Tuesday, October 1, 2013

Alternative fuels: maybe not so fast

Someone long ago pointed out that we'd run out of atmosphere -- meaning its ability to safely soak up excess CO2 -- well before we ran out of coal. Now that global warming has progressed from a seemingly remote risk to a clear and present danger, it's heartening that U.S. leaders are finally starting to tackle greenhouse gas (GHG) emissions from power plants where coal use is concentrated. Addressing such energy sector emissions is a centerpiece of the new climate plan announced by President Obama in July.

As it turns out, such action to address GHG emissions upstream, meaning in the energy and resource systems that supply the fuels used downstream in our everyday lives, is also the next important step needed to control CO2 emissions from cars and other forms of transportation.

Monday, September 30, 2013

Back and forth on biofuels

Several comments on my Yale e360 piece on alt fuels policy take the common view that biofuels are "essentially carbon neutral" and "inherently sustainable," as Mr. Lloyd puts it. However, nothing is inherently sustainable, and the carbon balance of any system is something that must be verified. My piece asks "Where's the climate benefit?" and for biofuels at market scale, it is not possible to answer to that question in an verifiable manner.

Simply substituting biomass carbon for fossil carbon does not suffice to ensure a net CO2 reduction, as shown by the example my article gives for corn ethanol. It may leave more fossil carbon in the ground, but that doesn't mean less carbon overall went into the air. A formal analysis of this issue is given in my new paper on "Biofuels Carbon Balance."

Saturday, September 21, 2013


This blog was first put up today but as noted in the About page, it is also being used to archive earlier material. Hence the pre-dated posts that follow below.

Monday, January 7, 2013

LCFS: some early history of the concept

The idea of regulating transportation fuels through lifecycle analysis (LCA) has now become widely accepted; it is the basis for California's low-carbon fuel standard (LCFS) as well as provisions of the renewable fuel standard (RFS) and other policies. Although my recent work criticizes the use of LCA to define policy, this disapproval reflects a major change of perspective from 15-20 years ago. Back then I was among the first to propose that LCA -- or "full fuel cycle" (FFC) analysis as we termed it -- would be a great way to regulate motor fuels in terms of GHG emissions.