This happens frequently - and it is called extinction.
If all plants vanish from the planet, then there will be no food for plant eating animals and they will die of hunger and the animal eating animals (Carnivorous.) die as they will not have plant eating animals to eat. Also Carbon bi oxide will go on increasing and Oxygen go on decreasing, as animals will respire to produce it and plants are are not there to convert it back to Oxygen. Vise verse if all animals vanish from the earth, then Plants will not get the Carbon bi oxide, required for photosynthesis and they will also die of starvation, as they also need food for there growth and respiration.
Although it may only have a minuscule effect, yes it does. If you take one animal species out of the food chain, say penguins, then there will be a chain effect and animals like sea leopards will begin to vanish, and therefore killer whales will vanish as well. On the other hand, there will be an overabundance of fish as there is nothing to eat them. So, in a sense, killing animals does have an effect on the earth.
nothing
We will all die!
we would have no food and die
The land will be full of dead bodies
We'd all become vegetarians.
our earth would be stinky dirty there would be dead animals everywhere
Without decomposers dead animals would just lay dead on earth forever.
They'd all die
All living animals, creatures, plants and humans
some animals would not be living here!