Sentences of a paragraph are given below in jumbled order. Arrange the sentences in the correct order to form a meaningful and coherent paragraph.
A. The sharp increase in our consumption of fossil fuels has led to their depletion at an alarming rate.
B. Unchecked burning of fossil fuel is like an unchecked dripping tap which will eventually run dry.
C. The toxic pollutants released from burning these fuels are also a cause for concern.
D. This has led to the tapping of various non-conventional sources of energy that are cleaner alternatives to fossil fuels.