This interview brings together Dave Murphy, an energy transition scholar, and physicist Tom Murphy, both founders of the Planetary Limits Academic Network (PLAN).
Across this series of discussions conducted by fellow founder Ben McCall, they explore a range of themes on the converging crises reshaping our world, including the polycrisis, ecological overshoot and the strengths and limits of modernity.
Read the whole series: Part One | Part Two | Part Three
Ben: Tom, I’d like to turn our attention to the two questions that sum up the “heart of the matter” for Dave. Let’s begin with his first question: What does it mean to be sustainable? Is any human perturbation to natural ecosystems, or any interruption to the natural energy flows through an ecosystem, unsustainable? Where is the space for humans, or human society, in this context?
Tom: To me, sustainable means living in a way that does not lead to rapid declines in ecological health or non-renewable resource stocks. The timescale for defining “rapid” must be in the context of evolution, which probably means at least tens if not hundreds of thousands of years. Proponents of modernity would likely call this timescale outlandish, which is actually part of the present problem. Humans have been on the planet for millions of years, and Homo sapiens for hundreds of thousands. So the number has a basis.
At a gentle-enough pace of change, the community of life has a fair chance of adapting. Sustainable does not mean static: evolution is never static. Perturbations happen all the time, accompanied by adaptation. Sometimes perturbations are enormous enough to cause mass extinctions, the sixth of which appears to be underway. One could argue that—like volcanoes and asteroids—humans are of this world, and that causing a mass extinction is fair play: it’s just nature doing its thing. Maybe, but I won’t label that outcome as sustainable.
Humans obviously have a place on the planet, as part of nature. Human societies and cultures have a place. Nothing excludes this, and indeed human cultures have coexisted in a more-or-less sustainable fashion for eons. The statement that “there isn’t space for humans or any type of human society” goes too far, in my view, as we have loads of evidence to the contrary, unless Indigenous people do not qualify as any type of human society.
Before getting to future possibilities, I should address megafauna extinctions. I don’t want to paint pre-agricultural humans as angels: we are now, and always have been, no more or less than animals on this planet. Humans represented a significant evolutionary perturbation. In Africa, the co-evolution of humans and other animals allowed megafauna to persist, understanding this gangly ape to be deceptively dangerous. Elsewhere, human migration outpaced evolutionary adaptation—but this is not unique to humans in evolutionary history, and the result was still “by the rules.” Today, the pace of extinction is orders of magnitude higher. Importantly, I can’t as easily excuse the current behavior, now that we know better.
So yes, I classify modernity as (woefully) unsustainable, given the ecological nosedive and its substantial reliance on non-renewable resources. I classify Indigenous hunter-gatherer cultures as being demonstrably sustainable—at least effectively so. That doesn’t mean these are the only two choices. What’s exciting to me is that we might yet invent new modes that perhaps blend elements of both with new ideas: I’m not calling to “abandon all human cultural heritage.” But to be sustainable, we may have to reject a majority of modernity’s tenets and would do well to build on a worldview closer to that of our sustainable ancestors—at least by adopting humility as foundational to our relationship with the community of life.
We have demonstrated ample capacity to destroy ecological health. Given this, success (synonymous with sustainability) requires prioritizing the health of the more-than-human world above human concerns—as incongruent as that notion is with modern cultural values.
Ben: Dave, I might now challenge you to offer a concrete definition of “sustainable,” if you disagree with Tom’s definition.
Dave: If Tom’s definition of sustainability is “living in a way that does not lead to rapid declines in ecological health of non-renewable resource stocks,” and the assessment of such rapid declines is to be conducted on the scale of tens to hundreds of thousands of years, then how should we be thinking about modernity? Surely the past 250 years is a mere blip on these orders of magnitude, and, if we are able as a global society to gradually move to a sustainable planet, even if that move were to take the next 200 years, would that not be within the timeframe of sustainability as outlined herein by Tom?
Is, or is not, culture valued in Tom’s view of sustainability?
Tom wrote: “It seems the only way we can live sustainably is by putting ecological health first and—through this lens— either rethink or abandon every human (cultural) construct.”
To which I responded with this: “I disagree that we need to rethink or abandon all human cultural heritage. I think the solutions will come from building on accumulated cultural knowledge, particularly from indigenous communities that have lived in harmony with nature for millennia. What do we humans gain from abandoning human culture, which is perhaps the defining characteristic of our species?”
Then Tom commented, “Humans obviously have a place on the planet, as part of nature. Human societies and cultures have a place. Nothing excludes this, and indeed human cultures have coexisted in a more-or-less sustainable fashion for eons.”
It is possible we are talking past one another here, so please clarify if I missed anything, but my question is: which is it? Is human culture important to the future sustainability of planet Earth, or do we need to abandon human cultural constructs?
Ben: Tom, we’ll come back to the question of human culture in a bit, but let’s first turn to Dave’s second “heart of the matter” question. Given the context of the (from at least your perspective) unsustainability of modernity, what ethical obligation do we have to the people currently living today? What does it mean to “love thy neighbor” if the future of modernity is bleak?
Tom: Inverting the order, the “love thy neighbor” part is simple for me. My neighbors include newts, eagles, squirrels, salmon, bees, and the plants, fungi, and microbes that make it all possible. I love them. We are nothing without them. The real world is one of innumerable relationships—humans are among many millions of nodes, incapable of existing in isolation. We are not the masters, the owners, or the most deserving. Just as we reject the “master race” stance of Nazism, I hope we can reject human supremacism and repudiate a dominant “Human Reich” regime on the planet.
That said, I love humans too. Humans are incredible: adaptable, intelligent, funny, empathetic beings. I don’t much like how modern culture abuses these gifts at the devastating expense of non-human (and some human) lives. But that’s only the modern way, and not baked into human DNA—as evidenced by tens of thousands of years of living under very different cultural norms that are practically unfathomable/nonsensical to denizens of modernity.
Our ethical responsibility, then, extends to the entire community of life. If we define “people” as all living beings, then the original question takes a different tone. If this seems absurd, I ask: how would the denial of “people” status to other life avoid strumming supremacist chords?
But, confronting the intent of the question: what ethical responsibility do we have to the humans alive today? I would say: we owe it to ourselves to be honest about planetary limits. To the extent that we can look to the long future and delineate the sustainable from the unsustainable, we ought to do our best. We honestly don’t know how to make modernity sustainable. Giving people the impression that we can continue business as usual, but powered by different technology, might be one of the most unethical things we could do—if it turns out to miss the larger truth, perpetuating/exacerbating ecological damage and courting chaotic collapse.
People may wish to hear good news, acquire goods and comforts, and maintain the familiar. But if we suspect that modernity is unsustainable, then let’s say so. I have faith that many are prepared to accept a retreat from “the modernity dream” if they understand the associated nightmarish damage to life and the non-viability of a future for future generations. In my view, our current culture is not honest about these things, proclaiming that we (in the human-only club) can continue to have it all.
If a proposal cannot validate a robust pathway to sustainable operation for the long haul and convince us that it is unlikely to constitute a net harm to the community of life (even indirectly), then is it ethical to pursue it? Choices that self-terminate within centuries or millennia strike me as unethical and ignominious—depriving future humans and countless other species of their lives and livelihoods. Do we care more about prolonging a temporary fireworks show or about the enduring health of all life on Earth?
Ben: Dave, I’m guessing that your sense of ethics gives a higher weight to sustaining the current “temporary fireworks show” for the benefit of today’s currently living humans…but Tom’s analysis would suggest that implies giving a lower weight to the needs and desires of future humans, as well as the rest of the community of life? What do you think Tom is missing here?
Dave: Now we are getting somewhere!
“I would say: we owe it to ourselves to be honest about planetary limits. To the extent that we can look to the long future and delineate the sustainable from the unsustainable, we ought to do our best.”
We ought to do our best indeed; in fact, we are ethically obligated to do our best for all life on this planet. It is clear that we may differ a bit on the spectrum of biocentrism to anthropocentrism, but the key is that we agree that we need to be honest about what is and is not sustainable, and then do our best to pursue the sustainable option.
So – how should we pursue that? Given your previous answers on sustainability measured over timescales of thousands of years, we have the time; we just need the right mindset to get it done. For me, I think we need to pursue the energy transition as quickly as possible (to reduce GHG emissions), promote policies to lift people out of poverty (which, among many other important health and social benefits, reduces population growth rates), create economic systems that do not require increases in physical output year after year to maintain economic well-being levels, pursue agro ecological food production systems (which have been shown to be able to feed the entire planet without the use of fossil fuels for fertilizers), and all the other amazing ways in which we can provide high quality of life at very low impact. Is there really any other choice?
This interview has been edited and condensed for length. This interview is part of a series that features conversations between Dave Murphy and Tom Murphy on the polycrisis and planetary limits.
Read the whole series: Part One | Part Two | Part Three
