The CO2 and SO2 emission values of different scenarios are listed in Fig. 4(c,d), and Table 5, respectively. Due to the continuous and rapid growth of China’s energy consumption and the dominating role of fossil energy in the energy structure, the CO2 emissions from energy consumption will increase from 7.05 billion tons in 2015 to billion tons in 2050. It will exacerbate China’s CO2 emission reduction pressure in the AED scenario. The SO2 emissions from coal combustion will be Mt in 2050, another major threat to the environment. By 2050, the CO2 emissions caused by energy consumption will be reduced by % compared to the AED scenario, which is only 7.07 billion tons, equivalent to the 2015 level. CO2 emissions per 10,000 yuan of GDP in 2020 will be only tons. SO2 emissions in the ERC scenario are reduced to Mt, only % of that in the AED scenario. Since the SO2 removal rate of per unit coal is increased by 2.3% more than that in the case of ERC, the SO2 emissions of the LOD scenario will drop to 9.79 Mt 85 .
In summary, the rapid economic growth and sufficient energy supply will accelerate the development of China’s urbanization in the case of AED scenario. However, this mode not only ignores the fact that the growth of fossil energy supply capacity is limited, but also imposes huge environmental pressures. While the ERC scenario will greatly reduce CO2 emissions, it also hurdles fast economic growth and urbanization. Moreover, China will face the risk of over dependence on external energy, with the increase of the gap between energy supply and demand. It could be safely concluded that an ideal mode to achieve a healthy and rapid development of urbanization is clearly illustrated in the case of low carbon oriented development, which is to prioritize the renewable energy development, optimize energy structure, as well as improve household lifestyle. It will achieve CO2 emission reductions, environmental protection, and the sustainable socio-economic development.
Discussion and you will Achievement
The trends of China’s economy, urbanization, and energy structure have been widely studied recently (Table 3 in Appendix C). Annual growth rate of GDP is estimated to be 5.5–7.0% in 2010–2035, 4.0–6.0% in 2035–2050, and below 3% after 2050. The urbanization level will reach 70–72% in 2035, and above 75% in 2050. Coal consumption will drop from 63.0% to less than 45%, oil from 20% to about 15%, natural gas from 5.5% to about 12%, and non-fossil energy from about 10% to about 30% by 2050. CO2 emissions will also drop from about 8.0 billion tons to about 5.0 billion tons by 2050. According to the simulation of energy-urbanization SD model, the GDP growth rate is set (the primary industry growth rate of 3–4%; the secondary industry growth rate of 5–7%; the tertiary industry growth rate of 6–8%) to achieve the urbanization rate of 75.0–80.0%. The total amount of energy consumption (Mtce) will reach – Mtce in 2035, and –1 Mtce in 2050. Non-fossil energy will be about 65% in 2050, and CO2 emissions will be about 7.07 billion tons in 2050.
Energy is not only the necessary driver for China’s urbanization but also the constraint factor in urbanization for fulfilling the mission of global CO2 emission reductions 86,87 . In order to estimate the urbanization development, energy demand and environmental status in China over 2015–2050, an integrated SD model composed of four sub-models has been developed 88 . The validity of the model has been confirmed by the simulation and sensitivity analysis using the data of 1998–2015, providing strong evidence that the effective energy planning and management policies are needed for the low-carbon oriented urbanization.