Carrara EnvironKits each have a Base Scene, which is the blank canvas that the presets were each built from. This base includes a full Carrara atmosphere using the Realistic Sky system and incorporates an artificial global illumination system built in, along with a volumetric cloud to add additional haze density and that gets replicated over cloud domes that have morphs built into them for animating storms coming or going or....

Then there's a base ground surface which is flat in the very center of the scene to make for easier use of animated poses and such. They also include a replicated Ocean primitive set up so that the waves are already animating at a fairly easy-on-resources setting that also looks great (See the Badlands Promo - the lava is the Ocean Primitive)

They also include a "Hero Light" setup to enhance whatever we drop into that group with additional lighting that doesn't affect anything else in the scene - to make it Pop.

Any of these systems are easily turned off or simply deleted.