Can humans effect the Earth?  Of course, the same way the Earth can effect humans.  Except with humans, it could take a shit load, or just one.  Either way, we can be dangerous to the Earth.  But the Earth is always in danger so merely increase the risk by humans not only destroying our own species but possibly taking a planet with it.  Too bad since She is home to countless Other species, we should help our Place thrive instead of cutting down our own sources of Oxygen.  We share a balancing point, between freezing and burning, drowning and floating, this void from the frigid vacuum of space time, we share a fragile existence.  It is in our best interest for us to care for our environment   If we had to abandon the Earth, where would our next source of Oxygen be?  If Mars is the future of Earth, then we should have a plan B.  Wake up, stop dreaming, see the reality of where we are.  We are among objects hurtling through space on a 3D pool table that endlessly filled and infinitely colliding.  Where did the moon come from?  Collision.  Open your eyes and realize that billions of years is a lot shorter than you think, for things are occurring faster (farther) and slower (closer) than you know.  Our lifetime, is a blink of the eye to change it - but they all add up.  We need concentrated effort for instantaneous change.  We need humans to think......or stop thinking.  We are just another animal in nature, like any other bug on the planet, we are beasts.  In lost time we beasts have cloud minds with past and forgot we are beasts, but beasts we still are.  We have forgotten what the earth feels like under our toes,  what if feels like to eat food raw still warm.  We have evolved away from a creature which can survive nature, we are weaker and fragile for it.   Our minds are our only defense. Is it our only offense.   Polluted, it is nothing.  For the cloud prevents all sight, it denies hearing,  it numbs touch, dulls taste,  it steals time and space.  What left is a zombie, pre-programmed, and set on auto pilot like some drone.  A shell of what could have been.  This insult to the existence and freedom due all Life is careless about disrupting the sanctity which is Earth.