On my climate journey I was struck initially by how passionately some people were denying the fact that climate change was real and 100% caused by greenhouse gas emissions. Since then, I have developed tools & arguments that I have used to both understand the science better, but also be able to debate climate change deniers.
You're most likely not going to be able to change their mind, even though any rational person that listens to facts cannot come to a different conclusion. However, I do believe debates are important, especially when they take place in public forums, because the people who are watching those debates are the ones that will be convinced and walk away with a greater sense of urgency regarding the climate crisis.