our energy we get from the sun.
http://www.ecoworld.com/energy-fuels/how-much-solar-energy-hits-earth.html
"Put another way, the solar energy hitting the earth exceeds the total energy consumed by humanity by a factor of over 20,000 times."
I for one do not believe that the Earth is so fragile that an energy increase of 1/200th of a percent is going to crash the ecosystem.