How Climate Change Elevates Wildfire Risk in Vulnerable Los Angeles Areas – Insights from World Weather Attribution

On January 7, 2025, two significant wildfires—the Palisades and Eaton wildfires—started in Los Angeles, California. Over the following week, these fires spread rapidly, causing widespread destruction and impacting thousands of lives.

As of now, the fires remain uncontrolled, with additional outbreaks reported in the San Diego area. Currently, at least 28 people have lost their lives, and more than 16,000 structures have been destroyed. The total damage from these fires will likely be assessed in the weeks and months to come.

Southern California has a Mediterranean climate characterized by dry summers and wet winters. This region features fire-adapted vegetation, making wildfires a natural, albeit dangerous, part of the ecosystem. Typically, the fire season peaks from July to September due to high temperatures and dry conditions. However, the most devastating fires often occur in the fall or early winter during the Santa Ana winds, a weather phenomenon where dry winds from inland mountains move towards the coast.

This particular outbreak is remarkable for its rapid spread, driven by these strong Santa Ana winds. These winds are common in the cooler months and were especially severe during the first days of the fire, worsened by specific weather systems arriving from the north.

Usually, by October, the arrival of rain would help curb fire risk. However, since May 2024, the region has seen very little rainfall. This extended dry period left grasses and brush highly flammable, intensifying the destruction when the fires ignited. Previous wet winters had encouraged dense plant growth, which also contributed to the fire’s intensity.

The impact of climate change is increasingly evident as it heightens the risk of wildfires through hotter, drier conditions. Researchers from multiple countries are examining how these changing conditions influenced the likelihood and severity of the LA wildfires.

To understand the fire weather conditions, scientists use the Fire Weather Index (FWI). This index evaluates factors like temperature, humidity, wind, and recent precipitation. The FWI was notably high at the start of these wildfires, indicating critical weather conditions that fueled their spread. Analyzing the lack of rain during what is typically a wet season provided insight into why the fires became so destructive.

• Coastal Southern California is especially prone to catastrophic wildfires. The region’s land use and fire management practices play a significant role in how destructive a fire can be.
• The current climate, with a modest increase in global temperatures, has made extreme fire weather conditions like the ones seen in these fires more frequent.
• Climate models show that human-induced warming significantly contributes to the intensity and occurrence of these fire weather conditions.
• Drought conditions have worsened, with less rainfall recorded compared to previous years, increasing the potential fuel for wildfires.
• Changes in the timing of seasonal patterns have elongated the dry season, placing a greater focus on the risks posed by Santa Ana winds.
• People most impacted by these wildfires include the elderly, those with disabilities, and lower-income residents who had difficulty evacuating.
• The fires also revealed weaknesses in local water infrastructure, underscoring the need for better emergency preparedness and resilient systems to handle larger fire events.