Exercise 7. it is estimated that humankind is consuming 92 million barrels of oil per day (2016). (i) what percentage of earth's current npp does this represent? (ii) how does the energy content of this much oil compare to the energy content of the daily food requirements for the earth's 7.5 billion human inhabitants? you will need to know that a reasonable estimate for the average energy content of crude oil is 61x10 u/bbl]. what does your answer tell you about the wisdom of replacing all fossil fuels with fuel derived (even at 100% efficiency) from biomass? exercise 8. it is estimated that the total amount of oil produced globally, since it was first discovered in pennyslvania, usa, in 1859, is approximately 1,500 [(gbbl express this volume as a fraction of the great lakes? does it fill lake ontario?