In ways few imagined in 1997, as then-Vice President Al Gore signed the Kyoto Protocol on behalf of the United States, the country is approaching and might satisfy the "greenhouse gas" reduction goals of the Protocol. Former Presidents Clinton and Walker Bush both refused to submit the Protocol to the Senate for ratification. World-wide, as of 2012 only the U.S., Canada and Afghanistan have not ratified the Protocol. [ Kevin Begos, Associated Press, CO2 emissions in U.S. at 20-year low, Boston Globe, August 17, 2012, at ]

Ironically, around the treaty's 2012 target date, the U.S. is close to the goal of cutting emissions to 1990 levels. The Energy Information Administration recently found energy-related carbon dioxide emissions in the U.S. have fallen to levels last seen in 1992. [ U.S. energy-related CO2 emissions in early 2012 lowest since 1992, August 1, 2012, at ]

The Protocol addresses three other emissions: methane, nitrous oxide and sulphur hexafluoride. There are no comparably recent surveys of U.S. emissions for those gases. The latest emissions inventory shows that after peaking in 2007, combined U.S. emissions had fallen in 2010 to about 1997 levels, when the Protocol was signed, but were then well short of falling to 1990 levels. [ Fig. ES-2 in Executive Summary, Inventory of U.S. greenhouse gases 1990-2010, U.S. Environmental Protection Agency, April 15, 2012, at ]

The U.S. emissions inventory is dominated by carbon dioxide, well over 90 percent emitted in burning fuels for energy. For 1990 and 2010, the inventory showed: [Table ES-2, million tons carbon dioxide-equivalent]

Net emissions____5,213___5,747
Carbon dioxide___5,100___5,706

For the first quarter of 2012, usually the highest-emissions quarter, the U.S. EIA found annualized carbon dioxide emissions of 5,360 million tons. For the full 2012 year it is possible that total emissions may fall to 1990 levels or below. Without ratifying the Protocol, the U.S. might find itself in the odd position of satisfying it.