Sustainable development refers to the development that meets the needs of the present without compromising the ability of future generations to meet their own needs. In simple terms, it means balancing economic, social, and environmental goals in a way that ensures the long-term sustainability of human development.

Summits for addressing environmental protection and economic development:

1. United Nations Conference on Environment and Development (UNCED) - This summit was held in Rio de Janeiro, Brazil in 1992 and is also known as the Earth Summit. The summit focused on the need for sustainable development and the need to integrate environmental protection and economic development.

2. United Nations Conference on Sustainable Development (UNCSD) - This summit was held in Rio de Janeiro, Brazil in 2012, and is also known as Rio+20. The summit aimed to secure renewed political commitment for sustainable development, assess progress towards internationally agreed goals on sustainable development, and address new and emerging challenges.

Details of the two summits:

1. United Nations Conference on Environment and Development (UNCED):

The Earth Summit took place in Rio de Janeiro, Brazil in 1992, and was attended by representatives from 178 countries. The summit focused on sustainable development and the need to integrate environmental protection and economic development. The summit produced the Rio Declaration on Environment and Development, which set out principles for sustainable development, and the Agenda 21, a blueprint for sustainable development. The summit also resulted in the formation of the United Nations Framework Convention on Climate Change.

2. United Nations Conference on Sustainable Development (UNCSD):

The Rio+20 summit took place in Rio de Janeiro, Brazil in 2012, and was attended by representatives from 193 countries. The summit aimed to secure renewed political commitment for sustainable development, assess progress towards internationally agreed goals on sustainable development, and address new and emerging challenges. The summit produced the Future We Want outcome document, which reaffirmed the commitment to sustainable development and provided a roadmap for future action. The summit also launched the Sustainable Development Goals (SDGs), a set of 17 goals aimed at ending poverty, protecting the planet, and ensuring prosperity for all.

In conclusion, sustainable development is an important concept that aims to balance economic, social, and environmental goals in a way that ensures the long-term sustainability of human development. The UNCED and UNCSD summits were important milestones in the global effort to achieve sustainable development, and the SDGs provide a roadmap for future action.