Events never have just one cause. We often talk about them as if they do, but that isn't how things actually work in an interconnected world. Climate change is one of the significant exacerbating factors in these forest fires. Other factors are fuel and forest management practices. It's fair to call all of these causes of the fires. But you will never find a fire where you can say that only one thing caused it, particularly if that thing manifests in statistical trends in the likelihood and characteristics of these fires. We can only say that climate change made them more likely to happen and more likely to be severe.