Why is nuclear power the core climate change solution?

[For accessibility, I’ve bumped the time-stamp on this post from Jan 2010 to May 2011. Ed.]

Here’s an email from critical-thinker friend and paleo oceanographer Will Howard:

January 2010: Trying to get my head around nuclear power issues. I would describe myself as a nuclear “agnostic.” But the more I read the more I can see the merits of Barry Brooks’ (and your) point of view, and realizing we’ve lost a lot of time bringing nuclear power online.

I replied:

I too was “agnostic”, but leaning against more nuclear generation. I was concerned about all that long-lived “waste”. Why do we need nuclear power — my optimistic-self wanted to believe Ray Kurzweil that “nanotechnology” would somehow enable solar to become the answer for clean, affordable energy. Or geothermal, wind, tidal, or bio-something.

As I studied energy policy it became clear that a necessary condition that must be satisfied by carbon-free energy is that it must be “cheaper than coal“. Otherwise, the dominant future polluters, the developing world, will continue building coal power stations. After 25 years of government subsidies, the results for “renewables” just don’t add up — not even close. Certainly, there are geographic niches where the free market will adopt wind or solar, but on a global basis, pushing for such “renewables” just prolongs the dominance of coal (and gas). The Big Green NGOs and Green parties have lost the plot — they have forgotten that the goal is to achieve zero emissions, not to promote particular popular technologies.

As you say “we’ve lost a lot of time bringing nuclear power online”. Instead of being coal-dependent, both America and Australia could easily have adopted the French model, which with almost entirely nuclear-based electricity generation, makes France the standard for other developed countries to achieve (the challenge for the rest of the planet is to catch up to where France is today!). Sigh… The good news is that China does not seem to be that stupid.

So — what solid information can we offer that is useful to our friends? For foundation reading I recommend David MacKay’s famous energy policy book “Sustainable Energy Without the Hot Air” . Dr. Mackay is now Chief Scientific Advisor to the UK Department of Energy and Climate Change. You can follow some of David’s efforts here, and you can find Seekerblog posts on MacKay’s work with this search.

Next, I recommend Australian environmental scientist Prof. Barry Brook (Adelaide University). Barry and colleagues have created a remarkable resource — the BraveNewClimate.com blog, where Barry has been applying his considerable critical-thinking skills to the energy policy issue. His September 2009 post “A necessary interlude” is a concise summary of why Barry eventually shifted his focus to concentrate on the nuclear solution. I recommend a careful read of the short essay. In brief, Barry wants the conversation focused on energy policy that will work in the real world. Near the end of the post Barry succinctly summarizes his view of the energy options — this is so good I have reproduced that segment here [the emphasis below is mine]:

(…) It is my conclusion, from all of this, that nuclear power IS the only viable FF [fossil fuels] alternative.

I am vitally interested in supporting real solutions that permit a rapid transition away from fossil fuels, especially coal (oil will, at least in part, take care of itself). If the conclusion is that wind/solar cannot meaningfully facilitate this transition, why bother to promote them? Now, I should make one thing quite clear. I am not AGAINST renewable energy. If folks want to build them, go for it! If they can find investors, great! Indeed, I’m no NIMBY, and would be happy to have a conga line of huge turbines gracing the hills behind my home, just as I’d be happy to have a brand spanking new nuclear power station in my suburb. But why should I promote something I have come to consider — on a scientific and economic basis — to be a non-solution to the energy and climate crisis? That doesn’t make sense to me.

To your questions:

1. Coal with CCS — doomed to failure. Why? Because the only thing that is going to be embraced with sufficient vigour, on a global scale, is an energy technology that has the favourable characteristics of coal, but is cheaper than coal. CCS, by virtue of the fact that it is coal + extra costs (capture, compressions, sequestration) axiomatically fails this litmus test. It is therefore of no interest and those who promote it can only do so on the basis of simultaneously promoting such a large carbon price that (a) the developing world is highly unlikely to ever impose it, and (b) if they do, CCS won’t be competitive with nuclear. CCS is a non-solution to the climate and energy crises.

2. Natural gas has no role in baseload generation. It is a high-carbon fossil fuel that releases 500 to 700 kg of CO2 per MWh. If it is used in peaking power only (say at 10% capacity factor), then it is only a tiny piece in the puzzle, because we must displace the coal. It it is used to displace the coal baseload, then it is a counterproductive ’solution’ because it is still high carbon (despite what the Romms of this world will have you believe) and is in shorter supply than coal anyway. Gas is a non-solution to the climate and energy crises.

3. The developing world lives in Trainer’s power-down society already, and they are going to do everything possible to get the hell out of it. The developed world will fight tooth and nail, and will burn the planet to a soot-laden crisp, rather than embrace Trainer’s simpler way. Power down is a non-solution to the climate and energy crises.

4. It is nice to imagine that renewables will have a niche role in the future. But actually, will they? They don’t have any meaningful role now, when pitted in competition with fossil fuels, so why will that be different when pitted fairly against a nuclear-powered world? I don’t know the answer, and I don’t frankly care, because even if renewable energy can manage to maintain various niche energy supply roles in the future, it won’t meet most of the current or future power demand. So niche applications or not, renewables are peripheral to the big picture because they are a non-solution to the climate and energy crises.

5. Smart grids will provide better energy supply and demand management. Fine, great, that will help irrespective of what source the energy comes from (nuclear, gas, coal, renewables, whatever). Smarter grids are inevitable and welcome. But they are not some white knight that will miraculously allow renewable energy to achieve any significant penetration into meeting world energy demand in the future. Smart grids are sensible, but they are not a solution to the climate and energy crises.

To some, the above may sound rather dogmatic. To me, it’s the emergent property of trying my damnedest to be ruthlessly pragmatic about the energy problem. I have no barrow to push, I don’t get anything out of it — other than I want this problem fixed. I don’t earn a red cent if nuclear turns out be the primary solution. I don’t win by renewables failing. The bottom line is this — if this website is looking more and more like a nuclear advocacy site, then you ought to consider why. It might just be because I’ve come to the conclusion that nuclear power is the only realistic solution to this problem, and that’s why I’m ever more stridently advocating it. This is a ‘game’ we cannot afford to lose, and the longer we dither about with ultimately worthless solutions, the closer we come to endgame, with no pawn left to move to the back row and Queen.

So what can you expect from BNC in the future? Much more on nuclear power (both Gen III and Gen IV), obviously, since I now consider this technology to be the core climate change solution — whilst openly acknowledging the yawning gulf between the scientific understanding of nuclear power and the public’s perception. This must change, and I hope, in my modest way, I can be an agent for that attitudinal shift. I also plan to launch an extended series on renewable energy, with an aim to break down the often complex and multifaceted critiques being made, into simpler, single-issue chunks, which can be more readily pinned down and understood. I will also profile some of the less well-developed low-carbon technologies, such as tidal, wave, microalgae, and geothermal, and speculate on their possible future roles. I hope in this way that I’ll be able to reinforce people’s understanding of why I no longer hold renewable energy to be a primary solution — and yet, by the same yardstick of maintaining intellectual honesty, I’ll also try my very best to keep an open mind to unconsidered possibilities and caveats that are raised by commenters (be these against nuclear energy, and/or for renewables). As I said, healthy thought should never cease to evolve.

When you see anti-nuclear propoganda, always ask yourself “Who Benefits?” And yes, the following is exactly our objective — to kill all coal fired generation (except for CCS plants, if they can make it work).

Nuclear power will kill coal

Summary of developing world nuclear planned and under construction:

China already has 9 GWe operating, with 61 GWe new reactors planned, including some of the world’s most advanced. Their goal is least 60 GWe (total) by 2020, and 120-160 GWe by 2030. China demands aggressive technology transfer in their contracts — e.g., in return for the large commitment to Westinghouse AP1000 reactors, China will be building and supplying most of the components after the first two plants are completed.

India expects to have 20 GWe nuclear capacity on line by 2020 and 63 GWe by 2032. It aims to supply 25% of electricity from nuclear power by 2050 [I think this goal is much less than India is likely to achieve]. India is a leader in Thorium Fast Breeder (FBR) technology and could turn out to be a major global supplier of new nuclear plants.

(…) India has uniquely been developing a nuclear fuel cycle to exploit its reserves of thorium.

Now, foreign technology and fuel are expected to boost India’s nuclear power plans considerably. All plants will have high indigenous engineering content.

India has a vision of becoming a world leader in nuclear technology due to its expertise in fast reactors and thorium fuel cycle.

Russia is producing some 22 GWe in 31 plants, including the BN-600, one of the longest operating fast breeder reactors in the world. Russia has another 37 GWe of new capacity under construction, planned, or proposed.

Brazil has about 2GWe power by two Siemens plants at Angra, and 8GWe more planned for 2030 and 60GWe total by 2060. The bad news is that there will be many megatons of coal burned before this turns around.

A Cherry Picker's Guide to Global Temperature Trends

This is a wonderful resource:

Cherry-Pickers Guide to Global Temperature Trends. Each point on the chart represents the trend beginning in September of the year indicated along the x-axis and ending in August 2009. The trends which are statistically significant (p [greater than]0.05) are indicated by filled circles. The zero line (no trend) is indicated by the thin black horizontal line, and the climate model average projected trend is indicated by the thick red horizontal line.

You will need to read Roger’s complete post. I’ll just highlight some examples of how cherry pickers operate. But you can detect their tricks by consulting the above chart.

(…) Here are a few general statements that can be supported with using my Cherry-Pickers Guide:

• For the past 8 years (96 months), no global warming is indicated by any of the five datasets.

• For the past 5 years (60 months), there is a statistically significant global cooling in all datasets.

• For the past 15 years, global warming has been occurring at a rate that is below the average climate model expected warming

Lots more.

Energy policy: real world engineering meets renewables

Even if solar cells themselves were free, solar power would remain very expensive because of the huge structures and support systems required to extract large amounts of electricity from a source so weak that it takes hours to deliver a tan.

This is why the (few) greens ready to accept engineering and economic reality have suddenly emerged as avid proponents of nuclear power. In the aftermath of the Three Mile Island accident—which didn’t harm anyone, and wouldn’t even have damaged the reactor core if the operators had simply kept their hands off the switches and let the automatic safety systems do their job—ostensibly green antinuclear activists unwittingly boosted U.S. coal consumption by about 400 million tons per year. The United States would be in compliance with the Kyoto Protocol today if we could simply undo their handiwork and conjure back into existence the nuclear plants that were in the pipeline in nuclear power’s heyday. Nuclear power is fantastically compact, and—as America’s nuclear navy, several commercial U.S. operators, France, Japan, and a handful of other countries have convincingly established—it’s both safe and cheap wherever engineers are allowed to get on with it.

But getting on with it briskly is essential, because costs hinge on the huge, up-front capital investment in the power plant. Years of delay between the capital investment and when it starts earning a return are ruinous. Most of the developed world has made nuclear power unaffordable by surrounding it with a regulatory process so sluggish and unpredictable that no one will pour a couple of billion dollars into a new plant, for the good reason that no one knows when (or even if) the investment will be allowed to start making money. – Peter W. Huber, 2009

Peter Huber, coauthor of The Bottomless Well, takes a hard look at the options in “Bound to Burn” at City Journal:

(…) Another argument commonly advanced is that getting over carbon will, nevertheless, be comparatively cheap, because it will get us over oil, too—which will impoverish our enemies and save us a bundle at the Pentagon and the Department of Homeland Security. But uranium aside, the most economical substitute for oil is, in fact, electricity generated with coal. Cheap coal-fired electricity has been, is, and will continue to be a substitute for oil, or a substitute for natural gas, which can in turn substitute for oil. By sharply boosting the cost of coal electricity, the war on carbon will make us more dependent on oil, not less.

The first place where coal displaces oil is in the electric power plant itself. When oil prices spiked in the early 1980s, U.S. utilities quickly switched to other fuels, with coal leading the pack; the coal-fired plants now being built in China, India, and other developing countries are displacing diesel generators. More power plants burning coal to produce cheap electricity can also mean less natural gas used to generate electricity. And less used for industrial, commercial, and residential heating, welding, and chemical processing, as these users switch to electrically powered alternatives. The gas that’s freed up this way can then substitute for diesel fuel in heavy trucks, delivery vehicles, and buses. And coal-fired electricity will eventually begin displacing gasoline, too, as soon as plug-in hybrid cars start recharging their batteries directly from the grid.

(…) To top it all, using electricity generated in large part by coal to power our passenger cars would lower carbon emissions—even in Indiana, which generates 75 percent of its electricity with coal. Big power plants are so much more efficient than the gasoline engines in our cars that a plug-in hybrid car running on electricity supplied by Indiana’s current grid still ends up more carbon-frugal than comparable cars burning gasoline in a conventional engine under the hood. Old-guard energy types have been saying this for decades. In a major report released last March, the World Wildlife Fund finally concluded that they were right all along.

But true carbon zealots won’t settle for modest reductions in carbon emissions when fat targets beckon. They see coal-fired electricity as the dragon to slay first. Huge, stationary sources can’t run or hide, and the cost of doing without them doesn’t get rung up in plain view at the gas pump. California, Pennsylvania, and other greener-than-thou states have made flatlining electricity consumption the linchpin of their war on carbon. That is the one certain way to halt the displacement of foreign oil by cheap, domestic electricity.

The oil-coal economics come down to this. Per unit of energy delivered, coal costs about one-fifth as much as oil—but contains one-third more carbon. High carbon taxes (or tradable permits, or any other economic equivalent) sharply narrow the price gap between oil and the one fuel that can displace it worldwide, here and now. The oil nasties will celebrate the green war on carbon as enthusiastically as the coal industry celebrated the green war on uranium 30 years ago.

The other 5 billion are too poor to deny these economic realities. For them, the price to beat is 3-cent coal-fired electricity. China and India won’t trade 3-cent coal for 15-cent wind or 30-cent solar. As for us, if we embrace those economically frivolous alternatives on our own, we will certainly end up doing more harm than good.

Consider your next Google search. As noted in a recent article in Harper’s, “Google . . . and its rivals now head abroad for cheaper, often dirtier power.” Google itself (the “don’t be evil” company) is looking to set up one of its electrically voracious server farms at a site in Lithuania, “disingenuously described as being near a hydroelectric dam.” But Lithuania’s grid is 0.5 percent hydroelectric and 78 percent nuclear. Perhaps the company’s next huge farm will be “near” the Three Gorges Dam in China, built to generate over three times as much power as our own Grand Coulee Dam in Washington State. China will be happy to play along, while it quietly plugs another coal plant into its grid a few pylons down the line. All the while, of course, Google will maintain its low-energy headquarters in California, a state that often boasts of the wise regulatory policies—centered, one is told, on efficiency and conservation—that have made it such a frugal energy user. But in fact, sky-high prices have played the key role, curbing internal demand and propelling the flight from California of power plants, heavy industries, chip fabs, server farms, and much else (see “California’s Potemkin Environmentalism,” Spring 2008).

Please read Huber’s essay top to bottom. I’m confident that reading and reflection will motivate you go on to read The Bottomless Well.
One quibble, Huber writes

They use energy far less efficiently than we do, and they remain almost completely oblivious to environmental impacts, just as we were in our own first century of industrialization.

Three points. One, If the decarbonization data presented in How to Get Climate Policy Back on Course is accurate, then China is at about the same value as the USA of tonnes-CO2 per $1000 of GDP. Point two, if LRL’s Mark Levine is correct in his presentation of Chinese decarbonization policy, then we should see China’s rate of decarbonization improve even faster now that the “policy holiday” taken by Beijing is over. Three, if America continues to ignore the reality of nuclear power, then they may never be able to catch up with China – who already are committed to at least 100 additional AP1000 reactors. All of my sources point to an acceleration of China’s nuclear power deployment. Same is true of India, but so far to a lesser degree.

How to Get Climate Policy Back on Course

The lesson of the recent past is clear to us. In the first instance, policy should focus directly on decarbonization rather than on emissions; on causes instead of consequences. (…) The Japanese target does not depend on the froth of purchased offsets.

Another blockbuster joint paper was released 6 July 2009 by the London School of Economics / University of Oxford. This report builds on the ongoing analysis of Kyoto by a distinguished group of researchers: why Kyoto went wrong, after Kyoto, what policies are likely to really work.

My own introduction to this program was the 2007 paper The Wrong Trousers: Radically Rethinking Climate Policy by authors Gwyn Prins and Steve Rayner. At the time I felt like I had been working in a dark room when Prins/Rayner stepped in to turn the lights on. They were willing to “speak truth to power” in the hope of changing the whole direction of climate policy onto a track that could be incrementally managed to achieve good outcomes: a policy covering the full range of options, from mitigation, to adaptation, to geoengineering.

The captioned new report, How to Get Climate Policy Back on Course , is authored by a formidable dream team. Inverting “ad hominem attack”, my defense would highlight the additional expert coauthors. Here by example are just a few names familiar to those of who have been seeking a practical policy framework: Christopher Green, Roger Pielke, Jr, Dan Sarewitz and Hans van Storch. The report exhorts policy leaders to drop the failed Kyoto-style framework and instead focus directly on decarbonizing global energy systems by applying the Kaya Direct Approach

The Kaya Identity shows that there are four – and four only – macro-scale policy levers in pursuit of emissions reductions. These are, respectively, population, wealth, energy intensity (meaning units of energy per unit of GDP) and carbon intensity (meaning the amount of carbon produced per unit of energy). Each of these factors is amenable to the action of a particular lever and each lever prescribes a particular approach to policy.

See discussion in R.A. Pielke Jr, ‘The British Climate Change Act: A Critical Evaluation and Proposed Alternative Approach’, Environmental Research Letters, 18 June 2009, doi: 10.1088/1748-9326/4/2/024010. 6 July 2009 In the case of population, the lever is population management. In the case of wealth, the lever is to reduce the size of the economy. In the case of energy intensity, the lever is to increase energy efficiency. And for carbon intensity, a switch to energy sources that generate fewer emissions is the primary lever.

The relationship between the four factors in the Kaya Identity can be expressed mathematically as follows:

carbon emissions = C = P x (GDP / P) x (TE / GDP) x (C / TE)   [where TE is total energy]

This paper is about the record of, the prospects for and the implications of decarbonisation as a focus of climate policy. In deference to Professor Kaya’s insight, we call it the Kaya Direct Approach. The Kaya Direct Approach means focussing on those factors that articulate with emissions and economic growth explicitly, rather than through an indirect and perhaps non-existent chain of causation. We do know something about how to improve efficiency: we’ve learned that from Japan. We do know something about decarbonising energy supply: we’ve been doing so for 200 years. So focusing upon incremental progress based on what we know, will begin to move us in the right direction.

Part I leads off with an clear statement of the challenge:

The abject failure of existing policy

The rate of global decarbonization can be broken down by region (see figure):

The historical record shows quite clearly that global and regional rates of decarbonization have seen no acceleration during the recent decade, and in some cases, show evidence of re-carbonization. Why is this so?

The axiomatic reason is to do with the nature of knowledge. It is a characteristic of open systems of high complexity and with many ill-understood feed-back effects, such as the global climate classically is, that there are no self-declaring indicators which tell the policy maker when enough knowledge has been accumulated to make it sensible to move into prescriptive action. Nor, it might be argued, can a policy-maker ever possess the type of knowledge – distributed, fragmented, private; and certainly not in sufficient coherence or quantity – to make accurate ‘top down’ directives. Hence, the frequency of failure and of unintended consequences.

Under the Kyoto Protocol, policy makers have been presented with frequent lessons about the unintended consequences of policy action. For instance, setting huge targets for renewable energy in a short time frame (from 8.5% to 20% by 2020) may unintentionally drive the whole of Europe into large-scale wood burning. This decision will almost double the wood demand for biomass energy in the EU-15 from 55% of harvested wood in 2001 to 100% in 2020 at current harvest levels, or it may increase harvest above 1950 levels – the peak moment when the harvested proportion of net primary production was 1.5 times today’s levels – and shorten forest rotation lengths. It has been calculated that wood consumption will be 453 million cubic metres in 2020 due to bio energy targets. There will be a huge demand-supply gap.4 There will be different sorts of hazard also. Decentralized wood burning may increase the already considerable number of deaths caused by fine-particle emissions in Europe. Furthermore, it will increase the atmospheric black carbon load, which is thought to have powerful climate forcing effect: the opposite result of what policy intends.


The fourth problem is that climate policy has come to serve many other political and social functions beyond its declared formal objective. Thus, undeclared political, religious, ethical and wider lifestyle and social purposes are being fulfilled which complicate the design and the application of a formal policy process.

Yes – the media contribute to this hidden agenda, attributable to some of the highest-profile anti-growth activists. Their agenda may be some variant of “back to nature, you can read by a candle” while their advertisements exhort “efficiency is the answer” and “Nuclear isn’t safe”.

The paper is rich in examples of the unintended consequences of the top-down target setting policies. E.g., on biofuel mandates

Recent analysis calculates that it would take 400 years to pay off the global ‘carbon debt’ caused by changes in land use induced by bio-fuel energy production. [Ed – the reference for that is J. Fargione, J. Hill, D. Tilman et al. ’Land Clearing and the Biofuel Carbon Debt’, Science, Vol. 319, 2008, pp. 1235-1238].

E.g., the anti-nuclear campaign

A final example: EU policies will set clean energy sources in competition against each other, especially nuclear against the available renewable energy sources (bio and wind). As a result of running down nuclear power, the consumption of fossil fuels is growing everywhere.

Part II is captioned “So what should be done instead?

For reasons of political feasibility as well as of efficiency, pointed out in the Kaya Identity, the Kaya Direct Approach focuses on energy intensity and carbon intensity and not on population and wealth. Population control policies are always politically explosive and so too would be attempts to reduce general wealth or to curb wealth creation. In democracies, there are no votes in making people feel poorer, and we suspect that such policies would be unpopular elsewhere as well, for example in China.

In contrast, we think the evidence encouraging if policy focuses directly on efficiency/intensity improvement through technology development and deployment. First, direct efficiency gains do translate into real reductions in emissions. (…) Secondly and related, pursuit of direct efficiency gains prioritises the heavy energy using sectors first and only concerns itself with lower impact sectors much later on. So, on this logic, world-wide there should be a sectoral focus on electricity generation first of all and then on other heavy user industries, such as iron and steel or aluminium production.


The Kaya Direct Approach would focus on expanding the provision of carbon-free energy. To this end, we support a low ring-fenced carbon tax in one form or another to fund innovation policies. The core argument of the Breakthrough Institute is an elementary political truth, namely that clean energy will only advance radically when it is made cheaper than dirty energy at point-of-use by the consumer.

The Kaya Direct Approach has another advantage over current methods – an advantage which is potentially of decisive importance, in our view. It is that it is incremental which means that progress can be continuously assessed. There are no arbitrary deadlines. It is the rate of decarbonization which is the ultimate arbiter of success. This means that we can avoid what we have just experienced, namely the danger of long periods of unobserved failure of policy.

The approach is preferable for other reasons. First of all, it addresses design shortfalls in the conventional approach. That much is already evident from our account above. In particular, it detaches the setting of targets from emissions. (…) The energies and time of the negotiating community currently engaged on the pursuit of a “bigger and better” Kyoto model for the Copenhagen Conference (which has already been shown to be nugatory at the Poznan and Berlin preparatory conferences) can be productively harnessed: for there will be a need for international agreement and review of best practice bench-marks, for example. This would be a much more practical and effective activity than setting aspirational and unachievable emissions reduction targets of which the UK Climate Act is the leading example.

Please read How to Get Climate Policy Back on Course, and The Wrong Trousers: Radically Rethinking Climate Policy, and Roger Pielke, Jr.’s related papers The British Climate Change Act: A Critical Evaluation and Proposed Alternative Approach, and Mamizu Climate Policy: An Evaluation of Japanese Carbon Emissions Reduction Targets.

The climate change record, evidence for sudden changes in climate

We’re collecting a few basic links to the climate record. Contributions of superior data and interpretations would be much appreciated. The Lisiecki and Raymo graphic above has a complex derivation, summarized briefly here — don’t mistake it for anything analogous to familiar contemporary temperature records.
The sudden onset of glaciation can be appreciated from the recent 450kyear reconstructions of Antarctic temperature
Moving from the recent climate history shown in the two graphics above, here is a 65 million year reconstruction:  
Continuing our interest in sudden climate shifts, here are a couple of short papers that look interesting. First is Sudden climate transitions during the Quaternary, which is in preparation by Jonathan Adams (1), Mark Maslin (2) and Ellen Thomas (3). The authors caution:

Article in press in Progress in Physical Geography    This represents an earlier version of our text. Some changes have been made since we stopped modifying this web version: e.g. we have added a discussion of the role of volcanic aerosols in sudden climate changes…evidence suggests the rapid cooling at the end of the Eemian interglacial was due to a big explosive volcanic event. Other ‘volcanic’ cooling events occured during the Holocene.

Excerpts from the Abstract and Introduction:

The time span of the past few million years has been punctuated by many rapid climate transitions, most of them on time scales of centuries to decades or even less. The most detailed information is available for the Younger Dryas-to-Holocene stepwise change around 11,500 years ago, which seems to have occurred over a few decades. The speed of this change is probably representative of similar but less well-studied climate transitions during the last few hundred thousand years. These include sudden cold events (Heinrich events/stadials), warm events (Interstadials) and the beginning and ending of long warm phases, such as the Eemian interglacial. Detailed analysis of terrestrial and marine records of climate change will, however, be necessary before we can say confidently on what timescale these events occurred; they almost certainly did not take longer than a few centuries.Various mechanisms, involving changes in ocean circulation, changes in atmospheric concentrations of greenhouse gases or haze particles, and changes in snow and ice cover, have been invoked to explain these sudden regional and global transitions. We do not know whether such changes could occur in the near future as a result of human effects on climate. Phenomena such as the Younger Dryas and Heinrich events might only occur in a ‘glacial’ world with much larger ice sheets and more extensive sea ice cover. However, a major sudden cold event did probably occur under global climate conditions similar to those of the present, during the Eemian interglacial, around 122,000 years ago. Less intensive, but significant rapid climate changes also occurred during the present (Holocene) interglacial, with cold and dry phases occurring on a 1500-year cycle, and with climate transitions on a decade-to-century timescale. In the past few centuries, smaller transitions (such as the ending of the Little Ice Age at about 1650 AD) probably occurred over only a few decades at most. All the evidence indicates that most long-term climate change occurs in sudden jumps rather than incremental changes.   


Until a few decades ago it was generally thought that all large-scale global and regional climate changes occurred gradually over a timescale of many centuries or millennia, scarcely perceptible during a human lifetime. The tendency of climate to change relatively suddenly has been one of the most suprising outcomes of the study of earth history, specifically the last 150,000 years (e.g., Taylor et al., 1993). Some and possibly most large climate changes (involving, for example, a regional change in mean annual temperature of several degrees celsius) occurred at most on a timescale of a few centuries, sometimes decades, and perhaps even just a few years. The decadal-timescale transitions would presumably have been quite noticeable to humans living at such times, and may have created difficulties or opportunities (e.g., the possibility of crossing exposed land bridges, before sea level could rise). Hodell et al. (1995) and Curtis et al. (1996), for instance, document the effects of climate change on the collapse of the Classic period of Mayan civilization and Thompson (1989) describes the influence of alternating wet and dry periods on the rise and fall of coastal and highland cultures of Ecuador and Peru. The beginning of crop agriculture in the Middle East corresponds very closely in time with a sudden warming event which marks the beginning of the Holocene (Wright 1993). Even the burial in ice of the prehistoric mummified corpse of the famous ‘Iceman’ (e.g., Bahn and Everett, 1993) at the upper edge of an alpine glacier coincided with the initiation of a cold period (‘Neoglaciation’) after the Holocene climate optimum (Baroni and Orombelli, 1996). On longer timescales, evolution of modern humans has been linked to climatic changes in Africa (e.g., de Menocal, 1995). But the full implications of these sudden changes for biogeography and for the evolution of human cultures and biology have barely begun to be considered; there has simply not been time for the message to be absorbed by biogeographers, archaeologists and palaeoanthropologists, and this review is intended to help the process along.Sudden stepwise instability is also a disturbing scenario to be borne in mind when considering the effects that humans might have on the climate system through adding greenhouse gases. Judging by what we see from the past, conditions might gradually be building up to a ‘break point’ at which a dramatic change in the climate system will occur over just a decade or two, as a result of a seemingly innocuous trigger. It is the evidence for dramatic past changes on the timescale of centuries to decades which will be the subject of this review.

More background from the Quaternary Environments Network (QEN)* can be found in A quick background to the last ice age where we learn of more evidence for sudden jumps in climate.

Energy policy: good policy can stabilize emissions and create wealth

200804270946Good energy policy can probably stabilize emissions at a 2050 GDP cost of less than 2% Studies project more like 1 to 1.5% but forecasting how it is all going to work out in 50 years is impossible. So 2% is just my speculation, based on my optimism about markets and innovation, and a recognition that humans can adapt and adjust policy as innovations and effects emerge.

What do I mean by good policy? Simple summary: a revenue-neutral carbon tax. Establish a predictable rising price on carbon from a low level of around $15/ton CO2, increasing to around $60/ton by 2050. If innovation is running ahead of plan, then that offers the possibility of reducing planned future increases. Inversely, if emissions are running ahead, increase the future carbon price. Something like Al Gore’s proposal could result in a GDP gain by 2050, not a loss [e.g., because energy not consumed is cost not spent]. Gore proposes rebates of the first dollars of payroll taxes — dollar for dollar with revenues from the carbon taxes.

For the details of how carbon tax revenues can be fully rebated and distributionally neutral, see e.g., “A Proposal for a U.S. Carbon Tax Swap – An Equitable Tax Reform to Address Global Climate Change” [Brookings Institution Hamilton Project Oct 2007] by Gilbert E. Metcalf, Professor of Economics, Tufts University.

The complexity of cap-and-trade vs. the simplicity of revenue-neutral carbon taxes

The previous post on the ecology of tree planting illustrates the mess that is about to be created by the cap-and-trade schemes. These require vast administrative bureaucracies to determine, measure, monitor both sides of every emissions “trade”. And it isn’t simple to determine whether an activity being sold as an “offset” is in fact. It may simply be scientific rubbish, such as tree planting above 20° latitude. Or as common today, it is an activity that was going to be undertaken anyway, but now is enormously profitable due to scalping an “offset fee” in addition to the already favorable project economics. I.e., tree planting.

A revenue-neutral carbon tax scheme has none of these problems, needing nearly zero administration — no complex determinations. And the taxes can be collected by already existing channels, such as corporate income tax.

Cap-and-trade schemes have already proven to be huge generators of new rent seeking special interest groups. Every single type of “emission offset” will gather around it a host of parties profiting from the activity and lobbying for more and more of it. Again none of this happens with carbon taxes.