Friday, December 11, 2015

Questions and responses on RFS testimony

House Science Committee Hearing on the RFS, November 3, 2015
(photo credit: Michael A. Waring) 
Following the recent hearing on the Renewable Fuel Standard (RFS) held by the House Science Committee, the subcommittee chairs asked me to respond to some questions for the record, following up on my testimony at the hearing. Here are the questions and an abbreviated version of the answers, summarizing my full written response

In his testimony, Mr. Coleman referenced cellulosic ethanol that is "129 times better than gasoline on carbon emissions." Based on your research, is this a reasonable claim?

No, that is not a reasonable claim. Such assertions are based on paper studies of hypothetical ethanol production methods. There is indeed a literature on the subject that applies lifecycle analysis (LCA) to proposed cellulosic ethanol production methods and projects that the resulting systems would not only fully offset tailpipe CO2 emissions but also offset other CO2 emissions such as those from fossil-based electricity generation.

However, as pointed out in my testimony (and in papers explained elsewhere on this blog), the LCA methods used to justify such claims are scientifically incorrect. Moreover, the cellulosic processing methods involved remain speculative as far as any meaningful commercial-scale operation is concerned. In short, claims of biofuels that achieve a more than 100% reduction in carbon emissions are rooted in flawed analysis of fantasy fuels. 

Wednesday, December 9, 2015

Think Progress and Out-of-Touch 'Persuasion'

There's no doubt that shifting political opinion toward effective climate action is going to take a lot of persuasion, especially of individuals and policymakers who don't already believe in the urgent need to drastically limit greenhouse gas emissions, or at least tend to rate the environment high on their list of concerns. 

But advocates trapped in the mental boxes of green-group group-think -- and that includes the dear former California governator, Republican though he may be -- are unlikely to change the minds of those in the most need of persuasion by approaching the issue as touted in this recent piece, "Did The Governator Just Come Up With A Republican-Proof Argument On Climate Change?" on Think Progress. 

The question that Mr. Schwarzenegger posed on Facebook was along the lines of "What room with a sealed door would you be rather trapped in, one with a gasoline car running at full throttle or one with an electric car running flat out?" (on treadmills, we presume).

Tuesday, November 3, 2015

Testimony on the RFS

Here's my statement at today's House hearing on the RFS; see links at the end to access the written testimony and related videos. 

My research shows that the Renewable Fuel Standard, or RFS, has been harmful to the environment from its inception. Now, ten years after the 2005 Energy Policy Act, the program has resulted in higher CO2 emissions than would have occurred otherwise. It also harms the environment in other ways. Sadly, the adverse impacts of the RFS have grown worse since it was expanded by Energy Independence and Security Act (EISA) of 2007.

The notion that renewable fuels readily reduce CO2 is based on a scientifically incorrect understanding of carbon neutrality. Only under certain conditions does substituting a biofuel for a fossil fuel neutralize the CO2 leaving the tailpipe. For that to occur, harvesting the feedstock must significantly increase how rapidly cropland absorbs CO2 from the atmosphere on a net basis. That condition is not met for the corn ethanol mandated by the RFS. It might be satisfied for cellulosic feedstocks, but once properly evaluated, the gains may not be as great as advocates assume.

Tuesday, October 13, 2015

Thinking Beyond Carbon Neutral

Global climate change is a defining challenge of the 21st century and efforts to address it have many dimensions. Reducing greenhouse gas (GHG) emissions through higher energy efficiency, using solar, wind and nuclear energy, deploying carbon capture and storage (CCS), reducing deforestation, reducing methane emissions and minimizing other causes of excessive radiative forcing are all important. No one option will suffice and it is crucial to integrate technology solutions with policy drivers.

Because the carbon dioxide (CO2) emitted by fossil fuel use is the largest source of anthropogenic GHG emissions, the climate challenge is often characterized as the need to "decarbonize" the economy by eliminating fossil fuels. However, carbon is literally the fuel of life; the natural carbon cycle annually circulates twenty times as much carbon as released from fossil fuels and the majority is biogenic carbon fixed through photosynthesis. Although rapid release of fossil carbon is the primary cause of rising atmospheric CO2 concentrations, the real problem is an imbalance in the carbon cycle rather than fossil fuel use per se. Thus, the real need is to bring the carbon cycle into balance and eventually restore a global net carbon sink.

Wednesday, September 16, 2015

The mistaken modeling behind biofuel boosters' emissions claims

Arguments about the pros and cons of biofuels such as ethanol have gone on for many years. The latest debates pertain to whether proposals to limit the ramp-up of the Renewable Fuel Standard (RFS) would result in higher or lower emissions of carbon dioxide (CO2) and other climate-disrupting greenhouse gases.

This week Environmental Protective Agency (EPA ) Administrator Gina McCarthy tweeted the benefits of biofuels: 

and signaled the agency's intent to further raise the RFS volumetric mandate: 

At the crux of the issue is the ability to determine the “carbon footprint” of biofuels using computer models. These models, such as the GREET model developed by Argonne National Laboratory in Illinois, use what are known as lifecycle assessment techniques that claim to account for all of the emissions associated with producing and using a fuel. GREET modeling is the basis for assertions by BIO (the Biotechnology Industry Organization) that the RFS has reduced carbon emissions since it was passed in 2005. It is also the basis for the recent University of Illinois statement that the proposed RFS limits would increase CO2 emissions as much as putting nearly one million more cars on the road. 

Wednesday, August 12, 2015

Bringing biofuels back to earth

After all that's been written about the pros and cons of biofuels over the years, it's fair to ask whether there's anything left to say. It turns out that there is, and a new insight comes from evaluating what actually happens on the earth, that is, on the land where the plants used to make biofuels are grown.

Thursday, May 7, 2015

When do biofuels really balance carbon?

The belief that biofuels are inherently carbon neutral rests on an assumption that the CO2 absorbed when their feedstocks are grown balances out the CO2 emitted when the fuel is burned. That's why it's said that biofuels recycle carbon, in contrast to fossil fuels' one-way flow of carbon into the atmosphere.

However, the extent to which CO2 emissions actually get balanced needs to be verified, not just assumed, even as obvious as it may seem. A careful analysis shows that biofuel carbon flows balance out only under certain conditions. Moreover, those conditions are at best only partly met for the biofuels now being used. To see why, it is necessary to understand some fundamental concepts about CO2 flows between the biosphere and atmosphere.

Saturday, March 21, 2015

Scrutinizing the logic on biofuels

This post picks up a thread based on comments that Prof. Robert Brown and Prof. Bruce Dale made on my "Don't pitch low-carbon fuel ..." post. Both Robert and Bruce take strong exception to my analysis. They invoke the commonly made assumption that substituting a biofuel for a fossil fuel reduces net CO2 emissions because biofuel use recycles carbon while fossil fuel use does not.

This widely used view of the biofuel lifecycle does not tell
the whole story.
  [Image credit:] 
Their argument is based on the following logic:

(1) Fossil fuels send old carbon on a one-way trip to the atmosphere, thereby increasing the amount of CO2 in the atmosphere.

(2) Biofuels use carbon recently taken from the air that is then released back to the air, resulting in no net change in the amount of CO2 in the atmosphere.

(3) Therefore, substituting a biofuel for a fossil fuel reduces the rate of CO2 buildup in the atmosphere.

Although this basic analysis neglects processing emissions, we can leave those aside for the purpose of this discussion. They are not what's at the heart of the disagreement, and in any case processing emissions do get tracked by lifecycle models, e.g., as used in the RFS and LCFS. 

Wednesday, March 18, 2015

Don't tout low-carbon fuel; track real carbon instead

My recent studies expose the fallacies behind California's Low-Carbon Fuel Standard (LCFS) and similar provisions of the U.S. Renewable Fuel Standard (RFS). Such policies claim to reduce the carbon footprint of motor fuels, but are more likely to actually increase CO2 emissions.

I'm not alone in expressing such concerns. A paper whose authors include the original developer of the lifecycle analysis method that underpins the LCFS points out how such approaches can mislead policy makers. A recent World Resources Institute (WRI) report faults policies that promote biofuels and create an adverse "food vs. fuel" trade-off.

Among the objections to my criticism is that it is merely academic and fails to offer a constructive solution for the transportation fuel-related CO2 emissions that remain after improving vehicle efficiency and limiting travel demand.

Governor Arnold Schwarzenegger signing AB 32 on Sept. 27, 2006
(Source: Getty Images via 
In California, however, the answer is right under policy makers' noses. The Global Warming Solutions Act [Assembly Bill (AB) 32] caps carbon emissions statewide, and starting this year also places transportation fuels under the cap. AB 32 is the best climate protection program established anywhere to date, and with a technical correction plus expanded provisions for carbon offsets, it would be an ideal policy for addressing fuel-related CO2 emissions.

Friday, February 20, 2015

Why bad bookkeeping undermines fuel policies

There's a problem with the policies now imposed on transportation fuels in an attempt to control CO2 emissions. The issue has to do with how carbon is counted when the policies are defined.
Good accounting needs to reflect the fact that motor fuels are liquids that contain carbon as their molecular backbone. By nature, liquids flow. That's one main reason why they are so valuable for fueling cars, trucks, ships and planes. Carbon flows with the fuels, and it's the rate at which the carbon flows to and from the atmosphere in the form of CO2 that matters for global warming.
Note the "to and from" in the previous sentence. A big focus of climate policy is reducing CO2 emissions, e.g., reducing the rate at which carbon flows into the air due to energy use. But the from part is also important, and in fact, the CO2 problem is best described as an imbalance in the global carbon cycle due to human activities that cause carbon to flow into the atmosphere faster than natural processes can remove it.
The Global Carbon Cycle
(Source: Carbon Cycle Toolkit)
The adjoining figure illustrates the global carbon cycle. As suggested by the relative thickness of the arrows depicting the flows, the overall cycle is much larger than the excess from fossil fuel use. In round numbers, the natural CO2 flow amounts to circulation of about 200 PgC/yr (petagrams, i.e., 1015 grams, or billion of metric tons, of elemental carbon per year) between the atmosphere and the earth's surface (both land and sea). The total flow into the atmosphere from fossil fuel consumption has been steadily climbing and is now about 10 PgC/yr. Roughly another 1 PgC/yr of emissions are due to deforestation. (The latest data can be found at the Global Carbon Project.)  
The carbon cycle matters a lot when biofuels enter the picture. To protect the climate, biofuels must increase the from part of the carbon cycle; that is to say, they have to increase the net rate at which CO2 is removed from the atmosphere. After all, they don't decrease the to part of the cycle because simple chemistry tells us that a given biofuel emits essentially the same amount of CO2 as the fossil fuel it replaces. As I've put it elsewhere, if biofuels have a benefit, it's not when they're burned.

Monday, February 9, 2015

Bread & Circuses vs. Getting the Prices Right

Two researchers just published an analysis showing something that many casual observers have long realized about the political challenges of using taxes to address externalities. Liddle & Lung (2015) find that countries whose citizenries consume a lot of fuel tend to tax fuel at lower rates than countries with relatively lower consumer demand for fuel. In other words, the nations having a greater need to "get the prices right" through some form of consumption tax are, politically speaking, less likely to pursue the types of taxation that economists would recommend.

The paper is:

Liddle, Brant and Lung, Sidney, The Endogeneity of OECD Gasoline Taxes: Evidence from Pair-Wise, Heterogeneous Panel Long-Run Causality Tests. Transportation Research A: Policy and Practice, 73: 31-38, 2015. DOI: 10.1016/j.tra.2014.12.009; available at SSRN:

Monday, February 2, 2015

CO2 sequestration more challenging than thought

Recent MIT simulations suggest that when CO2 is injected underground into saline aquifers, much less of it may solidify than most carbon capture and storage (CCS) studies have assumed. The implications are that such CCS may be less stable than hoped and also that the capacity for CO2 sequestration would be much lower than past research has calculated (see "Sequestration on shaky ground" from MIT News).

This form of CCS is not very relevant for mitigating emissions from liquid fuel use. However, the hypothetical "BECCS" (bioenergy with CCS) systems that some analysts have highlighted as a potential source of so-called low-carbon liquid fuels would also face such limitations.

Tuesday, January 13, 2015

Are falling fuel prices good or bad?

Yesterday in Automotive News, Richard Truett penned a piece titled, "Why falling fuel prices are bad, bad news."  His point was that lower pump prices make fuel-efficient vehicles a harder sell, risking the billions of dollars that automakers have recently invested in hybrids, electric cars and other alternatives as well as lightweight materials and advanced combustion engines.

The argument that high fuel prices are good for cutting oil use and carbon emissions follows directly from basic economics. Mr. Truett hopes that oil prices will head back up this year and, guided by economics, many conservation advocates have long called for higher taxes to address oil-related concerns. I'm certainly not one to argue with those principles, but I also believe that lower fuel prices are on balance a very good thing for American consumers and the economy.