Carbon dioxide and other greenhouse gases (GHGs) are responsible for global warming, the long-term worldwide average warming experienced since the industrial revolution. GHGs arise from human use of fossil fuels for energy. Major emitters of GHGs include both industrialized countries and, in recent decades, developing countries as well. Higher global temperatures cause the extremes of hot and cold, and wet and dry, weather of recent years. This blog examines global warming and its effects.
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This blog is expressly directed to readers who do not have strong training or backgrounds in science, with the intent of helping them grasp the underpinnings of this important issue. I'm going to present an ongoing series of posts that will develop various aspects of the science of global warming, its causes and possible methods for minimizing its advance and overcoming at least partially its detrimental effects.
Each post will begin with a capsule summary. It will then proceed with captioned sections to amplify and justify the statements and conclusions of the summary. I'll present images and tables where helpful to develop a point, since "a picture is worth a thousand words".
Summary.Last year President Obama stated that approval of the Keystone XL
pipeline, which would transport as much as 830,000 barrels of tar sands oil per
day from Canada to the GulfCoast, requires a finding that the pipeline be in
the national interest.As part of the
approval process the U. S. Department of State released an environmental impact
statement earlier this year.Its
findings and arguments suggest that the pipeline would not have a significant
effect on the environment, including greenhouse gas emissions.
In a new journal
article, however, Erickson and Lazarus conduct a comprehensive lifecycle
analysis of the effects of transporting the additional oil, pointing out shortcomings
in the Department of State’s environmental analysis.They find that when operating at full
capacity, the XL pipeline would increase global oil consumption by 490,000
barrels per day as of 2020, leading to new greenhouse gas emissions that are
four times higher than the environmental impact statement estimated, throughout
the 50 year lifetime of the pipeline.
In an era when the
world should be making every effort to reduce greenhouse gas emissions, the
findings of Erickson and Lazarus clearly show that approval of the XL pipeline
would increase emissions, and so would not be in the national interest.President Obama should not approve its
Introduction.President Obama is weighing whether to approve construction of the
proposed Keystone XL pipeline (XL) segment from the Canadian border to an
existing pipeline terminal in Oklahoma.At
full capacity it is intended to carry 830,000 barrels of oil per day (bpd) of
“heavy crude” oil, also called “tar sands” oil, from Alberta to refineries in the U. S. along the Gulf of Mexico.The
Department of State (DOS) is evaluating the application, since it involves
international policy, to determine whether the project serves the national
interest.DOS weighs “a wide range of
factors, including … environmental… and economic impacts; [and] foreign
policy”, among others.As part of its
review DOS issued its Final SupplementalEnvironmental Impact Statement
(Final SEIS) concerning the application In January 2014.
The Final SEIS, as
part of its lifecycle analysis of greenhouse gas (GHG) emissions, estimates
that transporting and consuming 830,000 bpd would lead to emitting between 147
and 168 million metric tons of carbon dioxide equivalents (MTCO2e)
per year throughout the operational lifetime of the pipeline, i.e., over
several decades.The analysis finds this
is 1-27 MTCO2e higher than would be obtained by consuming a
comparable amount of a reference crude oil such as Mexican Maya.
Lazarus find that the Final SEIS radically underestimates the lifecycle
emissions from operation of XL.Peter Erickson and Michael Lazarus published
their article, “Impact of the Keystone XL pipeline on global oil markets and greenhouse gas emissions”, in Nature Climate Changeon Aug. 10, 2014.The
authors conducted a comprehensive economic analysis of the principal
contributions to lifecycle GHG emissions (see Details at the end of this post).It includes important considerations that
they state were not apparent in the Final SEIS.An important feature of their analysis evaluates the decrease in the global price of oil as a
result of adding the tar sands oil to world supply. This would lead to higher consumption: “for
every barrel of increased production, global oil consumption would increase 0.6
barrels”, corresponding to an increase in consumption by 490,000 bpd.This in turn would lead to an increase in emissions,
when the oil is burned, of as much as 110 MTCO2e annually, four
times higher than the upper estimate presented by DOS in the Final SEIS
(see Details; these upper estimates assume operation of XL at full capacity).Erickson and Lazarus ascribe this serious
discrepancy to inadequate evaluation in the Final SEIS of the economics of the
global oil market.
In President Obama’s
address at Georgetown University on climate change delivered on June 25, 2013, he stated that
approval of the XL application required a finding that the pipeline was in the
“nation’s interest. And our national
interest will be served only if this project does not significantly exacerbate
the problem of carbon pollution. [XL’s] effects … on our climate will be
absolutely critical to determining whether” to approve the project.
Lazarus have made a significant contribution to the task of assessing whether
approval of XL would be in the nation’s interest.They have pointed out two errors in the DOS
Final SEIS which effectively show that the nation’s interest would not be met.
First, whereas the
Final SEIS finds that the incremental increase in annual emissions rate would
be at most 27 MTCO2e compared to a reference crude, the economic
analysis presented by Erickson and Lazarus concludes that emissions would be
about four-fold higher than the DOS estimate, when XL operates at its full
capacity.Second, the Final SEIS stated
that production of tar sands oil would not be affected whether or not XL would
be approved because alternative means of transporting the oil to the GulfCoast would be used.(This writer has commented on the moral
implications of this argument here.)In contrast, Erickson and Lazarus
show by widely recognized economic methods that shipment of tar sands oil through
XL would require expanded production, and that global consumption of oil would
increase by 490,000 bpd when XL is operated at full capacity.
Intergovernmental Panel on Climate Change has set forth the urgent imperativethat the nations of the world
have to agree on meaningful reductions of GHG emissions very soon.Increased levels of GHGs in the atmosphere
result directly in higher long-term global average temperatures, bringing
physical damage, and ecological and societal harms with them.Any project such as the XL pipeline
contributes to increased GHG emissions throughout the operating lifetime of the
project, which the present authors estimate at 50 years.As a result XL clearly would not meet
President Obama’s criterion for approval, namely that it be in the nation’s
interest.The President should not
approve the XL pipeline project.
The Final SEIS
evaluated lifecycle emissions from projected operation of XL, and compared the
result to emissions expected from production of reference sources of heavy
crude oil.The analysis included
extraction, processing, transportation, refining, and final uses including
gasoline for fuel, as well as co-products such as petroleum coke.
Extraction of tar
sands oil was acknowledged to emit about 17% more GHGs than occurs in
extraction of crude oil in the U. S. as of 2005.Overall, the annualized burden of GHG emissions from tar sands oil was
found to be 147 to 168 MTCO2e for operation of XL at its full
capacity of 830,000 bpd, compared to 124 to 149 MTCO2e for four
reference crude oils.The incremental lifecycle
burden from use of tar sands oil was evaluated to be in the range 1.2 to 27.4
MTCO2e per year.(The Final
SEIS states that the broad range of these values arises because several
reference crudes were used and because the result depends on which lifecycle
study was used in the comparison.)
Lazarus conducted a comprehensive
economic lifecycle analysis of oil use and emissions arising from operation of
XL, evaluated for the year
2020.They formulate the increment in yearly emissions over
the projected lifetime of the pipeline as the total from a) those required
during construction, b) those required to operate XL compared to pipeline
shipment of reference crudes that would be displaced by sending tar sands crude
through XL, and c) consumption of tar sands refined products compared to
consumption of displaced reference crudes.The authors agree with the Final SEIS that contributions a) and b) are
trivial in comparison with c); they did not analyze those further.
rearrangement of their simple expression showed that a principal factor in the
economic analysis is a ratio that expresses the extent to which expanding oil
sands production may increase global oil consumption.The authors state that the Final SEIS did not
assess this contribution, and furthermore that it has not been treated
adequately by others either.
The authors evaluated
this ratio using methods of economic lifecycle analysis employed for other
proposed fossil fuel extraction projects.The principal contributions to evaluating the ratio are first, a
projection of how worldwide prices for crude oil would decrease as the
additional supply from operating XL would ramp up to its maximum capacity, 830,000
bpd; and second, how demand would be shifted to higher levels at any fixed
price as shipment of tar sands oil increased up to the maximum.
Lazarus conclude that net worldwide consumption of crude oil would increase by
490,000 bpd when XL operated to capacity over the 50 year-lifetime of the
pipeline.This translates to an incremental
GHG emissions burden of 100-110 MTCO2e per year, an estimate that is
about four times higher than the highest value of 27 MTCO2e per year
estimated in the Final SEIS.According to the authors, the “sole reason for this difference is that
we account for the changes in global oil consumption resulting from increasing
oil sands production levels, whereas the State Department does not…. Our simple
model shows that, to the extent that Keystone XL leads to greater oil sands
production, the pipeline's effect on oil prices could substantially increase
its total GHG impact.” (They also point
out that the analysis used in the Final SEIS is proprietary and “is opaque with
respect to key assumptions and features”.In contrast, Erickson and Lazarus state that they use openly available
peer-reviewed methods.Also, their
article itself underwent peer review prior to publication.)They conclude that the Final SEIS issued by
DOS has failed to consider the most important factor determining global
consumption of crude oil: the increase in use due to increased supply and its
effect leading to lower prices.