Scientists who are concerned about increased carbon dioxide in the atmosphere believe global warming is caused by

They believe its caused by these MAIN MAJOR global warming causers, pollution from cars engines, factories airing out pollution, and by human actions as well.

So basically the answer is A. human actions.

Aristotle thought so every portion of the earth tends toward the center until by compression and convergence they form a sphere. travelers going south see southern constellations rise higher above the horizon.~ hope this !