Toyota News Release;
"TMC will advance its research and development of plug-in hybrid vehicles..."

Sweeter sounding words
I've never heard

:-)

The extra bits required for AC mains plug-in/plug-out capability are actually not that difficult or expensive. Plug-out would be handy for the great outdoors. A lock on the externally accessible socket would be a good idea.

The hard part is getting an affordable battery of sufficient capacity and energy density to permit PHEV operation. Perhaps wisely, Toyota has refrained from a specific commitment to do any more than increase its R&D funding in this respect. It would be more in keeping with Japanese engineering philosophy if they made do with incremental improvements to the electric-only range. They are way ahead of the pack anyhow. From a marketing perspective, they could stress plug-out over plug-in functionality at first.

Any chance Toyota will start working on converting tUSA's production of electricity from coal to wind/solar/bio or even more natural gas? After all, a PHEV isn't going to do much good for the environment if it's feedstock is dirty burning coal or fuel oil.

Honda has proposed a concept for distributed hydrogen production based on solar power. VW is partnering with Shell and Iogen to test cellulose ethanol production in Germany.

However, I am not aware of any efforts by Toyota to get into the fuels or electricity business. Perhaps that is just as well, you have to draw the line somewhere. Carmakers are looking for ways to ensure their products can adapt/be adapted to whatever the future mix of energy sources turns out to be.

As for PHEVs, Toyota is is not aggressively pushing the technology, merely responding to clarion calls from James Woolsey and others. These are focussed primarily on national energy security rather than greenhouse gases. In pure energy terms, PHEVs are almost certainly no better than cheaper HEVs. In CO2 terms, they may be since a large fraction of the electricity that would be used to recharge PHEVs at night would come from nuclear power stations (one reason I'm against PHEVs).

The costs of global warming, borne mostly by the environment and by the poorest peoples of the world, will be much greater than the costs of safe, clean nuclear power. Environmental dilettantes should educate themselves, overcome their squeamishness, and become part of the solution.

In CO2 terms, they may be since a large fraction of the electricity that would be used to recharge PHEVs at night would come from nuclear power stations (one reason I'm against PHEVs).

You're also forgetting that coal fired power plants are much more efficient than a gasoline engine in a car. And the emissions from a single smokestack that powers a few hundred thousand cars can be much more easily regulated.

Rafael,
I drove an EV-1 and used a RAV-4 electric at work. The EV-1 is a 1991 era design, the Toyata a 1996. The EV-1 had great acceleration for the time, the RAV-4 was fine.
You know since there is so little energy in batteries, the consumption was measured in watthours/KM or Mile. And the numbers were low. The cars had the capability to be truely zero emission unlike any other car using windmill, or hydro, or for two of my friends solar panels. BEV Cars on grid power get cleaner each year as the grid power improved, unlike cars with a fixed emissions control system on the date of manufacture. It is easier to change a powerplant's system or fuel source than a car's after being built.
Power electronics has advanced since then. So has on-board computing power. Each cell on a battery pack can be easily monitored.The charger inductive/conductive problem has been solved. Fast recharging is now a reality at any place that has 3 phase power, leaving out most homes of course. Cars can even put electricity back into the grid while being charged during peak times to help grid and make back operating costs, then recharge later off-peak.Carbon fiber is much cheaper and working with aluminum is now routine for automakers.

Could you Please explain to me why I can not have a serial hybrid electric car with a 30 mile range battery only and a PZEV emissions system on the engine. An engine that will burn ethanol or biodiesel or CNG? Take out half of the EV-1 lead acid pack (60-90 mile range) and put in the ICE systems (turbocharged). Offer the same car With a bigger battery and no ICE to spread costs out.
They make a car for every demographic group from surfers to cigar smoking bigwigs. I have to buy a prius toyota to get 50% of what we had from GM 10 years ago.
Carbon fiber is much cheaper and working with aluminum is now routine for automakers.
For the record, I own stock in one of those small companies trying to bring back BEV's after the ZEV mandate fell apart. The company's biggest stumbling block is that serious investors feel it is not too hard to make a car like I described, but too Easy!
They say if our expensive hand built models get popular, the big boys could make one within 18 months with better price and finish.
For the record, I do think the true cost of oil is over 5 dollars a gallon when the costs to society from externalities like pollution, health care, and national security is factored in.
I also do not like trading with an illegal cartel, and I do not mean the diamond guys from South Africa.
I also do not like trading with people who do not have our best interests in mind.
Driving a car that costs more but uses cleaner and less fuel is a small price to pay.
The next time you are taking your shoes off at the airport remember Congressman Dingel protected the big three untill they died. He still be around.
If you can not answer my question, why is every car, truck, SUV etc not equipted with a SULEV/PZEV engine if the car companies care about anything?

As an environmentalist who used to be activly opposed to nuclear power, I would like to think that we could safely have a more nuclear future to avoid greenhouse gases. However, that future may be somewhat limited by the fact that there a large volume of fossil fuels must be burned in the mining and processing of uranium, the construction and maintenance of the plant, and the storage and oversee of nuclear wastes for the indefinite future.

I don't know whether a serious ramping up of nuclear power makes sense or not. But like everything else, we need to ensure that a serious and objective energy analysis is done before we commit the billions of dollars and billions of btus necessary to make a nuclear future a reality.

I am less concerned with the safety issues than I am the fossil fuel energy input and economic issues.

Rafael: I am curious as to why you appear to be against nuclear power, primarily because I respect your opinion.

For a recent analysis of nuclear power go to http://www.worldchanging.com/

Richard Schumacher -

you're welcome to disagree with anyone on this forum, but perhaps calling them dilettantes may be counterproductive. You may think nuclear is clean and safe but I for one am not convinced on either score. Of course, fossil fuel use is now widely believed to contribute to global warming. Both choices are ultimately unpalatable. That is why INHO we need to focus on conservation/fuel economy and biofuels NOW since it will take a few decades to figure out how to make ends meet with just those.

Icelander -

modern coal plants reach full load efficiencies of ~40% but the installed base is closer to ~35%. However, even with sophisticated demand prediction algorithms, power plants must be operated such that they can very rapidly ramp up their output by several percent in response to unexpected load spikes. This margin of safety can reduce thermodynamic efficiency by another 1-2%. Add in the losses in the grid and especially, in battery charging, discharging, power electronics and electric motors and you're down to 20-25%. A gasoline engine with a manual transmission will get 15-30% depending on engine load point; the corresponding numbers for diesels are 20-40%. Usually, the lower number applies. Plus, coal produces more CO2 per kWh than hydrocarbon combustion does.

J Padula -

the Univ. of Zwickau (Germany) demonstrated a Citroen Saxo subcompact with a 20kW engine and a serial hybrid transmission. It was perfectly serviceable in city traffic and featured high fuel economy in that type of traffic. On the freeway, it did predictably less well (the electric path is only ~70% efficient vs. 98% for a manual transmission). The two electric machines plus the batteries and power electronics were also deemed too expensive for this price-senstive segment.

t -

in a nutshell, I am no fan of nuclear power the problem of radioactive waste is still not adequately solved. Despite billions spent on site preparation, the long-term repository at Yucca Mountain is still not operational. Spent fuel is therefore stored on-site, where capacity is limited and the waste is inadequately protected against a determined terrorist attack (which would be incredibly expensive). In many cases, it is possible to reduce the volume produced through various forms of reprocessing, but this also concentrates the radioactivity. In addition, the material has to be transported overland and/or shipped back and forth, with the risk of hugely expensive accidents and terrorist attacks.

Sellafield (UK) is reported to have "lost" some 30kg of plutonium over the years, with similar discrepancies eleswhere. The hope is that this is a rounding error in the clerical work. Imagine the dollar cost in homeland security measures if even a tiny amount of such material got into the hands of Islamist terrorists.

Then there are the very high decommissioning costs to consider, estimated at at least GBP 50 billion in the UK alone. Even then, the most radiactive parts are actually merely covered and left to cool down for a century or more. A future generation will have to spend yet more money to finish the job.

Finally, whenever you decide to build a new reactor for yourself, it becomes virtually impossible to persuade other countries (e.g. Iran) not to do the same. Since civilian and military uses of radioactvity are technologically closely related (e.g. enrichment cascades), this immediately leads to proliferation concerns and the huge dollar cost of somehow containing the perceived threat.

Bottom line: nuclear looks cheap only if you downplay the true costs of radioactive waste and the risks to national/global security.

I’m very excited to hear Toyota actively talking about PHEV’s. However, the paragraph seemed guarded. Perhaps they don’t want to let known too many details because of competition. I understand their next Prius model will be out in 2008 (2009 model year). If that doesn’t materialize, I’m heading for Edrive or Electro Energy, or Hymotion as fast as you can cay “plug-in hybrid electric vehicle”!

Rafael, a PHEV getting 100+ mph would mean offsetting more than 4 X the oil and pollutants people are currently burning in their average 22 mpg car. Now if the plug-in is also E85 capable, and reading that Toyota is working on cutting the emissions of the gas engine even further, I have to believe that a plug-in Prius is much better for the environment. Worst case, it’s displacing pollution in urban areas (electric mode), where there are many coughing people, and repoluting in rural areas (electric production), where there would be fewer coughing people!

Then, consider all the energy going into the oil guess and discovery phase, drilling, coming up dry, then drilling again until they hit pay dirt, transporting oil all over the world, spilling some, but not a lot (how many dead fish and animals is not a lot?), then refining, and trucking all over the continents. And, how many gas stations are there in each country? And how often does each one get each grade of gasoline tanks filled, before the non plug-in gas guzzling tanker trucks drive back, get refilled and drive around to each gas station in each country in the world, again? Whew!

Can you plug these things in without getting your hands dirty? People, especially women, don't want to come into work or into the house with their hands smeared with grease looking like motorcycle mechanics.

Any chance Toyota will start working on converting tUSA's production of electricity from coal to wind/solar/bio or even more natural gas? After all, a PHEV isn't going to do much good for the environment if it's feedstock is dirty burning coal or fuel oil.
Let's not forget there is a lot of spare electric capacity overnight. Currently a lot of that electricity goes to waste, which is why o/n rates for electricity is so low. So we are already getting the CO2 and other pollutants, with no real benefit. PHEV would at least capture some of that energy.

Fuel cells. Toyota will continue its work on fuel-cell passenger vehicles.
Don't you just love it? Toyota won't say: Fuel Cells are bunk! Watch GM hang themselves on this one! What a load of BS!

But you can read between the lines...

Hal asked how women would be convinced to plug in their cars. I'd like to know how women refuel them. Gasoline is a lot dirtier than an electric plug, so unless all women live in New Jersey or Washington or Oregon where full service stations are commonplace, I don't think that having people refuel their own cars is a big deal.

As for the comment about how there is no environmental improvement from electricity via coal versus gasoline, that has been shown not to be true. The thermal efficiency and polutants per kw/h from coal are still better than gasoline, even when you factor the transportation costs (not like gasoline is cheap or perfectly clean to transport either) of each fuel.

I too am an environmentalist that is a strong supporter of nuclear power as a means to counter global climate change. There are a lot of irrational fears and misconceptions regarding the radioative waste. The material decays exponentially. After about 40 years the level of radiactivity has dropped by a factor of 1000. As time goes on it decays slower and slower but the most dangerous level of radiactivity is over with relatively quickly. The waste storage issue would carry a lot more weight with me if there were no waste in existence right now. Since there is already 50 decades worth of waste and we have to manage that, the thought of several more decades of waste doesn't worry me too much given the positve aspects of the CO2 free energy of a nuclear power plant.

You must be talking about Washington DC. In Washington state, in the "upper-middle class" neighborhoods I have yet to see a full service station. Oregon there is ONLY full service.

George- They don't guess and drill (I know you were just over simplifying the process). They do spend alot of money on those geologists and petroleum engineers though. In fact the major oil companies don't search for oil at all!!! Oil field services companies do that (Schlumberger, Halliburton, etc).

people dissing nuclear power, look up thorium and molten salt core reactors
thoriumenergy.blogspot.com
wikipedia.org, Molten_salt_reactor

as for toyota PHEVs .. i just hope Mitsubishi will deliver on their promise to get full BEVs to market by that time. I can always buy a generator trailer, should i ever need one.

Anti-nuclear environmentalists have been the strongest force for preventing technology to recycle nuclear waste in the US. Also it has made sure we are still using the oldest nuclear technology available since a new plant hasn't been built on US soil for over 30 years.

I am not agains nuclear power as an energy source per definition but what are we doing here? We are simply using way too much energy. Surely developing technology that is more efficient is the better way to go here.

The bottom line is that every KW/h of energy that is released from stored energy resources, is one that keeps going in the earth's energy circulation. Yeah, we can find more energy in nuclear power but does that automatically mean we should release that energy rather than looking at how we can use less energy?

It seems the cheap and easy way out to quickly turn to another energy resource as long as we don't need to change our ways.

Still an energy efficient plug-in vehicle is a step in the right direction but plug-in/hybrid SUV's are not!

Hal, my wife drove a Honda Civic plug-in. That is, it was a cold weather add-on that warmed the engine block (she is in home health and frequently parks outside at night). The soket was in the front above the bumper. Her only complaint was the socket got ice and salt stuff on it. But, it never stopped the plug from going in ok.

However, the PHEV that I drove (CalCar’s Prius!), had the socket in the back of the car. I don’t see a problem there.

Batteries are increasing in energy storage density at 9% per year. So by 2014 we should see double what we have now. Each year all electrics will become more compelling.. At first for the secondary vehicle a family has, then for both vehicles.

But in the meantime the plug in hybrid is a good next step. And can dramatically lower gasoline use by itself.

Paul I don't think people are going to use less energy. Even if we went to smaller vehicles I think it would only slow down growth in energy use for a time. Because we are using energy for more and more applications. As technology creates new products and services that we want.

Like the obvious example of these computers we are communicating on, and the background network that makes it possible. I read once an estimate that 14% of electrical useage today is internet related. So that is a totally new and large growth to the grid just over the last 10 years. I think we will see more technologies come online that have a similiar impact.

Bottom line: nuclear looks cheap only if you downplay the true costs of radioactive waste and the risks to national/global security.

High level radioactive waste can be economically handled by dry cask storage. The casks may need to be replaced in (say) 100 years, but the present cost of that expenditure is small.

As for proliferation: a decision on our part to not build nuclear powerplants will not, by some sort of sympathetic magic or whatever, prevent other countries from building nuclear bombs. Indeed, it doesn't appear that much of anything will deter a determined proliferator from acquiring bombs, as Iran and North Korea illustrate.

Anyway, if you're so all-fired concerned about proliferation, you should be opposed to the hydrogen economy, since production of hydrogen from water (by electrolysis or thermal watersplitting) allows one to also produce heavy water at low marginal cost (by passing the incoming water past the outgoing hydrogen in a catalytic exchange column, which strips the deuterium back into the water stream). Heavy-water moderated reactors have been a popular means of achieving nuclear weapons capability, since they can be made smaller than graphite moderated reactors and do not require uranium enrichment.

Anti-nuclear environmentalists have been the strongest force for preventing technology to recycle nuclear waste in the US.

No, the strongest force has been the very low price of uranium ore. Reprocessing of spent commercial reactor fuel has been, and continues to be, economic idiocy, and that will continue to be the case until uranium prices increase by nearly an order of magnitude from their present values. I suspect this will not happen in the lifetime of anyone now alive, even if many new reactors are built.

Zealots...

aa2: Are you certain that the current per capital energy usage (in industrial countries) will not come down in the next 20 years.

With more efficient vehicles, houses, appliances, home and commercial electronics, buses, trains, airplanes, street lights, home and commercial lights, industrial processes etc., a one percent (1%/year) decrease per year should be easy to reach.

A more ambitious program (with enough direct and indirect incentives) could give 1.5%/year to 2%/year results.

Energy conservation, by limiting waste and by using more efficient machines is one of the best option to manage the present Oil/energy crisis.

We get more productivity in dollars per kWh now then we ever have (adjusting for present day dollars).

Energy star appliances are widely available and used.

Some utilities even offer rebates to those who do simple things like purchase CFL bulbs to replace incandescents.

We are using less energy now for each separate appliance. Even with a greater number of electrical appliances available it is the USA's population growth more than anything that causes an increase in energy usage. My current LCD monitor sitting right in front of my face uses 1/10th the electricity my old CRT monitor from 10 years ago used...and this screen is bigger with better resolution.

Solar to charge PHEV's is cheaper than burning $3 per gallon gasoline. $3/gallon x 3413 btu/kwh / 114,000 btu/gallon / 25% Eff. = $0.36/kWh. Just about every form of renewable generated electricity is cheaper than gasoline. Solar costs between $0.25 to $0.30 per kWh. Wind power typically costs between $0.07 to $0.05 per kWh.
While wind power is intermittent, in east Texas it typically blows at night, which is why City of Austin Electric is so enthusiastic about PHEV's.
In central Washington state, 350 square feet of solar modules mounted on the roof of a home would generate more energy than a PHEV-40 would use driving 15,000 miles per year. During the day solar power would feed into the grid, and at night grid power could be used to recharge the PHEV. Current off-peak rates for our local hydopower is less than $0.01 per kWh.

aa2: Are you certain that the current per capital energy usage (in industrial countries) will not come down in the next 20 years.

While I am not sure about the next 20 years, I expect, in the long term, that energy demand will increase, energy costs will decrease, and that ultimately the cost of energy (and many economic activities) will be almost entirely due to environmental externalities. I think this because I expect productivity to continue to improve, probably at an increasing rate, as information technologies continue to improve. This will reduce the cost of capital goods, which dominate the cost of non-fossil energy sources.

Consider what would happen if human-level AI were developed. At $.10/kWh, assuming that 50% of the cost of operating the AI is the electric bill (not unreasonable considering how price/electric power usage on computers has been going) then to replace a single person in an advanced country one could afford to have the machine using about 50 kW continuously. The 'population' of these machines could increase very rapidly.

aa2 - I'm interested in the battery energy storage statistic (increasing 9% per year in energy density). Got a source?

Paul Dietz -

I have not problem with hydrogen per se, though on-board storage remains a serious challenge. I am, however, not in favor of producing that hydrogen using nuclear or fossil fuel power. If you can do it with renewables, that's fine but let the market decide if it is willing to pay the premium.

Rafael: so why don't you have that problem with hydrogen? If hydrogen is produced by electrolysis on a global scale, even using solar energy to drive its production, it will become difficult to prevent clandestine manufacture of heavy water at low marginal cost.

It appears to me you have a serious double standard on the proliferation issue.

Paul, I really do not understand your argument.

What's exactly the problem with hydrogen? Can't I do electrolysis in my shed, and thereby contribute to proliferation of nuclear technology? And what would large scale hydrogen production exactly do to help axis-of-evil-countries to build more (cheaper) nuclear plants/bombs?

Paul,

Another question for you. You said in your post:

"High level radioactive waste can be economically handled by dry cask storage. The casks may need to be replaced in (say) 100 years, but the present cost of that expenditure is small."

Will the casks need replacement another 100 years later, and 200, 300, 400, etc.?

How would pebble-bed (Ithink) nuclear reactors fit into these scenarios? Do they need dry cask storage when depleted? Any handling problems?

Also back on topic, Toyota claims all their vehicles are good for E10. Arent all vehicles made since 1980, or perhaps 1975, E10 compatible? Remember we had a big gasohol push in the late seventies, under prez Jimmy Carter.

Will the casks need replacement another 100 years later, and 200, 300, 400, etc.?

They might. But through the miracle of non-zero interest rates, this doesn't change the present cost of this option significantly.

More likely, in a few centuries the technology will be so advanced that disposing of waste will seem like child's play. Most conservatively, reprocessing at that time is easier, since the intense shortlived radioactivity is gone. Worst comes to worst, they just bury the unreprocessed spent fuel then like they plan to bury it now. Delaying that expense for a few centuries saves lots of money also.

If you are concerned about society collapsing in the meantime, then the death and woe from that will far exceed the damage from unmaintained casks.

About the best objection I can see to the scheme is that casks on the surface might be targets in a full scale nuclear war, causing enhanced fallout if they're vaporized. This would require a direct hit with a large nuclear weapon, though.

What's exactly the problem with hydrogen?

If hydrogen is produce on the gigaton scale, as it would be to power a global economy, then any country with these electrolyzers would be able to produce heavy water at low marginal cost. This reduces the entry cost for acquiring nuclear weapons.

Can't I do electrolysis in my shed, and thereby contribute to proliferation of nuclear technology?

The catalytic exchange column has to be a certain height, so I doubt your shed would be big enough, nor would the mass flow through your system be anywhere near enough to get enough heavy water for a reactor. The mass flow of a full-scale hydrogen economy would be far more than enough, though. There's also the fixed cost of developing the exchange catalyst, although it's described in publically available patents.

1st, Pebble Bed Reactor should be used and China & South Africa are working on it.

2nd, Breeder Reactor should be used and Russia, Japan, India, China are working on it.

3rd, Both Pebble Bed and Breeder should be combined to 1 unit which will generate 50-60 times more energy for given amount of fuel and will never fail.

Thats the way to go combined with Wind, Solar, Geo, etc.

Toyota, Ford & GM can move the Auto-world from Combustion to Hybrid to Plugin-Hybrid, etc.

How would pebble-bed [...] nuclear reactors fit into these scenarios? Do they need dry cask storage when depleted?

Pebble bed reactors combine the fuel and the moderator, so they may make spent fuel disposal more difficult, since the fuel is dispersed as coated grains in a larger volume of graphite. I don't know if it's practical to separate the graphite from the spent fuel particles short something approaching full reprocessing.

On the other hand, if PBR uses a near-breeder cycle with thorium it may achieve higher burnup, which would reduce the volume of the spent fuel (if not its total radioactivity.)

@Paul:

In a nutshell: a hydrogen economy lowers the price of heavy water. I think I'll have to sell my computer, because it contributes to cheap computing power, which is also very helpful in producing a nuclear bomb :-).

anne: I'm glad we're in agreement that easing nuclear proliferation is not sufficient reason to reject a technology.

BTW, having very large quantities of heavy water also makes it easier to build extremely large thermonuclear devices, the cost of which is dominated by the cost of the fusion fuel. These devices would get around any conceivable nuclear defense, since they could have yields much greater than the aggregate yield of today's nuclear arsenals and have globally catastrophic effects. I could see a country like North Korea building such a 'doomsday bomb' as an ultimate deterrent.

http://www.rmi.org/sitepages/pid1151.php

@Paul:

Perhaps we agree a little bit, but it's not so black/white for me. There is never one single reason to reject a technology. You should take all aspects into account, they all add points to the equation.

In the case of computers: it's obvious that the technology is far too useful to reject on non-proliferation grounds.

In the case of nuclear plants, the most realistic statement is that their usefulness is open for debate. My main concern is not safety, but economics. I suspect that many invisible billions of dollars have been (are being) spent on research, hidden somewhere in military spending. Because it is deemed 'of strategic importance'. The mind boggling decomissioning costs of nuclear plants is only now becoming clear, see: http://news.bbc.co.uk/1/hi/business/4859980.stm. What other surprises can we expect? For me it just doesn't add up. Under these circumstances the proliferation issue can be just enough to tip the scale and decide to not travel further down the nuclear path.

B.T.W. Thanks for the warning on the doomsday bomb. Better stock up on canned food an bottled water ;-)

I expect we will burn all the fossil fuel in the earth, and we will fission most of the U235. BTW, if we "burn" the U235 up in commercial reactors, then the feedstock for the cascades will be gone. So the safest idea may be to burn it all.

Dry storage containers have a design life sufficient to bridge the gap to future reprocessing and waste volume reduction.

In any event, the long term future production of energy will come from renewables like solar panels, wind, and biofuels.

Hybrids are a stepping stone to EV's, and nuclear power is a stepping stone to non-fossil fuel energy.

I expect we will burn all the fossil fuel in the earth, and we will fission most of the U235.

This will depend on where you draw the line on ore quality. The total quantity of reduced material in the Earth (organic compounds, graphite, reduced metals, sulfur) that could arguably be considered 'fossil fuel' is enough to completely consume all the oxygen in the atmosphere, and then some -- it's just disseminated over a large volume and very difficult to exploit. (Actually, the material in the first 100 meters or so of the Earth's crust would be enough to deoxidize the atmosphere; in the very long term, humanity may have to artificially produce O2, or bury biomass, to compensate for oxidation of material exposed by digging and mining.)

The quantity of 235U in the crust is just enormous, even if you stop at the 10 ppm or so of U in granite.

Why is making an electric vehicle so difficult? It was done by GM in the 1990s and here we are in 2006 with new Lithium Ion batteries and nano-techs, yet they can't make a good Plug in vehicle..... cmon!!!!

Would burning all the fossil fuel deplete the 20% or so oxygen in the atmosphere? Nope. Just as there are processess that unite oxygen with carbon, such as burning fossil fuel, there are processes that separate oxygen from carbon, such as plants.

However, my second point, using commercial reactors to burn it all does seem not to pass muster; it would take hundreds of years, and if we toss breeders into the mix perhaps thousands of years to "burn it all." But commercial reactors is still a fine place to burn the weapons grade stuff, which removes one path (obtaining already enriched material)to the bomb.

Van: there is orders of magnitude more reduced material in the Earth than there is oxygen in the atmosphere to react with it. The mantle, for example, contains enormous volumes of ferrous ions that would fix oxygen by oxidizing to ferric ions, if they were exposed. The core is a huge mass of reduced metal and sulfur. Is this 'fossil fuel'? Perhaps air should be called 'fossil oxidant'.

The natural burial of plant material in sediments has acted as a pump to maintain an oxidation gradient from the surface to the interior of the planet. However, this pump did not create the initial reduced condition of Earth; that was set by the reduced state of the material from which the Earth was formed. The level of O2 in the atmosphere is set by a balance between the net O2 added by this burial (unburied organic matter just reoxidizes, contributing no net O2) and O2 consumed by oxidation of rocks during erosion. If (thought experiment here) all life were to be killed off, natural erosion would expose rocks and absorb the O2 over a period of roughly 1 million years, which isn't very long on a geological timescale.

Last I checked, it's an open problem in geochemistry about why atmospheric O2 levels have remained stable, since there isn't an agreed-upon stabilizing feedback mechanism. Perhaps high O2 levels would promote wildfires that would cause more charcoal to formed and (eventually, because it resists further oxidation) washed to sea and buried.

Paul, any way you slice it, burning the recoverable fossil fuels will not deplete the O2 significantly given the feedback loop of plant life.

But having said the obvious, I certainly agree that burning it all does not seem a wise course of action, we should transition to renewables and not unnecessarily tickle the unknown.

In order to transition, we must conserve, and the path to conservation will include implimenting a pricing structure that creates an incentive to conserve.

The barriers are the availablity of Lithium Ion batteries with a price less than $600 per KWH of storage capacity, opening a monitored retrievable storage facility for spent nuclear fuel, and overcoming legal knots created by the NIMBY environmentalists who are preventing construction of renewable generating facilities.

Paul, any way you slice it, burning the recoverable fossil fuels will not deplete the O2 significantly given the feedback loop of plant life.

This assertion makes no sense to me. What feedback loop, and why should it be expected to have this effect? Growth of plants by themselves causes no persistent increase in atmospheric O2, since oxidation of biomass consumes quantitatively all the O2 produced during photosynthesis. Only biomass that is buried before being oxidized can contribute, and that is a very small fraction of primary productivity (particularly if we are talking about biomass buried for very long times, in ocean sediments). Current fossil fuel consumption already greatly overwhelms the net biological O2 production. Atmospheric O2 levels have been measured to be declining, although this is much harder to detect than increases in CO2.

Further anthropogenic consumption of O2 could be prevented if CO2 reached toxic levels (10,000 ppm or so, IIRC), granted.