The Warming Climate Aggravates Atmospheric Nitrogen Pollution in Australia
emission inventories, N use efficiency, and coupling degree of emissions and production values in Australia during 1961-2013: (a) total emissions to air; (b) total emissions to water; (c) emissions and nitrogen use efficiency (NUE) of cropland; (d) emissions and NUE of livestock industry; (e) coupling index of total environmental emissions with GDP; (f) coupling index of environmental emissions with production value of livestock industry. GDP: gross domestic product. In (e, f), the green lines represent integrated environment indices, while the blue lines indicate economic growth indices. Values of all those indices only suggest the fluctuations of those two indicators on temporal scale, respectively. The red lines are coupling index (CI), expressing the degree of connection between environmental systems ( emissions as indicators) and economic systems (gross domestic production as indicators) by complex correlation model calculation. A higher CI would indicate a closer relationship between emissions and economy and less sustainable environment management, while a lower CI with low emissions would suggest decoupling and more sustainable environment management.