Monday, October 1, 2018

Reconsidering bioenergy

Accelerated restoration in progress at the Malheur National Forest, Oregon  [photo: U.S. Forest Service] 

Protecting the Earth's climate takes on greater urgency every day. The vast majority of carbon dioxide (CO2) and other climate-wrecking greenhouse gas (GHG) emissions comes from the unmitigated use of fossil fuels. But that doesn't mean that every form of alternative energy is helpful for the planet. Case in point: bioenergy, such as liquid biofuels to replace oil or forest products to replace coal.

Indeed, using biomass for energy at large scales does not belong on the short list of actions to take for climate protection. This is the conclusion of a commentary by Bill Schlesinger and myself just published in the Proceedings of the National Academy of Sciences. Given the real-world limitations of not only technology but also land-use governance, we argue that the priority policymakers have given to promoting bioenergy is profoundly misplaced.

As bioenergy use has grown over the past decade and a half, so too has the evidence that the net effects on GHG emissions are marginal at best and that in many cases it makes matters worse. Extensive bioenergy use also harms biodiversity and worsens other environmental problems. Over a decade ago some astute analysts warned that biofuels might be a cure worse than the disease. We now know that the adverse impacts of bioenergy use are even worse than feared.

The bioenergy blunder is a morality tale of what can go wrong when researchers fail to adequately check their computer models. All of the modeling studies used to justify bioenergy were premised on the belief that it is inherently carbon neutral. This common assumption holds that the CO2 released when burning bioenergy products instead of fossil fuels does not increase the net amount of CO2 in the atmosphere because the emissions are fully offset by the CO2 absorbed when biomass is grown. But this assumption turns out to be simplistic and misleading; it is not a problem that can be patched over with ever more complex computer modeling, which only serves to make the results even more uncertain and difficult to verify.

The scientifically correct way to look at the situation starts with the fact that using bioenergy emits CO2 into the atmosphere at the same rate or faster than the fossil energy it replaces. The burden of proof then becomes whether diverting biomass for energy speeds up the rate at which CO2 is removed from the atmosphere by the biosphere. In other words, one must empirically check the additionality of the carbon accumulation in biomass harvested to replace fossil carbon.

In this context, once one realizes that CO2 mitigation requires increasing the net rate of carbon uptake, it is clear that there are much better ways to do that than bioenergy. First of all, it is crucial to redouble efforts to halt deforestation and the destruction of grasslands, peatlands and other carbon-rich ecosystems. Bioenergy increases the pressure to convert natural lands, which are already under stress due to the rising demand for food, feed and forest products. Moreover, there are many opportunities for natural climate solutions including reforestation, habitat restoration and rebuilding soil carbon.

Legitimate ways to reduce CO2 emissions from fossil fuel use include higher energy efficiency and truly carbon-free energy sources such as photovoltaics, wind and nuclear energy. Replacing fossil fuels with bioenergy does not "decarbonize" the energy system; it is a flawed strategy now and for the reasonably foreseeable future. The programs and policies devoted to bioenergy should be pared back and redirected toward greatly expanded efforts to protect terrestrial carbon stocks and recarbonize the biosphere.

References 


DeCicco, J.M., and W.H. Schlesinger (2018) Reconsidering bioenergy given the urgency of climate protection. Proc Natl Acad Sci 115(39): 9642-45.  http://doi.org/10.1073/pnas.1814120115

Doornbosch, R., and R. Steenblik. 2007. Biofuels: Is the Cure Worse Than the Disease? Roundtable on Sustainable Development. Paris: Organization for Economic Cooperation and Development (OECD), September. https://iet.jrc.ec.europa.eu/remea/biofuels-cure-worse-disease

Griscom, B.W., et al. (2017) Natural climate solutions. Proc Natl Acad Sci 114(44): 11645-50. https://doi.org/10.1073/pnas.1710465114

Haberl, H., et al. (2012) Correcting a fundamental error in greenhouse gas accounting related to bioenergy. Energy Policy 45: 18-23. http://doi.org/10.1016/j.enpol.2012.02.051

Lal, R., et al. (eds., 2012) Recarbonization of the Biosphere: Ecosystems and the Global Carbon Cycle. Heidelberg: Springer. http://doi.org/10.1007/978-94-007-4159-1

Lambin, E.F., and P. Meyfroidt (2011) Global land use change, economic globalization, and the looming land scarcity. Proc Natl Acad Sci 108(9): 3465-72. https://doi.org/10.1073/pnas.1100480108

Schlesinger, W.H. (2018) Are wood pellets a green fuel? Science 359: 1328-29. http://doi.org/10.1126/science.aat2305

Searchinger, T. (2010) Biofuels and the need for additional carbon. Environ Res Lett 5, http://doi.org/10.1088/1748-9326/5/2/024007


Tuesday, September 25, 2018

No justification for weaker CAFE standards

Interior view of the 2019 Ford F-150 Limited edition pickup truck. Such luxurious features in what were once utilitarian vehicles showcase automakers' impressive design and technology capabilities. The key policy question is how well these capabilities can be harnessed to improve fuel economy rather than offering ever more niceties at the expense of better protecting the environment. [photo: Ford Motor Company media] 

This week the administration is holding public hearings on their proposal to weaken Corporate Average Fuel Economy (CAFE) standards after 2020. What follows is the comment I prepared for the hearing being held today in Dearborn, Michigan. 

Comment on CAFE and GHG Standards Proposed Rule
for MY 2021-2026


John M. DeCicco, Ph.D.
University of Michigan Energy Institute*

Thank you for the opportunity to present this comment today.

Having reviewed the proposed rule, I find that it fails to scientifically or economically justify freezing the standards for model years 2021 through 2026. My assessments show that the greenhouse gas emissions and fuel economy standards for those years remain sound.

My overarching conclusion is that there is no justification for changing the standards.

The one new development with any significance is that fuel prices are lower now than projected. However, this does not justify weakening the standards. Lower prices are all the more reason why fuel economy and emission standards should remain untouched.

Lower fuel prices increase consumer payback time from 3½ years to roughly 5 years. This change in economics is not enough to justify weaker standards, which remain highly cost-effective for both consumers and society over the life of the vehicles.

Strong standards, such as those we have now, will help keep oil prices down and buffer consumers from inevitable fluctuations in fuel prices.

The fact is that technology is available to cost-effectively meet the standards.

A more conservative study that I conducted several years before EPA’s Technical Assessment Report showed that we could cost-effectively achieve a fleet average of 52 mpg, higher than the new average projected under the current standards. Moreover, these standards have already adjusted to the shift from cars to light trucks and SUVs and they will continue to adjust – as they were designed - to accommodate changes in vehicle sizes and classifications.

While the standards' flexibility helps them track the changing market, we have also seen outstanding progress in automotive engineering. This progress provides automakers with many affordable ways to achieve steady gains in efficiency. The past decade saw average fuel economy rise by 23 percent, even as vehicle sales and performance reached new highs. This is a tribute to the engineering ingenuity of our domestic automakers as well as the industry as a whole. Such gains refute any concerns that the standards put sales or jobs at risk.

In summary, the proposal to effectively freeze the standards after 2020 reflects a denial of basic science and a denial of the auto industry's extensive capabilities to engineer, market and successfully sell ever more fuel-efficient cars and light trucks.

I urge the agencies to set aside this ill-considered proposal and issue final rules for 2021-2025 that maintains steady progress on both fuel economy and emission reduction.
Thank you again for the opportunity to comment.

* These comments represent the professional assessment of the author alone and should not be taken to reflect views or positions of the University of Michigan or any of its units. 

Monday, June 11, 2018

The precarious state of fuel economy policy

Rated at 25 mpg, the Toyota RAV4 is a good example of the average new personal vehicle now being
sold in the United States, emitting 5.2 metric tons of CO2 per year over 15,000 miles of driving.
 
Any day now, the Trump Administration will formally propose its revisions to the coordinated program of Corporate Average Fuel Economy (CAFE) and greenhouse gas (GHG) emission standards for cars and light trucks. EPA Administrator Scott Pruitt has determined that the existing standards, set in GHG terms by the previous administration for model years 2021-25, are too tough. Everyone expects that the proposal will weaken the regulations; the question is by how much.

As a long-time analyst of automotive fuel economy policy, over the past few weeks I've written several pieces providing perspectives on the issue as linked here.

Even though it's not a good reason to weaken the standards, automakers do have a valid concern about low consumer interest in ever-higher fuel economy. The tension between what consumers desire and the need to cut GHG emissions is a problem to take seriously and address creatively. This challenge is discussed in my recent piece "Why aren't automakers connecting better with green-minded consumers?" in Automotive News.

A broader look at the regulatory dispute is given the piece, "After Years of Green Promises, Automakers Renege on Emissions Standards," published last week by Yale Environment 360. Hooking to visionary-sounding statements by GM's chief executive, it highlights the contrast between the automaker's promise of technological solutions and the efforts to fight the policies needed to bring such solutions to fruition. That's an old story in the long-running debates about clean cars. However, with automakers now able to exploit the empowered political hostility to the environment that they (and some other industries) cultivated over the years, progress may soon grind to a halt. My comments echo those of others who point out California's crucial leverage on the issue.

A concise take on this very point is given by my Axios Expert Voices piece, "Automakers struggle to head off the California–EPA legal battle," published earlier last week.

A couple of months back, shortly after Administrator Pruitt issued his notice about the process to revisit the CAFE and GHG emissions standards, I argued that "Stronger fuel standards make sense, even when gas prices are low" in The Conversation (and also republished by Salon and other outlets).

Sunday, June 3, 2018

Breaking down biofuels analysis

Debates about the merits of biofuels have gone on for at least a generation. Over time, one might think that the accumulation of data would resolve key issues, especially those about biofuels and global warming. Nevertheless, the arguments not only persist but have become even more heated.

What has taken things to a new level of contention is that some researchers (myself included) are now rethinking the heart of the matter, namely, the belief that biofuels are inherently carbon neutral. This is the assumption that the CO2 emitted when biofuels are burned does not lead to a net increase in emissions because the carbon in the biofuel is recycled during feedstock growth. My new paper, "Methodological issues regarding biofuels and carbon uptake" published in the journal Sustainability, breaks this aspect of the debate down to its bare essentials.

Friday, April 6, 2018

Stronger fuel standards make sense, even when gas prices are low

The current Republican administration is taking steps to weaken EPA's greenhouse gas (GHG) emission standards for cars and light trucks. One of the stated reasons is that lower fuel prices make it more difficult for automakers to comply with the regulations. However, car companies are already well on the way to re-engineering their vehicles to cut emissions through higher fuel economy. Fuel prices are a fickle friend when it comes to the crucial long-term quest to cut climate-disrupting GHG emissions. So that's all the more reason to keep strong standards in place, as explained in this recent piece published on The Conversation. 

Thursday, February 8, 2018

Biofuels vs. Biodiversity and the Need to Think Beyond Carbon Neutral

Seminar given at the University of Michigan, Thursday, February 8, 2018, as part of the 2016-2018 "Beyond Carbon Neutral" seminar series.

Download the presentation slides [PDF]

ABSTRACT

Just over a decade ago, policymakers gave a big boost to biofuels through the Renewable Fuel Standard (RFS) and similar policies. These policies included sustainability provisions for protecting sensitive lands; the intent was to spur the production of advanced biofuels that would be sustainable in many ways including low CO2 emissions. Now, new studies appear each year revealing the destruction of diverse habitats as biofuel production amplifies the global demand for land. There have also been multiple bankruptcies of highly-subsidized advanced biofuel operations. What went wrong and how can we find a better path forward?

Friday, November 17, 2017

Carbon balance effects of biofuel expansion

The 4th biennial America's Grasslands Conference organized by the National Wildlife Federation was held in Fort Worth, Texas, on 14-16 November 2017. What follows is the narrative with key slides from my presentation in the session on "The Ethanol Mandate as a Driver of Land Conversion and Carbon Emissions." 

I imagine that you have often heard that ethanol and other biofuels are "clean and green" compared to ordinary gasoline. Even if not perfect, aren't biofuels better than petroleum because they recycle carbon from the atmosphere instead of getting it from under the ground? That makes them inherently carbon neutral, many people believe.

Unfortunately, that belief is quite misleading. Take, for instance, the claim that corn ethanol reduces greenhouse gas emissions by 43% compared to gasoline, as given by a recent USDA study (which is critiqued here). That value is based on computer modeling and the assumption that biofuels fully recycle carbon is hard-coded into the model. However, when using field data to evaluate how much CO2 is actually recycled, it turns out that such modeling is off base, and not by just a small amount. In fact, biofuels fall so far short of being truly carbon neutral that they cause higher rather than lower CO2 emissions than petroleum fuels.

Monday, September 18, 2017

Carbon taxes and the affordability of gasoline

Although new taxes can seem like a third rail in American politics, taxing carbon seems to be an approach that is slowly gaining ground in public discussions of ways to tackle global warming.

We recently explored what a carbon tax would mean for how U.S. consumers feel about the affordability of gasoline. It turns out that for over 90% of Americans, a $40 per ton carbon tax -- which translates to an extra 36 cents per gallon -- would still leave them a gasoline price range that they consider affordable.

Of course, consumers' views on the issue depend on their household incomes, with lower income households expressing a lower price threshold for "pain at the pump," so to speak.

Further details on these survey findings can be found in the article on "A carbon tax: how much would be too much?" at the University of Michigan Energy Survey website, where the full report is also posted.


Wednesday, August 16, 2017

A new and deeper wrinkle in the biofuel debate

Two short articles just published by the journal Climatic Change highlight the divide in scientific thinking about the effect of biofuels on CO2 emissions. A commentary by Robb De Kleine and colleagues at Ford Motor Company criticizes a paper on the topic published last year by myself and colleagues at the University of Michigan. My response to their commentary explains why I believe that our approach is correct, in contrast to the established lifecycle analysis method that our critics say is the best way to address the question.
Cropland adjoining patches of forest. All arable land
removes 
carbon from the atmosphere at varying rates. 

This quarrel reflects a new stage in the long-running debate because it does not involve disputes about net energy use or even the food-versus-fuel and land-use change issues raised over the past decade. It is instead a disagreement about the core assumptions to use when examining the question, particularly whether or not biofuels should be treated as inherently carbon neutral. That's the assumption that the CO2 emitted when biofuels are burned does not count because it is biogenic, i.e., newly removed from the atmosphere when feedstocks are grown. My work challenges this assumption, showing that it only holds under certain conditions. De Kleine and colleagues defend the assumption, arguing that it is true unconditionally.

The disagreement is not merely academic. Because new oil production technologies have expanded the supply of economically attractive fossil-based liquid fuels, the business case for biofuels rests increasingly on their value for mitigating CO2 emissions. The stakes are high for both the biofuels industry and for policies to address global warming.