Limiting global temperature from rising more than 2oC is a widely agreed upon target, but even with a temperature change of only 2oC , we can expect to see habitat destruction, reduced crop yields, and increased flooding and drought. If the temperature rises more than this we can expect to see even greater repercussions, and on our current track, we can expect a temperature rise well above 2oC . In the search for solutions to mitigate climate change, Bioenergy with Carbon Capture and Sequestration (BECCS) has emerged. The idea behind BECCS is that we will grow plants that can be burned for energy, called biomass, which will pull CO2 out of the atmosphere. Then when the biomass is burned to produce energy, we will collect and store the CO2 that would normally be released back into the atmosphere. This process results in net negative CO2 emissions. While BECCS is presented as a potential solution to climate change, many questions are left unanswered on what we can expect the impacts to be. To make BECCS more attainable, researchers should continue to assess BECCS to reach more precise estimates on its impacts, there should be a push for agricultural improvements that will free up land and use less water so these resources will be available for growing biomass, and the IPCC should explore other solutions as well as make BECCS more attainable for the future.
The Nature editorial “Outside the Bubble” discusses the scientific controversy surrounding BECCS. The authors main criticisms are the number of questions regarding BECCS that remain unanswered as the topic gains support. The editorial begins by introducing the main idea of BECCS, and calls it an “overnight sensation” and a “one-hit climate wonder.” The article expresses a lot of doubt for BECCS, but never states that it won’t work. The article supports its claims by naming some questions that remain unanswered, and bringing in the opinions of experts. For example, it states, “climate scientist Kevin Anderson compared BECCS to a fairy godmother, conjured up to wish away reality in a puff of optimism.” Although the article holds a negative perspective of BECCS for most of it, the author begins the final paragraph by stating that “BECCS may yet prove to have staying power.” He then explains that the groundwork must be done, and governments must be willing to pay for this. The article ends with the statement, “climate change must be based on the science of the probable.” Although the article is quite negative, the author doesn’t condemn BECCS. Instead, he critiques the amount of support it has while it is still lacking in scientific support.
As the Nature article touches on, many uncertainties surround BECCS, and there is debate over what we can expect the impacts of it to be. In a GCB Energy article, “Economic and ecological views on climate change mitigation with bioenergy and negative emissions,” Felix Creautzig discusses the differences in integrated assessment models and ecological models in evaluating BECCS. He writes, “integrated assessment models tend to emphasize economic dynamics and long timescales, whereas ecological models are more grounded in biophysical processes and today's observations.” While his article discusses the differences in these models, it still leave uncertainty about the accuracy of any of these models. One issue with having these different models is that they disagree on the amount of energy that we will be able to produce with BECCS. Creautzig describes, “a systematic overestimation of the estimation potential of bioenergy, or alternatively, a systematic underestimation of the area needed for mitigation by bioenergy.” These differences translate to big differences in the amount of energy we will be capable of producing through BECCS. A third debate surrounding BECCS is the amount of land that will be required to grow biomass, and how this will become available. BECCS implementation hinges on resources being available to produce the biomass that is burned to produce energy. This leads to another discussion on the impact BECCS may have on food and water. Creautzig writes, “biomass plantations could compete with food for water resources, and other food-energy market interactions.” These are the issues that make up the foundation for the controversy surrounding BECCS.
In order to resolve multiple controversies, scientists need to continuous assessments of BECCS and the impacts it holds. Current estimates for BECCS energy production vary greatly. Creautzig describes, “IAM studies, in general, display a range of uncertainty, projecting between 20 and 300 EJ yr−1 bioenergy actual deployment in 2100.” When estimates vary by this degree, it is hard to assess how much of an impact BECCS will be able to have. I we can decrease this uncertainty, it would decrease the amount of doubt surrounding BECCS. In addition, we need a better understanding of the environmental impacts of BECCS. BECCS is proposed as a solution to climate change, a global environmental problem. If it is to mitigate an environmental problem, we should be aware of what environmental problems it could cause. Finally, more precise estimates could tell use what impact we can expect a large scale implementation of BECCS to have on food supply and water availability.
To address the concerns over land availability, there should be a push for agricultural improvements that will free up land and use less water, so these resources will be available for growing biomass. Biomass is made up of the plants that will be used as fuel to create energy for BECCS, and large scale BECCS will require large amounts of biomass to be produced. Many predictions about BECCS are based off of assumptions that land will become available to grow this biomass. The GCB Energy article states, “The FAO assumes an agricultural productivity increase of 1.63 and projects an increase of agricultural land for food production by 70 Mha from 2005 to 2050...This is possible by an assumed high increase in agricultural productivity of about a factor of 2.” For this land to be available, we will need to use agricultural land more efficiently. Making land available cannot be done instantaneously, so we need to start moving towards this. With the implementation of BECCS, land costs will rise which will pressure people to use land more efficiently. By pushing for changes sooner as opposed to later, this transition to producing lots of biomass will be much smoother. While making land available for biomass production, we need to simultaneously ensure that water will be available to grow this biomass. The best way to ensure that this water will be available is to reduce water waste. Because much of the energy production of BECCS depends on the amount of biomass available, we need to work towards having land and resources available to grow this biomass.
As we work towards making BECCS more attainable, the Intergovernmental Panel on Climate Control should continue to explore other options that can be used to supplement BECCS if we cannot reach a high enough yield for it to stand alone. The IPCC has voiced support for BECCS stating in a report that “combining bioenergy with CCS (BECCS) offers the prospect of energy supply with large-scale net negative emissions which plays an important role in many low-stabilization scenarios, while it entails challenges and risks.” It is important for the IPCC to continue to explore other options because BECCS has yet to be implemented on a large scale, so there remain many uncertainties. The also need to consider the criticism for BECCS even though they are in support of it. In addition, even though some models show us being able to rely on BECCS alone, many do not. The GCB Energy article describes, “a central result of the IPCC assessment – bioenergy and BECCS as main mitigation option – hinges on a few crucial assumptions in integrated assessment models.” Because of this, the IPCC need to continue to assess other options because although BECCS has potential, we have yet to see the real impacts of it being implemented on a large scale.
We need to work to make BECCS more attainable because currently, it may be our best option for climate change mitigation. To do this, we should continue research on BECCS, push for agricultural improvements, and in the meantime, continue to explore other options as well. Keeping Global temperature from rising more than 2oC is vital to avoiding devastating consequences, and BECCS can help us do this.
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On the net:
Nature Editorial: http://www.nature.com.prox.lib.ncsu.edu/news/outside-the-bubble-1.19324
Bioenergy Article: http://onlinelibrary.wiley.com/doi/10.1111/gcbb.12235/full
IPCC Report: http://mitigation2014.org/
Huffington Post Article: http://data.huffingtonpost.com/2015/11/two-degrees-will-change-the-world
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