Mr Harper and his advisors are also aware that while Mr Bush blocked states' efforts to regulate greenhouse-gas emissions (California and Vermont, for instance, both wanted to set a carbon standard for transport fuels), Mr Obama may permit such state-by-state laws.

ECONOMIST: Stephen Harper looks to Washington, not Alberta

Over the past decade Pemex has loosened its regulations on who may transport its fuels, and its oversight of sales at petrol stations.

ECONOMIST: Oil theft in Mexico

The exploding price of oil, meanwhile, cripples transport firms and fuels inflation for everything that has to be moved around.

ECONOMIST: Business-minded voters have doubts about both candidates

The fossil fuels used to transport that waste, experts say, is not typically considered in calculating solar's carbon footprint, giving scientists and consumers who use the measurement to gauge a product's impact on global warming the impression that solar is cleaner than it is.

NPR: Solar Industry Grapples With Hazardous Wastes

That reinforces the case for increasing duties on ordinary diesel, and reducing it on less toxic fuels and less polluting forms of transport.

ECONOMIST: Vehicle taxes

Strobel says ethanol plants could be retrofitted to generate the mycodiesel, which would be a lot easier to transport than ethanol (which corrodes pipelines) and would be more easily blended with petroleum-distilled motor fuels.

FORBES: Magazine Article