From 2005 through 2020, total US greenhouse gas (GHG) emissions are projected to rise by 4% under a “with measures” scenario (but without a cap-and-trade program and other complementary policies), from 7,109 Tg CO2 Eq. to 7,416 Tg CO2 Eq., while the US GDP is projected to grow by 40%, according to the fifth National Communication on US climate change actions submitted by the US Department of State to the United Nations Framework Convention on Climate Change.
The report projects that transportation-related CO2 emissions will drop 1.5% to 1,853 Tg CO2 Eq. from 2005 to 2020. This calculation, as with the other energy-related sources of CO2 emissions in the report, is based on updates of the US Energy Information Administration’s AEO 2009 report. The transportation calculation noes not include the implementation of the new national light-duty vehicle greenhouse gas standards (earlier post) or other coming regulatory measures.
The projections represent a “business-as-usual” scenario that incorporates major policies in place as of 31 March 2009, including the Energy Independence and Security Act of 2007 (EISA) and ARRA, as well as a number of other federal and state measures. In this sense, the “business-as-usual” projections equal the “with measures” scenario called for under the UNFCCC Guidelines for Annex 1 Communications.
The submission of the document, also called the US Climate Action Report 2010, is a requirement under the UN Framework Convention on Climate Change. The US submits a National Communication to the UN every 3-5 years. The United States released previous Climate Action Reports in 1994, 1997, 2002, and 2006.
Emissions other than CO2 currently represent about 15% of US GHG emissions. The current report estimates that increases in emissions to 2020 from a 2005 baseline will be:
|Gas||2005-2010 change||2020 Amt.|
|CO2||+1.5%||5,813 Tg CO2 Eq.|
|CH4||+8%||605 Tg CO2 Eq.|
|N2O||+5%||332 Tg CO2 Eq.|
|HFCs||+140%||279 Tg CO2 Eq.|
|PFC||0%||6 Tg CO2 Eq.|
|SF6||-27%||13 Tg CO2 Eq.|
A large portion of missions growth is driven by HFCs, because demand for refrigeration and air conditioning is increasing and because HFCs are predominantly used as alternatives for ozone-depleting substances, which are being phased out under the Montreal Protocol. The report attributes the relatively slow growth forecast for CO2 emissions to increasing use of renewable energy and policies implemented to increase efficiency.
With additional mitigation measures, such as those that would be implemented under the American Clean Energy and Security Act of 2009, the United States would have a GHG reduction goal of 17 percent by 2020, though US GDP is projected to grow by 40 percent in that time. Over that period, with additional mitigation measures, CO2, CH4, N2O, and PFC emissions would decrease significantly, and HFCs—among the most potent of GHGs—would be subject to a targeted cap and phase-down process.
—US Fifth Climate Action Report
The Climate Action Report also used EPA’s Applied Dynamic Analysis of the Global Economy (ADAGE) model and projected that total US greenhouse gas emissions will gradually increase by about 18% between 2010 and 2050.
Calls for rapid action on HFCs. The surge in growth of HFCs highlighted by the new report has already prompted calls for their quick phase out. Micronesia, for one, is proposing the use of the Montreal Protocol treaty to phase out HFCs as the most important fast-action strategy for saving their island. The US, Mexico, and Canada also submitted a formal proposal to tackle HFCs under the Montreal Protocol.
If not aggressively phased out, HFCs could contribute up to one-third or more of total global warming. The total global mitigation from eliminating HFCs would be between 125 and 209 billion tonnes of CO2-equivalent by 2050. This is nearly 10% of the total mitigation needed to avoid passing the 2 °C temperature increase many countries consider to be the maximum tolerable rise above pre-Industrial levels.
We have climate friendly alternatives that can eliminate one of the six greenhouse gases if the US acts aggressively. This would buy the world an insurance policy equal to a delay of a decade worth of CO2 emissions.
—Durwood Zaelke, President of the Institute for Governance & Sustainable Development