Cap and Trade is one of the systems proposed to "lower" greenhouse gases for the United States. This is basically a system where the amount of emissions has a hard top and companies buy and sell credits to get around the cap. At his blog, Reducing Greenhouse Gas Emissions: Five Lessons of Economic Analysis, Congressional Budget Director Douglas Elmendorf says that the effect of a cap and trade system would be " lower overall GDP, employment, and households’ purchasing power by a modest amount relative to what would occur otherwise".
He then goes on to state that this would be similar to one or two years growth in GDP for the U.S. Looking at TradingEconomics the U.S. growth in GDP since 2006 has been 2.53%, -1.83%, >1% and 3.2% for the first quarter of 2010.
Implementing a cap and trade system would not help the U.S. economy grow in the short term and would only be doable if one assumes some growth in the future. Despite the first quarter's rate I don't see 2010 being a very good year considering what has happened in the last month.
This does not even take into account the fact that there may be no reason to limit greenhouse gases beyond what we are already doing.