Ruben Zondervan is the executive officer of the Earth System Governance Project and programme officer at the Secretariat of the International Human Dimensions Programme on Global Environmental Change, Bonn, Germany.

In the early evening of 4 December, the 2009 Amsterdam Conference came to an end with a closing plenary entitled 'The Earth System Governance Vision Factory: I Have a Dream'. Chaired by Frank Biermann and Roberto Pereira Guimaraes, this plenary was held in a slightly different, innovative and more dynamic format than is usually chosen. All the keynote speakers from the conference were invited to present their dream or vision of earth system governance for 2050. They were all given a maximum of two minutes and were allowed just one slide. The preparation process of this closing plenary session made clear that the limited time and number of slides posed a real challenge to the presenters. Or, as one keynote speaker remarked, it was 'one of the most intimidating things I ever had (to do)'.

The resulting vision factory of dreams was not intimidating at all, though. While being serious in content, the sequence of dreams was presented with a large amount of humour and creativity. The chairs presented some slides as ‘dreams by proxy’ of keynote speakers that already had to leave the conference venue – the global environmental governance community is a travelling circus, after all – and they commented on the other dreams. Although the participants were seriously tired after three days of research presentations, long evenings of networking, brainstorming and debating, the dreams, in their large variety and humorous presentation, excited the participants.

Some speakers stayed within the scientific realm by presenting dreams of specific target numbers and scenarios of earth system governance. Others transcended visions of imaginary reincarnations through the history and future of earth system governance, or shed new light on old stories, for instance by asking what would have happened if Moses had had to do an Environmental Impact Assessment before parting the waters of the Red Sea. Beautiful pictures of landscapes were presented that, as is possible in dreams alone, turned into symbols and graphs of a future with more sustainable governance and development. While the visions for earth system governance in 2050 were characterized by a positive, hopeful perspective, one keynote speaker said that given the reality, he would probably be woken up before his dreams come true. But, as Roberto Pereira Guimaraes remarked in his closing words, 'when you dream alone, it's just a dream, (…) but if you dream together, it is a pre-emption of reality'.