3. Li Xiaojin, a professor at Civil Aviation University of China's Economics and Management College, said that rapidly increasing numbers of flights and limited airspace for civil aviation are the major reasons for delays.
6. Everyone was hugely cheered that global greenhouse gas emissions were flat between 2014 and 2016, even though recorded global growth was OK. The trouble is that this wasn’t the improvement in global economic efficiency everyone celebrated, but just a slowdown in northern China. As this part of the world recovered its economic mojo in 2017, carbon dioxide levels began to rise again.
西西软件园 United States emissions had been declining because of increased burning of natural gas in power generation, which emits less carbon dioxide for each unit of energy than does coal. But the nation reported an increase in 2013 as coal regained some market share. If that trend continues, it could prove to be a challenge for the Obama administration as it seeks to institute tighter policies on greenhouse gases.