Study On Evaluation Method Of Substitution Of Low - Carbon Rationality In The Background Of Urban Renewal

At present, since China is in the process of large-scale urban renewal, it has become an important issue whether the situation can be taken as an opportunity to build low-carbon cities. As an important part of urban renewal, technology replacement is highly desirable to establish a set of evaluation methods to determine it is low-carbon or not. In the context of existing low-carbon technologies emphasis on the flow of carbon, ignoring the stock of carbon, the former level is where China’s low-carbon practice lies on. There is a certain number of research abroad on technology replacement assessment combined with life cycle carbon footprint thinking, but still varying degrees of drawback exist. Therefore, it is necessary to explore a new assessment method on low carbon technology replacement.In this paper, by combing literature on life cycle carbon footprint concept and classification, present mainstream low-carbon technology, assessment methods on low carbon technology replacement, etc., the progress and shortfalls of current research are summarized to reveal the most noteworthy drawback is lack of understanding and distinguishing of different nature of the stock of carbon and the flow of carbon. Thus, the possibility of conflict between "low-carbon" respectively defined by the stock of carbon and the flow of carbon is ignored. With the discovery of accelerated depreciation effect of stock of carbon of the replaced technology, the conflict is confirmed.In this paper, based on existing research results and analysis of defects, a creative way to identify, quantify, and allocate accelerated depreciation effect of stock of carbon is applied to improve the assessment method on low carbon technology replacement. According to the improved method, the new technology must bear the loss of stock of carbon caused by technology replacement behavior, and make sure its advantage in flow of carbon is enough to offset this loss, otherwise the techno logy replacement is hardly low-carbon.In this paper, the improved method is applied to the case of street light technology replacement, proving that the so-called low carbon technology replacement may probably be the opposite, unless the replacement behavior takes place within some certain time period. Therefore, some policy recommendations are made to ensure technology replacement benefits low-carbon city construction. The recommendations include:promoting the popularization and application of life cycle assessment method, establishing national statistics and monitoring system of stock of carbon of buildings, infrastructure and public facilities, and doing low-carbon assessment on development activities involving large-scale urban renewal.