I think human's being selfish acts will bring about the earth's doom as we are polluting the environment making the 'earth sick'. Even though we have already damaged earth, we still can mend it back. For example the 3 r, reduce, reuse and recycle. We can also use greener source of energy like the wind power, solar power, etc. Actually we can also help just by simply switch off the lights when you are not in the room or to make it better change the bulb to a energy saving fluorescent tube.