Hello,
Here is your answer:
Pumping to much carbon Dioxide in the air causes climate change:
1. Volcanos
2. Forest Fires
3. Machines such as (Cars, trucks, motorcycles, etc...)
4. Factories
(Remember I gave two causes from nature (1, and 2) & causes from humans (3, and 4).
If you need anymore help feel free to ask me!
Hope this helps!
~Nonportrit