Published online by Cambridge University Press: 13 May 2016
A brief account is given of how environmental challenges to astronomy have grown and diversified and how the IAU has addressed the problem. In the 1970s and '80s, appeals and Resolutions of increasing urgency were addressed to governments and other authorities. In the 1990s, interdisciplinary organisations such as ICSU and UNESCO were enlisted as allies. The present Symposium marks the beginning of a new phase, where direct collaboration with United Nations Member States is sought through the UN Committee on the Peaceful Uses of Outer Space.