The research reported here forms part of a major international study entitled "Emergent Environmentalism". The overall purpose of the Emergent Environmentalism research is to investigate the acquisition and development of environmental knowledge, awareness and concern in both adults and young children. This report is of the results of one aspect of this study, namely the development of UK children's ideas about certain distant places and environmental issues between the ages of 4 and 10 years. Our results are grouped into three sections. Firstly, the children's factual knowledge about two distant environments (rainforests and polar lands) is considered. Secondly, the children's ideas about the reasons for and the effects of environmental change in the two areas are discussed. Thirdly, the types of reasoning used by the children in their explanations of the effects of environmental change are examined. In conclusion, the analysis of understanding shows that children as young as 4 years of age are capable of making simple accurate statements about the effects of major environmental change on habitats and living things. Occasionally by the age of 8 and certainly by the age of 10, pupils are capable of appreciating and explaining the complexity of some of the relationships that exist among plants, animals and their habitats, and to provide accurate reasoned explanations of some of the effects of significant changes to global environments.