Scientists and lay people alike have become increasingly aware of a ticking “doomsday” clock, and never has it beat so loud, nor so fast. When the clock strikes midnight, it will be too late, with the effects of global warming becoming irreparable — our world riddled with floods, famine, droughts, and frequent natural disasters. The term “global warming” refers to the increase in Earth’s temperature from the emission of greenhouse gases (GHGs). GHGs can be emitted naturally, as they are when a volcano erupts, but the main contributions to global warming have been from human activities. According to a review by the University of Kentucky’s Loiy Al-Ghussian (2018), 45% of added GHGs come from the burning of fossil fuels, which produce harmful gases like carbon dioxide and nitrous oxide. Since fossil fuels power our cities, cars, and lifestyles in countless ways, developing a cleaner substitute is critical. This is where biofuels, alternat­­ive sources of energy derived from natural, more environmentally friendly processes, come into play. At least, that was the hope just decades ago.

Though biofuels were once touted as a promising solution to global warming and our crippling dependence on fossil fuels, the attitude toward them has since turned pessimistic. Even back in 2011 when David Biello wrote “The False Promise of Biofuels” (Scientific American), the conversation around biofuels was growing sour. In his article, Biello briefly examined one of many failed biofuel startups, Range Fuels, pointing to this failure as an indicator of a much greater problem the biofuel industry had been facing: a lack of tangible progress toward a feasible fossil fuel replacement. In particular, corn ethanol, a biofuel derived from corn mass, was the subject of much disappointment despite being the most widespread and commercialized biofuel in the United States to date. Not only is it not energy efficient or carbon neutral, but its fermentation process also requires plenty of fertile land and corn that could otherwise go towards feeding the global population. If corn ethanol were a contender for replacing fossil fuels, though, perhaps these tradeoffs would be worth it. However, as Biello explains, a gallon of corn ethanol only carries two-thirds the amount of energy in a gallon of gasoline. These factors made it hard to be optimistic about corn ethanol and biofuels in general. As a result, Biello’s article ends on a somber note, urging his readers to scale back their expectations for biofuels and be more realistic about the applications for which biofuels could be useful. A decade later, what has changed?

Essentially, it has become clearer that biofuels’ hyped feasibility from decades past has steadily dwindled. An article by Harish Jeswani and his team of chemical engineers from the University of Manchester, “Environmental Sustainability of Biofuels: A Review,” opens with startling results. According to their 2020 study, transport biofuel potential will fall short of the International Energy Agency’s 2050 projections by at least 30%. Perhaps the most jarring change beyond definitively missing our goals for the future, however, is that corn ethanol is mostly out of the discussion when it comes to fossil fuel alternatives. And when corn ethanol is mentioned, it is used as a benchmark that up-and-coming biofuels claim to be able to exceed one day. In essence, it has remained the modern-day status quo, but therein lies the problem researchers are striving to address. One biofuel scientists are exploring as a potential successor to corn ethanol is derived from beets (Fig. 1), according to “Sugar Beet Ethanol (Beta vulgaris L.): A Promising Low-Carbon Pathway for Ethanol Production in California.” Reasonably, the title of the article alone merits some skepticism. Corn ethanol was also, at one time, considered promising, but decades later, we have had to abandon it and search for other fossil fuel alternatives. How will sugar beet ethanol be any different?

The answer: It is virtually impossible to say. After Anthy Alexiades and her fellow researchers at the California Air Resources Board summed the estimated GHG emissions from the beet cultivation, irrigation, and transportation processes, the total came to around 3,060 kilograms of CO₂ per hectare (a hectare is about two and half acres (2018). Alexiades explains that this carbon intensity is 44% lower than that of corn ethanol and 71% lower than that of California gasoline.  Given these figures, it is hard not to place faith in the future of biofuels via beet ethanol. After all, this could be exactly what the field needs to reach the high hopes of decades past. However, the authors of this article are very deliberate about not thinking that far ahead, instead encouraging other researchers to conduct more comprehensive studies about how varying irrigation techniques and soil emissions impact the feasibility of beet ethanol.

This article’s conclusion hints at an understandably frustrating but prevailing truth: research and scientific inquiry take time. It is frustrating in the sense that issues like global warming still loom, with hopes of addressing them decreasing ever so slightly as another year passes. But because the scientific method requires trial and error, disappointments like corn ethanol are inevitable. Even from a purely scientific standpoint, analysis of a biofuel’s feasibility is a multifaceted discussion about how food chains, the atmosphere, and preexisting environments could react in complicated ways. Jeswani mentions but a subset of considerations: how the soil’s carbon content levels change with time, how often vegetation needs to be replaced, and whether the development of biofuels can keep pace with the global food supply. Complicating the situation further, such considerations are difficult to compare across biofuels. How does one compare biofuels derived from algae to biofuels derived from beets? The answer to this question is not yet clear. The nature of biofuel research is, at least in part, responsible for its trickling progress in the past. The development of a grand and versatile biofuel that can replace fossil fuels in their entirety is still a long way away. Perhaps Biello’s words from more than a decade ago still ring true today: We should be lowering our expectations for biofuels, developing them deliberately for specific applications.

Back then, Biello had in mind applications on the scale of replacing jet fuel, but what if biofuels could provide power to entire islands? Hawaii is a particularly interesting case study that could benefit tremendously from local biofuel production, as Muhammad Usman and his Tokyo Institute of Technology colleagues explain in “Biomass Feedstock for Liquid Biofuels Production in Hawaii and Tropical Islands: A Review” (2021). Because islands like Hawaii need to import fossil fuels, they pay a hefty price in simply getting access to gasoline, a price that trickles down to its residents and affects their quality of life. Here, the environmental cost of fossil fuels is compounded by the financial cost of their transportation. In 2018 alone, Hawaii imported 43.92 million barrels of refined petroleum, culminating in residents having to pay twice as much for energy as those living in mainland United States. Evidently, the current solution to Hawaii’s energy demands is unsustainable on both economic and environmental fronts. However, the incentive to produce biofuels in Hawaii comes from more than just this difficult financial situation.

Thanks to Hawaii’s tropical location, its climate is naturally suited to producing biofuels with potentially greater yields than those in mainland United States. Usman outlines a research study conducted over the past thirty years to determine potential feedstocks for biofuel production. The kamani tree (Fig. 2) stood out as the top contender, producing (on average) 17.7 tonnes (1 tonne is roughly 1.1 U.S. tons) per hectare per year. This was about three times as much as biomass produced from the jatropha plant and twice as much as produced from the pongamia plant. And in direct contrast with corn-sourced biofuel, which cuts into the world’s food supply, kamani is inedible.

Despite these impressive results, Usman and his team are cautious about making any bold claims this early in the research process, a fair approach given biofuels’ admittedly disappointing history. Instead, they urge policy makers to slow down and build relationships with local communities that would be affected by biofuel productions. Because the biofuel industry has a history of not consulting locals before beginning production, energy from biofuels lacks mass support in Hawaii, especially after past production of biofuels from papaya resulted in its crop’s eradication. Usman’s emphasis on local cooperation is a much-needed reminder that the biofuel issue does not exist in isolation within science or even economics. When it comes to biofuels, there are numerous community discussions to be had about food availability, the economic rise and fall of energy industries, and the effects of climate change on people’s health. Each one of these touches peoples’ livelihoods at the individual level, making the biofuel issue an inherently social one.

Moreover, an effective solution to the stagnant state of the biofuel industry is one that takes social impact into account. Surprisingly, most modern studies of the efficacy of proposed biofuels only consider environmental or economic impacts, according to an article published in 2018 by Parisa Rafiaani and her team at Hasselt University’s Environmental Economics Research Group. “Social Sustainability Assessments in the Biobased Economy: Towards a Systemic Approach” outlines current ways of analyzing social impact, with the most common indicators being health and safety, social acceptability, and food security. Though these are the most common, it clear that some indicators may be more relevant for certain biofuels than others, especially when it comes to land concerns or energy security. And it is exactly this open-ended question about which factors to consider that makes social analysis of biofuels complicated, compounding what is already a complicated scientific field. Like Alexiades, Rafiaani makes no grand claims here, but just states that more research must be done to create an all-encompassing system for quantifying social impact. It seems, yet again, there is unresolved nuance to be explored.

Analyzing the feasibility of corn ethanol alternatives and methodologies for assessing social change has yielded little more than calls for more research. It might seem that the current state of the biofuels industry is no better than it was a decade ago when Biello first published his critique. To fast-forward more than a decade into the future and find that the problem has yet to be solved can be discouraging. However, not all is doom and gloom. Since then, researchers have identified key applications for biofuels, that, if implemented properly, could lead to tremendous economic improvement. Specifically, islands like Hawaii would be relieved of the financial burden that comes from importing millions of gallons of gasoline. And even if biofuels ultimately do not end up replacing fossil fuels in their entirety, endeavors like self-sustaining islands are worth pursuing.

It might be tempting to dismiss the research described above as overly academic and inapplicable to the real world, especially when the articles seem only to provide a rough basis for where to go next — with “more research needs to be done” being a common message among them. But so long as scientists like Alexiades keep trying different biofuel derivations, and social scientists like Rafiaani keep exploring ways to quantify social impact across biofuels, we still have a fighting chance at slowing down the ticking clock. There is not much more that we can do than follow leads such as Hawaii’s kamani tree or California’s sugar beets, until we find an alternative to not only corn ethanol, but fossil fuels as well, to whatever degree that is possible. More than a decade after Biello wrote we have yet to find the ideal biofuel solution, but at least we know where to look next. In that sense, biofuels have yet to break their promise to the world, despite what his gloomy conclusions might lead us to believe.

 

Further Reading

Alexiades, Anthy, et al. “Sugar Beet Ethanol (Beta Vulgaris L.): A Promising Low-Carbon Pathway for Ethanol Production in California.” Journal of Cleaner Production, vol. 172, 20 Jan. 2018, pp. 3907–3917., doi:10.1016/j.jclepro.2017.05.059. Accessed 9 April 2022.

Al-Ghussain, Loiy. “Global Warming: Review on Driving Forces and Mitigation.” Environmental Progress & Sustainable Energy, vol. 38, no. 1, 2018, pp. 13–21., doi:10.1002/ep.13041. Accessed 20 April 2022.

Biello, David. “The False Promise of Biofuels.” Scientific American, Scientific American, 1 Aug. 2011, www.scientificamerican.com/article/the-false-promise-of-biofuels/. Accessed 7 July 2022.

Jeswani Harish, et al. “Environmental Sustainability of Biofuels: A Review.” Royal Society Publishing, 20 Oct. 2020, pp. 1-37, doi:10.1098/rspa.2020.0351. Accessed 9 April 2022

Rafiaani, Parisa, et al. “Social Sustainability Assessments in the Biobased Economy: Towards a Systemic Approach.” Renewable and Sustainable Energy Reviews, vol. 82, Feb. 2018, pp. 1839–1853., doi:10.1016/j.rer.2017.06.118. Accessed 9 April 2022.

Usman, Muhammad, et al. “Biomass Feedstocks for Liquid Biofuels Production in Hawaii & Tropical Islands: A Review.” International Journal of Renewable Energy Development, vol. 11, no. 1, 2021, pp. 111–132., doi:10.14710/ijred.0.39285. Accessed 9 April 2022.

 

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