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An open letter to James Hansen on the real truth about stabilizing at 350 ppm

By Joe Romm  

"An open letter to James Hansen on the real truth about stabilizing at 350 ppm"


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To James Hansen (and his fellow 350 ppm-ers):

You make a compelling case we must ultimately return atmospheric concentrations of carbon dioxide to 350 parts per million to avoid catastrophic climate impacts (see “Stabilize at 350 ppm or risk ice-free planet, warn NASA, Yale, Sheffield, Versailles, Boston et al“).

But you have made an uncompelling case about how President-elect Obama should go about achieving 350 ppm in your new draft essay Tell Barack Obama the Truth — The Whole Truth and in previous essays (see here). You are, for instance, overly dismissive of cap-and-trade and overly enamored of a carbon tax, when, in fact, neither holds any prospect whatsoever of achieving your goal. Your discussion of as-yet non-commercial 4th generation nuclear technologies is equally off the point, as we’ll see.

If the truth is that we must have a target of 350 ppm, then you must be equally truthful in insisting on national and international policies that could achieve that goal. So far, you haven’t. Nobody has.

I have yet to seen anybody lay out just what is required to achieve 350 ppm from an energy technology and policy perspective, so let me do so here using the incredibly demanding carbon targets from your paper:


[Note: Sadly the ship has sailed on your blue line. We hit global carbon emissions from fossil fuels of 8.5 billion metric tons (GtC) in 2007, according to the Global Carbon Project (see here).]

Absent such specificity, everything else is pure handwaving. The simplest tool for explaining the scale of the solution is the much misunderstood “stabilization wedges” approach of Princecton’s Socolow and Pacala (technical paper here, less technical one here, my discussion of its analytical problems here). Used properly, it is almost as good as an expensive economic and energy model (see “IEA report, Part 2: Climate Progress has the 450-ppm solution about right“).

Wedges are strategies that reduce emissions steadily until they achieve a 1 GtC/year saving — in 50 years in Princeton’s original framework, but for those in a hurry like all of us now are, it must be less.

The bad news about 350 ppm is that you need some 18 standard (50-year) wedges from 2010 to 2060, if I’m reading your paper right — plus a whole lot more after that — just to be on a path to get back to 350 ppm in 2150. The really bad news is that, to achieve your frontloaded reductions from shutting down all traditional coal plants in the next two decades, you need eight of those wedges by 2030.

Why is this bad news? Three reason:

  1. An individual wedge is a staggering amount of carbon-free energy
  2. There isn’t political support to do even a single 20-year wedge today.
  3. Doing eight such accelerated wedges simultaneously is far beyond the capability of the market on its own no matter how high a carbon tax you impose.

Here is one possible list of all the (20-year) wedges the world must achieve simultaneously starting almost immediately:

  • 1.5 wedges of concentrated solar thermal — ~2500 GW peak.
  • 1.5 of wind power — 1.5 million large (2 MW peak) wind turbines
  • 2 of efficiency — buildings, industry, and cogeneration/heat-recovery for a total of 10 to 13 million GW-hrs.
  • 1 of nuclear power — 700 GW
  • 1 of solar photovoltaics — 2000 GW peak [or less PV and some geothermal, hydro, and biomass]
  • 1 wedge of vehicle efficiency — all cars 60 mpg, with no increase in miles traveled per vehicle.
  • 1 of forestry — End all tropical deforestation.

Note 1: Links to my extended discussion of most of these wedges can be found at “An introduction to the core climate solutions.”

Note 2: I threw in an extra electricity wedge since I have no doubt that everybody will find something objectionable in at least 1 of these wedges. Again, I am NOT proposing these wedges, but based on my research and blogging they are the most plausible I have seen. If you don’t like one, you need to find a replacement strategy (look here, but most of the others are far less plausible, if not inherently impractical [I'm talking about you, would-be hydrogen wedges]).

Note 3: Bear in mind that another 10 or so accelerated wedges will be needed from 2030 to 2060.

Is it clear yet why a carbon price is hardly among the most important policies needed to achieve 350 ppm? A price isn’t what is needed to stop building any new coal plants and shut down every existing one in 10 years in rich countries and 20 years everywhere else — and replace all that power (plus growth) with carbon-free generation and efficiency.

Indeed, I can’t imagine how high a price would be needed but it is probably of the order of $1000 a ton of carbon or more starting in 2010. Talk about shock and awe. Remember, we are talking about a carbon price so high that it actually renders coal plants that have been completely paid for uneconomic to run. And once you stop new demand and start shutting down existing plants, the price of coal will collapse to almost nothing.

Once you start building all of the alternatives at this unimaginable pace, bottlenecks in production and material supply will run up their costs. The collapse in coal prices, making existing plants very cheap to run, together with the run up in the price of all alternatives will force carbon prices even higher.

But, in any case, if you want to replace all those existing coal plants with carbon free power that fast, again the carbon price is almost beside the point. How are you going to site and build all the alternative plants that fast? How are you going to site and build all the power lines that quickly? How are you going to allocate the steel, cement, turbines, etc? How are you going to train all the people needed to do all this?

There is only one way. As you and your coathors conclude:

The most difficult task, phase-out over the next 20-25 years of coal use that does not capture CO2, is Herculean, yet feasible when compared with the efforts that went into World War II.

Yes, this is a WWII-style effort, as I noted in the conclusion to my book:

This national (and global) re-industrialization effort would be on the scale of what we did during World War II, except it would last far longer. “In nine months, the entire capacity of the prolific automobile industry had been converted to the production of tanks, guns, planes, and bombs,” explains Doris Kearns Goodwin in her 1994 book on the World War II homefront, No Ordinary Time. “The industry that once built 4 million cars a year was now building three fourths of the nation’s aircraft engines, one half of all tanks, and one third of all machine guns.”

The scale of the war effort was astonishing. The physicist Edward Teller tells the story of how Niels Bohr had insisted in 1939 that making a nuclear bomb would take an enormous national effort, one without any precedent. When Bohr came to see the huge Los Alamos facility years later, he said to Teller, “You see, I told you it couldn’t be done without turning the whole country into a factory. You have done just that.” And we did it in under five years.

But of course we had been attacked at Pearl Harbor, the world was at war, and the entire country was united against a common enemy. This made possible tax increases, rationing of items like tires and gasoline, comprehensive wage and price controls, a War Production Board with broad powers (it could mandate what clothing could be made for civilians), and a Controlled Material Plan that set allotments of critical materials (steel, copper, and aluminum) for different contractors.

That is what you are talking about — or should be — not “tax & dividend” and fourth-generation nuclear power. Indeed, you spend way too much time — 2 out of your 8 pages — on nuclear power when it simply is not more important a solution than any other, certainly not more important than, say, concentrated solar thermal, which you mention not at all.

NUCLEAR: The single nuclear wedge requires building 35 nukes a year — roughly 10 times the current production rate, more than 50% higher than the greatest rate the world ever sustained for even a single decade, and far in excess of what current production bottlenecks would allow. Nuclear plant prices in this country have already tripled since 2000 to nearly price themselves out of the market (see “The Self-Limiting Future of Nuclear Power, Part 1“).

Is it now clear why your extended nuclear power discussion is off the mark? You point out that

The common presumption that 4th generation nuclear power will not be ready until 2030 is based on assumption of ‘business-as-usual”. Given high priority, this technology could be ready for deployment in the 2015-2020 time frame.

Sorry, too late. The incomprehensibly fast scale up of low carbon generation we need for 350 ppm leaves no time for such hypotheticals, no time for hoping things get commercialized within 10 years. After all, somebody has to build the massive manufacturing capacity right now, and somebody has to train all of the people needed to build these reactors right now (not to mention training people to run them), and somebody has to contract for all of the relevant raw materials pretty damn soon.

Maybe fourth-generation nukes could be useful in the next set of post-2030 wedges, which is why a major ramp up of R&D remains incredibly valuable. But for getting off of coal in two decades, we gotta go with what we have.

Again, I’m not advocating building 700 nuclear plants over the next 20 years, and certainly agree with the myriad failings of existing commercial nuclear plant designs that you describe. I am merely pointing out what the logical technology and policy implications of your paper is.

RENEWABLES: I am very, very bullish on renewables, but each of these renewable wedges are immense undertakings. For instance, 3000 GW of wind in 20 years, is 150 GW a year. “Last year’s global wind power installations reached a record 20,000 MW, equivalent to 20 large-size 1 GW conventional power plants.” So we’ve got to quickly increase the production capacity by a factor of seven fast and then sustain it. The good news is that wind has been on a very fast ramp up, so this isn’t completely implausible, but the siting, the material, the construction, the transmission, and, the energy storage required to enable the deployment and use of that much wind that fast is simply beyond the capacity of the marketplace to manage on its own.

And the other renewable wedges require an even more challenging ramp up. Solar thermal electric (aka solar baseload power) holds perhaps the most promise of all renewables because it can be integrated with low-cost high-efficiency storage to provide power when it is most needed, because it has no obvious production bottlenecks, and because the United States, China, and India have vast solar resources. The market might plausibly achieve 50 to 100 GW a year of growth, but only after a steady ramp up for the next 5 to 10 years. If you wanted to do that faster, you’d again need the WWII-style approach.

EFFICIENCY: Just one 20-year wedge of efficiency requires, by my rough calculation, every country in the world doing as much efficiency in five years as California did over the last three decades — and then repeating that again, again, and a fourth time. And that is no mean feat, since California had to change its utility regulations, adopt aggressive building codes, train lots of people in every aspect of energy efficiency, and have a very smart, very well-funded Energy Commission pushing, funding, and fine tuning this.

Interestingly, China may be the only country poised to scale efficiency up fast enough, since they did it before. But, of course, they used a government-led effort that is, arguably, near-WWII-style (see “China’s immoral energy policy — Part II: The efficient alternative“).

CONCLUSION: You end your impassioned plea to President-elect Obama:

Frank communication with the public is essential. At present, all around the world, governments are guilty of greenwash, an implausible approach of goals and half-measures that will barely slow the growth of CO2. The world, not just the United States, needs an open honest discussion of what is needed.

I could not agree more. That is precisely why I blog and why why I have written this open letter.

I have no argument with proposing politically unrealistic strategies. Indeed, I have an ongoing multi-part series on just how politically unrealistic stabilizing at 450 ppm currently is (see, most recently, “Is 450 ppm (or less) politically possible? Part 7: The harsh lessons of the financial bailout“). If avoiding catastrophic climate impacts were politically plausible today, both of us would find better things to do with our time.

But the staggering and immediate price shock you propose is more than unrealistic — it just won’t get your job done, as I’ve explained, no matter what tinkering around the edges you do with R&D, building codes, and the like.

I am not entirely convinced that 350 ppm is needed this century from a purely scientific perspective. But I am utterly unconvinced that you have a technology and policy strategy needed to achieve 350 ppm or come anywhere close.

For now, I’ll stick with 450 ppm.

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74 Responses to An open letter to James Hansen on the real truth about stabilizing at 350 ppm

  1. Joe, Kirk Sorensen and I certainly favor a zero carbon approach. We just have chosen a very different, and from our view far more effective approach than renewables in controlling CO2 emissions. You have overlooked what else Jim Hansen said in Tell Barack Obama the Truth – The Whole Truth:
    “Nuclear Power. Some discussion about nuclear power is needed. Fourth generation nuclear power has the potential to provide safe base-load electric power with negligible CO2 emissions.

    There is about a million times more energy available in the nucleus, compared with the chemical energy of molecules exploited in fossil fuel burning. In today’s nuclear (fission) reactors neutrons cause a nucleus to fission, releasing energy as well as additional neutrons that sustain the reaction. The additional neutrons are ‘born’ with a great deal of energy and are called ‘fast’ neutrons. Further reactions are more likely if these neutrons are slowed by collisions with non-absorbing materials, thus becoming ‘thermal’ or slow neutrons.

    All nuclear plants in the United States today are Light Water Reactors (LWRs), using ordinary water (as opposed to ‘heavy water’) to slow the neutrons and cool the reactor. Uranium is the fuel in all of these power plants. One basic problem with this approach is that more than 99% of the uranium fuel ends up ‘unburned’ (not fissioned). In addition to ‘throwing away’ most of the potential energy, the long-lived nuclear wastes (plutonium, americium, curium, etc.) require geologic isolation in repositories such as Yucca Mountain.

    There are two compelling alternatives to address these issues, both of which will be needed in the future. The first is to build reactors that keep the neutrons ‘fast’ during the fission reactions. These fast reactors can completely burn the uranium. Moreover, they can burn existing long-lived nuclear waste, producing a small volume of waste with half-life of only sever decades, thus largely solving the nuclear waste problem.

    The other compelling alternative is to use thorium as the fuel in thermal reactors. Thorium can be used in ways that practically eliminate buildup of long-lived nuclear waste. The United States chose the LWR development path in the 1950s for civilian nuclear power because research and development had already been done by the Navy, and it thus presented the shortest time-to-market of reactor concepts then under consideration. Little emphasis was given to the issues of nuclear waste. The situation today is very different. If nuclear energy is to be used widely to replace coal, in the United States and/or the developing world, issues of waste, safety, and proliferation become paramount.

    Nuclear power plants being built today, or in advanced stages of planning, in the United States, Europe, China and other places, are just improved LWRs. They have simplified operations and added safety features, but they are still fundamentally the same type, produce copious nuclear waste, and continue to be costly. It seems likely that they will only permit nuclear power to continue to play a role comparable to that which it plays now.

    Both fast and thorium reactors were discussed at our 3 November workshop. The Integral Fast Reactor (IFR) concept was developed at the Argonne National Laboratory and it has been built and tested at the Idaho National Laboratory. IFR keeps neutrons “fast” by using liquid sodium metal as a coolant instead of water. It also makes fuel processing easier by using a metallic solid fuel form. IFR can burn existing nuclear waste, making electrical power in the process. All fuel reprocessing is done within the reactor facility (hence the name “integral”) and many enhanced safety features are included and have been tested, such as the ability to shutdown safely under even severe accident scenarios.

    The Liquid-Fluoride Thorium Reactor (LFTR) is a thorium reactor concept that uses a chemically-stable fluoride salt for the medium in which nuclear reactions take place. This fuel form yields flexibility of operation and eliminates the need to fabricate fuel elements. This feature solves most concerns that have prevented thorium from being used in solid-fueled reactors. The fluid fuel in LFTR is also easy to process and to separate useful fission products, both stable and radioactive. LFTR also has the potential to destroy existing nuclear waste, albeit with less efficiency than in a fast reactor such as IFR.

    Both IFR and LFTR operate at low pressure and high temperatures, unlike today’s LWR’s. Operation at low pressures alleviates much of the accident risk with LWR. Higher temperatures enable more of the reactor heat to be converted to electricity (40% in IFR, 50% in LFTR vs 35% in LWR). Both IFR and LFTR have the potential to be air-cooled and to use waste heat for desalinating water.

    Both IFR and LFTR are 100-300 times more fuel efficient than LWRs. In addition to solving the nuclear waste problem, they can operate for several centuries using only uranium and thorium that has already been mined. Thus they eliminate the criticism that mining for nuclear fuel will use fossil fuels and add to the greenhouse effect.

    The Obama campaign, properly in my opinion, opposed the Yucca Mountain nuclear repository. Indeed, there is a far more effective way to use the $25 billion collected from utilities over the past 40 years to deal with waste disposal. This fund should be used to develop fast reactors that eat nuclear waste and thorium reactors to prevent the creation of new long-lived nuclear waste. By law the federal government must take responsibility for existing spent nuclear fuel, so inaction is not an option. Accelerated development of fast and thorium reactors will allow the US to fulfill its obligations to dispose of the nuclear waste, and open up a source of carbon-free energy that can last centuries, even millennia.

    The common presumption that 4th generation nuclear power will not be ready until 2030 is based on assumption of ‘business-as-usual”. Given high priority, this technology could be ready for deployment in the 2015-2020 time frame, thus contributing to the phase-out of coal plants. Even if the United States finds that it can satisfy its electrical energy needs via efficiency and renewable energies, 4th generation nuclear power is probably essential for China and India to achieve clear skies with carbon-free power.”

    Hansen adds
    “Prompt development of safe 4th generation nuclear power is needed to allow energy options for countries such as China and India, and for countries in the West in the likely event that energy efficiency and renewable energies cannot satisfy all energy requirements.

    Deployment of 4th generation nuclear power can be hastened via cooperation with China, India and other countries. It is essential that hardened ‘environmentalists’ not be allowed to delay the R&D on 4th generation nuclear power. Thus it is desirable to avoid appointing to key energy positions persons with a history of opposition to nuclear power development. Of course, deployment of nuclear power is a local option, and some countries or regions may prefer to rely entirely on other energy sources, but opponents of nuclear power should not be allowed to deny that option to everyone.”

    Instead of fighting against safe and low waist nuclear power, you should back it.

  2. Wes Rolley says:

    So much attention on the supply side of energy and so little on the demand side. Much of this could be attained from the built environment if one were to follow the guidance from Architecture 2030. This is not “tinkering around the edges” as you dismiss it.

  3. Joe says:

    Wes — I have 3 full wedges on the demand side. They would be incredible achievements to do in 5 decades, let alone 2.

    I do NOT dismiss efficiency as “tinkering around the edges.” They are the core solution. But traditional government policies like building codes are bit players if you want to shut every coal plant in the world down by 2030.

  4. Joe says:

    Charles — I am publishing your long comment even though it most clearly misstates what I just wrote. Please don’t make a habit of that if you want to be a regular commenter.

    I’m all for R&D into nuclear, as I said. And I’m not even against nuclear been part of the solution now.

    But Hansen (and I guess you and Kirk) are kidding yourself if you think that you can design one of the 20-year wedges that start in 2010 and end in 2030 around a technology that is not even close to being commercial today.

    Hansen’s discussion of 4th generation — and yours and Kirk’s — is simply academic in the crucial first phase of a 350 ppm strategy.

    So next time, read what I wrote for telling me I need to read what other people wrote.

  5. john says:


    Do the math. In the US, for example, the built environment accounts for 40% of GHG — if you were to cut energy use in the BE in half — no mean feat but doable- you’d only get a 20% reduction, assuming you weren’t adding new buildings and loads.

    I believe Dr. Hansen and others want to rely on prices — either through taxes or a cap and trade — because there is still this notion that “the market” can save us without draconian interventions.

    Not sure that was ever true, but if it was that ship’s sailed after 8 years of negligence. The nature of the challenge demands a coherent industrial strategy with an end in mind — and whether that’s 450 or 350 ppm, it’s an undertaking more ambitious than any endeavor in human history.

    We have run an experiment on this price thing.
    Over the last year, we saw a de facto carbon tax in the run-up of gasoline prices and it reached the equivalent of over $400 per ton before consumer behavior was modified and folks drive less and stopped buying SUVs. A price that high is neither politically, nor economically sustainable.

    Cap and trade systems at least have a cap. But price alone won’t do it.

    Finally, I’d argue that the wedges are better than expensive econometric and energy models — models have historically provided false precision, but little or no accuracy. The wedges at least have the advantage of being qualitative and flexible.

  6. G.R.L. Cowan says:

    Hansen often says CO2 dispersed in the atmosphere cannot be removed, but it can. The biggest carbon sequestration demonstration we’ve seen was inadvertent. I recommend a really fat wedge of doing this on purpose.

    Also, boron is a more suitable material to make wedges of than hydrogen.

  7. Many interesting points, and thanks for the careful analysis. It’s worth noting that assuming Hansen et al are right about 350–and anyone would have lost betting against them over the years–we’re going to get shock and awe one way or the other. At the very least, raising the fact that 350 represents a boundary condition for the earth will move the discussion about what to do closer to the science than it’s been so far.

  8. paulm says:

    Can this be a case of not seeing the forest for the trees?
    I think Hansen is trying to expound what he means by a WWII effort. He and a number of other climate scientist are trying their best to show us the reality of the situation.

    A couple of points to ponder:

    1 Does anyone know what the CO2 footprint of implementing each of the different wedge kinds will be? With us being so close to tipping points will these wedges tip us over?

    2 How many/much of a wedge is an extended world wide depression?
    Is a deep world wide depression the only answer now? I think we need to realize that we wont get to a Climate solution with out big time pain and does this mean we will not get to a solution?

  9. Bob Wallace says:

    Most of the wedges seem to involve building things – wind, solar, whatever plants. Some involve changing the way we build things like cars and buildings.

    All this building stuff creates jobs, tax revenues (and wealth).

    We can use this recession we’re now in. Business as usual has stalled. It’s probably easier to change direction from a stopped condition than while charging ahead in a different direction.

    Spend government money to kick start projects that produce clean energy. Get people working and they will pay back those startup funds via their taxes.

    There’s a lot of investment money sitting on the sidelines right now. If the government gets things going there is likely to be a multiplier effect via private money flooding to companies that are showing productivity.

    I think we’re at a unique point in this country’s history. People are anxious to do something to make things better. Most of us are disgusted at what has happened to our country in the last few years and Obama has us fired up about making some changes.

    Today’s news is that Congress will have an economic recovery plan on Obama’s desk on Inauguration Day. I’m betting that Obama’s going to put us to work….

  10. Paul K says:

    Are you rejecting setting a carbon price as a priority in favor of outlawing coal through regulation?

    [JR: No, but the latter can happen faster.]

  11. Peter Wood says:

    How much will we need to reduce emissions per year if we are to stabilize at 350 ppm? Or at 450 ppm? I get global reduction rates of -5.2% for 350 ppm and -2.2% for 450 ppm from Meinshausen et. al. Multi-gas Emissions Pathways to meet Climate Targets, Climatic Change (2006) 75: pp. 151-194.

    Hansen prefers a tax to cap-and-trade, but doesn’t specify what tax level would be required to stabilise at 350 ppm. I don’t know what tax level would be required, and I don’t know what the social cost of carbon is, but I do know the level of the cap that would be required (globally). This is why Stern prefers cap and trade – it is much easier to work out the cap required for a particular target than calculate the social cost of carbon. The hard part is achieving global cooperation – getting developing countries on board would be much easier if high per-capita emitters such as Australia and the US are willing to pay low per-capita emitters for some of their emissions.

    If you are a policy-maker, and 5% or 2% annual reductions is too politically difficult, then consider a price floor. This way people can work towards the possibility of doing better than the target. If emissions reductions are cheaper than expected, then there will be more mitigation. A price floor can be introduced by have a reserve price when auctioning emissions; or could be introduced by having firms pay a fee when they exercise their permits, so the carbon price becomes equal to the permit price plus the exercise price.

    A problem with Hansen’s tax and 100% dividend approach is that too much is left up to the market. Public investment is needed to address many of the market failures, such as poor public transportation networks, and electricity transmission networks. Other economists, such as Garnaut, have suggested a 50% dividend. The rest of the money raised could be invested in addressing these market failures. For several renewable wedges to be feasible, it will require huge public investment in electricity transmission networks – first mover disadvantages mean that leaving it to the market would be very inefficient.

  12. Bill Woods says:

    “Last year’s global wind power installations reached a record 20,000 MW, equivalent to 20 large-size 1 GW conventional power plants.”

    20 GW of wind is equivalent to ~5 GW of conventional power.

  13. jorleh says:

    Don´t be stupid, Joe. You forget the potential energy of the Greenland and Antarctic ice masses.

    There are your wedges. All. Calculate. Don´t be stupid.

  14. Peter Wood says:

    What emissions price would we need to introduce to stabilize at 350 ppm? How likely is it to be of the order of “$1000 a ton starting in 2010″?

    Lets start by looking at a higher stabilization target. In their report The carbon productivity challenge: Curbing climate change and sustaining economic growth, The McKinsey Global Institute estimates that to stabilise at 500 ppm CO2-e, we would need to reduce global emissions in 2030 by 27 Gt CO2-e versus “business as usual” (of 62 Gt) to 35 Gt CO2-e. They estimate that this could be done at a carbon price of less than 40 euro per tonne CO2-e. Note that 27 Gt Co2-e is 7.37 Gt C, or 7.37 wedges.

    Meinshausen’s trajectory for 350 ppm has global emissions in 2030 at roughly 20 Gt Co2-e. This is 15 Gt CO2-e less than McKinsey’s 500 ppm scenario. This suggests reductions of 42 Gt CO2-e (11.46 Gt C) compared to business as usual for 350 ppm in 2030 — 11.46 wedges. This is higher than Joe’s estimate of 8 wedges, and 4.1 wedges more than the McKinsey 500 ppm scenario. I suspect the differences in numbers of wedges for 350 ppm is due to different estimates for “business as usual” emissions.

    It seems incredibly unlikely that 4.1 wedges would lead to an increase in price from 40 euro to over 1000 dollars.

    [JR: I think you may be confusing average prices from marginal prices. $40 a ton does not get you 500 ppm. It gets you 1000 ppm. Just look at Europe.

    IEA says 550 requires $90 a ton of CO2 in 2030 and 450 requires $190 a ton of CO2. Obviously, 350 is proportionally tougher. Remember, you need to shut down existing coal plants in a world where coal prices will be crashing and the cost of the competition will be soaring. And again, you have to render of those coal plants uneconomic to run, not merely a little more expensive to run than siting, financing, building, and operating a new plant.

    Finally, the transport sector is tougher -- IF you are using primarily a price based mechanism.

    Remember the point of this post is to criticize a price-focused strategy.

    Finally, I don't know Meinshausen. Look at Hansen's trajectory. The IPCC says that if we average 5 GtC this century, we probably get 450 ppm. So I think Hansen is right.]

  15. vakibs says:

    Hi Joe

    I am amazed that a scientist like you committed to saving the environment is so mired in dogma. This is the moment, no more time left to waste on baseless fears. I understand the thought of a major ramp up of nuclear power sends shivers down your spines, but this is what is needed in this hour.

    Concentrated solar thermal power is a total joke. I think we should have as much of them as possible, and as permitted by time, but it is clearly impossible to run our world on CST. We just cannot afford the land, water (for cleaning the mirrors), raw materials (iron, copper and so on) to build that monstrosity.. not to mention the investment dollars.

    Wind and solar can chip in, as much as they can. Efficiency should be ramped up, as much as is theoretically possible. They can supply 2 to 3 wedges. Everything else has got to be nuclear. It is as simple as that.

    Being a trained physicist, please take the time to educate yourself on the basics of 4th generation nuclear power (reactors such as IFR and LFTR). Please learn about what has already been done, what technical challenges remain, and how rapidly this technology can be commercialized.

    There are no construction bottlenecks for IFR, like we have currently for PWR. IFRs operate at atmospheric pressure : any industrial foundry can supply pipes and the materials for this. The design of the power plant is also extremely simplified – the passive safety feature of these reactors eliminates the need for active safety equipment. This means lot fewer valves and pumps. Please don’t take my word for it. Check it for yourself on the PRISM reactor design.

    There is no reason why 4th generation nuclear power plants cannot be built on a mass-production scale starting from 2015. Indeed, we can build them for cheaper than the current 2nd and 3rd generation plants. And we can build them in record times (faster than the record 4 years construction time of the ABWRs in Japan).

    All the technology that needs to be demonstrated has been done for IFRs. LFTRs are only a little behind. Prototype plants of these reactors can be built by 2015, and mass deployment can begin straightaway.

    In the end, this is what has to be done for preventing climate tipping points. There is clearly no other solution. We can delay this eventuality by 10 or 20 years so that fossil fuel lords in coal & natural gas industries can squeeze all their profits, but do we need to put the planet in peril for this ?

    Yes, all coal and natural gas power plants can be shut down by 2030. This is what we are going to do.

  16. john says:

    OK, Nuke lovers — here’s the deal. It costs too much and takes too long. And I’ve read this post a couple of times now and I can’t find anywhere where Joe opposes Nukes — in fact, he says they could be a part of the long term solution.

    In terms of time to implement, it works like this — demand response measures can be done in under a year; end use efficiency — under a year; distributed renewables — 1-2 years ; large scale renewable projects 2-5 years; large centralized power plants 7 or more years; nukes — a decade or more.

    If you have to design a 4th generation nuke before starting the siting process, you’re into 20 years or so before the first one goes on line.

    THIS DOESN’T WORK. We need to take action today.

    Taxes don’t work either, because they’d have to be too high. The commitment to taxes is a left-over from the Reagan era — and beloved by conservative economists because it leaves the decisions in the hands of the sanctified free-market. There was a time when we could have taxed the equivalent of external costs and left it to the market to respond, but that time is long gone.

    Finally, paulm, your question about the carbon footprint of the wedges is silly — it’s negative — which is sort of the point …

  17. jorleh says:

    Let´s be honest and admit we have no possibility ever to stop CO2 below 600 ppm and that means not below 1000, 2000 and so on.

    It´s not a WW II task before us, it´s ten or hundreds of them.

    Our wedges are only for fun, where is the action?

  18. john says:


    Water to clean the mirrors? That’s a joke, right? Do you have any idea how much water a Nuke demands?

    CST is not a joke, it’s a vast, proven energy source.

    The one source we are overlooking is geothermal. To date, all the resource assessments of GE have focused on geothermal hot spots — but there is a natural geothermal gradient — indeed, one of the most serious problems the deeper oil wells have is coping with the extreme temperatures they must operate in. At 10,000 or more feet, most of the crystalline rock is above 100C. That’s a lot of energy and it can be tapped with mostly conventional technologies developed for oil — hydrofracking can use a lot of water, but that’s about the only downside.

  19. Emil Möller says:

    imo a focus on technology (including political), as is displayed here, is a part of the problem.

    when we do not address the place from which we operate, the blind spot I dare say, we will continue in tinkering mode.

    this ‘place from which we operate’ is where our drive, commitments, fears, clout, will power resides. Or lack thereof.

    we address presumed actors in positions of presumed power more or less as free, rational, walk the talk enabled best of breeds. Think again.

    at some level all indeed want to be a part of a solution. But overridingly denial rules. Read Cohen’s ‘States of denial’.

    this denial is cloaked and/so the self image remains in tact. When interacting, arguments addressing the blind spot (‘who are you and what is your work on this planet?’) are easily dismissed or at best superficially dealt with

    this is a difference as significant as when your own child is in peril, or not:
    1 ones’s own child in peril: there’s nothing that stops a worried parent
    2 children far away in time and/or space in peril: all (including parents) talk, visit conferences, write and read reports, make compromises, disempower others

    its an existential human quality that we can go from 2 to 1

    going from vicious circle enabling ineffectiveness towards happy soldiers for the common good (which by then is experienced/recognized as one’s own good)

    perhaps Marianne Williamson’s ‘A Return to Love’ can help us here:

    “Our deepest fear is not that we are inadequate. Our deepest fear is that we are powerful beyond measure. It is our light, not our darkness that most frightens us.

    We ask ourselves, Who am I to be brilliant, gorgeous, talented, fabulous? Actually, who are you not to be? You are a child of God. Your playing small does not serve the world.

    There is nothing enlightened about shrinking so that other people won’t feel insecure around you. We are all meant to shine, as children do. We were born to make manifest the glory of God that is within us.

    It’s not just in some of us; it’s in everyone. And as we let our own light shine, we unconsciously give other people permission to do the same. As we are liberated from our own fear, our presence automatically liberates others.”

  20. vakibs says:


    Please.. Joe is not the strongest pro-nuke advocate I have seen so far :)

    All these arguments that nuclear costs too much is devil’s advocacy. There is only one technology that can compete with nuclear (current 2nd generation nuclear) in costs, and that is natural gas. This capital cost advantage for natural gas soon disappears due to astronomical fuel costs.

    So please remember that you are arguing for the devil, when you complain that nuclear costs too much. It costs less than coal, and in any case, it costs much less than wind or solar thermal. In fact, this is a obvious conclusion when you compare its power density to any other technology. The requirements of nuclear on land+ raw materials is much lower than any competitor.

    And nuclear plants can be built to use waste water. And they can be run on air cooling instead of water cooling (as mentioned in the letter of Dr Hansen). One of the strongest arguments for using nuclear power is their potential for using towards water desalination : we are running into a grave fresh-water crisis due to our overpopulation and climate change.

    Geothermal is good, if not for the earthquakes it seems to generate when you drill all those pipes into the fissures. In any case, its energy potential is marginal, as investigated by Dr Mackay in his book (Sustainable energy : without hot air, chapter 16).

  21. Joe,
    Very convincing piece.
    Still, it seems to me that a carbon tax like Hansen’s would have the real benefit of providing revenues that could be used to fund the things that really make a difference…even if it does nothing to reduce coal burning directly.

  22. Joe says:

    Larry — Thanks.

    Don’t get me wrong, though. We very much need a carbon price. The top priority is a power plant emissions standard that blocks coal without 80% CCS. A ramped up price is crucial — a cap&trade for the utility and industrial sector is fine, but it won’t do anything for the transportation sector.

  23. Joe says:


    There is no question I have an over-emphasis on technology, since behavior change is hard to legislate. But as the nation and the world become increasingly desperate about reducing greenhouse gas emissions over the next 10 to 20 years, I don’t have much doubt that conservation broadly defined could easily be another wedge.

    Obviously, we waste a lot of energy in this country. I am planning to do a blog post on this at some point.

  24. Hello,
    With friends in France we have just launched an organisation named TACA, meaning TAxe CArbone and also, in phonetic ‘you just have to ‘ act and cut your carbon emissions.
    We support 350.org and we have just organised a carbon free picnic on a rainy sunday in Bordeaux and we gathered more than 200 bikes for our first rally. Very encouraging.
    Back to your interesting discussion.
    I don’t understand the point about 1000$ par carbon tonne being unrealistic.
    First as we propose with TACA, it is more accurate and ‘human’ to count in kilo: it would be 1$ per kilo. In the metric system a kilo is equal to a liter, when it is water, and this is a good approximation with oil, 1l = 1 carbon kilo (if you include the carbon needed to extract and bring it to your tank, and so on).
    A carbon tax of 1$ per kilo is just the target we propose with TACA (and even it is 1€ per kilo). we think a 10 years ramp up would be fine for the industry to adapt its offer and its organisation.
    In agreement with Hansen a great part of this tax will be yearly reimbursed on an equal basis per individual. With such a mechanism, I really don’t understand where is the social price of such a tax. Clearly it will cost a lot to the people throwing a lot of carbon (professional flying around the world or from coast to coast), but it will be break even for the low middle class and even a source of revenu for the poorest.
    I agree, it is a huge change, but it is what is needed to change our way of living and to drastically reduce our carbon consumption. In France we have to divide by 4 our carbon consumption. For the US people it may be a division par 6 or even more.
    This is a huge political move, but the administrative organisation of this tax is very simple. In France it would be the equivalent of the existing TIPP (Taxe d’Importation des Produits Petroliers), and I am sure that you have somehow copied us because we in france, are the smartest in the world about tax (or this is the classical song we hear in the US newspapers).
    I hope my broken inglish is undertandable and that we will have good discussions on this extremly important topic.

  25. Dear James Hansen,

    Keep going. Thanks for telling the truth as you see it and for speaking out loudly, clearly and often about what everyone knows but precious few will say.

    As you know better than most of us, “denial” is not only a river in Egypt. However we choose to look at the taxonomy of denial, you help us easily see that many too many leaders are collusively engaged in its practice. Even though it is perverse, denial is consensually validated behavior. If enough elite people remain in denial, something more attractive…ie, something illusory…can be put in place of what is more real and somehow likely to be more truthful.

    Doing good work along the path toward a good enough future for children will not be an easy task for anybody. Evidently, everybody wants to be a somebody, but nobody in a position of power willingly assumes the requisite responsibilities and performs the duties of office. Such so-called ‘leadership’ is both ubiquitous and woefully inadequate.

    Occasionally a great person like you can be found who goes against the tide of people with power…who disputes the elitists, the ones uniformly favoring whatsoever is politically convenient, economically expedient, socially agreeable and religiously tolerated.

    Certainly I share the view that everyone-in-power’s silence with regard to what is happening in any “here and now” moment of space-time is the most formidable foe that the family of humanity faces.



    Steven Earl Salmony
    AWAREness Campaign on The Human Population,
    established 2001

  26. Ronald says:

    We go thru in our minds the huge area and amounts of material;steel, mirror glass, etc. that would be needed for Concentrated Solar Power (CSP) or what this website calls Solar Baseload, but we don’t have a good measure of the amount of materials that is needed on a macro scale. Except indirectly with the price of electricity.

    I’m suggesting we need a measurement system. State how much material; steel, mirror glass, etc. is needed to build CSP’s that would supply 100% of the electricity the US produces in a year.

    We would then have some idea of how much material is needed. If the number is high, like the amount of steel needed for CSP is the equivalent of 10 years of steel production to supply 100 % of US electricity production, we do have a problem with the steel material to build enough of these CSP’s. If the number is low, like 1 percent of a years US steel production builds enough CSP’s for 100 % of US electricity consumption, it might work.

    We do somewhat the same thing with the area needed for CSP. I’ve seen estimates that we would need the area of square 92 miles by 92 miles to produce 100 % of the US consumption of electricity, which is doable. (knowing it would not be put all in one place)

    The same could be done with wind turbines and the electrical transmission lines, even nuclear plants.

    Some of these comparisons would have to be adjusted to costs as example, Nuclear uses much more expensive steel.

  27. Bob Wallace says:

    A good idea Ronald, but…

    When you say “CSP” I assume you mean thermal solar. CSP could not provide 100% of our power unless we built massive amounts of energy storage to carry us through the dark hours.

    Right now wind is the least expensive way to create new electricity generation. Thin-film solar is likely to move into the same price range.

    Geothermal is looking very promising and should be similar to thermal solar in price per kWh.

    We’re likely to go with a mix of least expensive along with most reliable to fill our grids. Prices are likely to adjust as demand for concrete, steel, aluminum, etc. rise and fall.

  28. For an analysis of the materials and land costs of the various alternatives I recommend the work of Mark Jacobson at Stanford:


    His focus here is on the replacement of petroleum use with renewably generated electricity. However his methodology and findings could be generalized in a comparative way to using wind or solar thermal electric to energize the grid for any use.

    I find his work very encouraging, especially if we can get the right policy instruments and political and financial support for New Deal/ WWII scale infrastructure investment.

  29. Bill E says:

    What about using algae to filter the carbon emissions from coal, and turning it into biofuel? It appears to work, is less costly, and while burning the biofuel releases carbon, it releases no more than existing fossil fuels that it would displace. Meanwhile, the electricity from burning the coal is then carbon-emission free.
    As a short term solution, it appears to make sense and be achievable near-term.
    What do you think?

  30. hapa says:

    @Bill E:

    1. the algae wouldn’t capture all the CO2.

    2. that would extend our dependence on coal. better to bolt infrastructure like that onto cleaner power plants like natural gas and biomass, or dirtier process heat facilities, that have a longer future among us.

    3. electrifying transportation looks like a better public investment.

  31. Joe says:

    I need to do a long algae post. Like all biomass, algae is an inefficient means of converting sunlight to usable energy. The basic question for algae — as for any biomass — is do you have something that minimizes the need for arable land and potable water. The CO2 source is almost irrelevant, except to the extent that the algae might thrive on the high CO2 environment. The DOE abandoned its algae program in the mid-19 90s when I was there — although I had nothing to do with that decision. So far I haven’t seen anything scalable.

  32. Emil Möller says:

    @ Joe

    when you say

    There is no question I have an over-emphasis on technology, since behavior change is hard to legislate.

    you imply that sheer application of legislation will deliver solutions. As part of a mix I agree. But in itself it will not do.

    it will take minds, hearts and hands of all stakeholders to make legislation effective. Moreover, since what is succesful in the applicable domain, should be inherently infective to other domains. What Khosla names ‘the Chindra criterium’: will it be effective, take root & scale in developing areas like China and India?

    imo this addresses our quest for large scale & fast decarbonization significantly more effective. A technological, legal or what have you sort of exterior approach alone will be at the mercy of underlying dynamics. Succes will come and go, as in hit and run.

    we collectively suffer from a underlying distrust and unwillingness to face that rational, external perspectives will not deliver what we need. That’s understandable, given the course we’ve taken as a Western society.

    overridingly I see our carbon & related predicament as a not so subtle invitation to acknowledge the limitations of our rational faculty. We have to supplement it with, let it be guided by wisdom. Which is built in every one of us, but must be discovered with appropriate means. Any means that delivers ‘know thyself’. Clues abound.

    But as the nation and the world become increasingly desperate about reducing greenhouse gas emissions over the next 10 to 20 years, I don’t have much doubt that conservation broadly defined could easily be another wedge.

    Obviously, we waste a lot of energy in this country. I am planning to do a blog post on this at some point.

    our so desperately sought wedges will become a matter of honour, where minimal legislation will deliver and spill over effects will be enjoyed by all. Wasteful lifestyles will be recognized as not honorable and will thus disappear.

  33. David B. Benson says:

    JOe Romm — You (and James Hansen) should seriously consider enhanced carbonate formation. G.R.L. Cowan found a useful paper about it, so my list now extends to these four:

    Olivine weathering:


    Peridotite weathering:


    Mine tailings:


    for which I estimate a cost for no more than about $40 perr tonne of CO2 removed (permanently). That’s (44/12)x40 = $146.7 per tonne of carbon. For 60% carbon bituminous coal, that’s a tax of $88 per tonne of coal on top of the current Central Applachian mine-head price of arond $140 per tonne.

    Carbonate formation, weathering, is completely natural and no further research is required, onlly development. There is vastly more than enough readily minable olivine or peridotite to remove all the excess carbon from the active carbon cycle, about 500 GtC. So this method can be as many wedges as are required. For example, to remove the 10 GtC added to the active carbon cycle in 2007 CE would require no more than $1.467 trillion out of a gross world product of about $67 trillion. (And possibly as little as one quarter of that.)

  34. Dan Borroff says:

    Michael Hoexter;

    The link for Mark Jacobson’s PDF is no longer current. Do you have a link that’s up to date?


    P.S. I did find an I-tunes site for his lecture on Oct. 1st this year. Woods Institute series. Not sure if his lecture is available because it seems to be highlighted in red…

  35. Dan Borroff says:

    Michael Hoexter;

    False alarm.

    Tried the link again and it worked.



    P.S. The I-Tunes are not current for Fall 2008 lectures, yet – at least not for non-Stanford students, faculty, or alumni.

  36. mitchell porter says:

    Joe, I believe you are misinterpreting that diagram. Those are not emissions *targets*, they are historic and projected emissions from oil and gas (not coal), with the two future scenarios deriving from two estimates of the size of remaining reserves, an “IPCC estimate” and an EIA estimate. Hansen always says that he thinks all the oil and gas will get used up – the most he advocates there is a freeze on further exploration. The only target he does set is for coal: zero emissions by 2030, whether through CCS or just by keeping it in the ground.

    But I’m glad to see you tackle this problem. In mid-year the IEA produced its multi-wedge scenario for maintaining 3% global economic growth (i.e. for avoiding global recession, as defined by the IMF) while aiming at 450ppm. They would have imposed these constraints on their economic models and then said, what levels of investment, technical progress, etc are required to satisfy them. The headline answer was, an extra $1 trillion of global expenditure per year, compared to their baseline scenario (which requires multi-trillion-dollar annual expenditures anyway, just to meet development needs). I’d like to see that exercise repeated with the 350 ppm target. One suspects that the levels of expenditure required are astronomical – in effect, that every spare penny would have to be spent on new energy. But it would still be better to know. We need to have that first quantitative analysis before we can think about how to improve on it.

  37. David B. Benson says:

    mitchell porter — See my previous comment here. About $1 trillion ought to be enoough to stabilize simply by removing the excess carbon dioxide. Any such enhanced cabonate formation above this level then moves us back down towards more desirable levels of CO2, the more $$ the faster we arrive at any given lower level.

  38. Joe says:

    Mitchell — I’m not misinterpreting the diagram I am reinterpreting it, since I think Hansen et al don’t explain it correctly.

    I am aware that Hansen thinks all the “conventional” oil and gas will be used up AND that government policy can stop all coal use by 2030 AND that government policy can stop all major unconventional oil and gas development.

    That multiple wishful thinking is hardly the basis on which humanity can hang its future. Thus I am reinterpreting the diagram as targets that need to be achieved through government policy, which, in fact, they are. The only way that you could plausibly stop all major unconventional oil and gas development is to provide alternatives.

    I really didn’t want to get into this, but Hanson’s entire vision is a muddle of things he thinks can only be solved with alternatives and things he thinks can be solved by fiat, but he bizarrely refuses to intermingle the two.

    Rather than making that mistake, I treat the figure as the targets they really are in that they only happen with strong government policy, i.e. the wedges or their equivalent.

  39. It would have helped put Joe Romm’s criticisms in better perspective if he had indicated that Jim Hansen’s “Tell Barack Obama The Truth – The Whole Truth” is in draft form; where he explicitly requests readers to make criticisms that might improve his arguments.

    The main thrusts in Jim’s draft are sound, and if understood by the President Elect, might promise that executive policy-making related to AGW, will hereafter be quite serious – and near the mark.

    That’s not to say that Hansen (or Joe Romm or bloggers above) have covered all the bases:

    I have 2 publications in the pipe at Climatic Change; (Joe Romm has seen an early draft of one).

    In one, I. Aleinov and D. Rind (both from GISS) and I show that planting the Sahara and Australian Outback with evergreen forests, irrigated with reverse osmosis desalinated sea water, would ramp up to a steady-state capture of about 8 Gt of carbon/yr (8 WEDGES/yr!). We show that the cost to capture the CO2 emitted per gallon of gas (or barrel of oil) would be quite tolerable – and the CO2 footprint would be small.

    In the second, I show that careful and prompt harvest of trunks of recently fallen trees in old-growth tropical forests (trees which otherwise would decay) could ‘forever’ provide about 1 to 5 Gt carbon/yr – 1 to 5 additional WEDGES/yr! (whether stored or burned to replace coal in existing power plants) with a small CO2 footprint (related to the difference in fuel consumption for the increased transportation of that wood – compared to the usually more local coal it replaces).

    As the seriousness of the AGW problem comes to be more generally appreciated, new technology and new understanding will almost certainly provide even more options. But as both Jim Hansen and Joe Romm emphasize, the time to act may already have passed!

  40. Mel Harte says:

    Hi Joe,

    John and I met you at Art Rosenfeld’s a year or so back. In that time, we have written a READABLE book for the public that answers your plea for a tech and policy plan to reduce current carbon emissions by 75% by the year 2030. It is available as a free download at:


    Would like your feedback! We hope you read it and spread the word! We, too, wonder if we are “too late” to avoid catastrophe… but then my brother reminds me that in the third act of Wagner’s Ring, the Norse gods go into their final battle, knowing they will be destroyed — but into it they go! We can do no less for our children….

  41. mitchell porter says:

    Joe, thanks for your reply, a few more comments. On this blog, you’ve now provided a target-450 plan and even the first twenty years of a target-350 plan, expressed in terms of global “wedges”. Meanwhile, we are clearly entering an era of action; the governments of the world are busy with economic plans (the G-20 plan, China’s stimulus plan, and Obama’s economic recovery plan come to mind), and we’re just a year away from the Copenhagen climate conference. We need to start figuring out what these wedges might look like, when implemented as actions by the polities and economies we already have; what opportunities for progress exist in the current economic crisis management; and what form a helpful post-Kyoto regime would take. The best concrete suggestion I’ve seen is on page 133 of ETP2008, where the IEA calls for a new international agreement on energy technologies, and volunteers itself to play the role of clearing-house and monitor.

    I think we also need greater clarity on where and when these wedges would be implemented, geographically. The majority of the growth in demand will occur in the developing world. The majority of that growth in demand will occur whether or not we care about climate. So a large part of the problem is really about ensuring that energy development outside the West is carried out using low-carbon technologies. Yet the majority of climate activism and new-energy politics is taking place inside the West. Certainly, if the US and Europe can decarbonize their energy systems, that will make it much likelier that the rest of the world will also be able to develop in a low-emissions way. But there must be things we can do now to facilitate that longer-term process.

    David Benson, I for one am interested to see whether some form of air-capture sequestration industry can contribute a mitigation wedge or two, or ten. You say there is more than enough olivine or peroditite to capture all the excess carbon; could you offer a source for that?

  42. vakibs says:

    [JR: I am deleting most of this post since it rather bizarrely misstates over and over again what I just wrote. One example will suffice.]

    You don’t want to get into details about 4th generation nuclear power, but just dismiss it as pipe dream ? You don’t want to get into details about why nuclear power should be more expensive than wind power, but say it is so. Very good, Dr. Romm.

    [JR: Anybody who actually read my post would see that I do not dismiss a fourth-generation nuclear power as a pipe dream. Indeed, I have already responded to commenters who willfully misstate my position. One last time: Hansen says we need to shut down every coal plant by 2030. Even one wedge of nuclear is 700 plants built from now through then. That staggering scale up simply leaves no time whatsoever for technology that is not commercial today. I would say "duh" but this obvious fact is apparently utterly lost on nuclear ideologues. I clearly say that we should pursue R&D into next-generation nuclear power since it might be part of the 10 or so wedges needed from 2030 to 2060.

    I have provided extended "details about why nuclear power should be more expensive than windpower" in the links in my post. And those links discussed many independent sources that make the same point, include the major California for the California Air Resources Board. The fact that you refuse to go to those links is but one more reason why your comments are going to have to be moderated from now on.

    I simply don't have time to waste on people who willfully misstate what everyone else can clearly see I wrote, nor do I have time to waste on people who refuse to go to the links that I provide. Obviously no one who blogs can possibly read post everything relevant that they have written about a subject in every post. That's what links are for. Try them some time.]

  43. vakibs says:


    Please give me references for your quote on why you believe 4th generation nuclear power cannot be done earlier to 2030. Just because it is not commercially available today (this due to a monumental mistake by the Clinton administration), has no rapport to why it cannot make a difference earlier.

    I will do a service and point you to two references on how rapidly we can expect nuclear breeder reactors to make a difference. I hope you have the courtesy of posting my comment in entirety :)

    Here is a study of how rapidly the world can convert to breeder reactors of the integral fast reactor type (GE’s S-PRISM “commerical” design).

    Here is a similar study of how rapidly the world can convert to breeder reactors of molten salt reactor type (similar to the LFTR design).

    The reasons why the scientists in these two studies are optimistic is because these new reactor types have no construction bottlenecks (because they operate at atmospheric pressure) and they have no fuel bottlenecks (they use up existing nuclear waste !)

    I am commenting on your blog to have a dialogue with you, and not to get some cheap publicity. I hope you respect my intentions.

    [JR: What does it "can't be done" mean? Could we have some reactors up and running? Sure. Could we have 700,000 MW by 2030? Gimme a break. Nobody does a study to prove the wildly impractical. I can't read the PDF of your second study and if I'm reading your first study right, then in 25 years we could have 38,000 MWe. Wonderful. Not going to make a lick of difference in getting to Hansen's 350 ppm, though.]

  44. paulm says:

    As I mention in my previous post here,
    we are not going to make it unless we move to depression economics. I think serious climate debaters are now realizing this. Look at some of the figures George Monbiot relayed in his article below…

    The planet is now so vandalised that only total energy renewal can save us

    It may be too late. But without radical action, we will be the generation that saved the banks and let the biosphere collapse
    George Monbiot

    Delivering a high chance of preventing two degrees of warming would mean cutting global emissions by more than 8% a year.

    Is this possible? Is this acceptable? The Tyndall paper points out that annual emission cuts greater than 1% have “been associated only with economic recession or upheaval”. When the Soviet Union collapsed, emissions fell by some 5% a year. But you can answer these questions only by considering the alternatives. The trajectory both Barack Obama and Gordon Brown have proposed – an 80% cut by 2050 – means reducing emissions by an average of 2% a year. This programme, the figures in the Tyndall paper suggest, is likely to commit the world to at least four or five degrees of warming, which means the likely collapse of human civilisation across much of the planet. Is this acceptable?

    As you can see they are pretty startling. But not really, we all have a level of denial and ignorance at the level of effort and sacrifice which is needed. And this is not entirely our fault things are just escalating way faster than our reflex for adaptation is.

    My worry about the energy and CO2 footprint to actively implement green solutions is real and others are considering this…from the same article….

    The costs of a total energy replacement and conservation plan would be astronomical, the speed improbable. But the governments of the rich nations have already deployed a scheme like this for another purpose. A survey by the broadcasting network CNBC suggests that the US federal government has now spent $4.2 trillion in response to the financial crisis, more than the total spending on the second world war when adjusted for inflation. Do we want to be remembered as the generation that saved the banks and let the biosphere collapse?

    This approach is challenged by the American thinker Sharon Astyk. In an interesting new essay, she points out that replacing the world’s energy infrastructure involves “an enormous front-load of fossil fuels”, which are required to manufacture wind turbines, electric cars, new grid connections, insulation and all the rest. This could push us past the climate tipping point. Instead, she proposes, we must ask people “to make short term, radical sacrifices”, cutting our energy consumption by 50%, with little technological assistance, in five years.

    This is bad news. But it is the only way forward. We have to some how Manage a deep economic depression in a way that ensures our reduced CO2 levels and then emerge from it as a more sustainable society and civilization.

    [JR: Almost. I can't argue with most of what is in Monbiot's column. Indeed, I have been saying it for a couple of years now. But the WWII-style approach I described is eminently doable -- and while it would incur a short-term increase in industrial activity, that is no reason not to do it. A deep economic depression won't help solve the problem, but a WWII-style effort could avoid the depression in the first place.]

  45. G.R.L. Cowan says:

    You say there is more than enough olivine or peroditite to capture all the excess carbon; could you offer a source for that?

    Peridot is another word for olivine. Peridotite — try dragging the mouse over text to copy it, or moving the text-entry cursor through it with the shift key held down — is an olivine-rich rock. Dunite is another olivine-rich rock type, or maybe another name for the same thing.

    When their names are spelled right, you can look these rocks up.

    — G.R.L. Cowan (‘How fire can be tamed’)

  46. Tom Blees says:


    There’s an awful lot said here with little real knowledge behind it, both from you and some of your commenters. Your contention that 4th generation nuclear can’t be deployed quickly enough to make a difference….

    [JR: Stop. Stop. Stop. You nuclear ideologues either need to read my posts or stop commenting. Possibly both. Honestly, you guys are more rigid than the deniers, who at least occasionally read what I say. Come back after you've read my posts and links.]

  47. David B. Benson says:

    mitchell porter — See


    and references 7, 8 and 9 therein.

  48. Over here in Wales, UK, the green shoots of change are starting to grow again after a couple of bad winters. We have a Minster for Environment, Sustainability and Housing (Jane Davidson) who is passionate about addressing climate change issues through policy, and most encouragingly, now have our first couple of public sector organisations looking at the implications of a dramatic (9% per annum) reduction in CO2 emissions on their day to day operations, along with the 5-10% a year reduction in oil dependency that may be needed with an uncomfortably fast back curve to peak oil. It’s also good to see at least some of the right questions being asked at Cabinet level in local and national government – finding and verbalising the ideas of how policy and practice can be delivered is going to be key before we can get a majority of people signed up.

  49. David B. Benson says:

    Here is a link to a Micael Tobis post about peridotite. It contains a link to the informative Tech News article about the ideas.


    If this works even a tenth as well as they estimate, it is still an unbelievably inexpensive way to remove unwanted caron dioxide; think pennies per tonne…

  50. David B. Benson says:

    carbon, not ‘caron’

  51. paulm says:

    360 would have been a much more rOunded figure, but a little more gimmicky.

    Whats 10ppm here or there.

  52. Joe,

    Thanks for this interesting and thought-provoking post. You conclude by saying:

    “I am not entirely convinced that 350 ppm is needed this century from a purely scientific perspective. … For now, I’ll stick with 450 ppm.”

    I agree with Hansen on the need to stabilise at 350 ppm, although I would use 350 carbon dioxide equivalents (CO2e), rather than 350 ppm CO2 to reflect what the IPCC says is needed to stabilise at a 1°C rise in mean global temperature: http://www.climateshifts.org/?p=683

    In my view, stabilisation at 350 ppm CO2e is what the science indicates is needed to protect our most vulnerable ecosystems, such as coral reefs. Levels above this represent “dangerous climate change” in terms of Article 2 of the UNFCCC: http://cmsdata.iucn.org/downloads/cel_op_mcgrath.pdf

    Whether it is technologically or economically feasible to return to 350
    ppm CO2e and stabilise the mean global temperature at 1°C or less should not be determiniative of whether we set it as our policy objective.

    Policy-makers should set targets based on what we want to achieve. We should not accept targets that will produce unacceptable outcomes.

    To illustrate this point: if we want to build a bridge across a river that is a mile wide we would not ask our engineers and scientists to build us a bridge that was half-a-mile long.

    We should apply the same logic to climate change policy and set targets for our engineers and scientists to achieve that produce results that we want to achieve. Your logic on aiming at 450 ppm seems like aiming to build half a bridge to me.

    Loss of coral reefs, such as Australia’s Great Barrier Reef, is not an acceptable policy outcome and policies that contemplate allowing its loss are akin to lunacy. The current economic debate on climate change is surreal in this regard: http://www.envlaw.com.au/surreal_debate.pdf

  53. Fergus Mclean says:

    As I understand it, 2% of biospheric CO2 is in the atmosphere, 3% in the soil, 1% in plant tissue. The rest is in the ocean.

    A century of fossil fuel-based agricultural practices and industrial forestry have driven immense amounts of carbon out of the soil and into the atmosphere. Soil carbon preserves water, enhances fertility and reduces the need for (fossil fuel-based) pesticides and fertilizers. The soil has the capacity to absorb an enormous amount of carbon, both in mineral form and in the form of the bodies of living organisms. Biochar- carbonaceous material combusted in a low oxygen environment- sequesters half of biological carbon and is stable for many hundreds of years.

    Let’s create incentives for returning carbon to the soil, like a tax credit or a market for sequestration based on accurate measurement of enhanced soil carbon (unlike the arbitrary no-till credits traded on the Chicago Climate Exchange). Dr Chad Kruger is doing this work at Washington State University.

  54. David Lewis says:

    That’s quite an argument you’ve got there. Because the best climatologist in the world can’t spell out, to your satisfaction, exactly what POLICY would achieve what his SCIENTIFIC studies indicate is necessary, you’ll reject the science.

    No one is saying Hansen is the best policy person in the world. I read his recommendations, and what I see is a person anxious to see a solution to the urgent problem his scientific studies have uncovered. I don’t find myself convinced that his policy prescriptions are the best that will ever be found, but I am convinced that Hansen is on very sound ground when he says what 450 ppm means. He’s studied historical records, and found that when there is 450 ppm CO2 in the air, there is no ice at the poles.

    Can you explain why your rejection of the best science is different than the rejection of science employed by global warming deniers? Can you explain why calling for implementing a global disaster, i.e. handing our descendants a planet committed to no ice at the poles, is a solution to global warming?

    You are losing whatever rationale you ever had to do the work you are doing. Your best move is to get out of it, stop writing for a while until you figure out who you are and what you are trying to accomplish.

    Do you realize that you are calling for implementing a global disaster?

  55. I am quite disapointed not to get any response to my mail on 24 november that contains some fresh ideas to go forward.
    I thought the boycot of french ideas was over now.

  56. G.R.L. Cowan says:

    Perhaps some behind-the-scenes reaction is occurring.

    What sort of response would you have liked to see here? Do a little keyboard acting, please. Type a couple of quotations marks — “” — then back up and play the responder between them.

    — G.R.L. Cowan (How fire can be tamed)

  57. Follow up with Cowan
    The fresh idea from TACA (http://taca.asso-web.com/) is the following:
    I don’t understand the point about 1000$ par carbon tonne being unrealistic.
    First as we propose with TACA, it is more accurate and ‘human’ to count in kilo: it would be 1$ per kilo. In the metric system a kilo is equal to a liter, when it is water, and this is a good approximation with oil, 1l = 1 carbon kilo (if you include the carbon needed to extract and bring it to your tank, and so on).
    A carbon tax of 1$ per kilo is just the target we propose with TACA (and even it is 1€ per kilo). we think a 10 years ramp up would be fine for the industry to adapt its offer and its organisation.
    In agreement with Hansen a great part of this tax will be yearly reimbursed on an equal basis per individual. With such a mechanism, I really don’t understand where is the social price of such a tax. Clearly it will cost a lot to the people throwing a lot of carbon (professional flying around the world or from coast to coast), but it will be break even for the low middle class and even a source of revenu for the poorest.
    I agree, it is a huge change, but it is what is needed to change our way of living and to drastically reduce our carbon consumption. In France we have to divide by 4 our carbon consumption. For the US people it may be a division par 6 or even more.
    This kind of huge effeort must be driven by financial drivers, wishfull thinking will not be enough.

  58. Shoshin says:

    Utter crap. 350 ppm? 400 ppm? A waste of time and breath even discussing this political manifesto. Eco-romantic dreams and breathless anticipation of an awaiting apocalypse aside, the planet is not warming, it is cooling. You people should look for other work.

  59. Peter Wood says:


    Thanks for your comments. To clarify, the McKinsey scenario is based on a marginal price of $40 per tonne by 2030. Their report has an estimated cost curve, which contains different ‘blocks’ each of which provides a certain amount of abatement at a particular cost. All of their abatement is based on activities that cost $40 or less. Their average is much lower than that due to a large amount of forms of abatement such as energy efficiency and better buildings, which have significant negative costs. This illustrates why a purely price driven approach (e.g. 100% dividend) is inefficient, because the market failures are so significant.

    I haven’t had a detailed look at the IEA figures and only have access to their executive summary (for the World Energy Outlook 2008). The costs of climate mitigation is a big uncertainty at the moment, I don’t know if McKinsey or the IEA is more likely to be correct.

    I agree with you on the transport sector requiring more than a price based mechanism. I would also add that land use and agriculture emissions would be very difficult to address with a primarily price based mechanism; and would be even harder to address with a cap-and-trade approach.

    It is worth noting that it is possible to estimate wedges from McKinsey’s approach. They have about 3 wedges of energy efficiency, better buildings, and things like ‘industrial motor systems’ and ‘industrial feedstock substitution’. They also had about 2 wedges of land use and agriculture related activities.

    Meinshausen’s work attempts to work out trajectories by looking at all greenhouse gases. I’m not sure which trajectory you mean when you refer to Hansen’s trajectory, the only one I am aware of is Fig 6 from Target CO2, that refers to emissions if we were to phase out coal by 2030.

    I think 350 ppm is what we should aim for because of Hansen’s work that suggests that climate sensitivity is somewhere around 6 degrees C, and because of Weitzman’s work that suggests that we cannot ignore the ‘fat tails’ in parameters around climate sensitivity. We cannot afford to ignore small probabilities of climate sensitivity being even higher than 6 degrees, e.g. 10 degrees. Even if the probability of climate sensitivity being 6 degrees was small, the catastrophic impacts of such a possibility would suggest that the expected cost of not stabilizing at 350 ppm is higher than the expected cost of stabilizing at 350 ppm.

  60. cliff says:

    joe, I feel for ya, man… There sure are a lot of idiots commenting here. (ie. how long does it take to get permits and approval for 1 nuke plant let alone for hundreds of some new design that may or may not be feasible at some time in the future.)

    keep up the good work!

    oh and it is very possible to be neutral even with older tech, see the maine solar house – http://www.solarhouse.com/

  61. mwildfire says:

    I don’t have the knowledge to evaluate either the economic or the technical claims made by Hansen, Romm or the subsequent commenters. But it’s an interesting discussion–interesting notably for the suggestion that there may actually be an acceptable form of nuclear power out there, eventually–something I had not been aware of.
    But I have an ugly remark to make. There is just one method of drastically and rapidly reducing anthropogenic greenhouse gases that is truly likely to work–a dramatic slashing of the human population. Reduction is inevitable soon anyway–even if we transitioned to entirely renewable energy, we’re straining beyond the bounds of what the planet can support, and continuing to increase our numbers like insects. In theory, we could achieve a slow and gentle reduction, without premature human deaths–while rapidly transitioning to whichever of the various discussed methods of replacing polluting energy sources and sequestering existing GHGm the experts end up choosing. Theoretically we could do all that. An immediate end to warfare would free up enormous resources. But in reality…it ain’t gonna happen. Whereas my hideous proposal has only this to recommend it–it almost certainly will happen, either before or after we emit enough GHG to drastically alter this pretty, luxurious planet we inherited but will not pass on.
    Pessimistic, yeah. I’d love to believe humans are not just larger insects, that we can see ahead and make rational choices for the good of all, for the long term. Some of us can–it seems that collective decision-making just doesn’t work beyond small groups, and that’s the fatal flaw that dooms us and the creatures unlucky enough to share our place and time.

  62. Larry says:

    Great source of (to me new ideas) esp the peroditite sequestration. I’m glad to see people talking in wedges – it gives us a common unit of account, which has been sorely missing.

    What bums me is the complete lack of consensus on the path out of the wilderness. It’s as though each poster has his own concept, and is completely unable to list the others behind their ideas. Is that because of poor accounting rules? Because the IPCC hasn’t spoken (“here’s our best assessment of where the wedges should come from and how much that will cost?”)

    Finally, I’d like to see taxpayer money going to try out the energy tower, polywell fusion, ocean fertilization, carbon capture, algae, etc., rather than to throw billions at scaling up what’s already out there, which we already know ain’t great.

    What I see likely to happen is that a great deal of money is going to get spent/invested, we won’t hit any of the targets, and as a result we will (ala Lomborg) end up shifting the warming graph to the right by something like 20 minutes over the next 100 years. And I’m not even a “denier”!

  63. Sully says:

    You take as a given that market or tax based solutions would not work because they would be politically infeasible.

    If those are politically infeasible I wish you good luck when you try to pass legislation to allocate WW2 levels of spending toward this project for decades.

    Why not push for something clearly doable as a first step. For instance, there is no way that consumer gasoline prices should have been allowed to drop from $4 as they have, and they should not be allowed to continue dropping. The very first thing to do is to slap on a 50 cent tax per gallon and include a proviso that the tax will grow steadily for the indefinite future so people and businesses can very clearly see the need to move toward more efficient vehicles.

    If we can’t politically do that we may as well all get used to the idea of warmer temperatures.

  64. Of course Sully is right. The carbon tax (with the dividend to help poor and middle income people) is the single major policy decision to take.
    Today the oil barrel is close to 40$: how do you want the people to choose low carbon solutions or products if they are é or 3 times more expensive than oil based solution or products.
    We have to put a price on carbon, right now in the weterne countries that are the major CO2 polluters and the first one to cut their CO2 emissions.
    Joe, please, give us an answer; if not, I will not ask Santa Claus to send me your book.

  65. Larry says:

    @Sully, @Jean

    The economy is visibly shrinking, and noone can yet see the bottom. We’re about to get a look at a world in which we consume a lot less, and as one consequence, emit less C02. Let’s see how we like it.

    The US auto industry may be done anyway, but a significant carbon tax now would surely finish it off, and quick. I’m not ready to speed its death. Now is not the time for a carbon tax.

  66. Ronald W. says:

    I’m new at this commenting activity, but I just spent several hours reading. I’m puzzled by the absence of any comment on population control. Has this issue somehow been settled? I would expect at least one wedge from population control.

    Shouldn’t there be at least one wedge from carbon sequestration? Not capture from power plant stacks, which seems to me to be futile, but charring and burying fallen trees or even felling and replanting trees. There are undoubtedly ways of sequestering without charring that would keep the carbon out of the atmosphere for long periods of time.

  67. Sully says:

    If the Iranians get a bomb and delivery systems and credibly threaten or launch on the Israelis we may get a population reduction wedge, and perhaps another wedge from sheer unavailability of oil from a big swath of current production territory. But maybe that wasn’t the kind of population control you were talking about.

    My point is that people had perforce gotten adapted to $4/gal gasoline. If we can’t act to hold the effective price that high then there is no hope of acting on the kind of massive program advocated here to hold CO2 to 350 or 450 level.
    I think the new administration and congress will follow your thought process, which will prove my point, so we only have a few months to wait for an answer.

  68. Of course I completly agree with Sully. Oil et 40$ a barrel is the perfect time to start a carbon tax.
    Today oil is getting too cheap versus clean energy. The carbon tax is the smart solution to ise the price of the carbon based energy and to get money available to invest in clea energy.
    For french readers, read our experimental web site:

  69. What I find most fascinating about this discussion are the options not considered.

    Over the past 30-40 years we have globally moved billions from the countryside where they had more or less sustainable lives to the global urban slums where they are dependent upon fossil-fuel intensive industrial agriculture and an economy based upon globalized, transportation intensive trade.

    That same sort of decision is replicated time and time again in the choices we make about economic organization.

    How many wedges from re-ruralization? How many wedges from eliminating the WTO?

  70. msn nickleri says:

    If the Iranians get a bomb and delivery systems and credibly threaten or launch on the Israelis we may get a population reduction wedge, and perhaps another wedge from sheer unavailability of oil from a big swath of current production territory. But maybe that wasn’t the kind of population control you were talking about.

  71. Steve Beers says:

    “Instead of fighting against safe and low waist [sic] nuclear power, you should back it.”

    Gee, didn’t they make the same claims for first through third gen nukes?

  72. Steve Beers says:

    To me, the most straightforward way to promptly act is a ban on all new coal plants without sequestration or verified permanent offsets.

    This one rule accomplishes the following:

    1. best kind of ‘cap’ on new coal plant emissions – ZERO.
    2. allowing sequestration or offsets as safety valve sounds less drastic than a total ban on new coal plants. Yet it’s still a drastic enough action to match the dire circumstances.
    3. prices ‘externalities’ by raising the average cost of electricity. Without a direct ban on coal, it still steers the market away from using more coal.
    4. marginal costs for new plants can be averaged in with costs for existing power – for a gradual impact to consumers
    5. no direct price increases as with a carbon tax. therefore politically easier to advocate
    6. stimulates the market for renewables and efficiency, both indirectly with the price increases for coal-fired electricity, and directly with offsets.
    7. a relatively simple measure, both to advocate for and to administer.
    8. sets stage for further improvements – “new coal” with sequestration becomes a demonstration for what’s technically feasible
    9. utilities using new coal become a possible ally to clean up “old coal” of its carbon b/c they are competing for market share.
    10. if sequestration isn’t ready yet, many offsets (efficiency, reforestation, some renewables) are

    another, not related, point:

    why is variability of supply supposedly such a killer for solar and wind options?

    The usually posed alternatives of “baseload” coal and nuke have to cope with variable demand by using natural gas peaking plants. so, variable supply sources like wind and solar will likewise have to use gas as backup and gap-filler. Whichever way you go, gas is the likely gap filler until or unless there are cheaper storage methods.

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