Develop Renewable Energy, Not the Keystone XL Oil Pipeline

Summary.  TransCanada, the sponsor of the Keystone XL pipeline project, filed an updated application for approval with the U. S. Department of State.  The Department issued a Draft Supplemental Environmental Impact Statement evaluating the application.

It addresses many immediate environmental concerns focusing on the pipeline route and its environmental integrity.  This post focuses on a more fundamental issue.  It restates the opposition of this blog to approval of the pipeline because if granted, the project would ensure a long-term commitment to continued and prolonged emissions of carbon dioxide, a principal greenhouse gas.

The energy economy is likened to a zero-sum enterprise, balancing investments in conventional carbon-based fuels for energy, worsening global warming, and developing renewable energy sources, improving the global climate.  The longer mankind accumulates higher and higher levels of atmospheric greenhouse gases, the worse global warming and its harmful effects on humanity become.  It behooves all nations to abate emissions and migrate to a carbon-free energy economy, sooner not later.  Accordingly, it is recommended to deny the XL permitting application.

Background.  The Keystone XL oil pipeline (XL) is an international transport pipeline project intended to carry bitumen (Alberta tar sands oil) from the Canadian border to refineries on the U. S. Gulf Coast.  Its sponsor is TransCanada Keystone Pipeline, LC.  Since the project has an international aspect, involving oil transport across the Canada-U.S. border, it requires positive review by the U. S. Department of State (DOS) and approval of the President.  The query to be resolved is whether approving XL is in the national interest.

         A first approval request was considered in 2011 with inconclusive results.  The proposed route passed over important subterranean aquifers in Nebraska.  The DOS Environmental Impact Statement (EIS) generated at the time dealt extensively with this issue.  Ultimately concerns over the susceptibility of the pipeline to failure leading to contamination of the aquifers led to failure to approve the project.

TransCanada has modified the proposed route through Nebraska to reduce  potential contamination of aquifers.  In addition, a portion of the original pipeline project from Oklahoma to the Gulf Coast is now under construction, as it does not require approval by the Administration.  The revised application has resulted in a Draft Supplemental EIS (SEIS) prepared by DOS in March 2013.  After formally releasing the SEIS in April 2013, any interested party may submit comments (see Note for details) for consideration and possible response before the final SEIS is issued.

         Tar Sands.  The oil available in Alberta is a surface-accessible mixture of a thick oily substance with the consistency of tar, called bitumen, with sand and clay.  Bitumen must be heated with hot steam to liquefy it, permitting separation from the minerals mixed with it.  Before shipping, bitumen is further refined to provide a synthetic crude oil suitable for pipeline transport.  Alternatively, bitumen can be diluted with liquid hydrocarbons to permit it to be pumped in the pipeline as well.

The Provincial Premier of Alberta, the province in which the tar sands are located, visited Washington, D.C. for the fourth time in 18 months during the week of April 8, 2013.  Alison Redford came to lobby for favorable action on XL.
 

Manmade global warming has become a serious problem in recent decades.  Mankind’s burning of fossil fuels, and other industrial and agricultural practices, are generating ever-increasing amounts of greenhouse gases that are released into the atmosphere.  These accumulate because most carbon dioxide, the product of burning, and some others of the gases, remain in the atmosphere for long times.  There is no natural mechanism that removes these gases once emitted.  They remain active, accumulating to create a more intense greenhouse effect, for a century or longer.  It is the total accumulated burden of greenhouse gases, not their annual rate of emissions, that governs the intensity of the greenhouse effect.

The Draft Supplemental Environmental Impact Statement.  This post discusses aspects of the SEIS presented in the Executive Summary.
 

The American portion of the pipeline under review extends from the Canadian border in Montana, traverses South Dakota and Nebraska and ends at Steele City, NE.  This portion is 875 miles (1408 km) long and 36 inches (91 cm) in diameter.  It will carry Canadian tar sands bitumen.  A branch, carrying shale oil from North Dakota, and other crude oils, will join it.  Its total capacity is intended to be 830,000 barrels per day, of which 555,000 barrels per day is currently committed to transporting Canadian bitumen.  Ultimately the sources of the oil stocks it will carry would be determined by market decisions. 
 

The SEIS devotes extensive attention to potential localized environmental effects, especially in the case of leakage.  These have been amply addressed elsewhere, including the SEIS, by both proponents of the pipeline and its environmental opponents. 

Construction of the U. S. portion of XL is estimated to cost US$3.3 billion for directly incurred expenses.  Direct employment during construction would be about 3,900 full time jobs over the 1-2 years envisioned for construction.  Once operating XL would need fewer than 50 employees.  The construction site is a moving front progressing along the route, requiring a 110 foot wide right of way during construction, which would be restored to a permanent 50 foot right of way upon completion, amounting to 5,584 acres (2,259ha) of land.  It includes 44 valve stations and 18 pumping stations along this segment. 

Climate change impact of XL.  The Executive Summary reports that operation of the proposed XL project is expected to lead to the emission of about 3.2 million metric tons of CO₂-equivalent per year of operation, mostly devoted to generating the electricity to operate the pumping stations along the pipeline.  The SEIS states this is comparable to the energy requirements of about 626,000 gas-powered cars, or about 398,000 homes using electricity, for one year. 

These figures account only for the operational emissions of the XL Project under review.  The full length of the U. S. portion of the pipeline from the Canadian border to a Gulf Coast terminus is about 1,700 miles, or almost twice the length of the proposed Project.  So the numbers in the preceding paragraph should be approximately doubled to account for transporting tar sands bitumen from the Canadian border to a Gulf Coast refinery. 

In addition, on a life-cycle basis extracting and refining of Alberta bitumen is more energy intensive than that of conventional oils, releasing about 17% more CO₂.  As noted above in the Background section, this is because of the extra heat energy needed to liberate the bitumen from its mineral composite.

This writer has estimated the CO₂ burden arising from actual combustion of tar sands bitumen, in the presumed form of gasoline, petroleum coke and other products of refining.  Depending on assumptions made, this estimate may have an error of perhaps 15%.  The result obtained is about 100 million metric tons of CO₂/year resulting from burning the full complement of bitumen proposed for transport by XL.  [Update 04/23/13:  This XL-derived annual emissions forecast represents about 4.5% of total CO₂ emissions for 2011 originating from burning petroleum-derived fuels in the U. S., according to data from the 2013 Annual Energy Outlook of the U. S. Energy Information Administration (Table A18), excluding international marine (bunker) fuels,]

 

Analysis

 

This blog has opposed the XL pipeline for a fundamental reason, one little argued by others.  It should be the policy of the U. S. to accelerate the transition of our energy economy away from one dependent on carbon-based fuels toward one that relies on renewable energy sources that do not emit greenhouse gases.  As pointed out in many recent posts, this should be done as soon as possible. 

Long Lifetime of Emitted GHGs. A major fraction of CO₂, the main greenhouse gas, emitted into the atmosphere remains there for at least one century and probably longer.  (Natural processes remove the minor portion, but cannot accommodate the full amount emitted.)  Thus atmospheric CO₂, and other manmade GHGs, will keep accumulating more and more until the rate of emission approaches zero.  This higher level of atmospheric GHGs worsens global warming and all its harmful effects on the planet and to mankind.  Thus early steps toward decarbonization of the energy economy are needed.

President Obama addresses climate change.  President Obama has proclaimed his support for efforts to combat global warming in both his Second Inaugural Address and his 2013 State of the Union address.  An important signal backing up his policy would be denial of a permit for XL.  This is because of the major additional annual rates of emission of CO₂ over the long term that its operation entails, as detailed above.  Transnational transport and burning of Canadian bitumen and its refined products would contribute about 106 million metric tons of CO₂ each year, for the full operational lifetime of the pipeline, i.e., for several decades.  The U. S. should take a policy stand that it will not be responsible for, or condone, such continued emission of GHGs, but rather that it will instead support deployment of renewable energy sources.

Pronouncements by TransCanada and the Alberta Premier are contradicted by their  actions.  The SEIS, presumably relying on declarations made by TransCanada, notes that it may not matter whether the U. S. approves the XL application.  Production of bitumen in Alberta and of crude oil in North Dakota would continue.  It states there are alternative modes of transport, involving other pipelines, rail, and truck, to carry Canadian bitumen to the Gulf.  Other destinations are also noted but were not evaluated. It also points out that the Gulf refineries already receive crude oil for processing by tanker transport from other sources.

Even so, TransCanada is actively campaigning for approval of XL and is laying groundwork for the Project.  For example, Mary Pipher, a Nebraskan opposed to the Project, points out in the New York Times of April 17, 2013 that TransCanada is using threats of exercising eminent domain (legal expropriation of property) against landowners along the XL right of way.

Alison Redford, the Premier of Alberta, has visited Washington, D.C. four times in the last 18 months seeking favorable action on XL.  During her most recent visit, she declared “We’re an exporting economy,” saying that Alberta’s bitumen would be harvested regardless of the approval of XL. “Alberta does have other options,” such as Canada’s Atlantic or Pacific coasts (New York Times, April 9, 2013).

The actions by TransCanada, described by Ms. Pipher, and the persistent campaigning in the U. S. by Premier Redford, clearly show that these interests are not ambivalent about the final decision on XL.  They are heavily invested in the outcome, and apparently actively pursue a favorable outcome.  To grant approval would further set back mankind’s pursuit of decarbonizing our energy economy by condoning continued fossil fuel use.

 

Conclusion: The energy economy is a zero sum enterprise.  In weighing whether to approve the Keystone XL pipeline, the choice is not whether to approve it or simply to reject it. Rather the correct decision to consider is whether to prolong the fossil fuel energy economy or to expand our renewable energy economy.

As noted above, the pipeline, if built, commits us to continued atmospheric emissions of CO₂ from this oil over its full service lifetime, i.e. 40 years or more.  [Update 04/23/13:  This represents about 4.5% of emissions from petroleum use in the U. S.]  The longer we delay to abate emissions, the harder it becomes.

The alternative strategy is to shift the investment that would be going into projects such as the pipeline into developing industrial scale, renewable energy sources and energy transmission infrastructure instead. We should stop harvesting tar sands oil and build wind farms and solar farms instead, and should reject new oil pipelines in favor of new transmission lines from those farms to energy consumers. The US$3.3 billion investment envisioned for the XL Project segment could develop significant renewable energy facilities such as these.  In this way, the overall energy economy is preserved, job demand remains vibrant, and global warming is addressed in a meaningful way.

[Update 04/23/13:  Cynthia Giles, Assistant Administrator for Enforcement and Compliance Assurance of the U. S. Environmental Protection Agency (EPA) commented on the SEIS in a letter to DOS dated April 22, 2013.  The comments identify aspects of the SEIS that are inadequate and require further analysis or support.  These include (among others) first, the 17% or higher greater emission of GHGs required to produce Alberta bitumen compared to a range of crude oils from conventional sources.  The letter requests an assessment of overall social costs for this increase.  Second, the letter requests a more thorough market analysis supporting the SEIS conclusion that regardless of whether the Project is approved Alberta bitumen production will not change significantly.  Third, the letter requests further details on how the U. S. and Canada can cooperate to mitigate GHG emissions in the production of bitumen (including carbon capture and storage) and possible use of renewable energy to power the operation of the pipeline.  These and other failings in the SEIS currently preclude the EPA from approving the XL Project.]

 

Note
 

Public comments on the SEIS may be submitted

a) by email to keystonecomments@state.gov,
 

b) using the internet at http://www.keystonepipeline-xl.state.gov/, or
 

c) by mail to:

U.S. Department of State

Attn: Genevieve Walker

NEPA Coordinator

2201 C Street NW Room 2726

Washington, D.C. 20520.

 

© 2013 Henry Auer

TransCanada’s Keystone XL Pipeline: Not in the U. S. Long-Term Interest

Summary.  The Keystone XL pipeline is proposed to carry Canadian crude oil originating in the Alberta tar sands to coast of the U. S. Gulf of Mexico.  As part of the approval process, the U. S. Department of State issued an Environmental Impact Statement on Aug. 26, 2011, which, overall, supports construction of the pipeline.  This post analyzes the report in the broader context of President Obama’s energy and environmental policies.  It is concluded that the XL pipeline would not be in the long-term interests of the U. S.  The project would not be consistent with the President’s policies promoting reduced emissions of greenhouse gases, since a) fossil fuels are burned to extract crude oil from Alberta tar sands, b) the additional flow of oil for decades means increased emissions of greenhouse gases when the refined oil is burned, and c) a considerable portion of the refined product is likely to be exported rather than being consumed domestically.  It would be far more beneficial to promote large-scale renewable energy projects in order to reduce our emissions of greenhouse gases.

Introduction.  The Keystone XL Project (XL) involves construction and operation of a pipeline carrying Canadian crude oil originating in the Alberta tar sands to refineries and ports on the coast of the Gulf of Mexico.  The applicant in XL is TransCanada Keystone Pipeline, LP (Keystone).  For an international project such as this, a Presidential Executive Order requires the U. S. Department of State (State) to determine whether the project is in the national interest.  As part of this review, State issued its Final Environmental Impact Statement (EIS) for XL on August 26, 2011.  This post is based on the Executive Summary of the EIS (link accessed Aug. 30, 2011). In addition to the EIS, State will consider further reviews from the U. S. Departments of Energy, Defense, Transportation, Homeland Security, Justice, Interior, and Commerce, and the Environmental Protection Agency (EPA).  Thus, consideration for approval assesses broad issues of national interest, as well as the need to satisfy various environmental considerations during both construction and operation.  This post reviews the environmental assessment as presented in the EIS, and discusses aspects of national interest from a broad perspective of energy policy.

The Proposed XL Project.  The pipeline is to be a 36 inch (91 cm)-diameter pipe capable of routinely carrying 700,000 barrels (1 barrel = 42 U.S. gallons, 147 L) of oil a day, with the option of increasing flow to a maximum of 830,000 barrels a day.  This represents 8-10% of U. S. imports in June 2011 from its 15 largest suppliers (link accessed Sept. 1, 2011).  The full length of the pipeline is to be 1,711 mi. (2,753 km), of which 1,384 mi (2,227 km) will be in the U. S. 

An existing Keystone pipeline extending from Steele City, Nebraska to Cushing, Oklahoma is part of the overall proposal.  Details of the issues considered in the EIS are presented at the end of this post.

Analysis.  Warming of the long-term average global temperature in recent decades is a reality that has been traced by temperature measurement at sites all around the planet.  The warming is directly traced to the increase in our atmosphere’s content of carbon dioxide (CO₂) and other greenhouse gases.  Global warming has already produced many extreme weather events around the globe whose effects on human welfare are severe, including drought and famine, flooding with consequent devastation, and forest wildfires.  These are predicted to become more severe as more CO₂ enters the atmosphere.

For these reasons it is important to strive toward a worldwide zero-emissions regime for greenhouse gases as soon as possible.  CO₂, once emitted into the atmosphere by burning fossil fuels for energy, remains there for a long time, at least 100 years (except for the CO₂ taken up by green plants in photosynthesis and absorbed by the oceans).  We can think of the atmosphere as a bathtub containing CO₂ (see this post).  The faucet is filling the bathtub with more CO₂ coming from fossil fuel combustion, but the drain is essentially closed, keeping most of the added CO₂ from escaping.  So the bathtub keeps filling higher and higher.  Increased atmospheric CO₂ is predicted to make extreme weather events, and detrimental changes in regional climatic conditions, worse than they are today.

President Obama has set the goal of reducing the greenhouse gas emission rate by the federal government by 28% by 2020 (link accessed Sept. 1, 2011). (We should remember that all remaining emission released each year continue to accumulate, as explained above, adding to the atmospheric CO₂ concentration.)  Laudably, the administration has supported small research and development projects, and granted start-up support, to small companies that are creating new technologies intended to achieve that goal.  In recent speeches the President has extolled job creation and enterprises engaged in renewable energy manufacturing, such as wind turbines and solar power.  In addition his administration has issued regulatory guidelines that significantly increase fuel efficiency of cars and trucks in the coming decade, first to 35.5 miles per gallon (mpg; 0.0662 L/km) by 2016, and further to 54.5 mpg (0.0431 L/km) by 2025, for cars and light trucks (link accessed Sept. 1, 2011).  Emissions standards are also being proposed for medium- and heavy-duty trucks.

The President’s recent decisions to resume limited offshore drilling for oil (link accessed Sept. 1, 2011), and opening the U. S. Atlantic and northern Alaska coasts to drilling (link accessed Sept. 1, 2011), however, are not consistent with his greenhouse gas goal. 

Nor would approval of the XL pipeline project support the President’s objective.  Although cast in the framework of helping the U. S. attain independence from foreign, potentially hostile, suppliers of our energy needs, approval of the pipeline would have the profound disadvantage of prolonging our dependence on fossil fuels.  The more oil and gas we burn, the more CO₂ is released and the more full the atmospheric “bathtub” becomes, worsening the effects of global warming.  The new oil wells and the XL pipeline transporting crude oil from Alberta represent fuelling commitments that last for decades, so that by these actions the U. S. is committing to increasing the atmospheric CO₂ concentration for decades to come. 

Offshore oil drilling costs billions of dollars.  The low-hanging fruit of drilling shallow wells has largely been harvested, so that the more expensive, and more risky, deep water drilling is all that remains.  The XL pipeline is forecast to cost US$7 billion.  This post respectfully proposes that energy companies that are willing to commit such large amounts of capital to prolong America’s demand for harmful oil and gas could just as easily commit to development of renewable energy.  After all, as energy companies, their business plans could justifiably be changed to develop renewable energy.  Their profits from undertaking such projects would be comparable to those expected from the oil-based development currently being programmed. 

A profitable renewable energy project is exemplified by Portland, Oregon’s solar-powered electric vehicle recharging stations (link accessed Aug. 26, 2011).  Portland is striving to have all forms of municipal transport based on electric power. This blog reviewed electric cars in an earlier post, pointing out precisely this need for renewable energy sources for these vehicles. 

A main argument used in the EIS to support the XL pipeline is that it would satisfy demand for crude oil at the Gulf Coast refineries (see Details, below).  It is implied that that demand originates domestically, and that the added supply would be consumed domestically in America.  In fact, according to the U.S. Energy Information Agency (link accessed Sept. 1, 2011) exports of finished petroleum products from the Gulf Coast increased from 703,000 barrels per day in 2005 to 1,580,000 barrels per day in 2010.  Thus support for the XL project cannot be based on domestic demand; rather there is no overriding national interest related to the U. S. domestic energy economy that is served by the project.  

Conclusion.  The XL pipeline project is proposed to transport large amounts of crude oil from the Alberta tar sands to U. S. Gulf Coast refineries in order to satisfy domestic demand and relieve reliance on petroleum imports from other foreign sources.  The project is not in accord with President Obama’s energy policies promoting renewable energy and reducing emissions of greenhouse gases.  Producing crude from the tar sands is far more energy intensive than producing crude from conventional wells, according to the U. S. Environmental Protection Agency (link accessed Sept. 1, 2011) and the EIS, detailed below.  Burning the refined products from this newly added source of fossil fuels would emit large, additional, amounts of CO₂ into the atmosphere, worsening global warming and its consequences, for many years to come.  Overall, the project does not appear to promote long-term U. S. energy and environmental interests.  Rather, the U. S. should strive to implement policies promoting energy efficiency and renewable energy sources as rapidly as possible. The world-wide benefit of working toward a zero-emissions energy economy would be considerable.

Details. 

This section summarizes the Environmental Impact Statement’s Executive Summary.

The proposed route of the pipeline is shown in the map below.

Source: U. S. Department of State. http://www.keystonepipeline-xl.state.gov/clientsite/keystonexl.nsf?Open (link accessed Aug. 30, 2011)

The pipeline itself is to be buried approximately 4 ft (1.2 m) below ground level, and passes at least that far below stream and river beds when it crosses these waterways.  Except in Nebraska, underground aquifers that the path encounters are far below the depth of the pipeline.  The project includes 30 above ground pump stations, over 100 valves, and an oil storage facility in Cushing, Oklahoma.  The overall projected cost is US$7 billion.  The pipeline, if approved, would begin operation in 2013.

Tar Sands.  The oil available in Alberta is a surface-accessible mixture of a thick oily substance with the consistency of tar, called bitumen, with sand and clay.  Bitumen must be heated with hot steam to liquefy it, permitting separation from the minerals mixed with it.  Before shipping, bitumen is further refined to provide a synthetic crude oil suitable for pipeline transport.  In addition, bitumen can be diluted with liquid hydrocarbons to permit it to be pumped in the pipeline as well.

Justification for XL.  The EIS states that demand for crude oil is high and growing in refineries on the coast of the Gulf of Mexico.  The principal objective of XL is to transport crude oil to the Gulf coast in response to this demand. A related objective is to fulfill market demand of the refineries, which currently get 5.1 million barrels per day, of their total capacity of 8.4 barrels per day, from abroad.

Safety considerations. The EIS states that Keystone agreed to 57 project-specific conditions, in addition to generic regulatory criteria already in place, for building and operating the pipeline.  The specific conditions govern design standards for manufacturing and testing the pipe, design and construction of the project including stringent pressure testing during construction, and remote sensing and data acquisition during operation that is intended to detect leaks at as low as 1.5 to 2% of the flow rate.

Frequency and severity of spills is discussed in detail.  The EIS reviews Keystone’s previous spill history, noting that they tend to be quite small in size and few in number.  Keystone projects a maximum potential spill volume of 672,000 gallons (note: not barrels) over 50% of the pipeline, and a maximum potential of 2.8 million gallons in a particular section of 1.7 mi (2.7 km).  Keystone is required to submit an Emergency Response Plan and a Pipeline Spill Response Plan for review before beginning operation.  In the event of a detected leak, pipeline pumps would stop, and isolation valves closed, all within 12 minutes.

Potential environmental impacts of leaks.  The most serious environmental impacts of leaks would occur in sensitive areas such as wetlands, rivers and streams, shallow groundwater areas, near drinking water supplies, and regions with sensitive wildlife or plants.  Both physical impacts on the oil on the terrain and toxicological impacts of oil on life forms are discussed in detail.

Passage through the North High Plains Aquifer System (including the Ogallala aquifer and the Sand Hills aquifer unit) is specifically mentioned.  These are important drinking water and irrigation water sources, and important sections of the aquifers pass close to grade surface for about 65 mi (105 km) in Nebraska.  State assessed in detail potential dangers to aquifers and water supply wells in preparing the EIS.  No sole-source aquifers, or aquifers that are principal drinking water sources, are crossed by the proposed pipeline route.  Based on previous spill experience, the EIS states that impacts of a spill would typically be limited to several hundred feet from the location of a spill, including, if at a shallow aquifer site, a limited area.  The EIS states “In no spill  incident scenario  would  the  entire Northern  High  Plains Aquifer system be adversely affected”.  

State specifies that Keystone should have an independent consultant approved by State and the federal regulatory agency, and the U. S. Environmental Protection Agency, to review its risk assessment, and identify any needed additional measures to be taken, based on the analysis.

Alternatives to the XL project were considered and dismissed.

First, not building the pipeline was considered.  It was assessed that even so, demand for Canadian crude on the Gulf Coast would remain undiminished.  It was evaluated that alternative use of rail or truck tank containers, or other pipelines, could partially fill the need.  Other crude would arrive from foreign sources by ocean tanker.  At the source, it was evaluated that Canadian producers would find other non-American consumers.

Second, system alternatives including alternate pipeline and transport modes as mentioned above were further evaluated.  None of the pipelines available would serve the needed volume of crude oil shipments, 380,000 barrels per day delivered to Texas alone.  Expanding other pipelines to fill the need would offer no better option than the XL project.  Trucking would worsen highway congestion and lead to significant greenhouse gas emissions.  Expansion of existing rail lines to provide the needed capacity would be somewhat better than the XL project, but their use would increase greenhouse gas emissions, emit considerable noise pollution and adversely impact communities on the route.

Third, five major route alternatives for pipeline construction were considered, all avoiding or minimizing exposure to the Ogallala and Sand Hill aquifers.  The alternative paths are all longer; all were eliminated based on cost and environmental factors.

Other alternatives still were also considered, in response to comments on a draft EIS.  State “did not find any of the major alternatives to be preferable to the proposed Project for the reasons presented in the final [full] EIS and summarized [here]”.   

Environmental Impacts.  The EIS considers numerous natural and societal impacts of the XL project.  The most significant evaluation relates to increased emissions of greenhouse gases as a result of sourcing crude oil from the Canadian tar sands.  It evaluated the full cycle from extraction, upgrading, transportation, refining and combustion.  Depending on specific assumptions made, the EIS concludes that for a gasoline product between 2 and 17% more greenhouse gases are produced than from conventional crude oils.  Based on assumptions employed, the EIS reports that the crude oil to be shipped by the XL pipeline would emit between 3 and 21 million metric tons of carbon dioxide (the main greenhouse gas) per year.

This writer finds this conclusion somewhat disingenuous.  Once at the refinery, the steps of refining and combustion are essentially the same for all sources, and should be removed from the total assessment.  It is widely known that extraction of crude oil from tar sands requires a high input of energy, not required to produce conventional crudes (see Analysis above).  This extra energy is obtained by burning fossil fuels, releasing greenhouse gases as a result.  Thus the production step enhances the percent greenhouse gas emissions significantly higher than the low range of 2 to 17% identified. 

A large number of other potential environmental impacts of the project are discussed in detail; essentially all are considered to be temporary in nature, occurring only during and shortly after construction of the pipeline.

© 2011 Henry Auer