Poor sleep affects everything you do. The human body needs the rest period in order to function efficiently, even though I do believe I read something about 8 hours not being optimal. What's more important is ensuring that you get enough cycles of REM (Need more than 6 hours, thats for sure). There are diseases that prevent people from ever sleeping, and it is very often fatal.
Losing sleep over climate change. A new study of US data suggests a sleep-deprived planet by century's end. Researchers show that unusually warm nights can harm human sleep and that the poor and elderly are most affected. Rising temperatures will make sleep loss more severe. Ref. Source 5n.