To provide a reduction in the aggregate greenhouse gas emissions per unit of energy consumed by vehicles and aircraft, and for other purposes.

Amends the Clean Air Act to require: (1) the Administrator of the Environmental Protection Agency (EPA) to promulgate low carbon fuel performance standards for fuels and other sources of energy used to propel vehicles; and (2) such standards to begin to apply in 2015. Sets forth a declining standard that represents a graduated percentage reduction in aggregate emissions of GHG per Btu for each five-year period beginning in 2015. Requires the Administrator to review available control technology, safety considerations, and land and other resources available for production of fuels and other sources of energy used to propel vehicles. Authorizes the Administrator to promulgate a more stringent standard if, based on such review, the Administrator determines it to be requisite to protect the public health and welfare from any known or anticipated adverse effects associated with GHG emissions.

Requires the Administrator, not later than January 1, 2010, to promulgate a low carbon fuel performance standard for fuels and other sources of energy used by aircraft. Provides that such standard shall: (1) apply for 2015-2019; and (2) remain in effect unless, for each five-year period thereafter beginning in 2020, the Administrator and the Secretary of Transportation determine after a thorough review of available technology and safety considerations that a more stringent standard is necessary to carry out the purposes of this Act.

Sets forth provisions concerning compliance with the standard and calculations of the GHG emission rate per Btu.

Requires the Administrator, not later than January 1, 2009, to identify and label low-carbon transportation fuels based on specified criteria.

Prohibits transportation fuel sold in interstate commerce after January 1, 2010, from being derived from biomass from: (1) lands where ecosystem conversion has occurred after enactment of this Act; (2) sensitive lands; (3) specified lands enrolled in the Conservation Reserve Program or the wetlands reserves program; (4) specified national interest lands; (5) recyclable postconsumer waste paper, painted, treated, or pressurized wood, or wood contaminated with plastic or metals; (6) municipal solid waste; or (7) materials produced, harvested, acquired, transported, or processed pursuant to an exemption from otherwise applicable environmental laws.

Requires the Administrator to ensure that no transportation fuel sold or introduced in interstate commerce after January 1, 2010, shall result in average per gallon vehicle emissions of air pollutants in excess of the 2007 emission levels or in a violation of any motor vehicle emission or fuel content limitation under such Act.

Authorizes sums to be appropriated to the Secretary of Energy for a cooperative program of research and development relating to lower carbon alternatives for aircraft jet fuel and fuel for other vehicles.