There are many ways to encourage climate action: Earth hour, Earth day, reading information on:

https://worldslargestlesson.globalgoals.org/

and

https://www.worldwildlife.org/

There is a lot of information on the United Nations website:

https://unfccc.int/news/8-ways-you-can-take-climate-action-right-now

Children keep an eco-diary for one week, recording their actions to help the environment (reducing waste, saving energy, recycling, etc.).
After a week, they exchange reports with children from other countries and compare their results.
They can create digital posters or short videos to present their experiences.

Each group explores how climate change affects their country (e.g., floods, heatwaves, loss of plant and animal species).
Children prepare short presentations or comics and share them with others through an online platform.
The goal is to identify similarities and differences between countries and come up with shared ideas for tackling the issues.