Our Human Boundaries – Part II

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In Part I, I presented a precis of the methodology the authors of Nature’s Earth System Boundaries had for the “… multiple levels of likelihoods to reflect underlying scientific uncertainties and variabilities.” As their findings “are meant as a transparent proposal for further debate” let’s now consider and debate the more contentious methodology underlying their proposed action – justice.

The authors have provided a bit of a summary of their proposals at The Conversation. While they detail recommendations, the guide rail for action, “justice,” is mentioned only in passing.

 “’Just,’ in this work, means boundaries which minimise significant harm to people.”

It works as a headline, but it fails, dare I say, to do Justice to their criteria, rationale, and limitations. This is vital to understand, as Justice suffuses the thrust of their recommendations.

“Minimizing significant harm is a cornerstone of national and international law and corrective justice.”

The experts identified three entangled justices.

  • “Interspecies justice and Earth system stability .. aims to protect humans, other species and ecosystems, rejecting human exceptionalism. …
  • Intergenerational Justice… examines relationships and obligations between generations, … recognizing the potential long-term consequences of short-term actions and associated trade-offs and synergies across time.” They consider two types, how past actions impact current generations and “…the responsibility of current generations to minimize significant harm to future generations.”
  • Intragenerational Justice: between countries, communities and individuals …includes relationships between present individuals, between states (international), among people of different states (global) and between community members or citizens (communitarian or nationalist). …Achieving intragenerational Justice means minimizing significant harm caused by one country to another, one community to another and one individual to another.”

Hard to argue with any of those concerns, but how to reconcile them when they do not align? As they write,

“…we cannot achieve and live within the safe ESBs [Earth System Boundaries] if inequality is high and resources are unjustly distributed.”

They note that psychological science has found that “perceptions of fairness significantly alter the outcomes.” This is easily seen from “tit-for-tat” experiments – over multiple rounds, you and your partner have $10, and you determine how the money is split, but your partner decides whether they will take what you offer or kill the deal, so no one gets anything. If the split is not close to even, your partner, feeling the outcome is unfair, kills the deal. The best results are achieved when you begin by being nice and then copying your partner's behavior – tit for tat.

“…such experiments suggest that climate change mitigation may not be achieved if rich countries are not perceived as pulling their weight.”

Caveats and limitations – when the rubber hits the road

Good ideas remain good ideas unless there is a workable proposal for achieving those goals.

Interspecies justice is the first of the justices to suffer from practical realities. Having said they reject human exceptionalism, I should remind you that the guide rails of setting the system's scientific boundaries were quite species-centric, nature’s contribution to people (NCP). Given a choice between us and the snail darter, who do you actually believe will be chosen?
Intragenerational Justice comes with a bias,

“In general, although not always, our ESBs protect future generations but not the present.”

Of course, we all honor our children in words, although not always in actions. And there is another human behavior that has been well characterized, hyperbolic discounting – choosing an immediate reward over one given later, even when the immediate reward is smaller. Although it was unclear from the paper whether any authors were trained ethicists or legal academics, it would be unwise to characterize the experts as fools. They recognize the significant trade-offs in protecting future generations.

“promoting intragenerational justice will also raise difficult issues regarding how to share resources, risks and responsibilities.”

Once again, a justice guideline suffers from practical realities.

And as with all methods, there are limitations,

“Although the proposals … makes space for future generations of humans, they may not guarantee safety for humans today …, do not address local human exposure to pollutants .. or may limit access to resources …”

And caveats,


“(1) While staying within the just boundaries … is crucial to avoid harm … they are by no means guaranteeing just outcomes.

 (2) While harm to humans is caused in part by increased exposure to biophysical changes, we recognize that harm is also a function of people’s social–economic vulnerability and lack of adaptive capacities. This is beyond the scope of the present paper.

(3) Our high levels of aggregation preclude systematic analysis of distributional justice issues in terms of which social subgroups are most harmed under what scenarios.

(4) We do not explicitly address possible trade-offs between the three justice criteria.”

[emphasis added]

The action plan to address those entangles justices, “redistribution, liability and compensation,” all subjective valuations without an identified global forum, let alone a global voice.   

They end on this note.

“There are many uncertainties and limitations in this justice analysis. Lack of sufficient data on humans, communities and countries worldwide harmed by biophysical degradation is a key constraint. There is also considerable uncertainty regarding impacts on current generations, future generations, and specific countries and communities. In this paper, we also do not quantify issues of access, explore the implications of access for the safe and just corridor or discuss why it is difficult to meet issues of access without transforming our governance systems.”

There are a number of reasons that big plans fail. From the “science” of effectively implementing large-scale projects, John List, writing in The Voltage Effect, lists five sources of failure.

  • Biases that prevent us from challenging our assumptions – like our perception of fairness (tit-for-tat) or hyperbolic discounting
  • Not recognizing your audience’s needs. The “WEIRD” (Western, educated, industrialized, rich, and democratic societies) may be a powerful audience, but they are not the only audience. - “…which social subgroups are most harmed under what scenarios.”
  • Applications that require human intelligence are difficult to scale because they need “political will” faithful to the plan. “Knowing this isn’t half the battle. It’s the whole battle.”
  • Spillovers are the unintended impact one event or outcome can have on another event or outcome – “There is also considerable uncertainty regarding impacts on current generations, future generations, and specific countries and communities.”
  • Costs – there can be many hidden costs in “redistribution, liability and compensation.”

The action plan is suffused with Justice, as we might all ethically require. What form Justice takes is subjective in many ways, but as John List suggests, the incorporation of Justice considerations into the Earth System Boundaries, as laudable as that might be, may well contain the seeds for failure.

Too Long Didn’t Read TL;DR

For the TL: DR, Part III will look at some of the proposals and their details. Hopefully, understanding the methodology gives them greater context.

Here are the other parts of the article:

Part I – Earth System Boundaries – the science

Part III – Earth System Boundaries, Climate, water, nutrients

Part IV – Earth System Boundaries, Aerosols, Biosphere and some final thoughts

Source: Safe and Just Earth System Boundaries Nature DOI: 10.1038/s41586-023-06083-8