CaCO3 ---> CaO + CO2
balenced

The answer should be vaporization 

The answer is 3.

Large asteroid and comet impacts. because they can have a huge impact on the environment, such as a loss of land, and crust on the earth with the big holes they produce. on the other hand, volcanic eruptions can also cause change within the environment by producing land, but im actually not quite sure which one would be a better answer, hopefully you read this and didnt just flat out choose the first sentence i have spoken! your welcome~

It’s completely renewable in that we don’t need to consume anything to get energy. essentially after we can harvest it, it’s free energy