The second Workshop on Sensing a Changing World takes place from May 9 - 11, 2012 at the Center for Geo-Information, Wageningen Universty in the Netherlands. Since the first workshop three years ago, developments in sensor technology have advanced rapidly. This Workshop presents and explores the current state-of-the-art developments, impacts and research challenges for sensor web technology in the context of environmental monitoring and analyses. Sensor Web Enablement is a key 52°North focus. 52°North Sensor Web experts will give the follwoing presentations.