Waste is what is left over after the usable bits are gone. Natural waste products decay over time and improve the environment. Man produced waste can frequently remain intact for thousands of years.
Animals produce waste products in a number of ways such as the food that is digested and excreted, dead skin cells which are shed, hair (fur,) and claw (nail) shedding are all frequent and necessary biological functions. Animal waste decays rapidly and leaves no environmental problems behind. All animal waste is organic but not all organic waste is from animals. Although animal waste is considered to be good for the environment the waste from caged or confined animals is a problem that needs to be dealt with.
Waste wasn't an issue until agriculture became a major part of human society. Prior to the ability of man to plant, harvest, and store crops permanent settlements could not form, at least not for long. Once we started staying in one place though, all that changed.
Agricultural waste is mainly the herbicides, pesticides, and fertilizers that are used on the crops. All of these chemicals wash off the crops and get into the fresh water supply. It also includes carbon emissions from tractors, all unused crops, and any other type of waste created by the agricultural industry.
Once farming was widespread, industry had a chance to start. People needed to transport excess crops for sale and metals were mined and refined for plows. Then next leap in waste evolution was large scale industries. This includes manufacturing plants and other industries related to the mass creation of products.
Industry produces large quantities of air pollution, pollutes the water, creates unwanted trash of various types, and generally makes things unpleasant. Regulations began to be enacted to prevent as much of this industrial waste from getting into the natural environment as possible. Plenty of industrial waste is still produced but it is much less than it was.
Household waste is produced by one or more people from their residence. There is a wide range of what constitutes household waste. Paper, shopping bags from the grocery store, empty food cans, emissions from vehicles, and anything else that is either thrown away or runs off into the sewer system.
The waste from homes includes both interior and exterior waste products. Some waste can be recycled or composted but most ends up in a landfill, as atmospheric pollution, or water pollution.
A new way to measure the impact of a person on the environment is called a carbon footprint. This is used to determine just how damaging a person, event, or group is to the buildup of greenhouse gases in the atmosphere which contributes to global warming.
As humans continue to increase in population the amount of waste produced will continue to rise. New efforts are constantly being thought up to help to control the impact of people on the environment.