US emissions reductions
Renewable energy sources have helped to reduce carbon emissions in the US, according to a new study.
As coal-fired power plants have closed, a broader suite of clean energy sources – from wind and solar, to smart grid and electric vehicle charging – have made a larger and more profound contribution to US emissions reductions than previously recognised .
Although, despite the decline in coal and fossil fuel emissions which increased at an annual rate of 1.6 percent between 2014 and 2016, total US greenhouse gas emissions remained flat at around 3.3 billion metric tonnes of carbon dioxide equivalent (CO2e), according to a new study .
The US is currently the second-largest emitter of CO2 in the world, behind China . However, the combined power of US renewable energy sources, mainly natural gas and wind, helped to reduce CO2 levels by 4.7 billion metric tonnes between 2008 and 2016, accounting for the bulk of the 13.5 billion metric ton reduction in CO2, the study found.
The expansion of renewable energy has driven the US to become a global leader in wind power, according to Bloomberg New Energy Finance . The impact of clean energy has been the main driver of the lowest electricity prices in the world.
The country has also joined an international coalition that aims to produce 100 per cent of its electricity from clean energy sources by 2050.
According to the US Energy Information Administration, renewables contributed about 23 per cent of total US electricity generation in 2016.
US Renewable Energy Sources
As the US diversifies its portfolio of clean energy sources, its reliance on imported hydrocarbons for electricity generation has dropped by half from 17 per cent in 2005 to 8 per cent in 2016.
US carbon dioxide emissions dropped by an annual rate of 0.8 per cent between 2010 and 2016, when electricity generation accounts for about 40 per cent of total US carbon dioxide emissions .
Natural gas accounted for 77 per cent of the emissions reduction in the power sector. The decline in coal-fired emissions was even more pronounced, with power sector emissions falling by six per cent per year between 2010 and 2016, even as coal-fired power generation increased by 1.4 per cent.
Even with relatively low growth in electricity generation, US carbon dioxide emissions increased at an annual rate of 1.6 per cent between 2010 and 2016, the study found.
The US Energy Information Administration attributes the increase in emissions to increases in the transportation sector, particularly in passenger vehicles, along with increased industrial emissions .
The reduced carbon intensity of the US economy, a measure of emissions per unit of gross domestic product, is the result of reductions in energy intensity, the paper said.
 Clean energy boom played key role in recent US carbon emissions drop, study shows, https://www.edf.org/blog/2018/03/30/clean-energy-boom-played-key-role-recent-us-carbon-emissions-drop-study-shows
 Global Energy & CO2 Status Report 2019, https://www.iea.org/reports/global-energy-co2-status-report-2019/emissions
 These countries produce the most CO2 emissions, https://eu.usatoday.com/story/money/2019/07/14/china-us-countries-that-produce-the-most-co-2-emissions/39548763/
 World’s top 10 countries in wind energy capacity, https://energy.economictimes.indiatimes.com/news/renewable/worlds-top-10-countries-in-wind-energy-capacity/68465090
 U.S. Energy-Related Carbon Dioxide Emissions, 2019, https://www.eia.gov/environment/emissions/carbon/
 Renewable Energy, https://www.c2es.org/content/renewable-energy/