(Recasts to focus on carbon emissions and coal and gas use by power sector)

June 6 (Reuters) - U.S. carbon dioxide emissions from energy sources are expected to hit a 25-year low in 2017 as the power sector burns less carbon-intensive coal and more low-cost natural gas, according to government data released Tuesday.

In 2018, however, carbon dioxide emissions from transportation, power plants, homes and businesses should climb about 2.2 percent, the U.S. Energy Information Administration said. That increase would be due to forecasts for a colder winter, higher economic growth and rising gas prices, the EIA said.

The projected 2018 increase in carbon dioxide emissions has nothing to do with U.S. President Donald Trump’s decision to pull out of the Paris climate agreement, the agency said. That exit will not take place until Nov. 4, 2020, the day after the next presidential election.

U.S. emissions have been falling for several years, largely because coal consumption is declining as power plants increasingly use gas to generate electricity. Coal lost its title as the primary fuel for power plants to gas in 2016 after holding that crown for a century.

EIA said coal’s share of generation would rise to 30.9 percent in 2017 and 31 percent in 2018 from 30.4 percent in 2016. Natural gas will take a 31.4 percent share of power generation in 2017 compared with 33.8 percent in 2016, before rising to 31.9 percent in 2018.

Energy-related carbon dioxide emissions were expected to fall to 5,134 million metric tons in 2017, which would be the lowest since 1992, before rising to 5,248 MMT in 2018, according to EIA’s latest Short-Term Energy Outlook (STEO).

The all-time peak of 6,021 MMT was in 2007.

EIA projected U.S. coal consumption would rise to 731 million short tons in 2017 and 743 million tons in 2018. That compares with 730 million tons in 2016, the least since 1982, and an all-time high of 1,128 million tons in 2007.

Gas prices are expected to rise to an average of $3.16 per million British thermal units in 2017 and $3.41 in 2018 from $2.51 in 2016.

EIA said dry gas production in 2017 would rise to 73.30 billion cubic feet per day from 72.29 bcfd in 2016. They said U.S. gas consumption would fall to 73.41 bcfd in 2017 from a record 75.12 bcfd in 2016.

EIA projected both production and consumption would rebound in 2018 to record highs with output hitting 76.57 bcfd and usage reaching 76.24 bcfd.