Understanding tipping points, feedbacks and the “carbon budget”
in the broader light of the possible:
   1) a radical threat to the continuity of civilization,    and
    2) the underestimated solution: a “regreening” of the Earth's surface.

Cumulative emissions of ~1000 GtC, sometimes associated with 2°C global warming,
would spur “slow” feedbacks and eventual warming of 3–4°C with disastrous consequences
James Hansen et al.

The ‘tipping point’ is only a crude metaphor, insufficient to understand climate dynamics, and thus the nature and full scope of the organizational shift that a stable climate presumes.

1. A suite of burps

First, each feedback does not “run away” indefinitely.  Once underway, it would eventually plateau, at some new, warmer equilibrium.  When the oceans stop absorbing CO2, so will the degradation of their role as a “sink.”  Once all the snow and ice have melted, the reflectivity of the planet’s surface will reach its minimum.  There is only so much methane in Siberia and the shallow oceans.  The self-accelerating warming feedbacks, in short, at some point saturate.  They might be better understood as a series of drastic heat “burps.” 

Once we start triggering the latent heat burps, however, and thereby fueling their interactions, we will be on our way to a different planet:  one in which something resembling what a thousand societies in history have known as the good life would no longer be possible.  It seems unlikely that in this new planet humanity would disappear from the face of the Earth.  For humans to go extinct, the sum and inter­actions of these separate processes would have to themselves trigger even greater temperature leaps that wipe out most of life on Earth, such as the methane clathrates in deep ocean sediments —the so-called “clathrate gun”—, surmised, by the scant evidence available, to be tipped off at 6ºC. 

We are reassured to learn that the IPCC regards this as “extremely unlikely” …until we learn that this means up to a 5% probability, and that other indications of “fat tailed” probability distributions put it at …10%.  It has happened before, so human extinction has now become a distinct scientific possibility.  Barring that extreme, however, and more plausibly, only a large (perhaps the largest) portion of us might disappear. For a 4ºC rather than a 6ºC world can still be feared to mean vast swaths of the planet becoming uninhabitable and much of the rest insufferable.

Perhaps any form of civilization would be impossible or at best sporadic in such a world, considering the survival pressures in the resource-degraded and disrupted planet that would follow from the continuation or universalization of (typically resource-intensive) industrial societies.  Indeed, consumption-intensive economies have met the ecosystem’s carrying capacity.  And because they can sustain fewer people, the scarcity fueled by their pressure on dwindling resources can henceforth be expected only to exacerbate or generalize competition, conflict and war —or, differently put, preside over a disintegrating civilization.

Such a fate is not written in the stars, far from it —only in our mental and economic habits.  Perpetuating or globally replicating the "American Way of Life" along which the modern world has been aligned, indeed leads to such an outcome.  For the “growth” economy that has embodied and sustained the consumption levels that define it, and organized the industrial societies that feed it, has exhausted its possibilities: it is unable to reduce its carbon footprint fast enough to avert likely catastrophe. This historical system, however, is already unraveling, by virtue of its systemic fragilities and dysfunctions, as its demise unfolds in historical slow motion ...and quite independently of the climate threat. Emergence of anti-establishment parties the world over, are already evincing the latent instabilities for whoever has eyes to see it.

An environmentally-sensitive economic alternative, as we shall see, lies in commodity-enhanced “post-industrial” economies, rather than the commodity-intensive and -centered societies that have thrived in modern industrial civilization, along which policy everywhere remains aligned.  To ensure the continuity of life, “industrial” as well as “developing” societies will have to abandon its pursuit and reproduction, whether to perpetuate it or to replicate it.  Different patterns, distribution, content and quality of “consumption” can ensure a good life for most far more decisively than ever higher consumption levels —quite plausibly even a better life.  It presumes a “post-growth” macro-economics, already in the making, capable of catalyzing and coordinating the mass reconversion of technology, production methods and ways that will be needed, over the next generation, to secure a livable future.

2. The slippery slope and the two carbon budgets

The second important thing about climate dynamics is a key distinction between a ‘tipping point,’ that an overshoot can exceed temporarily (as we probably already have), and a ‘point of no return.’ 

This is why the path to climate “apocalypse” might be better described as a slippery slope, at some point in which we can no longer climb back to stability.

Most importantly, the difference between a temporary overshoot and a point of no return reveals that there is not one “carbon budget” but …two.  We are already into the slippery slope:  we may have not reached a point of no return, but we have probably already past a tipping point —as the methane bubbling in the melting Arctic and permafrost suggests.  Such feedbacks can only be firmly controlled with a “cool back” following removal of CO2 from the atmosphere.

The long-term stable livable carbon concentration to which we must return, and the limit to the tempo­rary overshoot, define the two budgets. Both can only be “guestimated,” i.e. determined by informed judgment:  by collective “pre-scientific” knowledge:  knowledge of the “known geophysical unknowns” (of identified but not fully quantified factors, that as a result does not make it into the formal scientific literature), which an independent panel of scientists can elicit.

To dispel the threat of cataclysmic climate change (beyond the localized catastrophes already in store) we need to control the geophysically decisive factor —atmospheric carbon concentration— which defines the managerially decisive factor: the carbon budget.  Management 101:  “if you can’t measure it, you can’t manage it.” 

Its nature and importance become obvious when the crucial difference between annual and cumulative emissions is clearly understood.  Even once we peak and start reducing annual emissions, cumulative emissions will continue to increase until we reach zero annual “net” emissions (the point at which human emissions = terrestrial uptake of carbon). 

This is why emission reduction paths are decisive: the same end result of zero annual net emissions can entail different cumulative aggregates —which are what will determine climate.

Gernot Wagner, presenting his book Climate Shock
in a March 27, 2015 Talk at Google.

This is why conventional responses to the climate threat provide tend to obfuscate the scale of the challenge, and implicitly condone or abet paths to disaster. Acting on Climate Change: Solutions from Canadian Scholars (n.d. –2015?), to take one example, collects the recommendations of the Canadian academic establishment on the central challenge of the century. But it does not even mention a carbon budget —the factor that will determine no less than the climate’s (and thus the world’s) future—, less still the question of international equity needed to clarify the Canadian share of the global budget, let alone the self-accelerating warming feedbacks that threaten catastrophe and tighten the allowable window of safe emissions (which have been ignored because they pertain to the “known unknowns”).

Framing the climate question in terms of the political watchwords of the day, the Report’s only indication of the geophysically and thus socially critical norm is its restatement of the political and notoriously fuzzy 2009 target that the G8 set for itself in Aquila —a “80% reduction in emissions by the middle of the century”— consistent with a 50% global reduction, that could well program a catastrophic future (and even evokes another political “2025 target of 26-28% GHG reductions relative to our 2005 levels” that would indeed program it). Significantly, the scholars who had addressed the key question (R Gignac and D Matthews) were not involved in the Report, despite the significance of their contribution (Allocating a 2°C cumulative carbon budget to countries, Environmental Research Letters, 10 (10 July 2015) 075004) on a key stumbling block in international climate negotiations. Although it erroneously assumes the politically defined pre-Paris 2ºC norm —ignoring the geophysical criterion of non-self-accelerating GHG concentrations, whose value remains undetermined— this is but an input of a model or algorithm of “common and differentiated responsibilities” that settles key questions of inter¬national equity that previous litera¬ture had not satisfactorily resolved).

This failure of Canadian scholars to cognitively register the decisive factor is obviously not a case of academia-wide intellectual corruption, or incapacity to “speak truth to power,” but another “systemic” failure. Defining the working assumption for GHG emission reductions in terms of a political rather than geophysical criterion follows from modern thought’s positivist epistemology —based on the standard distinction between “normative” and “positive” judgments, i.e. between prescription and description (or “values” and “facts”)—, by virtue of which politics defines the former based on the latter. Because the climate challenge forces us to recognize the centrality of nature (“climate does not comply”), it brings into question even the epistemological basis of modern thought! See ALR, Factoring the “known unknowns” into climate decisions. Prophecy as falsifiable discourse: positivist epistemology as a special case of adaequatio intellectus ad rem –and its implication for climate security.

Even the budgets associated with the (erstwhile “radical” and after Paris 2015 quasi standard) 1.5ºC limit to global warming will have to be revised to account for the effects of feedbacks.  For the carbon budget is derived from the cumulative emissions allowable after deducting the amplifying effects of natural feedback processes from what scientists guess “safe” (non-self-accelerating) atmospheric concentrations to be.  As we shall see, however, it can also be partly offset by the removal of carbon from the atmosphere, as we begin to potentiate “negative emissions” now, rather than decades ahead).

The temporary carbon budget is thus defined by the peak in cumulative carbon concentrations before we reach what scientists estimate to be, under conditions of uncertainty, a point of no return.  This may, however, turn out to be below 1.5ºC —which is no less a political norm than 2ºC.

For long-term climate stability presumes an atmospheric concentration of GHG emissions well below the level they have already attained:  the “absolute” carbon budget is negative.  The continuity of civilization, indeed, seems to rest in our capacity to massively remove CO2 from the atmosphere. 


3. The conceptual enlargement of the possible

This seems unrealistic to the best expert judgment today, who knows that negative emissions presume heroic assumptions on the practical feasibility, technical reliability and economic rationality of so-called BECCS (Bioenergy with Carbon Capture and Storage), and regular CSS (imagined to allow for coal use) —which is why they are usually envisaged in a hypothetical future many decades ahead.  If, however, temperature/ cumulative emission targets are set not in terms of geophysically safe levels but of economically convenient criteria —which is like saying that since we only have a hammer the problem must be solved with a nail—, and are thus defined by the techno-economically “possible,” we are faced with a radical choice between fundamental innovation and doom.  And since there is no credible technology in sight capable of removing CO2 from the atmosphere on a massive scale, the only techno-economically “possible” future is geophysically catastrophic.

Fortunately, most experts are wrong again.  Due to an ideological carryover from the industrial era, they have been looking at the anthropogenic impact on climate have focused on renewable energy.  They have thus disregarded reductions possible not only thanks to low-carbon energy, but in low-energy economies —as well as thanks to carbon removal …where it is actually happening. 

For just like the scale of the climate threat (and thus of the re-organizational challenge) have been underestimated, so has the potential of available solutions.  Specifically, 1) the unrecognized capacity of organic farming/ agroecology to store carbon and water in the soil is now dangling the possibility of removing vast amounts of the atmospheric carbon that climate stability will require in addition to 2) drastic emission reductions.  Both conditions are simultaneously dictated by a carbon budget.

The methods and ways of socio-economically humble, conceptually invisible and policy-marginalized small farmers, which embody responses to the climate challenge that standard industrial methods do not even dream of, are off the radars of policy and politics because they contradict modern society’s founding myth:  “progress,” in whose light these alternatives are, well, primitive.  This is tantamount to being an atheist in a religious society.  By forcing us to look at nature, indeed, climate brings into question the shared worldview on which industrial civilization is built.  That many “primitive” ways also happen to be far more resource-efficient than modern methods —which to a large extent are viable and thrive economically only because they are artificially sustained by policy— only becomes apparent from environmental or even economic readings of production.

Tried and tested techniques of proper husbandry of the land —a regreening of the world rather than the complex “technological” fixes that now occupy most social imagination— are estimated by experts to have the theoretical capacity to remove some 50 ppm of CO2-e in the atmosphere (of the 450+ parts per million already in it).  And nonconventional techniques might do even better.

Agroecology, in short, is a key lead to a safe future, whose technical and micro-economic potentialities should be explored and developed, as much as its macro-economic implications.  A “full price on carbon,” for instance —one that also reflects “negative emissions” with a negative tax or subsidy commensurate with carbon removal— would be necessary and perhaps sufficient to catalyze its full potential.  Be it as it may, its deployment in a wide scale would involve entirely new patterns of social and economic organization.  Not only would it require the development of a vast and well integrated program of carbon accounting, for instance, but it would change the very texture of society and life. 

One thing, however, is clear:  it drastically enlarges the domain of the possible.

A climatologically safe future can and must emerge from “the ground up” thanks to a (“top-down”) carbon-constrained, carbon-equitable and carbon-neutral macro-economic framework that ensures an environmentally level playing field globally and nationally.

How many years of 2013 emissions would use up
the IPCC’s carbon budgets for different levels of warming
Credit: Rosamund Pearce/Carbon Brief.