Washington, April 16:

Greenhouse gas emissions by the US dropped 3.4 per cent in 2012 from the previous year and by 10 per cent since 2005, according to an official report.

The US Environmental Protection Agency has made this assertion in its 19th annual report, “Inventory of US Greenhouse Gas Emissions and Sinks”, submitted to the Secretariat of the UN Framework Convention on Climate Change.

Greenhouse gas emissions in 2012 showed a 10 per cent drop below 2005 levels.

Total emissions of the six main greenhouse gases in 2012 were equivalent to 6,526 million tonnes of carbon dioxide.

These gases include carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride, the report said.

Major contributors to the decrease in emissions from 2011—2012 were the decrease in energy consumption across all sectors in the US economy and the decrease in carbon intensity for electricity generation due to fuel switching from coal to natural gas, the EPA said.

Other factors included a decrease in transportation sector emissions attributed to an increase in fuel efficiency across different transportation modes and limited new demand for passenger transportation, the agency said in its report.

Greenhouse gases are the primary driver of climate change, leading to increased heat-related illnesses and deaths, worsening the air pollution that can cause asthma attacks and other respiratory problems as well as expanding the ranges of disease-spreading insects.

Climate change is also affecting the frequency and intensity of heat waves, droughts and other extreme weather events, it said.