The IPCC reports are some of the most highly anticipated of 2007. An obvious sign? Within two weeks of one report’s release, papers are already covering a leak from the next.

IPCC Working Group III’s focus is on mitigation, meaning a fair number of policy implications can be derived from its conclusions. So here’s a hint for America’s auto industry: the report calls for urgent action on road pollution.

In the United States, there are 483 passenger cars per 1,000 people (EarthTrends). The world average is about 100, and few countries outnumber our car count (Australia, for example, had 492 in 1996).

Overall, U.S. auto emissions account for seven percent of annual greenhouse gas emissions, a huge part of the case against the EPA in Mass. v. EPA, and knowing such a significant source of the problem informs where policies are most productive. In a few words: renewable fuels such as E85, plug-in hybrids, and more stringent CAFE standards.

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World energy use by transportation is expected to grow by two percent each year, but as California has demonstrated with its electricity consumption, it is possible to flatline the curve. Not to mention both climate security and national security interests call for it.