In 2016 I read and reviewed environmental scientist Johan
Rockstrom’s and photographer Mattias Klum’s 2015 book, Big World, Small
Planet: Abundance Within Planetary Boundaries. It was a beautiful book with
very nice graphics and photographs. Rockstrom has championed the idea of planetary
boundaries at least since publication of his first book in 2012, The Human
Quest, Prospering Within Planetary Boundaries. The planetary boundaries paradigm
was first introduced in 2009 when Rockstrom originally proposed the framework. Nine
planetary boundaries were described, only one of which is climate change.
Indeed, we are stressing the earth, our resources, habitats, and the ability of
our earth systems to naturally mitigate imbalances, in more ways than climate
change. The nine planetary boundaries are as follows: Biosphere Integrity,
Climate Change, Novel Entities, Stratospheric Ozone Depletion. Atmospheric
Aerosol Loading, Ocean Acidification, Biogeochemical Flows, Freshwater Change,
and Land-System Change.
Source: Earth beyond six of nine planetary boundaries. Katherine Richardson, Will Steffen, Wolfgang Lucht, Jorgen Bendtsen, Sarah E. Cornell, Jonathan F. Donges, Marcus Druke, Ingo Fetzer, Govindasamy Bala, and Johan Rockstrom. Science Advances. Vol 9, Issue 37. September 13, 2023. Earth beyond six of nine planetary boundaries | Science Advances
It should be
pointed out that these kinds of things are difficult to quantify, some were
left unquantified for years, and some of these quantifications may be disputed.
There are other concepts regarding things like resource depletion and earth
system resilience that turned out to be inaccurate and not so useful. These include
notions like resources depletion models failing to account for technological
improvements. Examples include biologist Paul Ehrlich’s profoundly incorrect
predictions about food availability that the first Green Revolution fixed readily,
ideas like “carrying capacity” that turned out to woefully inadequate in
some cases, and predictions about resource depletion that turned out to be far
off the mark, again due to huge underestimation of technology and human
ingenuity. We hear a lot in the media about the 6th mass extinction.
Scientists differ on this idea, some saying that it is likely or occurring but
many others saying it is not. Certainly, it is not occurring on the level of
previous mass extinctions. Other groups of scientists regularly report doom. The
Bulletin of Atomic Scientists’ wacky Doomsday Clock is one cringeworthy
example.
Science is all
about consensus and paradigms that change, according to Thomas Kuhn who wrote about
scientific revolutions in the 1950’s. It takes time for consensus and paradigms
to change. Consensus can be seen as a subjective aspect of science, which is
considered the model of objectivity. We should consider that science is not
objectivity, but an attempt at objectivity, or an approximation of objectivity.
We might also consider Heisenberg’s Uncertainty Principle, that the observer alters
the observed by the mere act of observation, to apply to a meta-view of science
as well.
Now, there is
no doubt that these nine “boundaries” are important to try and understand and quantify.
However, one thing about boundaries is that they can be shifted considerably by
changing scientific consensus, new understanding, and by the goals of
particular research. One example is climate change where the consensus on the
goal and the point of no return from unwanted impacts was considered to be 2.0
deg C. Under the influence of activist climate scientists like Jim Hansen and
others, the IPCC began to promote and provide more data for 1.5 deg C warming
scenarios. While that is good and fine, somehow, the perceived “tipping point” moved
from 2 to 1.5, especially after the IPCC’s 2019 1.5-degree report. I have argued
elsewhere that where to put boundaries is the key feature of most
environmental and political debates.
A new paper in
Science Advances - Earth beyond six of nine planetary boundaries – published
on Sept. 13, 2023, made quite a bit of headlines. The authors write about the
planetary boundaries framework as follows:
“The planetary boundaries framework draws upon Earth
system science. It identifies nine processes that are critical for maintaining
the stability and resilience of Earth system as a whole. All are presently
heavily perturbed by human activities. The framework aims to delineate and
quantify levels of anthropogenic perturbation that, if respected, would allow
Earth to remain in a “Holocene-like” interglacial state. In such a state,
global environmental functions and life-support systems remain similar to those
experienced over the past ~10,000 years rather than changing into a state
without analog in human history. This Holocene period, which began with the end
of the last ice age and during which agriculture and modern civilizations
evolved, was characterized by relatively stable and warm planetary conditions.
Human activities have now brought Earth outside of the Holocene’s window of
environmental variability, giving rise to the proposed Anthropocene epoch.”
Thus, the stated goal of the framework is to delineate
and quantify. That is an ongoing process, subject to change that may be based
on access to new data and new understanding. The graphic below shows the
changes in the framework from 2009 to 2023. We can see that a big part of the
new change from 4 to 6 boundaries now considered to be breached has to do with considering
previously unquantified boundaries to now be quantified. That does not mean
there was a big change toward boundary breaches in the time between non-quantification
and quantification as the paper’s title and the headlines suggest. Of course,
the authors do conclude that there were changes toward breaches but people
reading the title and headlines could only conclude that is the case, without a
caveat saying that the new breaches had already been breached but not declared
so, but due to new quantification confidence are now considered to be breached.
That is a bit misleading in terms of change, making smaller changes seem like
bigger changes.
The framework
is based heavily on modeling as it must be when considering the future.
Predictive modeling has some limitations and necessarily has uncertainties. Correct
modeling is dependent on correct assumptions that undergird the model. Similar
to climate change modeling the framework considers human “forcings” that lead usually
toward boundary breaches, and natural feedbacks, buffers, and the resilience of
natural systems that can absorb the forcings. Another similarity of planetary
boundaries modeling with climate change modeling is that it is systems-based
and some are global in scope.
The authors do
address the criteria for emplacement of the boundaries:
“Boundary positions do not demarcate or predict
singular threshold shifts in Earth system state. They are placed at a level
where the available evidence suggests that further perturbation of the
individual process could potentially lead to systemic planetary change by
altering and fundamentally reshaping the dynamics and spatiotemporal patterns
of geosphere-biosphere interactions and their feedbacks.”
Of course, this does not remove uncertainties and the necessarily
somewhat arbitrary nature of emplacing such boundaries due to those inherent and
as yet unresolved uncertainties. Where before they had a “zone of uncertainty”,
this has now been replaced by a “zone of increasing risk” to account for some
new understanding. This reminds me a bit of the IPPC’s % certainty declarations
in their reports. For instance, they put the beginning of the zone of
uncertainty for climate change at 350ppm of CO2. This was the atmospheric
concentration of CO2 in 1987-1988. They note that: “In recognition of the
buffering resilience of Earth system, most boundaries are nevertheless set at
values higher than their observed range through the Holocene up to the
Industrial Revolution.” They also note: “The distinction between zones of
“increasing” and “high” risk cannot be sharply defined. There is accumulating
evidence that the current level of boundary transgression has already taken
Earth system beyond a “safe” zone. However, we still lack a comprehensive,
integrated theory, backed by observations and modeling studies, that can
identify when a transition from a rising level of risk to one with very high
and dangerous risks of losing a Holocene-like Earth system state may occur.”
This is why they adopt the IPCC’s “burning ember” color coded system in their
zone of increasing risk.
Source: Earth beyond six of nine planetary boundaries. Katherine Richardson, Will Steffen, Wolfgang Lucht, Jorgen Bendtsen, Sarah E. Cornell, Jonathan F. Donges, Marcus Druke, Ingo Fetzer, Govindasamy Bala, and Johan Rockstrom. Science Advances. Vol 9, Issue 37. September 13, 2023. Earth beyond six of nine planetary boundaries | Science Advances
Are Planetary Boundaries Fixed?
In 2018, Ted
Nordhaus made a pretty convincing argument (in my opinion) that Earth’s
carrying capacity for human life is not fixed. The concept of carrying capacity
is very similar to the concept of planetary boundaries. All of the planetary
boundaries, while presumed natural boundaries, are being stressed by humans.
Populations of other species have been known to stress ecosystems but rarely
affect whole earth systems. In the geologic past bacteria and plants have
altered the composition of the atmosphere, causing some stresses to earth
systems. Nordhaus pointed to a 2018 study in Nature Sustainability that
concluded that the Earth can only sustain 7 billion people at subsistence
levels, even as we were then at 7.6 billion people. The implication of the
paper was that those of us in wealthy countries with higher life satisfaction,
the same life satisfaction that those living at subsistence levels would like
to have as well, are the ones stressing the Earth’s systems. The authors of the
paper attempted to quantify the levels of resource use required for subsistence
in 150 countries. They concluded that “no country meets basic needs for its
citizens at a globally sustainable level of resource use.” “Physical
needs such as nutrition, sanitation, access to electricity and the elimination
of extreme poverty could likely be met for all people without transgressing
planetary boundaries. However, the universal achievement of more qualitative
goals (for example, high life satisfaction) would require a level of resource
use that is 2–6 times the sustainable level, based on current relationships.”
Thus, they conclude that due to population and resource use we are living
unsustainably, whatever that really means. Presumably, it means we are stressing
earth systems toward dangerous tipping points. That may or may not be true, but
people need to escape poverty and it is human nature to seek a comfortable
life. While we can do what we can to improve efficiency and sustainability, we
only have so many economic resources to do so, and that money competes with paying
for our needs and wants. Thus, as the authors note, it is challenging. Below is
a flow chart from the paper of their methodology.
Source: A good life for all within planetary boundaries. Daniel W. O’Neill, Andrew L. Fanning, William F. Lamb & Julia K. Steinberger. Nature Sustainability volume 1, pages88–95 (2018). A good life for all within planetary boundaries | Nature Sustainability
However, such
predictions are not new. Nordhaus points out that ecologist William Vogt in the
1940’s predicted that the overuse of agricultural land would result in soil
depletion followed by catastrophe. While there has been some soil depletion
there has been no catastrophe. Thus, what Vogt considered to be unsustainable
turned out to be quite sustainable now even as the global population has more
than tripled. The Green Revolution and continued improvements in agricultural science
and technology have allowed us to grow much more food with much less land and
those improvements continue. He also points out that Ehrich did the same with
food production and the Club of Rome with resources. Nordhaus writes: “The
long-term trend in market economies has been towards slower and less
resource-intensive growth. Growth in per-capita consumption rises dramatically
as people transition from rural agrarian economies to modern industrial
economies. But then it tails off. Today, western Europe and the US struggle to
maintain 2 per cent annual growth.” He reaches back into ancient history
and notes that it once to took 6 times more farmland to feed a person a much
poorer diet than a person eats today. He says: “What the palaeoarcheological
record strongly suggests is that carrying capacity is not fixed. It is many
orders of magnitude greater than it was when we began our journey on this
planet.” He then notes that technologies like solar and nuclear energy can
lead to carbon emissions reductions to allow us to lower our level of stress on
the planetary boundary of climate.
According to Wikipedia: “The carrying capacity of an
environment is the maximum population size of a biological species that can be
sustained by that specific environment, given the food, habitat, water, and
other resources available. The carrying capacity is defined as the environment's
maximal load, which in population ecology corresponds to the population
equilibrium, when the number of deaths in a population equals the number of
births (as well as immigration and emigration).”
“At the global scale, scientific data indicates that
humans are living beyond the carrying capacity of planet Earth and that this
cannot continue indefinitely. This scientific evidence comes from many sources
worldwide. It was presented in detail in the Millennium Ecosystem Assessment of
2005, a collaborative effort involving more than 1,360 experts worldwide. More
recent, detailed accounts are provided by ecological footprint accounting, and
interdisciplinary research on planetary boundaries to safe human use of the
biosphere. The Sixth Assessment Report on Climate Change from the IPCC and the
First Assessment Report on Biodiversity and Ecosystem Services by the IPBES,
large international summaries of the state of scientific knowledge regarding
climate disruption and biodiversity loss, also support this view.”
Thus, the consensus seems to be that humans are stressing
Earth’s systems by exceeding the Earth’s carrying capacity. While the Earth’s carrying
capacity has to do with the Earth’s ability to accommodate growing population,
planetary boundaries are more detailed in that they address the effects of
various human activities on earth systems that may be approaching the limitations
of those earth systems. The accuracy of placing planetary boundaries is based
on levels of understanding of those earth systems. It involves predicting tipping
points and impacts.
As noted, one
of the early proponents of carrying capacity was the ecologist William Vogt,
who was depicted in the fascinating book, The Wizard and the Prophet, as
the prophet of the environment alongside Norman Borlaug as the ‘wizard’ who
used agricultural science and technology to help the world. The book compared hard
(technology-based) and soft (impact reduction-based) approaches to
problems. In this case, it is hard to deny that the wizard was the real hero
compared to the prophet who while helping in some ways also caused some harm.
Vogt advocated for things like population control as did Ehrlich, which was detrimental
to families in developing countries as things like forced sterilization were
tried. Ehrlich also advocated that we should not give food aid to malnourished countries,
invoking what ecologist Garret Harding called the Lifeboat Ethic, which noted
there was simply not enough to help others, so it was pointless and cruel to
help them thrive. While they believed this was true at the time, it turned out
to be very wrong and even seems sinister in hindsight. At the very least it
shows the potential dangers of adopting policies based on limits. The two
approaches in the Wizard and the Prophet are similar to a hands-on
technological approach to problem solving based on feasibility and cost-benefit
analysis and a pre-emptive hands-off approach based on ideas like the Precautionary
Principle. Extrapolating these approaches to policy one might consider the hard
approach to favor incentives for new technologies and the soft approach to
favor mandates and limits on impactful activities. In reality we need both the
carrot and the stick, but those who favor the wizards want more carrot and less
stick and those who favor the prophets want more stick and less carrot.
Nordhaus makes
the following conclusions:
“Today, demands to impose planetary boundaries
globally are couched in redistributive and egalitarian rhetoric, so as to avoid
any suggestion that doing so might condemn billions to deep agrarian poverty.
But they say little, specifically, about how social engineering of such
extraordinary scale would be imposed in a democratic or equitable fashion.”
“Ultimately, one need not advocate the imposition of
pseudo-scientific limits on human societies to believe that many of us would be
better off consuming less. Nor must one posit the collapse of human societies
to worry deeply that growing human consumption might have terrible consequences
for the rest of creation.”
“But threats of societal collapse, claims that
carrying capacity is fixed, and demands for sweeping restrictions on human
aspiration are neither scientific nor just.”
Nordhaus’s words seem to favor a voluntary-based approach
to a mandate-based approach.
Planetary
boundaries are more or less assumed to be fixed but since the systems are
resilient, they should be fixed within a certain range defined by that system
resilience. It is a threshold based on the ability of those systems to handle
certain stresses. Carrying capacity involves the ability of the systems to accommodate
humans and their activities, but since we use science and technology to change
the impacts of our activities, those activities can stress or destress the systems
based on how we mitigate the impacts. Thus, I would argue that planetary
boundaries may be fixed within certain ranges but carrying capacity is not
since it involves the capacity to carry humans and their impacts which vary according
to degree of mitigation. It is more or less a semantic argument. However, with
media help, it can lead to being a scientific consensus of a group of scientists
that lends support to catastrophist narratives. I do believe these issues are
concerning and challenging. I don’t think the answer to solving them is
mandates and burdensome regulations that increase costs for consumers. Anything
that increases consumer costs disproportionately affects the poor as those new
costs are a bigger part of their income. Thus, I don’t think that punishing
poor people by driving up costs is the best way to address these challenges.
In his book, Big
World, Small Planet: Abundance Within Planetary Boundaries, Rockstrom
argued for a change of approach to environmental and climate issues from a top-down
approach to a bottom-up approach, in line with the ‘systems thinking’ or
systems approach to ecology and sustainability. Of course, the two main stressors
to these earth systems are population growth and economic growth. Both are
likely to continue, although population growth may peak by 2064 or sometime
before 2100 as scientists predict, and economic growth does have some ability
to decouple from things like greenhouse gas emissions and resource use due
mainly to technology and efficiency. However, economic growth is desirable for
all countries, developed ones and especially developing ones. That is how we
reduce poverty and provide opportunity. Degrowth is not a feasible, sensible,
or even a moral solution. An example is that “leapfrogging” to inadequate solar
and wind with high upfront costs in poor countries where domestic fossil fuels
are available is not fair to those countries.
Rockstrom does
acknowledge the significant ranges of uncertainties inherent in predicting global
systems change and the level of resilience built into those systems: “Earth
is a complex and self-regulating system, in which everything is connected to
everything else. This means, in very simple terms, that when nature is in good
shape, Earth’s resilience is high.” They consider three of the boundaries
as being hard-wired into the earth-system and thus having sharp well-defined
boundaries: climate change, stratospheric ozone, and ocean acidification. These
effects are all global. Another grouping is of four slower processes, what they
call the slow boundaries: land-use, freshwater consumption, biodiversity loss,
and interference with the nitrogen and phosphorous cycles. These have more
regional and local effects. However, if those are multiplied enough around the world,
they could become global effects. The third grouping is of two human-induced
threats: 1) aerosol loading in the form of pollutants like soot (black carbon),
nitrates, sulfates, and other particles, and 2) chemical pollution (novel
entities), mainly in the form of heavy metals and persistent organic pollutants
(POPs). Those two are the ones recently quantified and now considered to be beyond
their assigned planetary boundaries. These scientists have done lots of
revisions through the past 13 years they have been attempting to quantify these
earth systems. Thus, even the ranges of resilience can change so the planetary
boundaries may not be very fixed after all, or rather some are more fixed than
others.
Source: Earth beyond six of nine planetary boundaries. Katherine Richardson, Will Steffen, Wolfgang Lucht, Jorgen Bendtsen, Sarah E. Cornell, Jonathan F. Donges, Marcus Druke, Ingo Fetzer, Govindasamy Bala, and Johan Rockstrom. Science Advances. Vol 9, Issue 37. September 13, 2023. Earth beyond six of nine planetary boundaries | Science Advances
Again, I feel
a need to emphasize the uncertainties of quantification of these boundaries. For
instance, evaluating biosphere integrity involves quantifying ecosystem
services. Such estimations are wrought with uncertainty. Coral reefs, mangrove
forests, tropical rainforests, and inland wetlands are probably the most
valuable systems in terms of the benefits they provide and the cost it would
take to restore them. Rockstrom and Klum note one estimate of their global
annual value (all ecosystem services) is about $125 trillion, about 1.5 times
global annual GDP (in 2015).
They recommend
limiting economic growth and increasing environmental regulations and think
that will spur innovation. They also recommend the UN Environment Program be
given powers like the WTO or the WHO. I don’t think that is the right approach.
While some such compliance-based rules have been established and will probably
increase, I believe a voluntary-based approach should be prioritized and would
spur more innovation. They also favor carbon taxes, planned fossil fuel
phaseouts, and many “soft” approaches like green chemistry, biorefineries,
bioplastics, circular economies, and agroecology. While these things have been
useful on small scales and should continue to be pursued, they are not likely to
be scaled up or become economical solutions anytime soon. In the 8 years since
their book was published the needle has barely moved on these technologies due
to cost and scaling issues. For instance, in considering “peak everything”
mostly metals and minerals such as phosphorus they recommend recycling. While that
is a good idea and should continue to be pursued, it is far cheaper to continue
to explore and mine new sources, which continue to be found in most cases. Phosphorus
is a required fertilizer for food production. Current reserves of the most
concentrated form as rock phosphate are limited, with 70% occurring in Morocco.
Some phosphate can be extracted from sewage waste, but it is not cost-effective.
It can be preserved by not wasting it by targeting and timing its use on
plants. That would also help address the problem of phosphate loading (nitrogen
and phosphate loading are considered to be one of the planetary boundaries as biogeochemical
flows). It is perhaps ironic that something so rare in needed concentrated
forms is also accumulating in waterways at unsafe levels. William Vogt first
experienced the notion of carrying capacity when entrusted to determine declining
guano reserves on islands off the coast of South America. Guano was the main source
of phosphate before rock phosphate. While the earth has an abundance of
phosphate it is rare in concentrations high enough to be economic to exploit.
Thus, peak phosphate is considered to be immanent or perhaps we already passed
it but that does not mean new sources won’t be found or that more reserves can
be exploited.
References:
Earth
Deep in Danger Zone Beyond Safe Planetary Boundaries, Study Warns. Environment.
Marlowe Hood. AFP. September 15, 2023. Earth
Deep in Danger Zone Beyond Safe Planetary Boundaries, Study Warns :
ScienceAlert
Big
World, Small Planet: Abundance Within Planetary Boundaries – by Johan Rockstrom
and Mattias Klum (Yale University Press, 2015)
Humanity
Has Overstepped Six of the Earth’s Nine Planetary Boundaries. Darren Orf.
Popular Mechanics. September 25, 2023. Humanity
Has Overstepped Six of the Earth’s Nine Planetary Boundaries (msn.com)
Planetary
Boundaries. Stockholm Resilience Center. 2023. Planetary
boundaries - Stockholm Resilience Centre
Earth
beyond six of nine planetary boundaries. Katherine Richardson, Will Steffen, Wolfgang
Lucht, Jorgen Bendtsen, Sarah E. Cornell, Jonathan F. Donges, Marcus Druke, Ingo
Fetzer, Govindasamy Bala, and Johan Rockstrom. Science Advances. Vol 9, Issue
37. September 13, 2023. Earth beyond six of
nine planetary boundaries | Science Advances
The
Earth’s carrying capacity for human life is not fixed. Ted Nordhaus. Aeon
Magazine. July 5, 2018. The
Earth’s carrying capacity for human life is not fixed | Aeon Ideas
Carrying
capacity. Wikipedia. Carrying
capacity - Wikipedia
The
Wizard and the Prophet: Two Remarkable Scientists and Their Dueling Visions to
Shape Tomorrow’s World. Charles Mann. Penguin Random House. 2018.
A good
life for all within planetary boundaries. Daniel W. O’Neill, Andrew L. Fanning,
William F. Lamb & Julia K. Steinberger. Nature Sustainability volume 1,
pages88–95 (2018). A
good life for all within planetary boundaries | Nature Sustainability
Peak
Phosphorus. Wikipedia. Peak
phosphorus - Wikipedia
