Education is critical for promoting sustainable development and improving the capacity of the people to address environment and development issues . . . it is also critical for achieving environmental and ethical awareness, values and attitudes, skills and behaviour consistent with sustainable development.

Agenda 21, chapter 36 

We consider that environmental education for equitable sustainability is a continuous learning process based on respect for life. Such education affirms values and actions which contribute to human and social transformation and ecological preservation. It fosters ecologically sound and equitable societies that live together in interdependence and diversity. This requires individual and collective responsibility at local, national and planetary levels.

Treaty on Environmental Education for Sustainable Societies and Global Responsibility - from Alternative Treaties from the International NGO Forum, Rio de Janeiro, June 1992 

Education for sustainability is a process which: 

• enables people to understand the interdependence of all life on this planet and the repercussions that their actions and decisions may have both now and in the future on resources, on the global community as well as their local one, and on the total environment; 
• increases people's awareness of the economic, political, social, cultural, technological and environmental forces which foster or impede sustainable development; 
• develops people's awareness, competence, attitudes and values, enabling them to be effectively involved in sustainable development at local, national and international levels, and helping them to work towards a more equitable and sustainable future. In particular, it enables people to integrate environmental and economic decision-making; 
• affirms the validity of the different approaches contributed by environmental education and development education and the need for the further development and integration of the concepts of sustainability in these and other related cross-disciplinary educational approaches, as well as in established subjects.

Good Earth-Keeping, Education, Training and Awareness for a Sustainable Future, S Sterling (ed.), UNEP-UK, 1992 

Education for sustainable development is about the learning needed to maintain and improve our quality of life and quality of life of generations to come. It is about equipping individuals, communities, groups, businesses and governments to live and act sustainably; as well as giving them an understanding of the environmental, social and economic issues involved. It is about preparing for the world in which we will live in the next century, and making sure that we are not found wanting. 

Education for sustainable development enables people to develop the knowledge, values and skills to participate in decisions about the way we do things, individually and collectively, both locally and globally, that will improve the quality of life now without damaging the planet for the future.

Education for Sustainable Development in the Schools Sector, 
Report of Sustainable Development Education Panel to DfEE/QCA, 1998 

Education for sustainable development has come to be seen as a process of learning how to make decisions that consider the long‑term future of the economy, ecology and equity of all communities.  . . . . . . .  This represents a new vision of education, a vision that helps people of all ages better understand the world in which they live, addressing the complexity and interconnectedness of problems such as poverty, wasteful consumption, environmental degradation, urban decay, population growth, health, conflict and the violation of human rights that threaten our future. This vision of education emphasises a holistic, interdisciplinary approach to developing the knowledge and skills needed for a sustainable future as well as changes in values, behaviour, and lifestyles.

Draft framework for the Decade of ESD, UNESCO, 2003, p. 4