During the carboniferous period, which occurred approximately 360 to 300 million years ago, most of earth was covered in dense rainforests. these rainforests were sustained by a humid and tropical climate that lasted for most of the carboniferous period. at the end of the period, earth's climate became much colder and drier, leading to a wide-scale collapse of the rainforests and a significant loss of vegetation.

The statement is - True.

The Carboniferous period/epoch is a period that lasted approximately 60 million years, being between the Devonian, and Permian periods. It got its name because it is the period from which most of the coal originates on our planet. During the first half of this period, the planet was mostly covered in dense swampy forests, and the land life was developing very well. In the second half of it, because of the geologic activities that caused the continents to collide and form Pangaea, the climate changed, it became much colder and much drier, and lots of mountain ranges appeared, and this caused a large scale demise of the vast rainforests.

a. decomposes use carbon from dead organisms as fuel for cellular respiration, returning carbon dioxide back into the atmosphere.

2%? i tried finding the exact sorry if it's not 100% correct ; -;