At the end of the 1960s, some members of the Rome Club issued a warning that everyone should be aware that certain economic activities were causing serious harm to the planet.
In 1972, a United Nations summit on the environment alerted countries all around the world to the exhaustion of natural resources.
In 1987, Ms Gro Harlem Brundtland, a Norwegian minister, found that in 50 years the standard of living of part of the world's population had developed greatly, but that on the other hand, ecological damage was huge (deforestation, pollution, industrial accidents, reduction of water resources, exhaustion of natural resources, desertification etc.). Urgent measures were necessary, and for the first time she used the term "sustainable development" to describe how behavior would have to change. Thus people became aware of the necessity to protect future generations.
In 1992, the United Nations held a conference on the environment and development in Rio de Janeiro (Brazil), known as the Earth Summit. One of the Earth Summit decisions:
Agenda 21, a joint program for the implementation of sustainable development in the 21st century, the Rio Declaration on the environment and development, and the United Nations Framework Convention on Climate Change, the Convention on Biological Diversity, and agreements on desertification and fishing on the high seas.
In 2002, the World Summit on Sustainable Development in Johannesburg (South Africa) was attended by 22,000 delegates (100 political leaders, delegates from 193 countries, representatives of NGOs and thousands of journalists). It ended with a commitment to reducing greenhouse gas emissions by 5.2 % during the next ten years and to bring together governments and people to implement joint plans of action.