Kinds of resources

Air, water, the Sun's energy, forests, soil, rocks, minerals and fossil fuels: resources we get from nature are called natural resources. We get heat and light from the Sun, water from rivers, food from plants and animals.

People use natural resources to make useful things: electric bulbs, furniture, solar panels, bicycles. Resources made by people are called human-made resources. A machine or a bicycle is human-made; it is not found in nature.

Some natural resources are renewed by nature. Remember the nellikai that Ajji let the children pick only from the ground? That left fruit for animals and birds, and seeds in their droppings grow into new trees (though it takes some years before those trees give fruit). Resources that are renewed, refilled or restored within a reasonable time are renewable resources: air, water and forests are examples.

Others take millions of years to form, exist in limited amounts, and once used are gone: they are not replaced in any reasonable time. These are non-renewable resources: minerals, rocks, coal, petroleum and natural gas. Petroleum is non-renewable because it takes millions of years to form and there is only a limited amount of it.