Department of Building and Construction, City University of Hong Kong, P. R. China
Global Warming is one of the major concerns in environmental issues. Its effects are being exposed faster than anticipated recently. It causes adverse ecological and socioeconomical effects. The 4th Assessment Report issued by the U. N.’s Intergovernmental Panel on Climate Change (IPCC) states that it is appropriate to define Global Warming was caused by greenhouse gases due to human activities which plays a significant role by over loading the atmosphere with carbon dioxide (CO2) emissions since 1750. One of the most effective ways to prevent global warming is to replace materials which emit high level of CO2 with those of low level CO2 emission materials. Usually, CO2 emission can be presented as embodied CO2 (ECO2) and operational CO2 emissions. In this paper, appraisal of the embodied CO2 emission level of using traditional building materials (i.e.cement, steel, glass and timber) and alternative building materials (i.e. slag cement, recycle steel, cullet glass and plywood formwork) have been made by case modelling. The results show that the amount of CO2 emission is reduced after using alternative building materials by more than one-third (34.8%).