For millennia societies have relied on animals and sometimes other humans, to provide energy for transportation, agriculture, and manufacturing — and burned wood for heat-energy.
In the last 150 years humans have used exponentially increasing amounts of energy, mostly from fossil-fuels, creating severe pollution of many kinds.
Reducing energy consumption and waste, and transitioning to ethical and sustainable energy sources is vitally necessary.
Renewable energy from the sun and earth's systems is plentiful, and technology for collecting it is increasingly available and affordable. Reducing energy use and waste is also essential.
Main uses of energy by humans include:
- Heating and cooling of buildings