Finally, sustainable development is a concept that is often difficult to communicate to the general public. The term itself is an abstraction that encompasses three more abstractions in the 'triple bottom line' concept. In 1992, many heads of state and government officials convened in Rio de Janeiro for the World Conference on Environment and Development. The conference resulted in the signing of some very significant international agreements (e.g. on climate change and biodiversity), and the publication of the lengthy 'Agenda 21' document.
"Rio+5" took place in 1997, and the Kyoto Protocol was signed after intense negotiations and several compromises, resulting in some modest commitments to reduce greenhouse gases. Ten years after Rio, the World Summit on Sustainable Development took place in South Africa, but the resulting 'Johannesburg Plan of Implementation' showed little ambition and was generally disappointing.
Three landmark reports commissioned by the UN in 2005 revealed the grand scale of problems to be addressed worldwide: the 'Millennium Project' confirmed that progress in reducing poverty was too slow; the 'Millennium Ecosystem Assessment' concluded that 16 of 25 ecosystem benefits to humanity were being critically degraded; and the Intergovernmental Panel on Climate Change clearly demonstrated the seriously negative impact of unsustainable development paths.
September 11, 2001 marked yet another milestone, though a grim one, in the history of sustainable development. With the appearance of global terrorism as a permanent threat, global and individual security became a top priority and, in many cases, the only priority.
In Europe, during the Cold War period that preceded the political changes of 1989-90, divided Europe engaged in little or no environmental cooperation. With the fall of the Berlin Wall and Germany's reunification, however, a host of brand new and unexpected opportunities to protect the environment became apparent. It was a time marked by great enthusiasm and, one might say, over-optimism, as millions believed that socio-economic justice was near at hand. However, the populations of many Central and Eastern European countries confronted high economic debt, economic recession, running inflation, complex privatisation, rising unemployment and individual insecurity. Populations forced to choose between bread and clean air will clearly choose the former.