1. Reduced production of waste materials
2. Increased reuse of older materials
3. Use more renewable sources of energy
4. Decrease the rate of fires through alternate means of warmth
5. Burn down less forests and find better means of farming
Decomposers eat dead remains of organisms that are quaternary consumer (no one eats them while alive). So, they break these down and therefore turn into nutrients in the soil for plants to use.
Like Geography, climate, times and environment system
Fossils can give information about past environmental conditions by showing the type of animal they belonged to. If a scientist found a whale fossil in a desert, he/she could assume that the desert was once an ocean as whales only live in oceans. If someone found a fossil of a lizard that inhabited trees, in the middle of the ocean, then he/she could assume that the ocean didn't exist at one point and instead, there might have been a forest in it's place.
Hope this helps!