Filling in the few fields of an online petition seems like literally the least we can do. But combined with other actions, online petitions can work.
Climate Crisis
We All Need Good News and Here It Is

While the bad news on the environment has been very bad, the good news has been very good. If you’ve been feeling hopeless, here is some relief.
Ask Anne Marie: How Can I Support the Climate Strikes?

“I want to go to the climate strikes but I have really bad anxiety. What else could I do?”
12 Simple Strategies to Cope with Ecoanxiety

The American Psychological Association defines ecoanxiety as “A chronic fear of environmental doom.” If you have ecoanxiety, try these coping strategies.