Abstract:Global warming caused by greenhouse gas emission may cause severe environmental and social problems. Greenhouse gas accounting has become a hotly debated research topic. Internationally, some research has been undertaken on greenhouse gas accounting and some progress has been made; however, there are many shortcomings in this field. The main problem is that current research is mainly focused on carbon emission, particularly carbon emission from fossil fuel combustion, and is less involved in carbon fixation and ways of assessing regional carbon emission levels. In addition, the actual emission figures for greenhouse gases nationally and regionally in China were unknown. Although much research relates to carbon emission, the results are difficult to compare owing to inconsistent research methods and standards. Xi'an City, a historical and cultural tourist city in China, lies in the radiation center of the Guan-Tian economic zone. It is the economic, cultural, education, manufacturing and high-tech industry hub of northwest China. Xi'an will be an international metropolis in China in the near future. However, research relating to the greenhouse gas footprint in Xi'an is scarce. In this paper, the author proposed an evaluation system for greenhouse gas (GHG) emission to the level of global benchmarking using the methods recommended by the 2006 IPCC Guidelines for National Greenhouse Gas Inventories and the Chinese Guidelines for Provincial Greenhouse Gas Inventories, and using this a dynamic analysis of GHG emission and evaluation of the extent of GHG emission in Xi'an City was performed. The results showed that, from 1995 to 2011, GHG emission showed a rapidly rising trend in Xi'an City, increasing from 1207.16×104t to 3934.17×104t, which represented an average annual increase of 7.66%. The largest increase was for cement (an average annual increase of 11.75%), waste (8.77%) and energy (7.63%) GHG. Agricultural GHG emission showed an annual reduction of 1.74%, while forestry carbon sequestration showed an annual average increase of 3.56%. In a breakdown of emissions, energy GHG accounted for 80.13%-90.55%, cement GHG for 1.75%-7.49%, agricultural GHG for 1.86%-8.01%, forestry carbon sequestration for -2.58%—5.22%, and waste treatment GHG for 7.52%-16.38%. An increase in energy consumption is the main cause of the increase in GHG emission in Xi'an City, and forestry carbon sequestration capacity needs to be improved. In Xi'an City, the GHG emission per 10,000 Yuan GDP was constantly decreasing, and progress in the science and technology of carbon emission has continuously improved. The GHG emission per capita, per unit area and per carbon emission index has increased very quickly, showing an average annual increase of 5.84%, 7.66% and 6.84% respectively. The carbon emission state in Xi'an City has increased continually from a low level (Ⅰc) to a middle level (Ⅱa), which was an increase of two sub-grades and which was two grades higher than the target set for the control of global climate warming. The increasing trend in carbon emission cannot be ignored.