activities, particularly the burning of fossil fuels. This belief is the foundation of global climate policies aimed at reducing carbon emissions. However, recent evidence, such as the 2023 Canadian fire season, challenges this simplistic view. According to a study published in Nature, this single fire season released more CO2 than all but three countries emit annually. While the study points the finger at greenhouse gas (GHG) emissions as a driver of these intense fires, a closer look reveals significant flaws in this argument, suggesting that our understanding of CO2’s role in climate dynamics is far more complex and nuanced than commonly portrayed.

The 2023 Canadian Fire Season: A Natural Anomaly or Evidence of Broader Issues?

The 2023 fire season in Canada was one of the most intense on record, with vast areas of forest burned in just a few months. The Nature study attributes the severity of these fires to increasing GHG concentrations, reinforcing the narrative that human activities are the primary driver of climate change. However, this interpretation is both reductive and misleading.

First, the sheer scale of CO2 emissions from this fire season, which surpasses the annual emissions of all but three countries, raises serious questions about the role of natural events in the global carbon cycle. If a single fire season can release such a massive amount of CO2, it becomes clear that natural processes play a much larger role in atmospheric CO2 levels than the study acknowledges. This complicates the narrative that human activities are the sole or even primary contributors to the increase in atmospheric CO2.

Source: https://www.nature.com/articles/s41586-024-07878-z

The Flawed Assumptions of the Nature Study

The Nature study is flawed in its assumption that GHG concentrations directly drive fire intensity and frequency. By attributing the Canadian wildfires primarily to rising CO2 levels, the study oversimplifies the complex interactions between climate, vegetation, and fire behavior. This is not just a minor oversight but a fundamental flaw that undermines the study’s conclusions.

Contrary to the Nature study, a paper published in Forest Ecology and Management offers a more comprehensive view of the factors influencing fire regimes. The paper from Forest Ecology and Management explores the historical fire regimes in California, revealing that the state’s forests experienced far more frequent and intense fires in the past than they do today, even at much lower levels of atmospheric CO2. Before European settlement, particularly during the Medieval Warm Period (approximately 900 to 1300 AD), California's forests burned at rates ranging from 4.5 to 12 million acres annually. This contrasts sharply with modern figures, where recent fire seasons typically see around 1 to 2 million acres burned, despite CO2 levels being significantly higher today (over 420 ppm compared to around 280 ppm historically). The paper states…

Our estimate of prehistoric annual area burned in California is 88% of the total annual wildfire area in the entire US during a decade (1994–2004) characterized as “extreme” regarding wildfires. The idea that US wildfire area of approximately two million ha annually is extreme is certainly a 20th or 21st century perspective.

The paper underscores the point that blaming modern California, or Canada, wildfires on GHG concentrations is not only simplistic but also ignores the complex and multifaceted nature of fire ecology. Historically, fire activity was driven by natural factors such as climate variability, vegetation patterns, and indigenous land management practices. The fact that California experienced much more extensive fires in the past, when CO2 levels were far lower, makes it absurd to attribute today’s wildfires solely to rising GHGs.

The table below from the IPCC's latest assessment report provides a clear visual representation of the varying levels of confidence in the projected changes for different climatic impact drivers (CIDs) across various time periods. Specifically, when it comes to fire weather, the IPCC categorizes it under "Wet and Dry" climatic impact drivers, and notably, the figure indicates a "low confidence in direction of change." This means that the IPCC does not have sufficient evidence to confidently predict whether fire weather conditions will increase or decrease in the future.

Moreover, the figure shows no significant change projected for fire weather, either historically or in future scenarios. This lack of confidence in the direction of change undermines the narrative that GHG-induced climate change is directly linked to increasing wildfire frequency or intensity.