Must-Read Caldeira: ‘The Only Ethical Path Is To Stop Using The Atmosphere As A Waste Dump For Greenhouse Gas Pollution’

Last week, I discussed a new paper on methane leakage, to argue that “Natural Gas Is A Bridge To Nowhere Absent A Carbon Price AND Strong Standards To Reduce Methane Leakage.” Last month, I wrote about a paper by climatologist Ken Caldeira and tech guru Nathan Myhrvold that came to a stronger conclusion: You Can’t Slow Projected Warming With Gas, You Need ‘Rapid and Massive Deployment’ of Zero-Carbon Power. I asked Caldeira to comment on the new paper. He slammed those who support a “fundamentally immoral” policy of delivering a hothouse climate to future generations, especially since avoiding the worst outcomes requires means redirecting at most 2% of our wealth. He expressed his views with a bluntness that is becoming increasingly common among climate scientists — JR.

Caldeira: “Basically, people are saying ‘If you don’t build this natural gas plant, we’ll build this coal plant.’ As the natural gas plant spews its CO2 into the atmosphere, we are supposed to be grateful that they didn’t shoot the dog.” [Apologies to National Lampoon].

By Ken Caldeira

1. Life-cycle analyses for natural gas.

Myhrvold and Caldeira (2012) presented a method for estimating climate consequences of energy system transitions. We used every Life Cycle Assessment study that we could get our hands on that provided the necessary level of detail. We also, in the Supporting Online Material that accompanied our paper, considered many cases with technological improvement. Our goal was to present a simple analytic framework that others could use to analyze energy system transitions in a physically defensible framework using numbers of their choosing. [See figure below.]

I am a climate scientist, not a power plant engineer. For the sake of discussion, I am happy to accept that 0.5 could be the ratio of emissions from a natural gas plant relative to those from a coal plant, and that something close to infinity could be the ratio of emissions from a natural gas plant relative to those from an intrinsically carbon-emission free technology (wind, solar, nuclear) constructed in a decarbonized economy of the future.

Under these assumptions, continued use of natural gas would delay but not avoid unwanted climate outcomes. Only the intrinsically carbon-emission free technologies can avoid these outcomes.

2. Overall framing.

Note: This is me speaking mostly as a human being, a moral and political animal, and not me speaking as a scientist. As a human being, I ask questions that are related to my values and my conception of what is right and wrong. As a scientist, I answer these questions as objectively as I possibly can.

Every CO2 molecule is the same to the atmosphere. The atmosphere doesn’t care whether that CO2 molecule came from coal or natural gas.

We are converting the climate of our planet to one that is similar to the hothouse climates that existed on this planet when dinosaurs were the top predators. To a first approximation, if we emit greenhouse gases half as rapidly as we do today, we will wind up in the same place but it will take us twice as long to get there.

Economists estimate that it might cost something like 2% of our GDP to convert our energy system into one that does not use the atmosphere as a waste dump. When we burn fossil fuels and release the CO2 into the atmosphere, we are saying “I am willing to impose tremendous climate risk on future generations living throughout the world, so that I personally can be 2% richer today.” I believe this to be fundamentally immoral. We are saying we want to selfishly reap benefits today while imposing costs on strangers tomorrow.

Would we like it today if the Romans had developed a modern technological society like ours, and their scientists told them that using the atmosphere as a waste dump for greenhouse gases would melt the ice caps, acidity the oceans, overheat the tropics, cause species extinctions, etc, and then they decided to go ahead and do it anyway, just because they were selfish and didn’t care about other people? Perhaps their economists too would do a net present value calculation that would tell them that selfishness is the way to go. Would we be happy to have all of this environmental damage comforted by the knowledge that they knowingly imposed these costs on us in order to be 2% richer?

All I am asking is that we follow the golden rule: “Do unto others as you would have them do unto you.” This is fundamentally a moral issue, not an economic issue. Given what we know now, it is simply unethical to impose risk of grave damage on future generations just so that we can have a few more consumer products today.

The only ethical path is to stop using the atmosphere as a waste dump for greenhouse gas pollution.

As a political strategy, are we supposed to believe that somehow atmospheric CO2 concentrations will be lower in the future if today we expand fossil fuel industries that rely on using the atmosphere as a waste dump? Am I really supposed to persuaded that the path to lower future CO2 concentrations is by building more power plants with smokestacks that dump CO2 into the atmosphere?

If the problem is that we have too many power plants that dump greenhouse gas pollution into the atmosphere, I am highly skeptical that the way we are going to solve this problem is by building more power plants that dump greenhouse gas pollution into the atmosphere.

Energy demand is going up exponentially. Natural gas relative to coal brings down emissions fractionally. If you multiply an exponentially increasing curve times a constant, you get an exponentially increasing curve. It takes a little longer to get to the same value, but it does change the long-term trend. We have to decide whether we are in the business of delaying bad outcomes or whether we are in the business of preventing bad outcomes. If we want to prevent bad climate outcomes, we should stop using the atmosphere as a waste dump.

I am reminded of the famous old National Lampoon cover “If you don’t buy this magazine, we’ll kill this dog.” ( Basically, people are saying “If you don’t build this natural gas plant, we’ll build this coal plant.” As the natural gas plant spews its CO2 into the atmosphere, we are supposed to be grateful that they didn’t shoot the dog.

If we build these natural gas plants, we reduce incentives to build the near zero emission energy system we really need. Natural gas is a delaying tactic. It is time to start building the near zero emission energy system of the future. There is no time to waste. There is plenty of energy in solar and wind, and I believe that nuclear power can be made safe. We need to improve these technologies, and come up with better ways to store and distribute energy. But we need to get started on this program now. Expansion of natural gas is a delaying tactic, not a solution.

The right wing says what they want: They don’t worry about political realism. They work to make what they want be the political reality.

Their political positions may be immoral, but at least they are usually logically coherent.

So-called “progressives” are afraid to say what they really want, and instead worry about “political realism”. They start out with a compromised and logically indefensible position. They are too afraid to say that we should not be using the atmosphere to dispose of greenhouse gas pollution, so they argue for building more power plants that use the atmosphere to dispose of greenhouse gas pollution. It is a fundamentally compromised and indefensible position.

It is time to say what we really want, and not just propose things that we think the saner elements of the right-wing nut community might accept.

It’s time for progressives to learn from the right wing that sometimes having a backbone can be good political strategy.

3. Climate-Impact approach vs.Technology Warming Potential approach

Myhrvold and Caldeira (2012) presented a very simple climate model to predict climate consequences of different energy system transitions. This model took into account the different atmospheric lifetimes of different greenhouse gases and the different radiative forcings of each gas, and also considered delays in the climate system caused primarily by the thermal inertia of the ocean. This is a simple and physically sensible way to look at the climate effects of different energy system transitions.

The Technology Warming Potential approach [of the new Alvarez et al paper] seems to be a step backward from simply calculating the temperature change caused by an emission. Thermal lags in the climate system matter, and it matters to the climate of year 2050 whether radiative forcing gets added to the climate system today or in year 2040.

Our approach of calculating climate-impacts using a simple climate involves calculations that are at about the same level of complexity as Alvarez et al (2012) used to to calculate their Technology Warming Potentials. I do not understand the advantage of sacrificing physical realism and ignoring the way thermal lags work in the climate system.

JR:  Here is the key figure from Caldeira’s paper:

Many decades may pass before a transition from coal-based electricity to alternative generation technologies yields substantial temperature benefits. Panels above show the temperature increases predicted to occur during a 40-yr transition of 1 TWe of generating capacity. Warming resulting from continued coal use with no alternative technology sets an upper bound (solid black lines), and the temperature increase predicted to occur even if coal were replaced by idealized conservation with zero CO2 emissions (dashed lines) represents a lower bound. The colored bands represent the range of warming outcomes spanned by high and low life-cycle estimates for the energy technologies illustrated: (A) natural gas, (B) coal with carbon capture and storage, (C) hydroelectric, (D) solar thermal, (E) nuclear, (F) solar photovoltaic and (G) wind.

JR: Caldeira subsequently sent me this follow-up email:

A lot of things I said in my previous email were the result of generally getting worked up about the natural gas question, and was not a response to Alvarez et al (2012) in particular.

(In fact, they didn’t even cite Myhrvold and Caldeira [2012], which seems to be a bit of an oversight. Any links to the YouTube video we made on this would be much appreciated:
Of course, their basic premise is correct:  If you are going to burn natural gas, we need to focus on methane leakage from  natural gas infrastructure.
My quibble is with the antecedent, not the consequent.
I do have a quibble with their methodology that considers time-integrated radiative forcing as the metric of choice.
You can see this most clearly by looking at the climate effects of deforestation many centuries ago, such as occurred in China and India, versus deforestation occurring in the recent past in Brazil and Indonesia.  The time integrated radiative forcing from ancient deforestation will be greater than an equivalent deforestation occurring 20 years ago, but the more recent deforestation will have a bigger effect on today’s climate. Recent deforestation will impact this century’s climate much more than will deforestation that occurred deep in history. The time-integrated radiative forcing approach fails to take the time dimension into consideration in a physically or economically justifiable way.
Our simple climate model approach of predicting the temperature consequences of human actions is both physically motivated and conceptually simpler and thus it is more useful and broadly applicable.
— Ken Caldeira
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44 Responses to Must-Read Caldeira: ‘The Only Ethical Path Is To Stop Using The Atmosphere As A Waste Dump For Greenhouse Gas Pollution’

  1. Mike Roddy says:

    This is an extremely important paper, thanks to Ken and Nathan. My only quibble is the way you framed the 2% wealth sacrifice.

    Down on the ground, this works out differently. The very wealthy typically don’t even do their own investing, but hire financial managers. The main cash cows for securities accounts for over a decade have been fossil fuel stocks, with very little risk. The main reasons the rich have been getting so much fatter are tax breaks and fossil fuel income.

    The same is true for lobbyists and members of Congress. What is reported is enormous enough, but word on the street is that it’s considerably more than that.

    We are truly up against the dark side, whose actions will do far more damage than the butchery and depravity of Rome. Scientists are beginning to realize this- and given the passivity and cowardice of government and media, we almost have nowhere else to turn for leadership.

  2. Eduardo Vargas says:

    Why would carbon capture and storage drive the temperature up? More importantly why does hydropower drive the temperature up at first and then decreases it?

  3. Quentin says:

    I think the answer is – when you flood an area you get a lot of methane from stuff rotting underwater.

  4. Gail Zawacki says:

    We are deforesting the planet even without cutting trees. We’re killing them with pollution. It’s not enough to reduce CO2, we absolutely have to stop pouring ozone precursors – methane and N2O – into the environment. “Pillage, Plunder & Pollute, LLC” will be published next month in the Coming Crisis website and new magazine (

    but is available for download now on googledocs:

  5. fj says:

    by these same arguments car use is immoral

  6. Ken Caldeira says:

    Yes, that is what I am saying. We can make driving become an ethical activity by electrifying cars and then decarbonizing our electricity generation system.

  7. h4x354x0r says:

    At current solar PVC efficiencies, and adding in extra for intermittency and peak usage, we would have to cover almost 5% of the continental US with solar panels to completely replace all fossil fuel (and nuclear) energy use. At current production rates, it would take about 30 years to manufacture and install all those panels.

    There are also un-solved technical issues surrounding storage and transport of solar-generated energy. Battery technology still sucks.

    But, it’s the ONLY option that will last for more than a few hundred years (at the most, for any fossil fuel source). The cost of any kind of conversion will be significant. Do we really want to convert from oil to gas, then just have to convert on to solar/wind when that runs out? That seems stupid. We might as well do it right once, the first time, instead of taking other dead-ends first.

  8. Raul M. says:

    humm, looks like some of the smart.ones are working their way out of the straight jackets of denial.

  9. Mike Roddy says:

    Your 5% figure is not correct. It’s closer to .04%. Try the math again: it takes 5 acres of panels to produce a megawatt of energy. That makes 128 mgw/square mile. If future demand for energy spikes way up to require 1,000,000 mgw (as an exercise), that’s 12,800 square miles, or .04% of land area not even counting Alaska. I think you missed a zero.

    Put another way, we could power the entire US from less than 25% of the Mojave Desert alone. Countries like Germany and Japan would love to have that option. We are wasting it, as the Kochs and the gas companies have gotten to some of the Greens on this one.

    It’s also absurd to claim that it would take 30 years to build the panels, and major transmission lines and corridors already cross the Mojave.

  10. fj says:

    As Amory Lovins says: Something is not possible if it already exists; and since one-half billion Chinese cyclists already exist, it seems it would be much easier and cost-effective to bump up this early stage mass net zero mobility to meet developed world needs.

    Further, existing and developing driverless electric cars and infrastructure have to cost many times more than much easier to develop small light-weight net zero vehicles and systems.

  11. Mulga Mumblebrain says:

    Yes-this is a battle between Good and Evil, and the Right (a silly anachronistic euphemism) is evil incarnate. We stand absolutely no hope until this moral truth is plain in every decent human’s mind. We produce more wealth that ever, yet the vast majority of humanity is condemned, thanks to the triumph of the Right, to work ever harder and live in ever more precarious circumstances, and see their grandchildren’s fate decided, all to feed the insatiable greed and lust for power of a tiny parasitic elite.
    And a sub-section of humanity, the most ignorant, arrogant, and viciously misanthropic, has been recruited to the destroyers camp by a mere appeal to ideological hatred. Denialism is a Rightwing cause, closely allied to visceral hatred of environmentalists, and it will never capitulate to mere facts, let alone undergo a moral metamorphosis. These creatures do not act selflessly, with respect for others, or in a spirit of self-sacrifice for the common good. We must defeat them, because they are beyond reason or remorse, or disappear. That is the simple moral truth, that so many are fearful of acknowledging.

  12. Mulga Mumblebrain says:

    If our leaders were not morally insane, massive reforestation would be an absolute priority. But they prefer building weapons for the coming wars of survival in an ecologically collapsing world.

  13. Mulga Mumblebrain says:

    It is the moral and spiritual denial that is holding us back. We must take the bold, hideously unpleasant and discomfitting step of looking the forces of evil straight in the face, and acknowledging them for what they are. While the polite charade of pretending that these are rational human beings who can be reasoned with is more comfortable, it is, in my opinion, a cop-out, a really dangerous form of wishful thinking and moral cowardice.

  14. Raul M. says:

    I think it is more the true bravery to make biochar full knowing that I could never make as much as I had already burned in gas for the various cars I have had

  15. John Atkeison says:

    Mike, this is A VALUABLE few paragraphs!
    Would you please provide references for
    “it takes 5 acres of panels to produce a megawatt of energy. That makes 128 mgw/square mile.”
    Thanks very much in advance!

  16. John Atkeison says:

    Consider the huge amount of concrete… but I suspect that the answer is in the paper they wrote…

  17. Artful Dodger says:

    Building a concrete Dam emits vast amounts of CO2, first to cook the lime for the concrete, and then more emitted as the poured concrete cools and cures. The embodied CO2 content is 727 kg CO2 per ton of concrete.

    Compare that to Coal, which has an embodied CO2 content of 2.86 tons C02 per ton of coal. So a green hydro-power project built with a concrete dam is the equivalent of burning 27% of the mass of the dam in coal.

    Earthen dams, then? Hope you have clean electric drag lines to move that earth…

  18. Just Google:

    how much acreage does it take to generate a megawatt?

  19. David B. Benson says:

    One ought to check the figure used by physicist David MacKay ih his “Sustainable Energy — without the hot air”. The area required is rather prodigeous as I recall.

  20. Judy Cross says:

    Are we really supposed to believe that a trace gas measured in parts per million and presently less than 0.04% of the atmosphere can change climate with the addition of a few more parts per million?

  21. David B. Benson says:

    Using the NREL simplified LCOE calculator I estimate that a new combined cycle gas turbine (CCGT) has an LCOE of around US$0.0375/kWh. That’s about half that for an NPP [still the least expensive of the low carbon alternatives]. However, the CCGT figure depends heavily on the price of natgas. If the price of natgas goes from the current figure of around US$2/MMBtu to US$7/MMBtu then the NPP has the lower LCOE.

    I suggest a carbon tax.

  22. David B. Benson says:

    Yes, this is now fully confirned on all relevant millennia scale phenomenon. The basic understanding was mostly completed in the 1960s and 1970s. All research since then is details; important but still details.

  23. Robert Nagle says:

    In the second section, Caldeira mentioned 2% conversion costs. This number sounds familiar. Where did you get it?

    By the way, I mentioned Cadeira’s paper in a Texas energy and environment conference last week (attended by lots of natural gas business types). I don’t think anyone had heard of the study before. But now they know!

  24. Mulga Mumblebrain says:

    To paraphrase Groucho, ‘You just think Google is your friend’.

  25. Mulga Mumblebrain says:

    I do hope that this is an aberration. This sort of nincompoopery has taken over all the MSM blogs in Australia, a land where scientists are reviled by the Dunning-Krugerites as ‘smart-arses’ and ‘know-it-alls’, and every dunce is a self-confessed expert and bashful genius.

  26. Speedy says:

    “and I believe that nuclear power can be made safe.”

    This is a candidate for understatement of the year, given that nuclear already is the safest energy source we have (measured in fatalities/TWh).

  27. Raul M. says:

    Speaking of nukes, is the waste land associated with the 1 in a hundred failure rate included in the figures for how much land is needed for a nuke plant?

  28. Raul M. says:

    On another note, biochar making could produce the intense heat necessary for metal smelting.

  29. Mike Roddy says:


    Hat tip to Richard for the google suggestion, which basically confirms my estimate. I had heard from solar developers that 4-5 acres is needed per mgw for solar thermal, but PV farms require about half as much land based on watts per panel. It’s correct to err on the high side even for PV, to allow for access, infrastructure, lines and substations etc. You won’t get a hard figure due to site variables.

    The point is that the notion that we would have to cover a huge amount of land to convert to solar is a rumor started by the gas and coal companies. They also lie about embodied energy, water consumption, etc, and their trolls dutifully repeat them all over the internet, and to MSM reporters, too.

  30. Mike Roddy says:

    Oops, I noticed my own error/typo (I wrote the previous after a long day working). I meant .4% of land area, not .04% (US land area not including Alaska is 3.2 million square miles or 2.07 billion acres). The .4% figure for solar farms is very conservative, or on the high side, and it’s probably closer to .2- .3%.

    We and Canada clearcut 5 million acres of forests every single year. The Greens who are trying to protect the barren Mojave should put on a pair of pants and go after the timber industry instead.

  31. TKPGH says:

    Regarding the solar power/grid storage issue:

    The Solar Roadways concept is visionary and technologically possible. Look for his coming out event this fall.

    Dr. Richard Sadoways new liquid-metal battery apparently works. And the TED talk is VERY inspiring.

  32. wili says:

    How does the Dylan line go?

    “Where the executioner’s knife is always well hidden…”

  33. Tim says:


    Yes, you’re really supposed to believe that. If you have a cup of water into which you’ve added 3 drops of blue Easter-egg dye, do you think the blue color will NOT deepen if you add 2 more drops of blue dye?

    The question is, why would someone who knows so little be so confident in exposing her ignorance? It is called the Dunning-Kruger effect. Look it up and learn something about yourself.

  34. Raul M. says:

    Credible sources have told me that personifying the weather is well beyond my abilities.

  35. There is a much better way of solarizing the country–concentrated solar power (CSP). Check out Gemasolar and Desertec. “Power towers” can provide more power using less space than PV systems.

    Ideally, CSP and PV would be coordinated on a smart grid.

    BTW: Regarding Mike’s calculations, PV doesn’t just have to cover deserts. There are miles and miles of rooftops, landfill areas and so on that can be covered.

  36. Paul Magnus says:

    It’s the only sane path!

    “continued use of natural gas would delay but not avoid unwanted climate outcomes”

    This is of course an understatement. We already have unwanted outcomes and it’s going to get way worse even if we could sequester ghg down starring today.

  37. This is an ethical issue, and the real evil of the fossil fuel companies isn’t just that they are fighting to maintain and even expand the status quo, but that they have clear, profitable alternatives. Fifteen years ago, I heard a representative of BP’s alternative energy department addressing a “sustainability” conference at Cooper’s Union in NY. He said words to the effect of “BP looks at itself not so much as in the oil business, but in the energy business.”

    Meaning, with their enormous resources and clout, the fossil fuel companies could be the ones developing renewable energy sources, smart grids and what have you. Instead, they continue to pursue destructive means and ends. Evil is as evil does.

    I have one bone to pick with Caldeira. I don’t believe nuclear “can be made safe.” Also, nuclear is not affordable, scalable, timely or an especially carbon-free source of energy.

    And, we don’t need it. Distributed renewables backed by 24/7/365 concentrated solar power can meet all of humanity’s energy needs hundreds of times over.

    But, back to the basic issue — Yes! Confront evil where you find it.

  38. colinc says:

    Consider the Golden poison frog.

    The average dose carried will vary between locations, and consequent local diet, but the average wild P. terribilis is generally estimated to contain about one milligram of poison, enough to kill about 10,000 mice. This estimate will vary in turn, but most agree this dose is enough to kill between 10 and 20 humans, which correlates to up to two African bull elephants. This is roughly 15,000 humans per gram.

    15K humans @ ~150 lbs/ea (low-balling average to maximize %) = 2,250,000 lbs / 1,022,727,000 grams

    So, a lethal dose amounts to just 0.000000098%, but don’t believe that either. Additionally, as a matter of scale, 0.04% is 409,090.8 times greater than 0.000000098%!

    Moreover, are the rest of us supposed to believe you are “educated?”

  39. Alex A. says:

    He uses 22 W/m^2 for PV in the UK, so roughly 100 kW per acre.

    Utility scale PV farms are delivering more like 5 W/m^2 – 15 W/m^2, even in very favorable locations.

  40. Alex A. says:

    A really, really good PV farm (20 W/m^2) would need about 12.5 acres.

    Utility PV farms are achieving more like 10 W/m^2, so 25 acres or so per megawatt.

    Solar thermal may be more space efficient, but not by a factor of five. I really doubt the 4-5 acres/mW number.

    Keep in mind, a megawatt is actually not all that much electricity.

  41. David B. Benson says:

    It is not a matter of belief but rather one of sttatistics: measured by deaths per unit of energy generated, NPPs are safer than any other form of generation [this from a study done just for Europe so includes Chernoybl].

    Affordable? In a comment on an earlier thread I gave some recent prices; NPP new build has a lower LCOE than wind turbines.

    Scalable? Easily so with the forthcoming small modular designs.

    Low carbon? NPPs require something like 20 times less steel and concrete than wind turbines on towers. Both steel making and Portland cemene making emit considerable CO2.

    Unfortunately even CSP requires backup as the sun does not always shine, even in the desert. Worse, a recent ORNL study suggests that there are actually relatively few locations suitable for CSP in the USA. Finally, CSP costs 2–3 times NPPs.

  42. Paul Magnus says:

    It is a moral issue… but why is there no moral majority?

    Can you believe that Obama contributed an excellent essay to this… ““The Future I Want for My Daughters”

  43. David Lewis says:

    I think Caldeira’s statement about the right, i.e. “at least they are usually logically coherent” is preposterous.

    When I think about today’s “right” in US politics, what comes to mind is their mindless opposition to whatever anyone they take their opponent to be is proposing no matter if its policy they themselves originated, eg the affordable health care act. This is pretty far away from being “logically coherent”.

    The widespread “right” wing denial of selected basic facts discovered by the scientific method and their acceptance of others also demonstrates a profound logical inconsistency.

    Eg. some of these clowns dispute how long life has existed on Earth, or that species evolve, and almost all of them dispute the properties of certain gases that are accumulating in the atmosphere. At the same time they accept other basic facts scientists have discovered about the Earth, i.e. it is a sphere, it orbits the Sun, etc. They don’t dispute what scientists have discovered about the non GHG gases in the atmosphere. Its hard to believe a lot of these geezers aren’t dependent on the scientifically discovered properties of viagra, etc.

    I think if they were logically consistent or coherent they’d be able to explain how they were able to detect that almost every climate scientist, worldwide, is a charlatan while almost every scientist in almost all other fields are not.