Sustainable development is an idea that has been evolving for over forty years. There have been some major landmarks in the development of a global strategy to tackle environmental and social issues. Some of the main points are described below.

The Stockholm Declaration

The United Nations Conference on the Human Environment in 1972 was the first major meeting to look at how human activity was affecting the environment.

A declaration highlighted problems of pollution, destruction of resources, damage to the environment, danger to species and the need to enhance human social well being.

The conference acknowledged the need for countries to improve the living standards of their population and stated twenty six principles that would ensure the development was sustainable.

Rio Earth Summit

In 1992, more than 100 countries met in Rio de Janeiro, Brazil for the first international Earth Summit. The meeting addressed the urgent problems of environmental protection, social and economic development.

Several major agreements were made:
The Convention on Climate Change - limits emissions of the greenhouse gases carbon dioxide (CO₂) and methane (CH₄).
The Convention on Biological Diversity - gives countries responsibility for conserving species diversity and using biological resources in a sustainable way.
The Rio Declaration and the Forest Principles - sets out the principles of sustainable development and pledges to reduce deforestation.
Agenda 21 - a plan for achieving sustainable development in the 21st century.

Agenda 21

The Rio Summit produced a major plan for sustainable development called Agenda 21. It proposes that poverty can be reduced by giving people access to the resources they need to support themselves. Developed nations agreed to assist others to develop in a way that will minimise the environmental impact of their economic growth.

Agenda 21 calls on countries to reduce pollution, emissions and the use of precious natural resources. Governments need to lead this change but emphasises that everyone can play their part in tackling non-sustainable practices. In this way, local actions can lead to the solution of global problems.

Kyoto Climate Change Protocol

In 1997, governments met in Kyoto, Japan to once more look at the problem of global warming.

Previous agreements had tried to limit emissions of carbon dioxide to the levels they were in 1990. Many countries had failed to achieve even this small reduction. The UK and Germany met these targets.

At Kyoto, a new set of targets for the reduction of greenhouse gases was agreed. By 2012, emissions of six major greenhouse gases must be reduced to below 1990 levels for the target period 2008-2012.

Johannesburg 2002 "Rio+10"

Ten years after the Rio Earth Summit, countries met to review progress towards sustainable development.

The conference focussed on poverty and the access to safe drinking water and sanitation. It agreed several aims, including:

• To reduce the number of people that are not connected to clean drinking water supplies from over 1 billion to 500 million by the year 2015.
• To halve the number of people without proper sanitation to 1.2 billion.
• To increase the use of sustainable energy sources and restore depleted fish stocks.

Many environmental groups protested at the lack of progress since the Rio summit in 1992. Politicians pointed out that the summit had moved on from issues like biodiversity and climate change to tackling poverty and poor living conditions.