In general, I find most channels posting 'positive climate news' honestly a bit annoying because they tend to focus on things that really don't matter all that much in the big picture, or present their solution as a silver bullet while in fact there is none. (But maybe I'm a bit too critical here.)

If you're interested, we've compiled a big list of climate-related resources on the Effective Environmentalism website - some of which are quite hopeful! For example, the books Not the End of the World and Regenesis. There are also a bunch of podcasts and videos on climate solutions that have a bit of a "yes we can" vibe.

https://www.effectiveenvironmentalism.org/resources

Outside EA circles, I really love the YouTube channel Just Have a Think for some climate hope. And (not a video, but a static image), the falling costs of solar is one of the most hopeful graphics in the climate cause area!