A new urban rail line is proposed in Honolulu, which is projected to cost $4.1 billion. Among the
benefits cited by rail line sponsors is the reduction of greenhouse gas (GHG) emissions. This is
not surprising in view of the international concern about greenhouse gas emissions reduction.
Yet, inexplicably the DEIS contains no estimate of the rail line’s impact on greenhouse gas
This report corrects that oversight. The Honolulu rail line is evaluated using international
Two cases are reviewed for the year 2030, differing only in the method of generating electric
power. The Worst Case assumes that Hawaii’s greenhouse gas emissions from the production of
electricity will diminish at the projected national rate. The Best Case assumes that 70% of the
state’s electric power would be generated by renewable energy sources, consistent with an
objective established by Governor Linda Lingle.
Step 1: Estimate Greenhouse Gas Emission Impacts: Based upon an analysis of project data, it
is estimated that:
• Worst Case: With rail, greenhouse gas emissions would increase 28,000 tons in 2030
compared to without rail (2.1% more than without rail).
• Best Case: With rail, greenhouse gas emissions would decrease 12,000 tons in 2030
compared to without rail (0.9% less than without rail).
Step 2: Estimate Greenhouse Gas Emission Reduction Costs: The generally accepted method
for costing greenhouse gas emission removal is cost per ton.
• A cost per ton of greenhouse gas reduced cannot be calculated under the Worst Case
because there is no reduction in greenhouse gases.
• The cost to remove each ton of greenhouse gas is $29,900 under the Best Case.
Step 3: Evaluate Greenhouse Gas Reduction Costs: The United Nations Intergovernmental
Panel on Climate Change (IPCC) has indicated that sufficient reduction in greenhouse gas
emissions can be achieved for no more than $20 to $50 per ton. The present price for greenhouse
gas offsets is between $10 and $15 per ton.
• Rail reduces greenhouse gas emissions only under the Best Case and this reduction would
be at an exceedingly high cost. The $29,900 per ton reduced is nearly 600 times the
maximum IPCC maximum and nearly 2,000 times the maximum price for greenhouse
• The cost per ton is so much that if the same amount were spent per ton to reduce
Hawaii’s greenhouse gases by 80%, it would cost nearly $650,000,000,000 ($650 billion)
The Honolulu Rail Project: Greenhouse Gas Emissions Evaluation 1
annually. This is more than 10 times the state’s gross domestic product and nearly
$500,000 annually per resident (under the Best Case).
• Under the Best Case, the reduction in greenhouse gas emissions with rail is so small that
greenhouse gas offsets could be purchased for a maximum of $180,000 annually. This is
the equivalent of 3 hours of rail costs in 2030. Purchasing greenhouse gas offsets would
be a far more cost effective strategy and would achieve the same reduction.
Optimistic Estimates: The estimates above are optimistic. A number of factors could materially
increase the greenhouse gas emissions relative to the case outlined above.
Conclusion: Despite being promoted as contributing to the reduction of greenhouse gas
emissions, the Honolulu rail line is likely to increase greenhouse gas emissions in the Worst
Case. In the Best Case, rail would marginally reduce greenhouse gas emissions at an extremely
high cost per ton. At the IPCC maximum of $50, an 12,000 ton reduction in greenhouse gases
should cost no more than $600,000, not $350,000,000 as in the case of the rail line. As a strategy
for reducing greenhouse gas emissions, the Honolulu rail line is exorbitantly expensive.
Full report at http://demographia.com/db-honrail.pdf