Question

19. Which of the following energy resources might replace dwindling petroleum supplies one day? (1 point)

Answer 1

Biomass and sun energy

Answer 2

however hydrogen is good to produce charge in electronic devices

Answer 3

shale gas

Answer 4

Why do oil supplies need to dwindle? Since we're all set up for a hydrocarbon energy economy, the most obvious thing to do is start farming the stuff instead of mining it. There's some very interesting and promising early work in which various types of unicellular life are genetically engineered to produce useful hydrocarbons by photosynthesis -- the way they make their own hydrocarbon fuel. It would seem easier to push that technology to maturity, to be able, in essence, to have ponds in the Midwest in which engineered pond scum turned air, water and sunlight into diesel, then to develop a whole new way of amassing and transporting energy. As a bonus, the part of the Earth's carbon cycle that comes from combustion would be "closed," meaning humans would consume the same amount of CO2 their combustion activities emit. So no climate change worries.

In short, the best possible "solar cell" will probably always be the green leaf (or green alga).