SUSTAINABLE DEVELOPMENT, CLIMATE-CHANGE, AND CARBON-DIOXIDE REMOVAL (CDR)

In this article the characteristics and requirements of a sustainable energy system are described. Special attention is given to the need to reduce greenhouse gas emissions, especially CO2. It is indicated that we may have to reduce the annual CO2 emissions due to our energy cons umption from 6 GtC at present to less than 3 GtC in the year 2100, and the cumulative CO2 emissions between the years 1990 and 2100 to 550-7 50 GtC. To reduce the CO2 emissions, one option we can develop and app ly is improvement of the energy efficiency with 50-90%. In addition st rong efforts are needed to develop a sustainable energy supply system with low or no CO2 emissions. Option number one, the use of renewable energy sources, offers a huge potential but major technological breakt hroughs are required to allow a massive application of these sources a t affordable costs, in a reliable way and in an acceptable manner. Thi s probably also holds for another option, nuclear energy. The impact o f a fuel switch from coal to oil and natural gas will depend on the re coverable amount of fossil fuels. Therefore, due attention should be g iven to Carbon Dioxide Removal (CDR), especially as it is the only opt ion that may allow continuing large scale use of fossil fuels. Applica tion of this option could prevent the emission of 300 GtC or more betw een the years 1990 and 2100. Studies in the Netherlands suggest its ap plication would be accepted socially. One of the main implementation b arriers is its high cost. In the power sector CDR may increase the ele ctricity production costs with 30-100%, although there is room to redu ce these costs. Lower cost CDR options are available outside the power sector, like CDR from natural gas recovery processes, from specific i ndustrial processes and from the production of hydrogen from natural g as, coal or biomass. Consequently, CDR may be applied at a cost rangin g from US$ 5-10 to 250 per ton Carbon avoided, depending on the option and circumstances involved. Given the pursuit of sustainability, furt her attention is needed not only for costs reductions but also for the environmental and safety aspects of CO2 disposal especially in aquife rs and in the deep ocean. (C) 1997 Elsevier Science Ltd.