The potential for this year's Rio+20 Summit to have a similar impact is less clear. Firstly, immediate economic problems are top-of-mind in much of the world, making it difficult for many leaders to prioritize longer term sustainability issues.
Furthermore, this time there are no grand treaties on the table that promise to result in international law. Instead, commitments made at Rio+20 will be voluntary and differentiated to take account of variations in development status and economic and social capacity.
Indeed, some observers suggest that the age of overarching international legislation on sustainability is past and the UN process now works best as an international forum in which to sustain momentum in national and regional commitments, actions and progress.
It is important to note, however, that there has been a significant change in language since the 1992 event with a new emphasis on the global "green economy". A green economy is defined by the United Nations Environment Programme (UNEP) as "one that results in improved human well-being and social equity, while reducing environmental risks and ecological scarcities". Simply speaking, a green economy is "low carbon, resource efficient and socially inclusive".
The discussions at Rio+20 are in large part focused on agreeing specific actions required to deliver a global green economy. In the same way as the Earth Summit 1992 marked a sea change in awareness of sustainable development, Rio+20 could do the same for the concepts of resource efficiency and green economic growth.
The fact that this Summit is happening at all, and the nature of the commitments on the table, should act as a clear indication to business: the question is no longer whether or not the world is heading towards a green economy, but what route we will take to get there and at what pace we will travel.