Children's ideas about how car exhaust emissions affect three global environmental problems have been studied using a graphic questionnaire in the form of flow charts. The majority of the children aprreciated that cars exacerbate global warming and half of these could accept that carbon dioxide is responsible. However, almost as many thought that heat from exhausts causes the greenhouse effect. Half of the children realised that cars contribute to acid rain. Few of these appreciated that oxides of nitrogen are responsible ; instead, carbon dioxide was seen as causing acid rain. The majority of the children thought, erroneously, that vehicle emissions damage the ozone layer. The most popular mechanism was again carbon dioxide, although some children thought that heat damages stratospheric ozone. Many children apparently see specific gases as 'pollutants' in general, contributing to a variety of environmental problems. A teaching strategy might be to avoid the generic term 'poluution' and link the idea of a 'pollutant' to the environmental problems it causes, so emphasising that a substance can be a pollutant in one context, but environmentally benign in another. (A)
Samenvatting