steady rise of greenhouse gases in the atmosphere, largely due to human
activities, is generating changes in Earth’s climate. Throughout the past
century, there has been a growing awareness throughout the United States of the
long-term ramifications of climate change. Climate change, as defined by the
accredited National Aeronautics and Space Administration (NASA), refers to “a
broad 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).
emerging issue of climate change has pushed environmental scientists to take
action, but approaches have been slow and largely ineffective. Thus, many
scientists argue that additional efforts may soon be required to lower global
temperatures. This has led to a growing interest in climate engineering (also
known as geoengineering or climate intervention) defined by the Journal of the
Royal Society Interface, a monthly peer-reviewed scientific journal, as “the
deliberate large-scale manipulation of the planetary environment to counteract
anthropogenic climate change” (Shepherd, 2009).
techniques can be divided into two major classes: carbon dioxide removal (CDR)
and solar radiation management (SRM). CDR is defined as the “removal and
storage of carbon dioxide from the atmosphere using biological or chemical
processes” (Campbell-Arvai, V., Hart, P.
S., Raimi, K. T., & Wolske, K. S., 2017). CDR is generally preferred over
SRM due to the fewer risks involved with its implementation and the greater impact
it could have on slowing and reducing climate change. However, despite the benefits
that CDR could bring, research should be conducted through a scientific vantage
point in order to determine the effectiveness and plausibility of pursuing
atmospheric concentrations of greenhouse gases (predominantly carbon dioxide, along
with methane, ozone, chlorofluorocarbons, and nitrous oxide) are the main
sources of anthropogenic climate change. Removing these greenhouse gases from
the atmosphere would, in theory, be able to slow the process of global warming;
further, removing sufficient amounts of these greenhouse gases would eventually
be able to stop climate change altogether and begin to cool the climate
(Shepherd, 2009). Thus, many scientists believe that directly targeting the
carbon dioxide in the atmosphere through CDR is the best solution to climate
change. 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 to
create changes in the environment, CDR methods would need to remove several PgC
per year and maintain the rate of removal for centuries (Shepherd, 2009).
Land Use Management
reforestation, and the prevention of deforestation all deal with the establishment
of forests, which have the potential to create more carbon sinks that can
absorb carbon dioxide. An article published in the scholarly, peer-reviewed Carbon
Management Journal states that a plantation of trees “could store up to
approximately 900 PgC by 2100” and “an upper limit of approximately 150 PgC
could be stored within 100 years.” This means that “all the carbon that has
been emitted by human land use change activities in the past could, in the
long-term future, be recaptured by permanent afforestation” (Lenton, 2010).
the land and maintaining trees in biomes is an affordable method that doesn’t
cause economic burdens to carry out. Furthermore, there are little risks
involved with its deployment. However, this method is long-term and must be
carried out for centuries before significant impacts can be seen. An additional
problem associated with its use is the demand for land. Establishing forests
would reduce the amount of land that is available for food production and other
human activities. This makes land use management somewhat difficult to carry
out, despite the benefits associated with its use.
living organisms die, they decompose and “most of the carbon they stored is
returned to the atmosphere.” Biomass methods aim toward storing “some or all of
the carbon fixed by organic matter” in soils, rather than allowing “decomposition
to return it it to the atmosphere” (Shepherd, 2009). Some methods propose
burying the biomass on land in landfill sites or in the deep ocean. Studies
have shown that approximately 30% of carbon dioxide could be buried in the
oceans without effecting the environment significantly. However, problems
associated with this method include a disruption in the nutrients, growth, and
viability of the ecosystems involved in this process” (Shepherd, 2009).
is a method that has gathered attention over the last few decades. Biochar is
essentially charcoal that is created through a process known as pyrolysis, when
“organic matter decomposes” and “produces both biochar and biofuels.” Biochar
is a much stronger material than charcoal, so it is “resistant to decomposition
by micro-organisms” and has the ability to lock in “carbon for much longer time
periods.” Furthermore, biochar can be used to “improve crop yields” and create “biofuels,
a renewable energy source” (Shepherd, 2009).
its effectiveness, however, biomass-related methods are often criticized for
the potential risks and the high cost associated with its deployment.
dioxide is naturally removed from the atmosphere through the weathering of
carbonate and silicate rocks. In enhanced weathering, scientists aim to
accelerate this process of rock weathering in order to store more carbon
dioxide in them.
Campbell-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.
Low, S. (2017, February 24). The futures of climate
engineering. Earth’s Future, 5: 67–71. doi:10.1002/2016EF000442 Retrieved
January 28, 2018 from http://onlinelibrary.wiley.com/doi/10.1002/2016EF000442/epdf
(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
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