Hybrid cars cost 100 times as much as corn ethanol plants for the same percentage carbon reduction of about 20 percent.

Judged with data available around September 2007. Test: per unit of carbon reduction (about 20%), was the cost of hybrid cars roughly 100 times the cost of corn ethanol plants? Because '100 times' is a rough figure, treat a credible cost-effectiveness comparison showing about 50–200x as true. Mostly true if the ratio is clearly an order of magnitude or more but outside that band (for example 20–50x or 200–500x), or if the roughly 20% reduction assumption is somewhat off. Mixed if analyses differ widely, with some supporting a very large multiple and others not. Mostly false if hybrids cost more per unit of reduction but only by a small multiple (under about 10x), so the claim overstates a real gap. False if analyses show hybrids cost the same or less per unit of carbon reduction.

Set before the research began.

1. E1 Climate Change Abatement Strategies Which Way is the Wind Blowing? PubMed Central (NCBI), reprinting an Environmental Health Perspectives feature · 16 June 2009

   “Moreover, the cost of abating carbon dioxide (CO2) with hybrid technology is a high $100–140 per ton of avoided emissions, according to Reducing U.S. Greenhouse Gas Emissions: How Much at What Cost?, a 2007 public–private study produced by groups including Shell Oil, the Natural Resources Defense Council, and the Environmental Defense Fund.”

2. E2 Climate Change Abatement Strategies Which Way is the Wind Blowing? PubMed Central (NCBI), reprinting an Environmental Health Perspectives feature · 16 June 2009

   “In particular, comparable improvement in fuel economy can be achieved in conventionally powered cars—at an overall gain over the lifecycle of the vehicle of $81 per ton of avoided emissions—by using lighter-weight materials, optimal aerodynamics, turbocharging, drivetrain efficiency, and properly inflated tires.”

3. E3 Climate Change Abatement Strategies Which Way is the Wind Blowing? PubMed Central (NCBI), reprinting an Environmental Health Perspectives feature · 16 June 2009

   “Furthermore, the sustainability of corn ethanol has been questioned repeatedly because the energy required to produce the ethanol—usually derived from fossil fuel—is almost equal to the energy in the ethanol, obviating any presumed emissions or net energy advantage”

4. E4 Climate Change Abatement Strategies Which Way is the Wind Blowing? PubMed Central (NCBI), hosting the article; the page text cites Environmental Health Perspectives (EHP) references but does not name the publisher · 16 June 2009

   “the cost of abating carbon dioxide (CO2) with hybrid technology is a high $100–140 per ton of avoided emissions, according to Reducing U.S. Greenhouse Gas Emissions: How Much at What Cost?, a 2007 public–private study”

5. E5 Climate Change Abatement Strategies Which Way is the Wind Blowing? PubMed Central (NCBI), hosting the article; the page text cites Environmental Health Perspectives (EHP) references but does not name the publisher · 16 June 2009

   “the report points to numerous measures ranging in cost up to $50 per ton that could be sufficient to cut U.S. carbon emissions projected for 2030 by about one-third”

6. E6 Climate Change Abatement Strategies Which Way is the Wind Blowing? PubMed Central (NCBI), hosting the article; the page text cites Environmental Health Perspectives (EHP) references but does not name the publisher · 16 June 2009

   “comparable improvement in fuel economy can be achieved in conventionally powered cars—at an overall gain over the lifecycle of the vehicle of $81 per ton of avoided emissions”

7. E7 Subsidies and Climate Change Earth Track, Inc. (Doug Koplow), presented for the Nonproliferation Policy Education Center · 28 January 2008

   “Cost unit GHG avoided still high.”

E1 and E4 cite a 2007 study that puts the cost of cutting CO2 with hybrid technology at $100–140 per ton of avoided emissions. E3 questions corn ethanol's net emissions benefit, and E7 says only that the cost per unit of greenhouse gas avoided is "still high", with no figure. None of the evidence gives a cost per ton for corn ethanol plants. Without that figure, the hybrid-to-ethanol cost ratio cannot be worked out, so the claim of about 100 times cannot be tested.