Simplify the following text for a Grade 11 native English-speaking person.
Original: According to them , on a planet where 20 % of the population consumes 80 % of the natural resources , a sustainable development can not be possible for this 20 % : `` According to the origin of the concept of sustainable development , a development which meets the needs of the present without compromising the ability of future generations to meet their own needs , the right term for the developed countries should be a sustainable de-growth '' .
Simplified: Sustainable development is a way for people to use resources without the resources running out . The term used by the Brundtland Commission defined it as development that `` meets the needs of the present without compromising the ability of future generations to meet their own needs . ''