They did not say at any point that climate change is the primary factor. They are rebutting the claim that climate change is not a factor at all, which Stossel

They did not say at any point that climate change is the primary factor. They are rebutting the claim that climate change is not a factor at all, which Stossel does claim in his video (although the fact check was not written to specifically address that video). Stossel also says that climate change has made things worse, but the fact that his video contradicts itself does not make the fact check invalid.