Study On The Changes Of National Population And Economy Based On The Grid Under The Shared Socioeconomic Pathways By IPCC

The rapid growth of population and economy makes the climate and environment face unprecedented challenges,and socio-economic development has become one of the core issues of climate change research.Establishing the gridded data set of China's future population and economic,and then analyzing its change characteristics,which can provide a policy formulation for national and local governments to formulate climate change.Based on the national population and economic census and annual statistical yearbook data,this study combines population and economic forecasting models with different shared socioeconomic pathways(SSPs),improves the forecast scheme under SSP1-5,reformulates the population and economic parameters adapting the current situation in China,and then establishes the gridded data set of population and economy in China for 2020-2100.The results show that China's population is increasing under SSP3,and it has been reduced under other pathways.By 2100,the largest population of SSP3 and SSP4 had reached 838 million and 1702 million people respectively.The proportion of elderly population is higher under SSP1,SSP4 and SSP5.The distribution of all ages is balanced under SSP2.The number of new population is more under SSP3,and the population ladder is reduced with the increasing of age.In 2100,the population of Guangxi Province is the most under SPP3,reaching 155 million.In other SSPs,the population of Guangdong province is the most,up to 163 million.The population growth is faster in those provinces under SSP3,which have high fertility rate,economic underdevelopment and more people moving out.In the future,population aging is more serious than most of the current problems.The areas with higher proportion of older people over 60 years old are mainly in northeast,North China,and Shaanxi,Sichuan and other places.National economy will rise up to 2070-2080 and then decline under SSP1 and SSP4 with peak GDP of about 200,000 and 250,000 billion yuan,respectively.GDP will continue to grow under SSP2,SSP3 and SSP5,with peak GDP will be about 260,000 billion yuan,170,000 billion yuan and 400,000 billion yuan.GDP still maintain about 6%growth rate before 2020,and then slows to 4-5%in 2020-2030.GDP growth will be slowdown or stagnation,or even show negative growth after 2030.The provincial economic growth trend among under SSPs is different.By 2100,maximum of GDP will be found in the Guangdong under SSP1,SSP2,SSP4,and Jiangsu is the highest under SSP3 and SSP5.By 2030,Shandong,Zhejiang can stay above 6%growth under SSP1 and SSP2,and most provinces growth will be lower than 3%under SSP3 and SSP4,only Guangdong,Zhejiang can maintain about 5%,part of the provinces appear negative growth;GDP growth rate is higher under SSP5,and the path of energy consumption level is very high which is difficult to maintain;the economic growth will have different degrees of slowdown or even negative growth after 2030 under different SSPs;the provinces GDP growth rate will be less than 1%in the 2090s.