Energy　is　considered　the　oxygen　of　an　economy　fueling　all　economic　activities.　Energy　utilization　and　its　type　have　an　intertemporal　and　size-based　effect　on　economic　development.　Therefore,　this　study　empirically　analyzes　the　relationship　of　fossil　energy　consumption　with　economic　development　in　the　case　of　BRICS　countries　between　1990　and　2019.　Fully　modified　ordinary　least　squares　is　used　with　the　quadratic　function　of　coal,　oil,　and　gas　consumption　to　assess　the　size-based　effect　across　time.　This　study　shows　that　coal　and　natural　gas　consumption　follows　the　inverted　U-shaped　relationship　with　HDI,　while　coal　consumption　shows　a　negative　relationship　with　HDI.　Hence,　coal　and　gas　energy　assists　in　development　when　its　share　is　small,　while　over-consumption　hampers　development.　The　BRICS　countries　should　optimize　coal　and　gas　consumption　with　respect　to　economic　development.　Reducing　fossil　energy　should　be　substituted　with　alternative　clean　energy　resources　by　using　advanced　technology　such　as　the　gasification　process.　Copyright　©　2022　Wang,　Asif　Amjad,　Arshed,　Mohamed,　Ali,　Haider　Jafri　and　Khan.