There are many problems with that study. The biodiesel greenhouse gas emissions is just one of the many problems (every other study has shown a drastic decrease in greenhouse emissions from biodiesel (78% reduction with current methods for producing biodiesel, based on the USDA/DOE study, with that reduction approaching 95% if methanol used in process is made from biomass)). It is simply inconceivable to anyone with an undergraduate college level science education that biodiesel would result in an INCREASE in greenhouse emissions. Delucchi seems to be assuming that biodiesel is produced by clear-cutting a forest each season to make new cropland, which is complete nonsense.

Another problem - every other study shows that CNG results in an increase in greenhouse emissions compared to diesel, not a decrease. At best, with domestic natural gas (which is dwindling, and we are already having to import liquified natural gas), you might end up with about the same level of greenhouse emissions

Other studies also don't give nearly as favorable greenhouse emissions for electric vehicles, with most showing an increase in greenhouse emissions with the current US mix.

A hydrogen vehicle with hydrogen made from petroleum should result in roughly no change, or potentially an increase in greenhouse emissions (can cite plenty of studies that back this up if anyone wants). In comparable vehicles, a hydrogen drivetrain gives at best marginally better efficiency than current gasoline drivetrains (for example, Ford's hydrogen Focus, despite using very expensive ultra-lightweight materials in place of the materials used in a normal Focus, gets 45 miles per gasoline-gallon-equivalent of hydrogen (roughly 1 kg) - only marginally better than a gasoline Focus without all the additional lightweight materials). Reforming the gasoline to get hydrogen results in additional energy input, which decreases the overall efficiency - end result has to be at least the same or more greenhouse emissions than the vehicle with a gasoline drivetrain would get - yet the author of this report claims a massive decrease. No way. He claims a decrease with every hydrogen option, which is simply the complete opposite of every other unbiased study on the matter.

A MUCH better study to look at is this one done by Argonne National Labs:
http://www.transportation.anl.gov/pdfs/TA/163.pdf
It was actually paid for mostly by GM, who was hoping it would show that their new hydrogen vehicles are the best way to go. The study was a well-to-wheel (lifecycle) assessment, and they gave hydrogen a very favorable vehicle efficiency - by apparently using GM's small hydrogen CAR as the hydrogen vehicle (the mileage figures on page 29 match their hydrogen car), and using full-sized trucks (Silverado) for all other fuels. Yet even with that advantage, the hydrogen vehicles came out looking horrible.

See pdf page 19 - you can see a plot there of total energy use for various vehicles. For fossil fuel based fuels, the amount of greenhouse emissions ends up being roughly proportional to this. Notice that all of the hydrogen vehicle options use FAR more energy than a simple current gasoline vehicle. Hydrogen from natural gas or electricity all use FAR more energy than current gasoline vehicles, and hence produce far more greenhouse emissions. Ethanol uses more energy, but due to the uptake of CO2 during the crop growth, ends up resulting in far less greenhouse emissions than other options considered.

With natural gas from the US, the energy use is slightly less than current gasoline vehicles. But since we are already having to import natural gas (our reserves are quickly dwindling), you should look at the non-north American natural gas - which requires more energy input than current gasoline (due to the high energy requried for transport).

The graphs on pdf page 20 show the FOSSIL energy use for each fuel pathway. Notice that all hydrogen options are far worse than current gasoline, and ethanol beats the pants off of gasoline (except corn ethanol).

Page 22 shows greenhouse emissions. Notice that Non-North American NG (which is what we are already starting to have to use, due to our reserves not being enough anymore) results in much higher greenhosue emissions than gasoline - due to boiloff of the natural gas as it is transported in liquified form. Notice on page 21:

"All H2 pathways have very high GHG emissions [/b]because all of the carbon in NG feedstock is removed during H2 production, for which we did not assume carbon sequestration. For the electrolysis cases, CO2 releases during electricity generation (attributable to fossil-fueled generation) are significant. L.H2 production, electrolysis H2 (both gaseous and liquid), and electricity generation have the highest GHG emissions."

And again, this was a study done at GM's expense, in the hopes of showing that their hydrogen vehicles were much better than current options. Even with favorable treatment for the hydrogen vehicles, they came out horrible.

If you want to compare how different fuels look, you should use studies like that Argonne one which uses actual data. Delucchi's numbers are completely contradictory of pretty much every other study on the matter, and contradict what simple science says.

Unfortunately, the Argonne study didn't look at biodiesel. But, for that you can look at many other studies, such as the DOE's "Life Cycle Inventory of Biodiesel and Petroleum Diesel for Use in an Urban Bus", http://www.nrel.gov/docs/legosti/fy98/24089.pdf
(which shows a 78% reduction over the life cycle, with current biodiesel production).

Personally, I think at least for the next 15 years the best solution _is_ going to biomass-derived diesel fuel.

Thanks to today's engine technologies, diesel engines are no longer the smokey, loudly clattering contraptions of the past. The development of common-rail direct fuel injection and modern catalytic converters with integrated particulate traps can make diesel engines very environmentally friendly. Also, because diesel engines have most of their usable torque in the low rev ranges, they are _perfect_ for applications in light trucks, minivans and SUV's.

The best thing about biomass-derived diesel fuel is that you can distill it from almost any plant source; unlike petroleum-based diesel fuels, biodiesel fuel doesn't create the diesel exhaust particulates that are harmful to human lungs. Also, with careful refining, biodiesel fuel won't even have the "French Fry smell" common with home-distilled biodiesel fuels. Finally, you can use the same fuel distribution infrastructure now in place to distribute biodiesel fuel, saving many billions of dollars or Euros in distribution costs.

If I remember correctly, scientists have found certain types of algae that could be used as biomass to be refined into biodiesel fuel. I've read about the potential plans to build a 160 square kilometer pond about two meters deep that could grow enough biomass to make enough biodiesel fuel for every vehicle in the USA! :-)

What kind of wood is being used in the production of Ethanol?
Waste wood. Like wood pallets etc, etc.
Or fresh cut tree's only