U.S. Rep. John Dingell is offering an online outline of his proposal to place a $0.50-per-gallon tax on gasoline usage and a $50-per-ton tax on carbon emissions from fossil fuels.

Some details of the plan appear on the Michigan congressman’s website, and he asks his constituents to offer input. Dingell considers the plan essential to putting the U.S. on track towards a reduction in greenhouse-gas emissions of 60%-80% by 2050.

The gas tax would call for consumers to pay an extra $0.50 a gallon of any petroleum-based fuel, such as gasoline and kerosene, in addition to the existing levy. The government would phase in the tax over five years and adjust it for inflation, Dingell says.

Some auto industry executives, including Ford Motor Co. CEO Alan Mulally, have expressed interest in such an idea.

But the plan would exempt the new clean diesel, the lawmaker says, because its fuel-economy benefits (30%) surpass its emissions reduction (20%). Such a caveat may provide Detroit auto makers an incentive to broaden their diesel-vehicle portfolios.

Dingell’s proposal also exempts petroleum-free biofuels. Biofuels blended with petroleum, such as ethanol, only would be taxed on their petroleum portion, he offers.

The plan additionally calls for a $50-per-ton tax on carbon emissions from fossil fuels such as coal, including lignite and peat; petroleum and any petroleum product; and natural gas.

To balance his proposal, Dingell suggests eliminating the primary mortgage interest-rate deduction available for houses that are more than 3,000 sq.-ft. (914 m) in size.

“These homes have contributed to increased sprawl and longer commutes,” Dingell says in the outline. “Despite new homes in and of themselves being more energy efficient, the sheer size, sprawl and commutes lead to dramatically more energy use – or to put it more simply, a larger carbon footprint.”

The tax would exempt historic homes built before 1900, farm houses and homeowners who purchase carbon credits, a scheme in which the government allocates emissions credits to individuals on a per capita basis within the national carbon budget.

Individuals would surrender their credits when buying fuel or electricity. Those wanting or needing more energy would be able to partake in emissions trading to secure more credits.

Dingell’s proposal arrives as lawmakers in Washington hotly debate higher corporate average fuel economy standards.