US Department of State Forecasts 4% Greenhouse Gas Rise by 2020

The U.S. Department of State published its annual emissions report detailing emissions trends between 1990 and 2007 and U.S. policies to reduce greenhouse gases. The Department of State is required to submit the report as a party to the United Nations Framework Convention on Climate Change. The report projects a 4% rise in greenhouse gas emissions by 2020, from 7.109 billion tons to 7.416 billion tons. This is in contrast to the pledge made by US administration to reduce emissions by 17% below 2005 levels by 2020. Congress has not yet passed legislation that will help the country meet emission reduction targets.

The report said carbon dioxide (CO2) emissions from electricity generation, which accounts for the largest share of US energy-related CO2 emissions, are projected to increase 4 per cent to 2.466 billion tons. Non-energy sources of CO2 emissions, including those from manufacturing, natural gas production, the cement industry, and waste-handling and combustion, are expected to remain constant at 368 million tons in 2020.

The growth rate is slower than in previous years because of the economic recession and increasing energy prices. Policies to increase energy efficiency and the use of renewable energy are also expected to moderate CO2 growth, the report said.

It found CO2 emissions from fossil fuel combustion increased at an annual average rate of 1.3% between 1990 and 2007. Petroleum remained the largest single source of US energy consumption in 2008, accounting for 37.7% of total US energy demand – down from 41% in 2005. Natural gas accounted for 24.4%, coal for 22.4%, nuclear for 8.1%, conventional hydro for 2%, and other renewables for 3%. Between 2005 and 2007, total US primary energy consumption grew by slightly over 1%, but fell 2.2% in 2008 as the economy weakened.

Between 2005 and 2020, methane emissions are expected to increase 8%, with fugitive emissions from increased natural gas production representing the bulk of the increase. However, this increase is expected to be mitigated through greater control of methane emissions from landfills, coal mines and manure, according to the report. Nitrogen oxide (NOX) emissions are estimated to rise to 332 million tons in 2020, an increase of 5% over 2005 levels. Emissions from agriculture, the largest source of NOX emissions, are expected to increase to 237 million tons in 2020 from 225 million tons in 2005. Much of the non-CO2 emissions growth is expected to be driven by hydrofluorocarbon (HFCs), which are expected to increase to 279 million tons in 2020, from 116 million tons in 2005. HFC growth is projected to double as they are used more widely to substitute ozone-depleting substances.