The patronizing and anti-scientific tenor of this conversation is weird — I'd have guessed that reef hobbyists would be on the other (empirically proven) side of this.
The truth is that neither side is completely right, or at least that's the stance I adopt given my work experience. Fossil fuels are still vital to industrialized sectors (e.g., transportation, plastics, electricity baseload) but should be gradually scaled back to lower GHG emissions. The proliferation of renewables and EVs is extremely beneficial in its own right and most market segments will achieve economies of scale in the (near) future. However, there are still issues such as mineral supply chains and mining practices, and related to solar + wind, intermittency and the need to pair them with storage facilities for maximum grid penetration if NG and/or coal will be supplanted.
Large-scale coral bleaching events are not normal and a signal that we could be doing things better. It's not really an ideological argument, imo.