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Study Concludes US LDV Fleet Needs to Reduce Carbon Emissions Per Mile By Up to 88% by 2050 to Meet 450ppm Stabilization Scenario; No Single Carbon Reduction Strategy Likely to Achieve This

29 January 2009

Keoleian1
Well-to-wheel carbon emissions limits (g/mi) for LDVs to meet target concentrations given a 2050 convergence date, two different VMT growth scenarios (0% and 1.7% per year), and a baseline LDV emissions share (25.3% of US emissions). Credit: ACS. Click to enlarge.

Researchers at the University of Michigan (U-M) have calculated quantitative sustainable mobility targets for US light-duty vehicles (LDVs) to help stabilize atmospheric carbon dioxide concentrations at 450 or 550 ppm, based on the well-to-wheel carbon emissions per mile driven.

Average fleet-wide on-road light-duty vehicle (LDV) well-to-wheel carbon emissions must be reduced from 160 g carbon/mile (equivalent to 586.7 gCO2/mile) to as little as 20 gC/mile (equivalent to 73 gCO2/mile) under one scenario by 2050—an 88% reduction—to contribute to a goal of 450 ppm, according to according to Greg Keoleian, co-director of the U-M School of Natural Resources and Environment, and his co-authors, Hilary Grimes-Casey and Blair Willcox of the Center for Sustainable Systems.

The researchers defined an allowed global emissions budget using atmospheric carbon stabilization scenarios developed by Wigley et al. (known as WRE) for the IPCC Third Assessment Report (TAR) on climate change. They considered two scenarios for allocating emissions to LDVs: one in which LDVs maintain a relatively constant share of emissions, and one in which the share of US GHG emissions from LDV use grows due to easier reduction activities in other sectors.

Keoleian2
Required changes in fleet fuel economy to achieve 450 and 550 ppm with baseline conditions for VMT growth and fuel mix improvements. Credit: ACS. Click to enlarge.

Improving vehicle fuel efficiency, the widespread use of low-carbon fuel, and reducing vehicle miles traveled (VMT) have all been suggested as ways to reduce carbon emissions in the LDV fleet. However, reaching the required carbon-reduction targets necessitates an aggressive combination of all strategies, the researchers write in a paper published in the 1 February edition of the ACS journal Environmental Science & Technology.

Attempting to reach the 450 ppm emissions-reduction targets by adopting just one of these approaches would require:

  • Fleetwide on-road fuel economy of 136 miles per gallon gasoline-equivalent (mpgge), given baseline conditions for VMT and projected fuel mix. This represents a 665% improvement over 2007 on-road average forecasted fuel economy. To stabilize emissions at 550 ppm, fleet fuel economy would have to reach over 94 mpgge.

  • Drivers would have to reduce their current driving activity by almost half, or their projected 2050 VMT by 75% to meet the 450 ppm target. For 550 ppm, current driving levels would have to be reduced 25% and projected 2050 levels would have to be reduced 37%.

  • Cellulosic (low-carbon) ethanol would have to capture almost 6% of the market by 2010, and almost 86% by 2050, in order to meet the 450 ppm sustainable mobility target for WTW carbon emissions.

In terms of the fuel mix, the authors modeled all petroleum-based fuel as gasoline (only 1.5% of the mix currently is diesel), and projected that total ethanol consumption will stabilize at 11% of LDV fuel energy by 2030. The study focused on spark ignition technology, and so excluded biodiesel and hydrogen.

In the U-M study, the authors assumed that grain-based ehtanol provides an 18% lifetime CO2-equivalent reduction on a per MJ basis, and that cellulosic ethanol provides an 88% reduction, also on that basis. These figures do not factor in land-use issues; the study thus “offers an optimistic scenario for the potential for biofuel use to reduce carbon dioxide emissions from LDVs.

The results of “pushing” social and technological levers to reduce use phase LDV carbon emissions according to a global target demonstrate that any individual vehicle carbon reduction strategy is not likely to be successful over the long term. A policy (or technology) package that promotes low carbon vehicles, provides incentives to manufacturers to increase fuel efficiency, and manages LDV travel demand is needed.

—Grimes-Casey et al. (2009)

The authors give plug-in hybrid electric vehicles (PHEVs) specific consideration in their discussion, noting that PHEV carbon intensity in CO2 equivalents per mile will depend on the carbon intensity of the future electricity generation mix.

Using baseline scenarios for energetic consumption of LDV fuels, if a 30 km-range (18.6-mile) PHEV was charged with the current US electricity generation mix, the PHEVs would have to replace 100% of gas powered vehicle driving by 2015 in order to meet the LDV target of 450 ppm. By 2017 this strategy, however, would be insufficient to meet LDV driving goals for vehicles powered by conventional liquid fuels. If future US electricity generation carbon intensity is high (130.2 g/mi assumption), PHEVs will not be sufficient to meet any of the analyzed targets by 2017.

This study demonstrates the need for a combination of strategies that significantly cut projected vehicle carbon emissions per mile according to the proposed emissions target pathways. Therefore, the development and market penetration of less-carbon-intensive vehicles and fuels must be accelerated in conjunction with a dramatic reduction in travel demand in order to achieve sustainable personal mobility...Even in the “best” or easiest to achieve case scenario, the LDV sector faces a substantial challenge in reducing CO2 emissions by 2050.

—Grimes-Casey et al. (2009)

Resources

  • Hilary G. Grimes-Casey, Gregory A. Keoleian, and Blair Willcox (2009) Carbon Emission Targets for Driving Sustainable Mobility with US Light-Duty Vehicles. Environ. Sci. Technol., Article ASAP doi: 10.1021/es801032b

January 29, 2009 in Climate Change, Emissions, Fuel Efficiency, Policy | Permalink | Comments (10) | TrackBack (0)

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The IPCC interim report, Tar III, in 1999, estimated CO2 levels rising at a rate 2.5 to 5 times times what the actual history in the interval since 1999 reveals. Using Wigley's figures from 1999 is like estimating from a a stacked deck.

Why didn't they use IPCC's AR IV updated figures from 2006-7? Because they wouldn't look as dire and threatening. Even so the "impossible" requirements for 94 mpge in 2050, will be met easily, long before then.

The Electrification of Ground TrRansport is coming. The Volt is estimated to have a 321 mpge, and will reach production in 2010. Any PHEV will easily exceed 100 mpge, and also thus exceed the "impossible" 94 mpge of which they speak. Long before 2050 these will be common and universal.

Wigley in 1999, assumed that CO2 was resident for hundreds or even more exagerated, thousands of years. Or once put into the atmosphere it is "always" there, and just builds up. This is not the case.

The IPCC itself, said in it's updated 2007 AR IV, that it is returning to residency times of 5.7 years in its IPCC AR V report, due in 2011. Because all these wild claims of exagerated CO2 residency times, have not been supported by a single scientific experiment published in the peer reviewed literature. It is all just pure conjecture.

On the other hand, Henry's Law of Solubility, gets corroboration of its calculation of 5.7 years residency, virtually every year by several science teams publishing their experimental results, affirming the correctness of Henry's Law of Solubility and its 5.7 year residency time for atmospheric CO2. So CO2 constantly washes out of the air, even as more is added.

Furthermore, there is no assumption about CO2 reduction in electric generation in Wigley's figures. Unless Mr. Obama's erstwhile true believers, (Browner, Chu and Holdren) somehow stop the Nuclear Renaissance begun under Mr. Clinton and Mr. Bush, some 35 new, larger, safer, nuclear powerplants will be on-line before 2018 raising non-carbon electric generation to over 40% of US electric production. By 2040 clean, inexahaustible, Fusion will be adding electricity to the Grid. Meanwhile, almost all of the present existing, smaller, nuclear facilities have been extended in their operational lifetimes to 60 years, by the NRC. This means none will be retired before the 2045-2060 timeframe. All the new plants will raise US nuclear electric generation from 19% to about 30-35% of all electricity produced by 2018, with more to follow.

Or for that matter, merely replacing older, worn out, coal plants with newer models reduces CO2 emissions by 20%, even without resort to Carbon Sequestration, merely due to improved thermal efficiency. It also significantly reduces large amounts of "grand-fathered in" genuine, toxic, emissions.

In short, there have been a series of impossible "studies" issued recently, of which this is one, that talk of impending doom, no matter what we do, even though the foundations on which they are based has been proven by historical results to be farcical. None of these are genuine reports of experiment. Instead, the "studies" take the results of already proven wrong model output; and then estimate some presumed future harm as if the incorrect model output were true and factual.

There is an apparent urgency to impose a Carbon Tax regime, and world-wide Carbon Trading system in place before the whole AGW GHG "Science" falls completely apart and is discredited by everyone, politicians, and the general populace. Today, most of the current scientific community is rapidly becoming disillusioned and skeptics; and that will spread to the populace, and is doing so even now.

Warmists like Mr. Gore, need that system to contribute to their financial fortunes. Mr. Gore went from a net worth of under $10 million, inherited from his Father's political Oil investments, to a net worth of $300 million from selling "Carbon Credits", Speeches, and Movies, harping on Global Warming. These "credits" consist mostly of official promises to plant a Tree, a Shrub or a Bush.

Notably, an acorn falling from an existing tree in a forest and growing of its own accord, into a new tree, does not "Officially" exist. It hasn't filled out the proper IPCC accounting paperwork, unlike Mr. Gore's companies. Even though N. A. Forests are now 30% larger than in the 1970s, due the to natural re-forestation and CO2 fertilization effects, and Mr.Gore and his associates have planted a miniscule amount of those new trees.

Never mind that North America is already a net carbon negative sink. NA sequesters all it makes by nature and man combined; and then some more, from the rest of the World.

This farcical "study" and others like it are all GIGO.

Wow Stan! That was an incredibly fast and long reply.

I'll pass on its merits since I look at this "studying" business another way.

Can imagining and projecting US LDV fleet emissions tell us anything about the stablizing World PPM by 2050?

To believe that really seems a stretch of the imagination.

That LDV fleet must be a very small portion of world CO2 emissions today. And it probably won't be any bigger portion in 2050.

The calculations themselves are probably right. But the assumptions about the future? For 41 years?

About EV carbon footprint.

The US electrical grid produces just about 600gCO2 per kWh generated. The Volt claims a 40 mile range on 8kWh from its battery pack, so 200 Wh (from the battery) per mile. With 15% conversion losses and 7% T&D losses that means 253 Wh must be generated per mile driven. That electricity generation produces (in the US grid mix) [600*.253] 152 gCO2/mile.

Burning a gallon of gasoline produces about 9000gCO2, so when in EV mode, the Volt has the carbon footprint of [9000/152] 59mpg.

In "Charge Sustaining Mode" the Volt probably gets 50-60 mpg. I don't know how you can claim 321mpge unless you're not counting the electricity at all. That would be worse than only counting the gasoline you burn if you drive on E85, and so multiplying your mileage by 6.67.

The only vehicle I know that honestly exceeds 100mpge is the Aptera (and some 50cc scooters), designed from the start to be hyper-efficient.

As I said back a good while this is why bush and gang pushed for h2. In the end they know for CARS most bio fuels will not reach the future mandated g/km of co2. Also they KNOW from the battery makers themseles that its highly unlikely a much better battery will come popping out anytime soon.

So they will need 400-500 mile range cars that dont produce co2 to replace all the current 400-500 mile range cars that do.

"The US electrical grid produces just about 600gCO2 per kWh generated."

Then it'll need to get it act together!
Honetly though, the US grid will be the biggest diapointment if it can't better that!
The potential to charge (real and useful) batteries from wind and solar energy component already exist.

Lets not throw in the towel everytime half a braincell is called.
The real challenge - for 2050 is to see rollout in the second and third worlds.
It never cease to amaze how people - and govts wish to arrive 'fahionably late.'

Those that can should (have) do (ne) more than their share knowing that the task and resources required become depleting at an increasing rate.
Dreams and 'gonna' don't cut it.

While there are many promising innovations around, only real (installed) accomplishment will count and the oil sands and 'burn the lot' mentality is still a going concern (despite the dead weight sycophant folowings) as evidenced on earlier comments.

I don't doubt your figures for present carbon output per KWH; but you are completely wrong if you think that will be the same in 10 or 50 years. And although so-called renewables like Wind and Solar are very polluting, even if that information is strangely never mentioned, they will contribute some few percent to the future mix.

But Nuclear and even modern coal will come, and will reduce CO2 output, as if that mattered any. You have to recognize that there is an anomaly that can't continue in the profile of US electric generation. There were a great many antiquated coal plants with no actual toxic controls, that were schedueled to be scrapped in the 1970s and 1980s by the Utilities. They were overaged and decrepid even then. But the anti-Nuke efforts cancelled many of their planned replacements. Those terrible "old smokers" are still runnng today in 2009. They distort the carbon use figures. They weren't modernized or even extensively maintained much, thanks to Carter Administration unanticipated consequences of their foolish emission "improvements".

Yet they had to soldier on as there was no alternative. That can't go on much longer; they will be scrapped, or simply fall apart.

Dr. Chu's call for research on "clean coal" that he hates is baloney. Clean coal technology already exists. An IGCC coal plant that you can order from GE today, examples of which are producing electricity across the country, produces substantially less, some 20% less CO2, from it thermal efficiency alone, never mind that it generated a lot less toxic emmisions, by 90% or more.

Sidenote: I do like Dr.chu's advocacy of research into Actinide Burning and Uranium reprocessing. together they solve the Waste disposal problem of fission-based nuclear energy use.


I don't doubt your figures for present carbon output per KWH; but you are completely wrong if you think that will be the same in 10 or 50 years. And although so-called renewables like Wind and Solar are very polluting, even if that information is strangely never mentioned, they will contribute some few percent to the future mix.

But Nuclear and even modern coal will come, and will reduce CO2 output, as if that mattered any. You have to recognize that there is an anomaly that can't continue in the profile of US electric generation. There were a great many antiquated coal plants with no actual toxic controls, that were schedueled to be scrapped in the 1970s and 1980s by the Utilities. They were overaged and decrepid even then. But the anti-Nuke efforts cancelled many of their planned replacements. Those terrible "old smokers" are still runnng today in 2009. They distort the carbon use figures. They weren't modernized or even extensively maintained much, thanks to Carter Administration unanticipated consequences of their foolish emission "improvements".

Yet they had to soldier on as there was no alternative. That can't go on much longer; they will be scrapped, or simply fall apart.

Dr. Chu's call for research on "clean coal" that he hates is baloney. Clean coal technology already exists. An IGCC coal plant that you can order from GE today, examples of which are producing electricity across the country, produces substantially less, some 20% less CO2, from it thermal efficiency alone, never mind that it generated a lot less toxic emmisions, by 90% or more.

Sidenote: I do like Dr. Chu's advocacy of research into Actinide Burning and Uranium reprocessing. Together they solve the Waste disposal problem of fission-based nuclear energy use.


Stan wrote; "so-called renewables like Wind and Solar are very polluting, even if that information is strangely never mentioned,"

Any 'so-called' pollution from renewables like wind and solar would be single point emissions [mines, factories, etc.] or in other words places where it can be contained and cleaned up. If CCS works for 'clean coal' it will work in a cement plant or an aluminium smelter.

Ai_vin,

Single point pollution from Solar? Don't you wish. The AGW doom that they are all so worked up about involves changes in temperature of a half to 1 degree, in a century. Albedo alteratiosn works from a mauch larger base, like 31% of the TSI. Or several humndred degrees of temperature difference. Solar pollutes, and it doesn't matter whether its a centralized solar farms; or thousands of decentralized, rooftop solar panels. It is the total cumulative Area of Albedo alteration that counts. A solar cell is approaching ZERO albedo versus the planetary albedo average of 31%. Every solar panel installed makes the planet absorb more Heat from the sun, than it otherwise would. It is potentially much, much worse than AGW.

But the un-scientists in the Green movement have zero brainpower, or have ulterior motives, like the Carol Browner Watermelons, and Solar is currently their "Deus ex machina".

Wind has other pollution effects. It is better to discuss those in depth, elewhere. Delaying temperature equalization, and potentially creating increasingly severe weather conditions to force that equalization. But once again the doofuses in the green movement look at that as their precious "Deus ex machina" and can't, or refuse to see, the detrimental consequences. But more of it is being installed than solar, and the warts are beginning to show themselves to all.

I was fascinated by the wildy fringe ideas coming from ExDemo, until I remembered it was Stan Petersen's other sock puppet account.

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