The Story of the Trillion Tons of Carbon

by Howard Silverman

Here is an axiom that bears repeating: Measure what matters. The classic case of faulty measurement remains Gross Domestic Product, whose counterproductive calculations were pilloried in a 1968 speech by Robert Kennedy and detailed in a 1996 essay, “If GDP is up, why is America down?

Yet even solid measures may offer narrow views. And so, a corollary: What matters may have multiple measures. Take the example of the three targets for action on human-induced climate change. Two may be familiar: 2ºC and 350 (or 450) parts per million. An additional figure, a trillion tons (metric tons), appeared only this spring. Each is distinct, and each has a story to tell.

Three Measures, Three Stories

Most intuitive and visceral among the measures is temperature change. We know what a 2ºC difference feels like. At least we think we do. In reality, projected and potential effects of a 2ºC warming on precipitation patterns, crop viability and human health are often greater than one might imagine. Seeking to keep these impacts to a minimum, many scientists have urged efforts to restrict temperatures rises to within 2ºC of pre-industrial levels, and the European Union has taken 2ºC as its warming target.

Human-caused temperature changes are the result of rising concentrations of CO2 and other greenhouse gases in the atmosphere. It is often said that limiting temperature increases to 2ºC requires stabilizing CO2 concentrations at 450 parts per million (ppm), but some studies suggest a lower figure. Climate scientist James Hansen and others have recommended 350 as the best target for minimizing planetary feedback like ocean acidification and ice sheet melting. Atmospheric targets can inform the design of emission caps in any cap-and-trade system, as Paul Krugman wrote in a recent column.

A fresh perspective is offered by the measure of total carbon emissions, tallied from the beginning of the industrial era and into the future. The authors of a recent paper published in Nature find that roughly a trillion tonnes (i.e. metric tons, each roughly equivalent to 1.1 tons) represents the total human carbon emissions budget, the amount that can be released with a fair probability of holding to the 2ºC margin of relative climate stability. And they find that we are about halfway there. A little more than half a trillion tons have been released since the beginning of the industrial era. (More on the Nature paper here.)

Progress by the Ton

Let’s continue the budget metaphor. Say that all of humanity – past, present and foreseeable future – has a dollar to spend on carbon-fueled economic growth. Those of us that have reaped the industrial world’s benefits doled out two [four] bits or so from 1750 to 2008, and some of those investments paid off handsomely. Standards of health, education and material living rose. And the global digital network emerged.

Fair to say, these expenditures largely preceded any broad realization that the carbon go-go days might be a passing phase. But that is no longer the case. The total bank – set, not by resource limits, but by the planet’s capacity for waste absorption – has been counted. One need not embrace central planning to wonder how a pragmatic and just CFO might eye the remaining balance. Future carbon-miserly development will depend on investments in renewable energy and energy-efficient infrastructure, as well as on institutions and norms that foster disruptive innovation. What other considerations arise?

The Global and the Multi-Generational
At last month’s Three Degrees Conference on Climate Change and Human Rights, philosopher Henry Shue stated directly: “Carbon emissions are zero-sum. … We are in direct competition for a scarce resource with future generations. … What portion of the remaining half trillion tons will be needed for global development to subsistence levels?”

Back in 1993, Shue advanced the idea (originally articulated by India’s Center for Science and the Environment) of allocating carbon emissions based on developmental needs. Shue distinguished subsistence emissions – those required for the satisfaction of basic rights to food, water and so on – from luxury emissions. It is a view that informs the more recent Greenhouse Development Rights framework, a climate stabilization program that allows for continued development among the world's poorest.

Bending toward Justice, Slowly

The difficulties of reaching an international rights-based agreement are clear. It has been said that, with broad consensus on the physical science-based understandings of climate change, the discussion now turns to social science-based explorations of human systems, responses and values.

Under the anonymity of Chatham House Rules at the Three Degrees conference, one speaker lamented the “path dependency” of international human rights and climate change conversations, with officials from the two areas barely consulting each other. Other speakers pointed to recent instances in which the two paths have begun to merge. In January, the Office of the UN High Commissioner for Human Rights issued a report on the relationship between climate change and human rights, and last month the Global Humanitarian Forum published a comprehensive look at the topic.

Measures and the Unmeasurable

The trillion tons serves to frame a historical narrative, an index with which to measure how far humanity has come, where we stand and where we might go. Still, I am reminded of the words of Donella Meadows. “No one can precisely define or measure justice, democracy, security, freedom, truth, or love,” she cautioned. “Pay attention to what is important, not just what is quantifiable.”

As so, while not misconstruing carbon-driven development for justice, let’s reflect on the lopsided consumption of the first half trillion. And consider that climate-friendly progress along the arc of history may depend on a more just agreement for the next half.  

Tags: history, climate



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  • One trillion tons of carbon

    Thanks, Howard. Let's look a little further into what you mean here by "one trillion tons."

    You say 1T ton is roughly equivalent to 1T tonne (metric tons; 1 tonne = 1.1 ton). Fair enough.

    You write, "The authors of a recent paper published in Nature find that roughly a trillion tonnes (i.e. metric tons, each roughly equivalent to 1.1 tons) represents the total human carbon emissions budget, the amount that can be released with a fair probability of holding to the 2ºC margin of relative climate stability."

    So "carbon" in your title and "carbon emissions" here apparently means CO2.

    Looking at Totaling Carbon Emissions | Nature, we note that these two studies come up with quite different figures. Not only are their timelines different, but one is looking at tonnes of carbon and the other at tonnes of CO2.

    From the "Informal Background Q&A" distributed by Nature:

    Allen, et al. say "One trillion tonne of carbon. In this case, the trillion tonne refers to carbon emissions (1TtC) over all times [1750-2008]."
    Meinshausen et al.): One trillion tonne of carbon dioxide. Here, the trillion tonnes (in the paper indicated as 1000 GtCO2) refers to carbon dioxide emissions (1TtCO2 = 0.27 TtC) refers to emissions over the time horizon 2000 to 2050.

    Then Allen, et al. are talking about 1 TtC emitted during the last 258 years and Meinshausen et al. about 0.27 TtC to be emitted in the next 41. A graph of these numbers looks reasonable.

  • Why can't we have both development and emissions reductions?

    The shared assumption undergirding the conflict between development rights and emissions reductions is that development by definition increases emissions. Questioning that assumption opens our thinking to the possibility of finding a conflict-transforming path to carbon-free development.

    Here's one interesting perspective.

    "Growth" is not the same as "development." Alan AtKisson makes that point in chapter 1 of his book, "Believing Cassandra: An Optimist Looks at a Pessimist's World," pp. 24-26.

    The central message of this book is that Growth must cease. If human beings do not stop their growth willingly, Nature will stop it forcefully. Paradoxically, however, for Growth to cease, Development must accelerate.

    Through all of human history, these two concepts, Growth and Development, have been joined together like Siamese twins. They must not be separated, or human civilization inevitably will come to a screeching halt. For the genuine Development of humanity to continue, our species' physical Growth must end. And for Growth to end, our understanding of Development must be reinvented.

    It is important to be clear about definitions. By "Growth," I mean the increase in human population, resource use, and the emission of waste. "Development," in contrast, refers to improvements in human technology and advances in the human condition, including health, education, intelligence, wisdom, freedom, and the capacity to love.

    "Growth" and "development" both have alternate, informal definitions that are in some ways more common, but also more confusion. "Growth" often refers to "economic growth," as measured by the Gross Domestic Product, the value of the stock market, and other economic indicators....

    Meanwhile, the word "development" is too often used to mean "Western-style industrial development" -- also known as "growth" -- which is tied to the propagation of free-market economies and ostensibly democratic governments. But this frame is far too limiting....

    My own view is that human beings have evolved to be ambitious, and are ambitious to evolve. We continually seek security, comfort, novelty, adventure, expression, understanding, and meaning. This search drives a continuous process of change in all cultures.....

    In simplest terms, then, Growth means increases in quantity, and Development means improvements in quality....

    There are limits to Growth....

    There are no limits to Development....

    Navigating this critical transition, away from "Growth equals Development" and toward "Development without Growth," is the great challenge of our generation, and must become humanity's fundamental project for the early twenty-first century.

    See also the new report from the UK Sustainable Development Commission, Prosperity Without Growth

    For two examples, see my next two comments.

  • Example 1. The Resilient Communities Construction Set

    Building the World's First, Replicable, Open-Source, Off-Grid, Global Village
    presentation by Marcin Jakubski, Founder of Factor e Farm at Oekonux 4, 28-Mar-09: slides, video part 1, video part 2, transcript


    We are building the world's first, replicable, open source Global Village. We are a land-based social experiment for creating unprecedented quality of life using on-site resources. Our working assumption is that open source physical infrastructure is the enabling prerequisite of such an experiment, and that the power of efficient, integrated, and ecological production must be seized in order for such a community to thrive and to be competitive with mainstream lifestyles.

    Initial technology development results have surpassed predictions, and we are currently developing a more rigorous program for a rapid-deployment, open source technology development pipeline. This pipeline relies on design of products that are simple, optimal, high-performance, low-cost, and therefore replicable....End goals are livelihoods beyond the ongoing struggle for survival, and personal evolution to freedom - and the first milestone to this is a complete, 30 person village - to be built by year-end 2010.

    adapted from brochure:

    Our aim is the full integration of small-scale, adaptable manufacturing with sustainable agriculture to produce the Resilient Community Construction Set prototyped in two years as a completely open source, self-replicating package so that you can build it yourself. People will be able to survive and thrive with a high quality of life that is not dependent on global supply chains, human exploitation, and environmental degradation.

    The key ... is the fabrication lab, a completely self-replicating, world-class microfactory churning out almost anything imaginable. Fully trained fabricators will be able to use the tools of the fabrication lab to re-build the entire lab at the cost of materials. We will re-make the means of production at the cost of scrap metal.

    Imagine the knowledge necessary for sustaining advanced civilization available to everyone, not just a limited technical elite. An Open Source Ecology integrating computers, communications, energy production, fabrication, and food production will lead to greater self-sufficiency and improved quality of life. A community in control of its manufacturing and food production will be resilient in the face of our increasingly uncertain global system.

    adapted from website:

    Open Source Ecology is a movement dedicated to the collaborative development of the world's first replicable, open source, modern off-grid "resilient community." By using permaculture and digital fabrication together to provide for basic needs and open source methodology to allow low cost replication of the entire operation, we hope to empower anyone who desires to move beyond the struggle for survival and "evolve to freedom."

    By our analysis, most of the technologies needed for a sustainable and pleasant standard of living could be reduced to the cost of scrap metal + labor. There is immense potential for social transformation once this technology is fully developed for building interconnected self-sufficient communities, since people will be freed from material constraints and able to seek self-actualization.

  • Example 2. "New Money to Save Civilization" by Jakob von Uexkull, Founder, World Future Council -- excerpts from his June 2009 draft Executive Summary

    In 1980, Uexkull founded the Right Livelihood Awards, known as the Alternative Nobel Prize, to honour those "working on practical and exemplary solutions to the most urgent challenges facing the world today."

    The current crisis has exposed many economic fallacies. The most life-threatening of them is that feeding the poor and protecting our environment is constrained by a shortage of money. Finance is a function of political will, not of private credit. Governments should authorize the creation of new interest- and debt-free money to fund urgent global humanitarian and environmental projects.

    Money producing new goods and services is not inflationary. Our ability to use all our resources to meet urgent needs must not be constrained by the preferences of money lenders.... We must change the legal rules to unleash the market's power to redesign our production and consumption in sustainable directions, supported by direct government action to provide the infrastructure required. The alternative is the collapse of civilisation as increasing numbers of people are forced to fight over ever scarcer resources on an increasingly inhospitable planet.

    Growing climate chaos and the end of cheap oil will ... force us to fight for our very survival, while growing mistrust will damage social capital and make concerted action increasingly difficult.... So it is time to change these rules and recognize our duty to assist the poor and do our best to preserve a healthy planet for future generations!  Economic and monetary dogmas must be subordinated to this duty.

    The transition to an equitable and sustainable global society will require a massive re-direction of money flows.  Global climate negotiations are stalling because of the ostensible lack of money.... This may be true if we stay inside the box of monetary correctness. But does it really make sense that our sovereign governments should have to borrow the funds needed to protect our common future from the private money lenders whom we as citizens and taxpayers have just rescued from bankruptcy?

    ... [N]ew money creation causes inflation only when used to pay off existing debts, i.e. when no new resources are produced in return -– inflation being too much money chasing too few goods and services. In our current world of massive unemployment, huge over-production capacities and unmet needs, that is far from the case.... Governments should use their privilege to create new money to support demand [from] ... the poor to cover their needs and us all to speed up the global transition to sustainable production and consumption systems. 

    Creating money is a legal agreement, a 'monetization' of expected future proceeds. Many governments have done this in the past, proving that new money created against performance, i.e. in payment for new goods and services, is not inflationary... The total upper limit for the creation of this new money should be constrained only by the need to ensure that performance targets are met and new goods and services are produced as contracted....

    Our duty [is] to assist those now suffering ... by funding the practical implementation of the UN Millennium Developments Goals.... Growing climate chaos and eco-systems depletion are approaching tipping-points beyond which maintaining the planetary life-support system may become impossible at any cost! A healthy natural environment is the macro-system on which our security, health, food, water and economic well-being are totally dependent.  Therefore, the idea that the protection of this macro-system should be subject to the current rules of our human economic micro-system is patently absurd.... But the daily misery of the poorest as well as the growing threats to our common future now demand that we stop subordinating our visions and actions to our fear of monetary incorrectness!

  • Replies to Peter Johnson-Lenz

    Thanks for your careful read, Peter!

    Carbon in this post means carbon. I am citing the Allen paper, which uses carbon as its measure and takes the historical perspective (1750-2500) that serves as the basis for this "story" of the trillion tons. As you noted, the Meinshausen paper takes CO2 as its measure and applies its analysis to a shorter time frame. I posted the excerpts from Nature so that a few of the distinctions could be examined. The two papers share co-authors and complement each other.

    Indeed! Development without growth, i.e. development with diminishing levels of raw material throughput, is a key measure of progress to a more "sustainable" society. In this essay i have followed the language used in international forums for human rights and climate change. They talk about development. When i write "carbon-miserly development," i am referring to the distinction you raise: development with diminishing levels of throughput.

    Looking at some of the potential global emissions curves for keeping temperature gains within a projected 2 degrees (if one accepts that as the objective), you'll see that the window for investment in is narrowing.

    My mention of not misconstruing carbon-driven development for justice might be supplemented with your point of not misconstruing carbon-driven growth for development.

This discussion has been closed.