Power on Earth
The world is NOT powered by coal, oil or nuclear energy.
The sources of energy are not even significant.
In fact the biggest source of energy by far is solar energy. The energy sources above are important only becuase they are useful in specific circumstances. Oil can ve refined and used to power cars.
Total power consunption in 2010 was about 1.78*1013 Watts. The total solar power available is about 1.78*1017 watts -about 10,00 times greater than all other power sources combined.
In fact all the worlds's energy requirements could be satisfied by covering the sahara desert with solar panels, if we could find some way to use electricity effectively to substitute for gas, oil and coal.
Far more useful than solar panels though is photsynthesis - ultimately the source of all the food on earth, as well as coal, oil and gas. We could honestly say that the the gretest design of man or nature is the leaf - where photosynthesis takes place.