Because of the connection between greenhouse gases and climate change, there has been a concerted to reduce greenhouse gas emissions. the decrease in co2 emissions in 2015 from fossil fuel combustion was a result of multiple factors, including all but: a) a slight decrease in the use of public transportation throughout the country. eliminate b) substitution from coal to natural gas consumption in the electric power sector. c) a slight decrease in electricity demand due to conservation efforts in all sectors. d) warmer winter conditions resulting in a decreased demand for heating fuel in the residential and commercial sectors.