"Thank you for your thoughts on this matter, I didn't read them. Here is a boilerplate statement espousing all the great things about this bill that you specifically criticized in your message to me. Please don't reach out again."
It certainly feels entirely pointless, even more pointless than voting. It's not really being involved with politics because it doesn't really change anything. It's like writing letters to Santa Claus, except Santa is polite enough not to write back "Fuck you I won't do what you tell me."
If you really care about climate change, you should firebomb a coal power plant or take a claw hammer to a private jet. That will be far more effective and fun than writing a senator who could not give two shits what you think.