fˈɑːsəl fjˈuːəlz ˈɔːlsoʊ ɹᵻkwˈaɪɚ sɪɡnˈɪfɪkənt ˈɛnɚdʒi ˈɪnpʊts wˌɪtʃ hæv sˈɛldəm bˌɪn ɐkˈaʊntᵻd fɔːɹ ɪnðə pˈæst.
Fossil fuels also require significant energy inputs which have seldom been accounted for in the past.