Sustainable development is not just a topic; it should be a lifestyle. It is about the economy, the environment, and the society being well-rounded. It means that the development of any area should meet the needs of both today and tomorrow. It entails the ability to support the needs of the present times without compromising the ability of the next generation to meet their future demands.
An essay on sustainability at school should be about how educators can instill the key concept of needs and limitations. When the issue of sustainability is addressed, students should be made to understand that attention should be given to particular needs such as those of the poor. It should be balanced with the concept of limitations – meaning they cannot consume all resources without thinking of the succeeding generations.

Nature should be able to meet both present and future needs. Sustainable development should thus create a system that should link together time, space, and generations. It should be noted that technological advancement may create pollution which can harm certain aspects of the environment to the point of destruction. For example, the use of pesticides in one area can harm wildlife in another area. Similarly, air pollution in one continent can affect air quality in another.

The decisions made today should consider the coming years. The farming of land, for instance, can affect the quality of soil. If the agricultural practice is wasteful, then future generations will not be able to enjoy the earth and its produce. It is the same with implementing economic policies.
To better understand sustainability, one need only to put down in writing the things that he thinks he needs in life. A common list may include good water supply, clean air, a house to live in, and a car to get around among other things. But if you are to study it closely, how can you have clean air if you also have a vehicle that emits air pollutants? If you are to choose only one, which would you rather have? This conflicting of needs on a personal level is multiplied on a bigger scale when you consider communities and cities. It is similar to thinking of ways to prevent erosion and conserving forests and topsoil while thinking of ways to satisfy the demand for firewood and lumber.

Educators on sustainability should also note that the quality of life is vital. If someone is physically healthy but is living in poverty, then how can he sustain a high quality life? If someone is rich or financially stable yet he lives in a polluted city, it also means that quality is not sustained. But while the issue of sustainability is complex, it can be addressed when people understand the need to innovate and implement measures that will make living on earth meaningful for its inhabitants now and in the future.

References:

http://wwf.panda.org/how_you_can_help/live_green/at_school/
http://sustainableschoolsproject.org
http://www.sustainablestamford.org/sustainable-at-school.aspx