An intriguing proposal from Oregon Rep. Earl Blumenauer:
Buried in the "minibus" spending bill approved by the House Thursday afternoon is a provision providing the National Academy of Sciences $1.5 million to conduct a carbon audit of the U.S. tax code...
Blumenauer had gotten the study signed into law in 2008, under George W. Bush's administration. But without appropriated funds, it never happened. Now the NAS will identify which tax provisions have the greatest impact on carbon emissions, and estimate how big that footprint is.
There are obvious candidates, such as federal subsidies to fossil-fuel industries like oil and gas, but then there are more subtle provisions, like tax incentives for larger homes or parking subsidies.
More on fossil-fuel tax incentives here. For an argument on how parking subsidies can cause congestion, increase pollution, and are just generally inefficient, Donald Shoup's the expert to consult. Of course, even if the NAS sniffs out tax provisions that increase carbon pollution, that doesn't mean Congress will necessarily change them.
P.S. Here's a good interview Dave Roberts did with Blumenauer about his audit idea.