Global Lightning-Ignited Wildfires Prediction and Climate Change Projections based on Explainable Machine Learning Models

TL;DR

This paper develops global machine learning models to predict lightning-ignited wildfires, analyze their trends, and assess climate change impacts, emphasizing the importance of explainability and regional specificity in wildfire prediction.

Contribution

The study introduces globally applicable, explainable machine learning models for predicting lightning-ignited wildfires, addressing regional limitations of previous models and analyzing climate change effects.

Findings

Lightning-ignited wildfires are significant for global carbon emissions.

Climate change has increased the risk of lightning-ignited wildfires over less than a decade.

Global differences exist between lightning-ignited and human-caused wildfires.

Abstract

Wildfires pose a significant natural disaster risk to populations and contribute to accelerated climate change. As wildfires are also affected by climate change, extreme wildfires are becoming increasingly frequent. Although they occur less frequently globally than those sparked by human activities, lightning-ignited wildfires play a substantial role in carbon emissions and account for the majority of burned areas in certain regions. While existing computational models, especially those based on machine learning, aim to predict lightning-ignited wildfires, they are typically tailored to specific regions with unique characteristics, limiting their global applicability. In this study, we present machine learning models designed to characterize and predict lightning-ignited wildfires on a global scale. Our approach involves classifying lightning-ignited versus anthropogenic wildfires, and estimating with high accuracy the probability of lightning to ignite a fire based on a wide spectrum of factors such as meteorological conditions and vegetation. Utilizing these models, we analyze seasonal and spatial trends in lightning-ignited wildfires shedding light on the impact of climate change on this phenomenon. We analyze the influence of various features on the models using eXplainable Artificial Intelligence (XAI) frameworks. Our findings highlight significant global differences between anthropogenic and lightning-ignited wildfires. Moreover, we demonstrate that, even over a short time span of less than a decade, climate changes have steadily increased the global risk of lightning-ignited wildfires. This distinction underscores the imperative need for dedicated predictive models and fire weather indices tailored specifically to each type of wildfire.