Arguments
The Road to Two Degrees, Part Two: Are the experts being candid about our chances?
Posted on 26 November 2015 by Andy Skuce
The first part of this three-part series looked at the staggering magnitude and the daunting deployment timescale available for the fossil fuel and bioenergy carbon capture and storage technologies that many 2°C mitigation scenarios assume. In this second part, I outline Kevin Anderson's argument that climate experts are failing to acknowledge the near-impossibility of avoiding dangerous climate change under current assumptions of the political and economic status quo, combined with unrealistic expectations of untested negative-emissions technologies.
In plain language, the complete set of 400 IPCC scenarios for a 50% or better chance of meeting the 2 °C target work on the basis of either an ability to change the past, or the successful and large-scale uptake of negative-emission technologies. A significant proportion of the scenarios are dependent on both. (Kevin Anderson)
Kevin Anderson has just written a provocative article titled: Duality in climate science, published in Nature Geoscience (open access text available here). He contrasts the up-beat pronouncements in the run-up to the Paris climate conference in December 2015 (e.g. “warming to less than 2°C” is “economically feasible” and “cost effective”; “global economic growth would not be strongly affected”) with what he see as the reality that meeting the 2°C target cannot be reconciled with continued economic growth in rich societies at the same time as the rapid development of poor societies. He concludes that: “the carbon budgets associated with a 2 °C threshold demand profound and immediate changes to the consumption and production of energy”.
His argument runs as follows: Integrated Assessment Models, which attempt to bring together, physics, economics and policy, rely on highly optimistic assumptions specifically:
o Unrealistic early peaks in global emissions;
o Massive deployment of negative-emissions technologies.
He notes that of the 400 scenarios that have a 50% or better chance of meeting the 2 °C target, 344 of them assume the large-scale uptake of negative emissions technologies and, in the 56 scenarios that do not, global emissions peak around 2010, which, as he notes, is contrary to the historical data.
I covered the problems of the scalability and timing of carbon capture and storage and negative emissions technologies in a previous article.
From Robbie Andrew, adjusted for non-CO2 and land-use emissions.Note that these mitigation curves assume no net-negative emissions technologies deployed in the latter part of the century.
The fossil fuel carbon budget is even smaller than we think
The IPCC AR5 Synthesis Report informs us that if we want to have a better than 66% chance of avoiding a 2 °C rise in global temperatures our total emissions between 2011 and 2100 must be below 1000 Gt of CO2. Even if we held current emissions of about 35 Gt CO2 fixed (something we are not yet on track to achieve), we would use up this quota in less than 30 years. At that point, to meet the target, we would have to stop the economy cold, which won’t happen.
The real target for fossil-fuels emissions is actually smaller than 1000 Gt CO2:
- Between 2011 and 2014 we emitted about 140 Gt of CO2, taking down the available budget to 860 Gt.
- Anderson uses one of the more optimistic estimate of land use emissions in the IAMs for the rest of the century of 60 Gt of CO2 to reduce the budget down 800 Gt.
- The industrialization of developing nations and the transition to low-carbon infrastructures in wealthier nations will see process emissions from cement manufacture rise. Even with optimistic assumptions on the deployment of new low-emissions technologies the total, across the century, will be around 150 Gt of CO2.
The budget now available for fossil-fuel emissions therefore shrinks to 650 Gt CO2, roughly two-thirds of the often-cited 1000 Gt amount.
Side note: What Anderson's Nature Geoscience article did not mention was the possibility that some carbon-cycle feedbacks that are unmodelled in the IAMs might shrink the budget even further. These would include emissions from the thawing permafrost, nutrient limitations on plant growth and die-back in tropical forests. There is no peer-reviewed, integrated assessment of these effects yet, but I did a very rough estimate that the permafrost and die-back feedbacks might amount to 200 Gt CO2 over the rest of the century even for a low-warming pathway. Therefore, instead of a 1000 Gt CO2 budget, we might only have 450 Gt available for fossil-fuel energy emissions.
Anderson, in a private communication, pointed out that the IPCC shows an optimistic double bias in excluding some carbon-cycle feedbacks in models (because they are currently deemed too uncertain and speculative), whereas they include speculative and untested mitigation technologies.
Feedbacks aside, Anderson argues that to meet the 650 Gt CO2 target, annual reductions in emissions of 10% would be required. If you assume 3% in annual GDP growth, that would imply a 13% year-on-year reduction in carbon intensity per unit of GDP.
Historical rates of carbon-intensity decline over the past 35 years have been around 1% per year. Quite clearly, to get to a sustained 13% over the next 35 years will require more than painless incremental change and giving current trends an extra nudge from modest carbon-pricing incentives. In his lectures (see links at the bottom) Anderson notes that economists conventionally see annual emissions declines of 4% as the maximum achievable).
Here is a chart that shows how the promised reductions in emissions from the three biggest emitters square with what needs to be done:
From Peters et al. (2015) showing the projected emissions from the USA, EU and China based on the Intended Nationally Determined Contributions (INDCs) that will be presented at the December 2015 meeting in Paris. The black line is a pathway consistent with 2°C.
Shortly after 2030, the USA, the EU and China, representing about 2 billion people, will have used up all of the world’s emissions on the road to 2°C. The grey area in the chart above represents the room left for the remaining 5 billion people. This group includes heavy per-capita emitters like Canada, Australia and Russia as well as poor, but rapidly industrializing countries in Asia and Africa with huge populations. It just doesn’t compute.
Dissonance
Anderson’s case, in summary, is that most of us, whether scientists, policy makers or citizens, are suffering from cognitive dissonance. We acknowledge the mathematics of carbon budgets compatible with the 2°C target, yet are unable to face the revolutionary implications of what we need to do to get there. Put simply, our entire way of life for most of us in rich countries—and for an increasing number of rich people in poor countries—has to change radically, starting now.
In his concluding paragraphs, he addresses his fellow scientists:
Explicit and quantitative carbon budgets provide a firm foundation on which policy makers and civil society can build a genuine low-carbon society. But the job of scientists remains pivotal. It is incumbent on our community to communicate our research clearly and candidly to those delivering on the climate goals established by civil society; to draw attention to inconsistencies, misunderstandings and deliberate abuse of the scientific research.
It is not our job to be politically expedient with our analysis or to curry favour with our funders. Whether our conclusions are liked or not is irrelevant. Yet, as we evoke a deus ex machina (such as speculative negative emissions or changing the past) to ensure our analyses conform with today's political and economic hegemony, we do society a grave disservice — the repercussions of which will be irreversible.
I admit to have been taken aback by the "curry favours with our funders" comment. For one thing, this is a bit too close to the myth that "scientists are conformists and only in it for the grant money" debunked with brio by Richard Alley. Secondly, many of the experts who are in a position to be listened to are in tenured employment and ought to be beyond the stage of needing to please their paymasters.
In a personal communication, Anderson points out that the three biggest grant-giving bodies in the UK (NERC, EPSRC, ERSC) all have explicit mention of the having research contribute to fulfil government goals of increasing economic growth. For example, the EPSRC, the Engineering and Physical Science Research Council, expresses the intent of having universities “become centres of innovation and entrepreneurship, generating commercial success to fuel growth.” Quite clearly, the funding of research projects that might challenge or undermine these notions would be going against the political grain.
Why then, if you accept Kevin Anderson's arguments, are so few experts sounding the alarm in the way he does?
- Perhaps many experts really do disagree with his diagnosis. If so, one wonders why they don't dispute rather than ignore what Anderson is saying. My impression is that his arguments cause discomfort, but nobody is willing to rebut them.
- Perhaps the scenario modellers are so absorbed in the details of what they are doing that they mistake the map for the territory.
- Perhaps it is a shared desire with the politicians to see a deal, any deal, made. Some progress on mitigation, even if it is manifestly inadequate to reach the 2°C target, is better than none. Emission reductions we make today will reduce the cumulative burden that we are passing on.
- Or perhaps, as Anderson notes, political expediency is what is driving this. The global "political and economic hegemony" in which growth-based economics is taken as a given and the political status quo is assigned the nature of an ineluctable fact, rather than an obstacle that we must overcome.
For American policymakers and scientists, particularly, an important element in this expediency is the pachyderm in the parlour of US politics. As Jonathan Chait put it:
The Republican Party’s complete refusal to accept any limits on greenhouse-gas emissions whatsoever is an unspoken force shaping the Paris negotiations. The outcome cannot be written as a formal treaty, since treaties require approval by the Senate, and Senate approval requires Republicans. Instead, the agreement will take the form of legally non-binding pledges, which the U.N. is calling “intended nationally determined contributions,” enforced by international diplomatic pressure. The entire world is, in essence, tiptoeing gingerly around the unhinged second-largest political party in the world’s second-largest greenhouse-gas emitter, in hopes of saving the world behind its back.
Acknowledgement by prominent scientists and policy makers that achieving the 2°C target requires a globally coordinated and revolutionary overhaul of the world economy would surely only increase the unhingedness of the Republican Party. The GOP already controls both houses of Congress, the majority of state capitols and, according to some, stands a near 50/50 chance of capturing the Presidency in 2016. If the Paris talks do make progress, it is far from certain that the USA will follow through on its pledges.
Face it, deal with it
I asked Kevin Anderson for a quote on what we need to do to address the climate crisis. He replied:
We have all the technologies and policy tools necessary to begin an immediate programme of deep decarbonisation.To deliver on 2°C requires a two phase plan. First, early and radical reductions in energy use by the small proportion of the global population responsible for the lion’s share of energy consumption, and hence emissions (see Chancel and Piketty). Second, and simultaneously, initiate a Marshall-style build-programme of very low-carbon energy supply alongside much greater levels of electrification. The details of different national approaches will vary depending on many factors, not least, renewable resources, existing infrastructures, population density, economic structure, and wider cultural and political characteristics.
As difficult as radical mitigation may seem, failure may entail imagining a functioning civilization at 4°C or higher, which is even harder. The reason that credible action appears so difficult is because we have procrastinated for so long. Making an apparently impossible future possible is the challenge we face, but we won't get there if we are not prepared to face the facts, unpalatable as they are.
References
Anderson, K. (2015). Duality in climate science. Nature Geoscience. (open access text)
Peters, G. P., Andrew, R. M., Solomon, S., & Friedlingstein, P. (2015). Measuring a fair and ambitious climate agreement using cumulative emissions. Environmental Research Letters, 10(10), 105004. Open access
Here is a recent lecture by Anderson: The Ostrich or the Phoenix?...dissonance or creativity in a changing climate.
For more details, with some overlap, watch this one: Delivering on 2°C: evolution or revolution?
Thanks to Kevin Anderson for patiently answering my questions.
In the last part of this series, I will look at perhaps the most difficult problem of all: the awkward questions of equity and fairness in allocating future emissions budgets between rich and poor.
Excellent article. I'd love to know what Anderson thinks of articles like the one in this SkS post that claim that the US can get to 100% renewables for all energy (without using nuclear or fossil fuels) by 2050.
We cannot ignore the opportunities for 'new' nuclear technologies, specifically thorium (molten salt) reactors, which China and India are working to ramp up (I believe Westinghouse may be part of the technology development on this).
There is far more thorium available than 'normal' uranium nuclear fuels, for several hundred years, and minimal nuclear waste as compared with present reactors.
Unfortunately, the word 'nuclear' has nuclear political implications to any candidate or party which backs it - this needs to be changed and change can only occur with an educated public on the opportunities we have for these reactors. Safer, cleaner nuclear could provide most, if not all, of the energy needed that solar and wind cannot deliver, and could produce energy to power our cars, etc.
please spare us the thorium salesman routine @Cooper13. It's no panacea, it's been around as a concept and experimental technology almost as long as gen two reactors. if it was so grand we'd have seen progress with it by now. Nuclear power has been on a ocst curve north for the last five decades, by contrast wind, PV and SolarCST with thremal storage have demonstrated impressive learnigns curves, with solar PV doubling in deployment every two years and reducing module cost for every doubling by 20%. As Kurzweil points out, that means our global current energy consumption will be exceeded by the PV capaicty by as soon as in 16 years. At the cost will be almost free. How is a thorium or any other centralised nuclear power indrustry going to compete with ubqiotous and near-free energy?
As Giles Parkinson has pointed out, even if coal fuel were free and emissions were free (no carbon price) it still can't compete with solar behind the meter due to network costs being ~50% of billed energy prices. How will you even get a single thorium reactor (that isn't designed yet) through a planning process in Australia sooner than the next 16 years, let alone built and operational. Nah nucelar power is dead as a dodo. Even nuclear posterboy France is cutting back from 75% to 50% and they found in a major research paper that abandoning the massive sunk cost nuclear fleet and going to 95-100% RE would actually save them money, despite all that state sponsorship of the industry, it still can't compete with RE and storage going forward.
[PS] To Cooper and WEP. The moment someone brings up "nuclear", discussions have a bad tendency to speed off-topic, often with a lot more heat than science. BraveNewClimate is a better forum for such discussions. On this site, the requirements to keep comments on-topic will be strictly enforced.
The water vapor and Lapse-rate feedbacks take 10 years to reach maximum warming after emissions. The earth is operating at 2008 levels on this factor. Aerosol emissions associated with fossil fuel combustion are currently offsetting HALF of the total warming impulse. As we mitigate emissions these aerosols will be removed rapidly. The melting polar ice cap produces about 20% of total warming and the ice caps will be gone by mid sept of 2022. The production of GHG from buring tropical peat (indonesia) the loss of the amazon, the burning of boreal peat and forests are all happening much faster than models predicted. The models do not include warming from permafrost emissions.
we are at 1.1 C above pre-industrial and we will shoot over 2C by 2035.
Unless we extract billions of tons of CO2 from the earth's atmospher over the next 3 decades (as well as reach net zero emissions by 2025) we will overshoot to 3C by 2055 and 4C by 2080.
The rate of warming of planet earth has doubled since 2007 as measured by the change in ocean heat content. This quarter's new measure will show continued increase in the rate of warming on an annually averaged level.
Thanks for this excellent post, it's exactly the sort of wake up call that I need. It's very easy to lose sight of how urgent the situation is, and to forget that we need urgent decarbonisation of our economic system.
'The global "political and economic hegemony" in which growth-based economics is taken as a given and the political status quo is assigned the nature of an ineluctable fact, rather than an obstacle that we must overcome'
...that's a very good description of our current predicament.
It is so tragic to have to have effort put into sussing out and presenting the fundamental cause of the tragedy faced today and in the future that had been so clearly stated in the 1987 UN Report "Our Common Future".
The following pair of statements are presented early in that document.
"25. Many present efforts to guard and maintain human progress, to meet human needs, and to realize human ambitions are simply unsustainable - in both the rich and poor nations. They draw too heavily, too quickly, on already overdrawn environmental resource accounts to be affordable far into the future without bankrupting those accounts. They may show profit on the balance sheets of our generation, but our children will inherit the losses. We borrow environmental capital from future generations with no intention or prospect of repaying. They may damn us for our spendthrift ways, but they can never collect on our debt to them. We act as we do because we can get away with it: future generations do not vote; they have no political or financial power; they cannot challenge our decisions.
26. But the results of the present profligacy are rapidly closing the options for future generations. Most of today's decision makers will be dead before the planet feels; the heavier effects of acid precipitation, global warming, ozone depletion, or widespread desertification and species loss. Most of the young voters of today will still be alive. In the Commission's hearings it was the young, those who have the most to lose, who were the harshest critics of the planet's present management."
That was based on what had been happening prior to writing the report. A much blunter statement would be made today, and no leader (political or in business) should be able to claim they were not aware of this.
The obvious threat to humanity is the shamelessness of the group of callous powerful wealthy people (undeserving of their wealth or power) pushing for what they want (and what they uderstand is unaccpetable) through fronts like the Tea Party and the House Freedom Caucus (powered by the science of misleading marketing).
That small group of undeservingly wealthy people understand that their wealth and power is not deserved. And they cannot be expected to care how much damage they cause trying to maintain and expand it.
They have abused their power in many ways including getting laws established that alow them to have the financial ability to ruin the political future of candidates in just enough regions to maintain their stanglehold on the most powerful nation on the planet (and fair to say also undeserving of its wealth and power) through a few elected representatives (willing to follow orders unflinchingly without consideration of the actual future consequences of their actions - or scarier is the potential that they believe that if they do not follow the orders eternal darkness will decend on the planet).
The belief that the developed economies are deserving of being maintained (let alone be expanded) is a grand fairy tale that the populations benefiting within them will struggle to free their minds from. And as long as those who do not care about the future can get away with their desired freedom of pursuits (by gathering support from easily impressed people through misleading marketing appeals to greed and intolerance) humanity's future is indeed bleak.
Gavin Schmidt, in
The Carbon Brief interview of Oct 15 2015, discussed those who talk of targets that simply should not be exceeded such as 2C or a set amount of CO2 emission allowed by naming Kevin Anderson in particular. He said: "I don’t think that that language is particularly useful, and I don’t think that concept is very helpful to making sensible decisions".
According to Schmidt, "Two degrees is not totally out of the question, though I think it is not likely that we will make it. But any of the decisions that we’re making now, to get us on a path towards reducing emissions, they’re the same decisions we’d be making if the target was 3C, or 2C, or 1.5C. The actual actions that people need to make are the same. So discussion of the target – quite frankly – I think is mostly a waste of time."
Anderson believes there is a some amount of warming civilization could get away with, but if there is some greater amount, civilization as we know it would end. And, he says, if people thought 2C looked like it was the borderline between these two conditions, as science has advanced, it has dawned on many that 2C is too much.
It would be of interest to know if types like Schmidt would argue the opposite, i.e. that increasing scientific knowledge indicates that it will be safe to exceed 2C. Will 3C, or 4C or 6C be just more of the same but hotter? No runaway feedbacks in sight? No dramatically escalating costs of coping? Civilization keeps humming along? How confident can anyone be?
I think many don't speak as clearly as Anderson because they believe that human beings need to be conned at this point or they will despair and do nothing.
"But any of the decisions that we’re making now, to get us on a path towards reducing emissions, they’re the same decisions we’d be making if the target was 3C, or 2C, or 1.5C. The actual actions that people need to make are the same." [Schmidt]
As much as I respect Schmidt as a scentist, I think this is not quite correct, or at least it is a statement that does not stand well in isolation. The type of actions required are the same, and the general directions in which we have to head are the same, but the urgency required for different targets is not at all the same.
This article is a timely reminder that the situation has already become urgent, and it is not enough just to vaguely embrace 'actions that people need to make', such as a slow move to renewables. The actions we needed to take in the 80s and 90s and 00s are not the same as the actions we need to take now, and the more we delay the more drastic the economic upheaval that will be necessary. We could have fixed things with minimal pain two decades ago; now it will take a bit more pain; wait any more and it will be worse.
Gavin Schmidt is probably right that there is no sudden risk-transition point in the region of 2 degrees, but people need to have the costs of each trajectory spelled out, both envirnomental and economic.
Frankly, as an Australian who lives on a dry continent prone to bushfires, I find the current ~1 degree of warming is already unacceptable for a number of reasons. The news is full of climate-related woe, not all of it obvious. There is even an argument to be made that droughts in Syria have contributed to the civil war there, and hence to the spread of terrorism. Dangerous climate change is not in the future; it is now. The idea of >2 degrees warming is simply awful.
My biggest concern about 2 degrees as a target is that it is already too much, especially after allowing for uncertainty in predictions and inertia in our economic and political institutions. But the fight for more aggressive targets should at least begin with the fight to defend the 2 degree target.
Leto @9.
I think that is a little unfair on Schmidt. He was actually answering the question of whether a 2ºC target was still relevant. His point involved the analogy of "the number of little old ladies you want to have mugged every year" which is obviously zero. But you wouldn't be discussing it if it was zero or if zero was possible. He says of a target for temperature, it should be as low as possible and of the 2ºC target "Two degrees is not totally out of the question, though I think it is not likely that we will make it." It is only in this context that your quote applies and it did come with an important finale answering the question being asked, a finale quoted @6 but that you cut away. Schmidt is saying we need to do as much as possible so it is the same decisions and same actions for 3ºC as it is for 2ºC or 1.5ºC. Thus the conclusion "So discussion of the target – quite frankly – I think is mostly a waste of time."
MA Rodger @10, I take your point, and I was actually impressed with Schmidt in is interview. I did throw in the caveat that the statement was not so much wrong as one that did not stand up well in isolation. (And I didn't mean to cut bits away but rather intended to point to the bit that concerned me, knowing the more complete quotation was still there upthread.)
My point is not really to criticise Schmidt. I am sure Schmidt has an excellent understanding of what is required (better than mine, I am sure), but there is still something in the (perhaps unfairly isolated) statement that concerns me.
Even in the case of mugged little old ladies we don't really, as a society, aim for zero muggings. Rather than putting every able-bodied adult on the street as a police officer to stop muggings, we accept a compromise, knowing that there are other demands on our resources.
Rather than little old ladies, think of speed limits. Tackling global warmng by 'doing as much as possible' is like tacklng road safety by 'driving as carefully as possible' - rather than by setting explicit speed limits and blood alcohol limits. We shouldn't avoid setting a target for fear of making an arbitrary decision about an artificial threshold, because the alternative is to get lost in vague motherhood statements.
Similarly, there is no simple image that comes to mind when you or Schmidt say 'do as much as possible'. Do you really expect me to do as much as physically possible to reduce my carbon footprint - give up all fossil fuels right now, today, stop heating the house, quit my job because it is beyond walking distance? You probably mean do as much as is reasonable, given the likely environmental, economic and societal costs of varying degrees of action... which demands some yardstick for reasonableness.
If climate scientists and economists collectively told me it would cost 10% of my income to keep warming below 2 degrees (assuming others followed suit), I would happily pay that in a carbon tax or some sort of renewable subsidy. If you told me that 10% wouldn't cut it, and we were heading for 4 degrees warming at that sort of cost, I would be keen to pay more, and do more, and I might look at restructuring my job and my life to avoid driving. It's not realistic to ask me to do everything possible, and even if I literally do everything possible, the world as a whole will never 'do everything possible' - it will do the minimum it thinks it can get away with, which is why I think we do need targets. Otherwise, there is a risk of sliding into some sort of vague, luke-warmist approach, which is effectively what the world is doing now.
Given how much time has been wasted debating the faux pause (not the fault of anyone here, of course), I really don't think this issue is 'mostly a waste of time'.
Leto @ 9:
"We could have fixed things with minimal pain two decades ago; now it will take a bit more pain; wait any more and it will be worse."
This statement is valid only if we are focused on the Earth's fever that is climate change, while ignoring the cancer that is our unsustainable economic growth. Such a fix would have continued economic growth using renewable energies, which would have continued with the planet's desertification and biodiversity loss with the rich developed world relatively oblivious of the collateral damage.
When I read Schmidt's critique of Anderson (i.e. "I don’t think that that language is particularly useful, and I don’t think that concept is very helpful to making sensible decisions") I thought of the debate in the runup to WWII as described by historian Dan Todman, in this exerpt from a BBC History podcast produced in Sept 2009. (I believe the podcast is here):
"Todman: ...the government believes that the way to end this war is to depose Hitler. And it thinks that can be done without a complete commitment of British wealth, of British power, of British personnel. And the problem is that it is not a limited aim, getting rid of the head of a totalitarian dictatorship, its a total aim. The only way to do it is to smash that dictatorship. So they misjudge how the war is going to be fought. But they're not alone in doing that. I mean that's a widespread misconception amongst the whole population. And the limits on their freedom of action are not just conceptual. Its not that Chamberlain and members of his Cabinet want to continue with business as usual because they are somehow bad people, or that because they believe that always, business must come before national survival. Its really more that they are trapped in a situation, where they can't gain compliance on the part of the population, either on one side because of there's a great belief in voluntarism, both from the left and from the right, there's a strange situation in which you have both the Daily Express complaining about rationing, Beaverbrook launches a campaign against rationing in 1939, and the left also complaining about excessive compulsion.
So really the Chamberlain government is trapped in a circumstance where it can't generate the national will that's necessary to fight a more total war, even as it gbecomes more and more convinced as it gets into the spring of 1940 that that is what it has to do. and really it is not until the circumstances change, until the fall of France, and this great threat to Britain that emotionally mobilizes the population, that ANY government can start to do that. And it has to be said that even when the Churchill government comes in in 1940 it takes a far more hesitant approach to the mobilization of domestic efforts than is often assumed. May to jUne 1940 is not as great and decisive a shift as we sometimes think in terms of things like rationing, and the conscription of women, those are events that take place much later in the war. And they're very concerned, the Churchill coalition, to stay behind the demand curve, really, they're operating inside the same set of limits as their predecessors, but they're doing so in a drastically changed international circumstance."
Anderson, in this context, aims to speak the truth as he sees it, without regard to whether anyone is ready to hear it.
Leto @9
The truth is the solution is painful and always has been painful because it requires sacrifice for a future, that one can maybe foresee, but not see.
The long term maintenance of a stable temperature requires zero net emissions. Further, to bring emissions down sufficiently for a 2 C target requires western nations to reduce to zero net emission by 2050 or there abouts, even if we do not set national emission quotas on an equal per capita basis (the only truly fair way to tackle climate change). That presents a major problem. From 10-20% of total emissions are a direct product of agriculture. That rises to about 30% if fossil fuel use in agriculture is included. Of the direct emissions from agriculture, about 50% is in the form of nitrous oxide from fertilization of crops, and an approximately equal amount is from methane production either from rice production or from enteric fermation from cattle.
While studies have been undertaken as to how these values can be reduced, it would be foolish to think they can be eliminated. Nor can we draw down from current levels of agricultural production without guarantteeing a global famine. Ergo, for the forseeable future (ie, for several centuries down the track) we can expect NO2 and CH4 emissions from agriculture to equal at least 10% or current CO2eq emissions. That is, absent carbon sequestration CO2 emissions cannot be reduced below approximately 10% of current values.
Ergo, any viable future pathway must include carbon sequestration of at least 10% of current CO2eq emissions. That is in addition to any carbon sequestration of continuing standing energy supply from fossil fuels, or from transport (some of which may be impossible to eliminate).
The key point is that large scale sequestration is going to have to be deployed withing 30-40 years regardless of whether or not total emissions ever go negative or not. That is, even the emmision reduction curves in the first figure above that "... assume no net-negative emissions technologies deployed ..." must in fact deploy large scale sequestration technologies to deal with agricultural emissions. That being the case, we cannot consistently argue that we must follow one of those paths or fail to limit warming to a 2 C target. If we can deploy sequestration technology that compensate for agricultural emissions, than we can deploy 50% more of that technology and generate substantial net negative emissions.
This is not necessarily an optimistic point. Such technologies may be unfeasible at large scales, in which case the view is very pessimistic indeed for in that case we will never reach carbon neutrality. But more probably such technologies are achievable (though potentially with significant difficulty). In that case the situation is not as cut and dry as Anderson suggests. It is not, then, that we should not reduce emissions significantly faster than we actually are - but that it is not necessarilly cause for despair if we do not. There probably will be a plan B, and must be if there is in fact a viable plan A.
Tom,
Can you post a link to support your claim that agricultural emmisions must be countered by sequestration to keep temperatures stable?
It seems to me (without citations) that agricultural emissions will not need to be sequestered for two reasons:
1) Methane and NO2 are shortlived in the atmosphere and after a decade or two decompose into CO2 and harmless gasses. This is different from carbon dioxide which is essentially permanent once it is emitted.
2) All agricultural emissions come from gasses already in the atmosphere. Therefore if agriculltural emissions are stable after a period of time the concentration of agricultural methane and NO2 will stabilize. (The resulting CO2 came from the atmosphere so it would not increase CO2).
Lowering CO2 emissions from deforestation is necessary for long term stability of the atmosphere and may be difficult. Some sequestration may be necessary but the scale required might not be as large as you suggest.
This summary reviews many methods of reducing agricultural emissions by altering farm practices. Greater farm efficiency and choice of crops that emit less greenhouse gases can help. Managed forrest produces substantial income in many locations as long as enough food is produced.
The required use of a technology as difficult as sequestration that has not yet been developed at any price is extremely risky.
I find it interesting that the IPCC declines to estimate sea level rise from the decline of the great ice sheets because it is not well understood while at the same time relies on unknown technology for sequestration.
Leto @11.
I am inclined to see the 'mugged old lady'analogy as not immediately applying to the full ΔTemperature resulting from AGW. There is obviously no bad stuff (no mugged old ladies) if AGW resulted in ΔT(full)=0.1ºC. So perhaps we should apply it to the ΔT(from now). Or better still apply it to emissions from now. But such meddling probably is too much of a strain on the analogy.
Howver, I do rather like the idea of David Lewis @13 who likens present AGW policy to the 1939-40 Phoney War. A lot is being done (the UK was re-arming big-time well before Munich) but there is so far no sanction to properly begin doing what is inevitably needed to be done. In the greater public consciousness, the bad stuff has yet to be seen as that bad. Mind, comparing the available perspecive of Nazi malevolence in 1939-40 and the available perspecive of AGW today, playing a Phoney War with AGW is far less excusable.
michael sweet,
N2O has an atmospheric lifetime of about 120 years, and a global warming potential 300x that of CO2 over a 100 year timescale.
Furthermore, the N2O emissions do not come from "gasses already in the atmosphere" unless you consider the Haber-Bosch process as doing that. The fact is that we have disrupted and dominate the nitrogen cycle far, far more than we have the carbon cycle.
Methane, while it does have a shorter atmospheric life, also has a GWP of 34x that of CO2 at the hundred year timescale. Which is surely germane if we are talking about hittlng the 2C target.
So I don't think your rejoinder to Tom really holds.
(N2O is also a powerful ozone depleting substance, just to ruin our days a bit more...)
Kevin Anderson has an interesting article at his website about methods of inducing a decline in the burning of fossil fuel. He contends that MBIs (market-based instruments) are inadequate to the task. By MBIs is meant such methods as carbon taxes and cap-and-trade.
(As an aside, I should mention that I've always wondered if instituting a carbon tax is like trying to divide by zero: for fossil-fuel use to tend to zero, the tax has to tend to infinity!)
It would be interesting to follow up this Part Two article with Anderson's view of MBIs. How about it, Andy?
Digby, we are arranging one, maybe two, interviews with Kevin Anderson over the next little while, so I will make sure to put that question on the list.
If you or other readers have anything else you would like an answer to, ask it here and I will pass it along.
Digby Scorgie @19, for a carbon price to eliminate the use of fossil fuels, it need only raise the cost of using the fossil fuel to greater than its next cheapest competitor. As there is no use of fossil fuel where the next cheapest competitor has an infinite price, the cost of the carbon price need never rise to infinity to eliminate the emission of CO2. It is dubious that it needs to rise even to US$200 in the long term, although with current technologies it would need to rise higher to completely eliminate CO2 emissions.
Andy @20: I look forward to that, thanks.
Tom @21: That makes sense; the tax must make fossil fuels more expensive than the next cheaper alternative. The only problem I then foresee is when it costs an excessive amount to get the alternative introduced — as perhaps with synfuels for aircraft and ships. Anyway, it will be extremely interesting to hear what Kevin Anderson has to say about this, because he doesn't think an MBI such as a tax will work.
Another example of how some scientists don't give the full picture (or even the correct one) is Schmidt's Carbon Brief interview where he gave completely inaccurate figures for US emissions, even praising them (claiming imaginary reductions). This leads to the notion that GDP can be decoupled from emissions, which I've read other scientists espouse. I've always felt that this idea is false as it likely didn't take into account exported emissions. This Monbiot article points to research that there is no evidence that decoupling is taking place at all (and may even be the reverse). I think scientists are guilty of not thinking deeply enough about this stuff, even though they think deeply about their subject area.
Anderson is absolutely right, IMO, to point to these failings of the scientific community.
Digby Scorgie @22, the product of air transport is not air transport itself, but efficient transport of people and goods. One of the cheapest competitors of air transport is sea transport (or rail transport, or blimp transport) and in some cases simply telecomunications. Therefore, even if no adequate substitute for jet fuel can be found, there will still be reasonably prices substitutes for the actual services provided by modifying our social expectations or rapidity of delivery. Indeed, much of the "expense" of converting to a low emissions economy is simply social inertia in the form of expecting the bundle of goods and services we currently have, ie, optimized for delivery using fossil fuels, to remain unaltered when we could instead optimize for delibery with renewables with no loss of utility.
That leave aside the fact that jet fuel can be synthesized direcly from biological fuels, and/or jet fuel exhaust can be captured and sequestered, in either case providing a zero net emission substitute at far below infinite cost. Indeed, I included these possibilities in my estimate of US$200 carbon price for complete subsitution (although early schemes in this direction may be more expensive).
michael sweet @16, methane decays as a function of the concentration of OH radicals in the atmosphere. Therefore increasing the quantity of ozone (thus preventing the photodissociation of H2O) and of methane will increase the average decay time of CH4 (currently about 12.4 years to reduce to 36.8% of the original concentration). NO2 decays by photodissociation, so the rate is controlled by insolation and hence is fairly stable (decay time 121 years). In either case, the effect is that at a given emission rate, there will be a equilbrium concentration such that 63.2% of the concentration equals the emisisions of the decay rate.
For NO2, that concentration is significantly greater than the current concentration, even if NO2 emissions were halved. As a result sequestration to avoid increased forcing from NO2 will certainly be required. Because of the high natural rate of CH4 emissions and short decay time, that is not necessarilly the case. Therefore it is possible that sequestration will not be needed for CH4. On the other hand, increases in arctic CH4 emissions as a feedback, in addition to ongoing agricultural emissions will likely require ongoing sequestration. In neither case will sequestration need to continue in perpetuaty, only until atmospheric concentrations stabilize. That, however, is likely to take more than 50 years for methane and several hundred years for NO2.
Beyond those points, RustNeverSleeps @18 makes excellent points.
I am not aware of any particular research on this. It is just a point that follows logically from the difficulty in reducing direct agricultural emissions combined with the at least doubling of human population over the coming century (with consequent increase in the need for intensive agriculture). It is, however, a point that can slip by unnoticed by treating all emissions as just CO2eq for emissions pathways.
Finally, my final conclusion was not that a small multiple of sequestration made necessary by agricultural emissions will also sequester the emissions from an ongoing fossil fuel industry. That is certainly not the case, and it is dubious IMO that even 50% of current fossil fuel use can be reconciles with net zero emissions by sequestration. However, some small level of sequestration will be necessary regardless, and that small level can be increased to reduce overshoot at a slow rate. We are still best of keeping that overshoot as low as possible.
@ 24,
This is the argument that makes 'baseload' power largely a myth. If the elite want bespoke industry that makes profits while they sleep then they need to find a way to subsidise it and at the moment it is done through the sheeple consumer being too distracted by Hollywood to care enough about their kids to complain about the externalities of a globally manifest 24 hour working day.
The definition of 'efficiency' is worth looking at. Methodical thought implies that a problem is first well defined.
@ 22,
Yes: but that is the exact politics of the matter- "..what is an excessive amount?"
You are talking about the invisible hand of free market theory that is of course corrupted by any, and all, form(s) of Government intervention. The difficulty you talk of is often referred to as being, "..when Governments pick winners!"
Here's another question to pose to Kevin Anderson (or anyone else who want to take a shot at it):
Given the lag time for full equilibrium effects of CO2, and given that we have been emitting at by far the highest rates over the last few years and decades, and given that we are already at about 480 ppm CO2 eq...isn't it likely that we are already locked in to about a 2 degree rise over preindustrial times, even if we were to stop all further emissions today?
(This is of course assuming that we won't suddenly come up with a way to massively sequester atmospheric CO2, and that there is not some massive, unknown negative feedback waiting in the wings to save us--the potentially massive and quick feedbacks all seem to be positive, and you could add those to my 'given's above.)
On feedbacks, see most recently this: GW will be faster than anticipated (because of methane feedbacks from lakes)
wili @28, no we have not. The reason is that, with zero net emissions, CO2 concentrations in the atmosphere will be drawn as excess CO2 is taken up by the ocean. This process is fairly rapid and occurs on approximately the same timescale as the rise in temperature from the Transient Climate Response to the Equilibrium Climate Response. It follows that, with zero net emissions, temperatures will remain approximately constant, as shown in this graph from Matthew's and Weaver (2010):
Although Matthews and Weaver show a constant or slightly declining temperature with zero net emissions, a more recent study (not to hand at the moment) has shown the possibility of a slightly rising temperature as well, although this is most probable with low ECS so the rise in that case would be gradual and restricted. In any event, so long as we achieve zero net emissions before we reach 1.5 C, and possibly 1.9 C, we can prevent mean decadal temperatures rising above 2 C above the preindustrial average.
That's the good news. The bad news is that even continuing emissions as low as 5% of current emissions may (and certainly emmissions at 10% of current levels will) be enough to kick us into the constant CO2 concentration path (red line above). In that case whether or not we exceed 2 C depends on whether the ratio of 2 C divided by current temperature above preindustrial is less than, or exceeds the ratio of ECS to TCR, which means even another 0.2 C rise will make us 50/50 to avoid 2 C at best. Further, ongoing emissions at the 5% rate will in the long term (400 plus years) result in an ongoing gradual rise in temperature for up to tens of thousands of years into the future (or until we reach zero net emissions).
Further, this analysis ignores the effect indicated @15 above. That probably means we require slightly negative net emissions of CO2 to achieve zero net CO2eq emissions. (Note, for the long term, multi-centenial temperature rise, it is zero net CO2 emissions that matter, not zero net CO2eq emissons, due to the relatively short atmospheric lifetime of WMGH gases other than CO2.)
I wonder, with respect to the cooling period from 1940 to the mid 1970s, which masked actual warming due to sulfate emissions; are there any projections as to what increased sulfates in Asia may be masking?
RickG @31, unlike CO2, aerosols do not become well mixed in the atmosphere. As a result the negative forcing in relation to US/European aerosols was largely confined to the North Atlantic region, while those from China are largely confined to China. That is significant because there is evidence that the North Atlantic region is more sensitive to forcings than most other regions of the globe. This is most obvious with the impact of the milankovitch cycles forcing the glacial cycle due to strong NH summer insolation despite near zero global forcing. (Note, nearly all the major glacial ice sheets are associated with the North Atlantic.)
The upshot of this is that it is not a given that a given aerosol concentration over China will have the same masking effect as the same aerosol concentration over Europe/NA. So while increases aerosol emission will mask some warming, it is difficult to determine how much.
Thanks, Tom. Was the other study you were thinking of the one discussed here?: www.skepticalscience.com/Macdougall.html
Tom Curtis @24
I didn't want to initiate a discussion of alternatives to fossil fuel, but in broad outline what I believe would be feasible, though not at all easy to implement, is the following:
Gradually change over to renewables for all electricity production, with some nuclear power to handle the baseload. At the same time increase the efficiency of electricity use. In addition, people need to scale down their consumption and expectations.
For transport, gradually change over to synfuels for aircraft and ships, but also reduce the amount of flying people do and the quantity of goods needing to be shipped. For land transport switch to both electricity and synfuels for vehicles and to electricity for trains. Rely on telecommunications more and forgo cheap holidays overseas.
Regarding synfuels, I have been told elsewhere at this website that these are indeed feasible. This was after I discovered that ammonia has already been shown to work in both vehicles and aircraft (but with reduced efficiency) and that ammonia can be produced using renewable sources of electricity. There is no carbon in ammonia. Presumably the synfuels under investigation are better.
I have also discovered that, while the foregoing seems reasonable to me, people will inevitably poke holes in it. Never mind, I can take it!
Tom Curtis
I've thought some more about carbon taxes. They not only have to make fossil fuels more expensive than alternative fuels, they also have to make it more economical to decommission the fossil-fuel infrastructure while introducing and developing the infrastructure for the alternatives. The net effect is therefore likely to be a carbon tax much greater than anticipated.
Digby Scorgie @35, in principle that is correct. In practise it is not so clear. In particular, the time line over which we must drop to zero net emissions is approximately equal to the design lifetime of most power plants and significantly larger than the design lifetime of most other infrastructure. Consequently a carbon tax introduced now which will predictably be maintained or increased into the future will not have to deal with sunk costs on current infrastructure which will be replaced over the relevant timescale in any event. Further, so long as its long term imposition is predictable, it will be factored into any new construction thereby limiting any new construction of fossil fuel infrastructure, and ensuring such sunk costs are factored into the investment decision on any such infrastructure. That is, any future fossil fuel power plants will be built and costed with a reduced lifetime expectancy if reasonable certitude of a carbon price can be generated.
In addition to that, the effect of sunk costs will be limited by the ability to retrofit carbon sequestration technology and/or the ability to gain "carbon credits" for paying to more rapidly decrease emissions, or sequester emissions elsewhere at lower cost.
Having said that, as we delay taking adequate action to reduce emissions (as we appear to be doing even with optimistic estimates of the outcome from Paris), the time scale required for decarbonization sinks and sunk costs become a much larger factor. Put another way, the more we delay implimenting a carbon price, the larger the carbon price will need to be to move us to zero net emissions in a timely manner.
Tom Curtis, I think your final paragraph is the one that's really relevant. It relates to the very first graph in the above article, from which we see that we only have about two decades in which to make drastic reductions in fossil-fuel use. And there are some parts of the fossil-fuel system that are built to last quite a bit longer than two decades — ships, aircraft and coal-fired power stations are some that come to mind.
Anyway, Tom, I don't know about you, but I find myself in the position of someone having an interesting philosophical discussion on the deck of the Titanic — after the ship has hit the iceberg. But then, being an old man, I can afford to take a dispassionate view of the whole catastrophe.
I'm arriving late to this discussion but I sure do have a couple questions for KA if he's still accessible.
His objection to a carbon tax is that it unfairly burdens the least wealthy in society. This opinion seems to imply that he is unaware of the revenue neutral option, a circumstance I find not probable, considering James Hansen's long and loud advocacy. So, what else might be his objection to the rev-neutral fee/dividend approach.
Similarly, Hansen has been advocating for a global policy of CO2 drawdown via deforestation and agricultural soil management methods, which he thinks can amount to 2 GtC/year once the program is in full swing. Such a capability would be a huge boost to our ability to moderate atmospheric CO2 levels. Has KA considered and rejected this notion, or is he unaware of the potential?
[GT] Image resized to fit page. Please ensure any images you insert are sized to no more than 500 wide - larger breaks the page.
O boy. Didn't mean for the image to be that big... hope I haven't broken the site. :)
If it's not clear from the image captions, each scenario assumes 2 GtC/year CO2
drawdown in the years 2031 -2080 by reforestation and agricultural soil management techniques.
The source article is here.
From instances where a carbon tax has been tried, indications are that emissions begin to come down
in the first year.
Source article:
Assessing Dangerous Climate Change
Moderator
Thanks very much for the reference to the three valuable Andy Skuce essays on this very issue of the requirement of “negative emissions” to meet the assumption of most of the IPCC global climate models. It is unfortunate that he is no longer with us to respond to this post. I have read all three essays along with the other two recent discussions of this topic. At your suggestion, I am reposting my comments on the second of the three essays by Andy Skuce in November 2015. This one was titled “Are the experts being candid about our chances?”
Andy Skuce’s articles were directed at the above topic which has now been raised front and centre by Economist’s November 18, 2017 edition lead article. The front page of the Economist is entitled “What they don’t tell you about climate change”.
Here is a salient comment from the Economist lead article:
“Fully 101 of the 116 models the IPCC uses to chart what lies ahead assume that carbon will be taken out of the air in order for the world to have a good chance of meeting the 2° C target. The total amount of CO2 to be soaked up by 2100 could be a staggering 810bn tonnes, as much as the world’s economy produces in 20 years at today’s rate. Putting in place carbon-removal schemes of this magnitude would be an epic endeavor even if tried and tested techniques existed. They do not.”
I highly recommend that everyone read all three of Andy Skuce’s essays as well as the lead article of the Economist. In the above essay, Andy Skuce in 2015 refers to a paper by Kevin Anderson raising this very issue. Here is Andy Skuce’s summary of the Anderson 2015 paper:
“Anderson’s case, in summary, is that most of us, whether scientists, policy makers or citizens, are suffering from cognitive dissonance. We acknowledge the mathematics of carbon budgets compatible with the 2°C target, yet are unable to face the revolutionary implications of what we need to do to get there. Put simply, our entire way of life for most of us in rich countries—and for an increasing number of rich people in poor countries—has to change radically, starting now.”
I am personally blown away by this revelation that we not only need massive reductions in emissions to meet a 2° C target but also massive “negative emissions” from technologies that today are unproven. I have to agree that there has to be some "cognitive dissonance" going on in that in about 10 months of focussing on issues related to climate change I had never heard of this major issue with the underlying assumptions of most of the IPCC global climate models.
The moderator has referred to me two more recent discussions of this issue. I highly recommend reading the Elizabeth Kolbert November 20, 2017 article in the magazine The New Yorker which, coincidentally, covers the same territory as the November 18, 2017 edition of Economist. This paper discusses various technologies that are being considered (one within about 30 miles from our home in West Vancouver) but clearly concludes that today there is no proven technology to achieve the required negative emissions.
I hope this post will provoke some discussion of the various technologies being considered. From my reading of the recent discussions, BECSS seems to be the “front runner” but as the Economist says:
“Persuading Earth’s swelling population to plan an India’s worth of new trees or crops to produce energy, as the climate simulations require, looks highly improbable”.
What do we do?
Perhaps someone could point out where in the Fifth IPCC Assessment (and for that matter in the recent American Global Change Research Report) this assumption of negative emissions (and the ramifications that at the present time there are no proven technologies to achieve these negative emissions) is discussed.
[JH] You're welcome and thank you for your empathy re Andy Skuce.
Norrism:
And then deniers say scientists are being "alarmist" and there is no problem.
michael sweet @ 42
It will be interesting to see if this Economist article might prompt the Republicans to start thinking more about spending more funds on CCS research because it would "fit" with their agenda of staying with fossil fuels. I may be wrong but "intuitively" this might be a better tact to use with the Republicans while they are in power. But capturing CO2 from the air rather than during the combustion process does not sound promising even based upon my limited understanding of physics.
Norrism:
It is now cheaper to build out new wind and solar power plants than it is to run old coal power plants that have no mortgage expense. It will at least double the cost of coal power to do CCS with it. Goldman Sachs expects wind and solar to drop in price another 40% in the next decade (and in the past renewables have exceeded expectations of cost savings).
It will be much cheaper to just build out wind and solar than to waste the money doing CCS research.
NorrisM , the comments by Michael Sweet are exactly correct, in a nutshell.
For 20+ years, there has been a pitifully small amount of action taken against CO2 emissions — and the consequences are grim. The "trainwreck" which is AGW, is growing in magnitude. This is plainly obvious to every well-informed observer who chooses not to avert his gaze.
Yet the deniers (of reality) cry out "Alarmism" . . . as though that piece of rhetorical nonsense will somehow negate the real physical problem. The deniers are afflicted with Head-in-the-Sand mental disease — and history will judge them harshly for their selfishness and stupidity. (Not that that will bother the deniers, since they will be dead before the worst of the trainwreck is obvious to even the meanest intelligence.)
NorrisM, I have read The Economist article you referenced. But it did not state anything really new or insightful. The situation has been plainly obvious for many years. Politicians can (and do) talk and talk about 1.5 degrees and 2.0 degrees, but they make very little effort to reduce the size of the slow-motion trainwreck which is already under way.
An ounce of prevention is worth a pound of cure. We (collectively) have undertaken so little "prevention" . . . that "cure" (in the form of atmospheric carbon reduction) is now to fall heavily on future generations. They are the ones who will be faced with picking up the pieces of the trainwreck: a much larger trainwreck than they ought to have to inherit.
At this stage, reducing the "up-sizing" of the problem — is the only practical thing to be done. Any other course equals insanity.
Sorry for pontificating. But the situation warrants it — don't you think, NorrisM ?
michael sweet @ 44
The difference between solar and wind power, on the one hand, and coal or natural gas with CCS technology, on the other, relates to issues of base load power. It is fine to talk about "marginal cost" when it comes to wind and solar power but we do not have realistic storage systems to keep the lights on in LA or New York at night. This comes right back to these issues of EROI with Weissbach assuming a storage system for "stand alone" wind power or solar in calculating the EROI. If you are happy with using natural gas as a base load source then fine but the costs of same have to be included in calculating solar and wind power. To the extent natural gas plants are already in place should be taken into account in making these calculations of the real cost of wind and solar.
As I noted to eclectic on another thread, my sense is that the US should be moving towards thermal solar and the construction of a continental HVDC power system but that will still require base load power from fossil fuels as far as I can see.
But none of this addresses the issues raised in the Andy Skuce essays regarding negative emissions if we have any chance of meeting a 2C limit on global temperatures by 2100. We simply are not going to choke off our economy in 2030 when the carbon budget runs out based upon the discussions in the Skuce essays.
If we do not have any valid answers should the models not recognize this invalid assumption as suggested by Kevin Anderson and, implicitly, by Andy Skuce?
Eclectic @ 45
I am still fighting my way through Chapter 13 of the IPCC Fifth Assessment on sea level changes but the more I see (especially after what at least is a revelation to me arising out of the the Economist article and the Andy Skuce essays) the more I think we have to face up to the best guess of the IPCC using RCP 8.5 which predicts a sea level rise of .52 to .98 m by 2100. This is not catastrophic. That is ballpark 82 years away. Even 2050 is 32 years away. Just think of the massive changes that have happened to our society in the last 50 years. We cannot count on technology but we really do not have a choice. It is totally impractical to expect the world to just stop using fossil fuels on or about 2030. As well, we are moving away from fossil fuels so we probably will be better off than RCP 8.5 (but maybe not given this "negative emission assumption" in the models).
Norrism:
With high penetration of renewable energy the issue quickly becomes one of providing peak power when it is not windy or sunny. "Baseload" power that is on all the time is not very valuable. That is why nuclear and coal already cannot compete on the open market. I have seen no scenarios where additional baseload assists renewable energy, only anecdotal stories by fossil fuel vendors.
The existing hydro storage facilities were built in the 1960's to store excess baseload power from nuclear plants to use as peak power during the day. The new energy system requires peak power, not baseload.
Existing gas peaker plants can supply peak power to back up renewable energy. Claims that renewable energy is harder to back up than fossil baseload plants ignore the majority of power plants in the USA.
Experts think the IPCC underestimated sea level rise (from 2013). New data since the IPCC report was written indicates sea level rise might be much higher than the IPCC estimated. The CSSR, written in 2017 states:
"A [global average] rise of as much as 8 feet by 2100 cannot be ruled out. Sea level rise will be higher than the global average on the East and Gulf Coasts of the United States." (my emphasis).
If you are a conservative engineer you might have to use a 10 foot rise to ensure your infrastructure will be usable in 2100, not .52 meters. Every time they write an IPCC report they have to significantly increase the estimate of sea level rise.
The best way to get off FF by 2030 is start now (or start 20 years ago but of course deniers chucked out enough junk to rob politicians of a mandate that would have created change).
It seems that the constant theme of your posts is trying to find a way to justify doing nothing, aided and abetted by numerous false beliefs that have been shown up here. When you take up a position based in incorrect information, isnt it more rational to reevaluate your position when those false beliefs have been exposed? Rather than trying to bolster them?
Frankly, I find it amazing when people say the renewables will destabilize power system when we have stable power system running on 80% renewables and growing.
michael sweet @ 48
I agree that "base load" was the wrong term. But rather than "peak power" I think perhaps "backup power" better describes what I was referring to. This obviously points to natural gas or hydro rather than coal or nuclear.