ترویج توسعه پایدار در چین را از طریق بهینه سازی یک طرح مالیات / یارانه در میان HFC و پروژه های CDM تولید برق

China is expected to reach record growth by 2020 in the energy sector by at least doubling its electricity generation capacity. In order to protect the environment and foster economic development, China will greatly benefit from transfers of state-of-the-art power generation technologies through international agreements such as the Clean Development Mechanism (CDM). However, a buyer-driven carbon market and a highly competitive environment due to more cost-effective projects attribute to China's need to achieve a balance between sustainability and profitability for CDM projects implemented in China. In the CDM Tax/Subsidy Optimization Model (CDMTSO Model) here developed, a sustainable development assessment method evaluates the CDM projects’ economic and environmental benefits and an optimization program returns tax/subsidy rates at which the greatest number of CDM technologies becomes viable and where “better” CDM projects can be the most profitable, bringing China's development on a more sustainable path. The results show that the CDMTSO Model brings the sustainable CDM projects’ Internal Rate of Return closed to 10%. If a discount rate of 9% is considered, it allows three clean energy technologies (natural gas combined cycle, wind energy, and hydropower) to become economically viable and the environmental costs avoided are increased by 37%.

Over the past 100 years, global mean temperature has increased by 0.7 °C and is expected to continue its growth by a further 1.4–5.8 °C by 2100 (IPCC, 2001). There is growing evidence that most of this warming can be attributed to the emission of greenhouse gases (GHG) and aerosols from human activities. The most concrete initiative to date is the 1997 Kyoto Protocol, a protocol to the United Nations Framework Convention on Climate Change (UNFCCC). Under this multi-lateral agreement, the responsibility of developed countries to play a proactive part is underscored with mandatory targets on GHG emissions while the needs of developing countries are taken into account through fostering transnational cooperation with flexibility mechanisms named Clean Development Mechanisms (CDM). This market-based solution works by assigning monetary value to the preservation of the earth's atmosphere through the trading of carbon credits. Under the CDM program, industrialized countries indirectly pay for projects that cut or avoid emissions in less developed nations by buying credits called Certified Emission Reductions (CER) that can be applied to meeting their own emission targets. Recipient countries benefit from the infusion of advanced technology and investment that allow their factories or energy generating plants to operate more efficiently. Lowered costs and increased profits contribute to a win–win business dynamic. Furthermore, ecological sustainability is promoted as future emissions are lowered. China's transition to a market economy has put this country among the world's fastest growing economies and has consequently led to a strong increase in demand for energy. The most populated country in the world also recently became the 2nd world's largest consumer of primary energy after the USA and will overtake after 2025 (EIA, 2006). As a result of this energy consumption, associated with significant inefficiencies in energy production and use,1 and a heavy reliance on coal,2 China is, with 12.7% of the world's total energy-related carbon dioxide emissions, the second largest emitter after the USA. China's share of world carbon emissions is expected to increase in coming years, reaching 17.8% by 2025 (EIA, 2006). Furthermore, environmental pollution due to energy production and use, especially from coal combustion, is damaging human health, air and water quality, agriculture and ultimately the economy. A recent study estimates that air pollution in China cost about $48 billion in 1995 (7% of GDP), including impacts of acid deposition as well as health effects from air pollution (WB, 1997). Moreover, it is projected that under business-as-usual conditions, pollution-related health costs for urban residents will increase to $98 billion by 2020 at current income levels or $390 billion (13% of GDP) with adjustment related to growth in income. Thus for China's energy production and use system, CDM is a unique opportunity to foster technology transfer with industrialized countries and to attract more foreign investment in the energy sector. Indeed, China would greatly benefit on economic and environmental levels from implementing CDM projects in this sector, and would so bring its all-time high growth on a more sustainable path. However, in a carbon market that might be buyer-driven in coming years, the energy-related CDM projects may have to compete with other kind of CDM projects with much lower abatement costs. Therefore, a solution must be found in order to balance between the great sustainable benefits energy CDM projects would mean for China, and the high profitability of the more competitive CDM projects.

Whether the discount rate is set at 7% or 9%, it can be considered that the CDMTSO Model achieves its goals. Through the optimization of the tax/subsidy policy, the greatest number of CDM technologies becomes economically viable, and the corresponding CDM projects’ Internal Rate of Return get closed to a threshold set at 10%. The CDM projects with the greatest benefits in terms of sustainable development are given priority in the subsidy flux. Their Internal Rates of Return are consequently among the highest and they are supposed to be the most attractive from an investor's point of view. The technological transfer in the energy sector is thus highly promoted, bringing China's development on a more sustainable path. Starting from the present advancement of the Model, improvements could be made under different aspects. To begin with, the external cost assessment of the HFC-23 decomposition project might integrate, in addition to global warming damages, ozone layer depletion impacts due to the HCFC-22 leakage effect. The inventory and the monetization of these last damages per ton of pollutant is the most challenging part of this improvement. Furthermore, the lack of consideration of the CDM projects’ time scope by the optimization algorithm might be solved by considering different starting dates for a typical project, or by differentiating the tax/subsidy rates according to the age of a project. In both cases, the complexity of the algorithm would be greatly increased. Moreover, a great improvement would be to define a new variable: the degree of implementation of a CDM technology in function of the Internal Rate of Return of the corresponding typical project. It would reflect more accurately the reality in which the more profitable a project is, the more it is likely to be implemented. The Model might also take into consideration other sectors such as agriculture, heavy industry, service, or transportation. Concerning the latter, although the abatement potential from a vehicle point of view might seem negligible, the technological transfer would have huge benefits. Indeed, China is actually expected to have 140 million cars on its roads by 2020, seven times more than now.