Introduction Thesteady rise of greenhouse gases in the atmosphere, largely due to humanactivities, is generating changes in Earth’s climate. Throughout the pastcentury, there has been a growing awareness throughout the United States of thelong-term ramifications of climate change. Climate change, as defined by theaccredited National Aeronautics and Space Administration (NASA), refers to “abroad range of global phenomena” including “increased temperature trends…sea level rise; ice mass loss… shifts in flower/plant blooming;and extreme weather events” caused “predominantly by burning fossil fuels,which add heat-trapping gases to Earth’s atmosphere” (NASA, 2016). Theemerging issue of climate change has pushed environmental scientists to takeaction, but approaches have been slow and largely ineffective. Thus, manyscientists argue that additional efforts may soon be required to lower globaltemperatures. This has led to a growing interest in climate engineering (alsoknown as geoengineering or climate intervention) defined by the Journal of theRoyal Society Interface, a monthly peer-reviewed scientific journal, as “thedeliberate large-scale manipulation of the planetary environment to counteractanthropogenic climate change” (Shepherd, 2009). Geoengineeringtechniques can be divided into two major classes: carbon dioxide removal (CDR)and solar radiation management (SRM). CDR is defined as the “removal andstorage of carbon dioxide from the atmosphere using biological or chemicalprocesses” (Campbell-Arvai, V.
, Hart, P.S., Raimi, K. T., & Wolske, K.
S., 2017). CDR is generally preferred overSRM due to the fewer risks involved with its implementation and the greater impactit could have on slowing and reducing climate change.
However, despite the benefitsthat CDR could bring, research should be conducted through a scientific vantagepoint in order to determine the effectiveness and plausibility of pursuingclimate engineering.Scientific Lens Abundantatmospheric concentrations of greenhouse gases (predominantly carbon dioxide, alongwith methane, ozone, chlorofluorocarbons, and nitrous oxide) are the mainsources of anthropogenic climate change. Removing these greenhouse gases fromthe atmosphere would, in theory, be able to slow the process of global warming;further, removing sufficient amounts of these greenhouse gases would eventuallybe able to stop climate change altogether and begin to cool the climate(Shepherd, 2009). Thus, many scientists believe that directly targeting thecarbon dioxide in the atmosphere through CDR is the best solution to climatechange. According to Shepherd, carbon dioxide is released at a rate of 8.
5 PgC(petagrams of carbon) per year from fossil fuel burning alone. In order tocreate changes in the environment, CDR methods would need to remove several PgCper year and maintain the rate of removal for centuries (Shepherd, 2009). Land Use Management Afforestation,reforestation, and the prevention of deforestation all deal with the establishmentof forests, which have the potential to create more carbon sinks that canabsorb carbon dioxide. An article published in the scholarly, peer-reviewed CarbonManagement Journal states that a plantation of trees “could store up toapproximately 900 PgC by 2100” and “an upper limit of approximately 150 PgCcould be stored within 100 years.
” This means that “all the carbon that hasbeen emitted by human land use change activities in the past could, in thelong-term future, be recaptured by permanent afforestation” (Lenton, 2010). Managingthe land and maintaining trees in biomes is an affordable method that doesn’tcause economic burdens to carry out. Furthermore, there are little risksinvolved with its deployment. However, this method is long-term and must becarried out for centuries before significant impacts can be seen. An additionalproblem associated with its use is the demand for land.
Establishing forestswould reduce the amount of land that is available for food production and otherhuman activities. This makes land use management somewhat difficult to carryout, despite the benefits associated with its use. Biomass-Related Methods Whenliving organisms die, they decompose and “most of the carbon they stored isreturned to the atmosphere.” Biomass methods aim toward storing “some or all ofthe carbon fixed by organic matter” in soils, rather than allowing “decompositionto return it it to the atmosphere” (Shepherd, 2009).
Some methods proposeburying the biomass on land in landfill sites or in the deep ocean. Studieshave shown that approximately 30% of carbon dioxide could be buried in theoceans without effecting the environment significantly. However, problemsassociated with this method include a disruption in the nutrients, growth, andviability of the ecosystems involved in this process” (Shepherd, 2009). Biocharis a method that has gathered attention over the last few decades. Biochar isessentially charcoal that is created through a process known as pyrolysis, when”organic matter decomposes” and “produces both biochar and biofuels.” Biocharis a much stronger material than charcoal, so it is “resistant to decompositionby micro-organisms” and has the ability to lock in “carbon for much longer timeperiods.” Furthermore, biochar can be used to “improve crop yields” and create “biofuels,a renewable energy source” (Shepherd, 2009). Despiteits effectiveness, however, biomass-related methods are often criticized forthe potential risks and the high cost associated with its deployment.
Enhanced Weathering Carbondioxide is naturally removed from the atmosphere through the weathering ofcarbonate and silicate rocks. In enhanced weathering, scientists aim toaccelerate this process of rock weathering in order to store more carbondioxide in them.WorksCitedCampbell-Arvai, V., Hart, P. S., Raimi, K.
T., &Wolske, K. S. (2017). The influence of learning about carbon dioxide removal(CDR) on support for mitigation policies. Climatic Change,143(3-4), 321-336.
doi:10.1007/s10584-017-2005-1Low, S. (2017, February 24).
The futures of climateengineering. Earth’s Future, 5: 67–71. doi:10.
1002/2016EF000442 RetrievedJanuary 28, 2018 from http://onlinelibrary.wiley.com/doi/10.1002/2016EF000442/epdf NASA.
(2016, January 19). What’s in a name? Weather, global warming and climate change. (NASA) Retrieved January 19, 2018, from https://climate.nasa.
gov/resources/global-warming/ Shepherd, J. (2009). Geoengineering the climate: science, governance and uncertainty. Retrieved January 27, 2018, from https://royalsociety.org/~/media/Royal_Society_Content/policy/publications/2009/8693.pdf.
Timothy M Lenton (2010) The potential for land-based biological CO2 removal to lower future atmospheric CO2 concentration, Carbon Management, 1:1, 145-160, DOI: 10.4155/ cmt.10.12 Retrieved January 28, 2018, from https://doi.org/10.4155/cmt.10.12