Question

what was the motivating factor behind theodore roosevelt's conservationist ideas?

Answer 1

the motivating factor behind theodore roosevelt's conservationist ideas is : To preserve the health if mankind
In order to do that, the conservation of the environment in which humans rely their lives on is extremely necessary

hope this helps

Answer 2

Central to Theodore Roosevelt's conservationist ideas was to protect the people living in the United States of America. Roosevelt asserted that a person's health was directly related to his or her environment. Therefore, his main theme, which motivated him, was to preserve the mankind in order to preserve the nature.
According to Theodore thoughts, it was man's responsibility to care for the environment as it had been Adam's responsibility to care for the Garden.