Fossil fuels are sources of energy that derives from fossil materials. Fossil means ancient organisms that in a long time have change their molecular composition. In this case, fossil fuels like oil derives from decayed plant material. In particular conditions of humidity and over time, the carbon present in the plant slowly trasforms in other things, like methan- another fossil fuels.
The Supreme Court ruled that the evacuation order violated by Korematsu was valid, and it was not necessary to address the constitutional racial discrimination issues in this case.