The
human cost of climate change: Estimating long-term mortality
A low-carbon
lecture tour of Australia, July-August 2019
Richard
Parncutt -- Watch the video here -- Read the paper here
Climate change is primarily a human
rights issue. It will be a matter
of life and death for
enormous numbers of people — especially in developing
countries. That is surely the main
point, but
almost no-one is talking about it. We are witnessing an
eerie silence in both public media and academic
publications.
I addressed this issue in different Australian
cities in July and August 2019, travelling only by train and bus (staying grounded;
my return flight to Europe was presumably my last ever). My
presentation was based on a manuscript that has since been
published by Frontiers
in Psychology.
All talks were open to the public and lasted
for about 45 minutes followed by
questions. I thank the organisers at each location for their trust and
support.
Melbourne
Time: Monday 15 July, 1 pm
Place: Monash University (Clayton), 9
Rainforest Walk, room 107
Organisers: School of Earth, Atmosphere and Environment; Sustainable
Development Institute
Sydney
Time: Thursday 25 July, 2 pm
Place: University of New South Wales (Kensington), Mathews Building,
4th floor, Seminar Room
Organisers: Climate Change Research Centre Info
Armidale
Time: Mon 29 July, 12 noon
Place: University of New England, Psychology Lecture Theatre
Organisers: Department of Psychology
Brisbane
Time: Thu 1 August, 10 am
Place: Queensland University of Technology (Kelvin
Grove), room OA-103 (O Block,
A wing, ground floor)
Organisers: Public Health and Social Work, QUT
Cairns
Time: Wed 7 August, 4 pm
Place: James Cook University (Smithfield), Cairns
Institute, room D3.054
(video-linked to ATSIP 145-030 Townsville)
Organisers: Centre for Tropical Environmental and Sustainability Science Info
- Video
Townsville
Time: Friday 9 August, 6:30 pm ("green drinks")
Place: Fish Inn
Organisers: North Queensland Conservation Council
Darwin
Time: Fri 23 August, 3:30 pm
Place: Charles Darwin University (Casuarina), Room
Yellow 1.1.39
Organisers: Research Institute for
the Environment and Livelihoods (RIEL)
Adelaide
Time: Friday 30 August, 1 pm
Place: University of Adelaide (North Terrace), G10
Benham Lecture Theatre
Organisers: The Environment Institute Info
- Video
Summary
So far, global mean surface
temperature has increased by about 1°C relative to the
pre-industrial period due to human activity —
mainly carbon emissions and deforestation. In 2018, the international
community of climate scientists, represented by the Intergovernmental
Panel on Climate Change (IPCC),
explained that a further temperature
rise of 1°C (making 2°C
altogether) will have catastrophic global consequences. Many of these
consequences can be avoided by limiting the increase to 1.5°C.
We can achieve the 1.5°C goal by
halving global emissions by 2030 and approaching net zero by 2050.
Currently, no such international agreement exists. If the 2015
Paris participants do what they promised (and
experience suggests otherwise), global mean surface temperature will
rise well above +2°C. The damage will
be existential and irreversible.
A 2°C increase would cause
a very large number of premature human deaths — in many
different ways. Among other things, it would exacerbate the existing
death toll in connection
with poverty: hunger, curable disease, preventable disease, violence.
This rate, which is currently some 10
million per year, could double by 2100.
In a very rough first-order approximation, 2°C will
cause a
billion premature deaths, spread out over one to two centuries.
That's 10%
of a future global population of 10 billion. I will present diverse
arguments in support of this preliminary estimate, including various
best- and worst-case estimates that take into account estimated
probabilities
of different possible catastrophic outcomes.
The 1000-tonne rule
To cause 2°C of warming,
humanity will have burned
approximately a trillion tonnes of carbon, creating about 3.7 trillion
tonnes
of CO2. If 2°C causes a
billion premature
deaths, a future person is dying prematurely every time
we burn 1000 tonnes
of carbon. The implications of this simple rule
are staggering:
Any
fossil-fuel industry that is
producing or burning hundreds of millions of tonnes of fossil carbon is
indirectly
killing hundreds of thousands of future people. For
example, the Australian coal industry is producing 300 million tonnes
of carbon per year. When burned, that coal is causing the premature
deaths of
roughly 300,000 future people — every
year. The Adani Carmichael coalmine, if it
goes ahead, will altogether produce two billion tonnes of carbon,
causing roughly two million future premature deaths.
In round figures, the
billion richest people in the world are in the process of
killing the billion poorest people. We are causing these future
premature deaths today, with our emissions. Put another way, the
average person in a rich
country is responsible for the premature death of roughly one future
person in
a poor country (cf. Nolt, 2011).
This
may initially seem like an abstract calculation — a
game with numbers. But the people in these examples are real. Many
of them are already alive now, as children. They could die
anywhere in the world and they could die for many different reasons. If
you are reading this text, you probably live in a rich country, so your
childen and personal acquaintances will probably not be mortally
affected. Most of the victims will
die in
poorer or tropical countries.
The most common direct causes of death will be
hunger, curable/preventable disease, violence, or direct heat. If
humanity manages to get climate change under control, most of the
deaths will happen during the coming two centuries.
In the many lively discussions following this talk in different
Australian cities, no-one argued that my main quantitative estimates,
based on IPCC reports, might
be too high or too low. Those estimates are:
roughly
one billion
future premature human deaths attributable to 2°C of global warming
lower
better- and best-case scenarios; higher worse- and worst-case scenarios
therefore,
roughly 1000 tonnes of burned carbon today for every future death
Nor
did anonymous expert reviewers question
these estimates when I submitted them to a
leading international peer-review journal.
Just how bad is this?
Fossil fuels are not all bad. On the contrary: until now, burning
carbon has
had an enormous positive effect on human quality of life and longevity.
Over the past couple
of centuries, life expectancies have steadily increased in
industrialized countries —
largely due to the ready availability of energy for diverse purposes
(transport, agriculture, heating, building). That is surely one of
humanity's
greatest achievements.
We should also remember that any major infrastructure project causes
future premature deaths. Consider West Gate Bridge in Melbourne, part
of which collapsed in 1970, killing 35 construction workers. It is
impossible to completely eliminate the risk of bridge collapse. A
typical large bridge will collapse sometime during its lifetime with a
given probability. Let's assume the probability of collapse is 0.1% and
the human cost is typically 100 lives. If that is true, constructing a
typical bridge effectively kills 1/10 of a person. But that human cost
is
surely outweighed by the benefits of the bridge to millions of users.
Nuclear power plants are a contrasting example. The Chernobyl
disaster in 1986 may have caused the premature deaths of as many as a
million people — mainly
because radiation increases the risk of cancer. If the probability of
such a disaster in a typical
nuclear reactor is 0.1%,
each new reactor is effectively causing 1000 premature deaths.
Most people would agree that a risk of that magnitude is too high
by comparison to the benefit of the electricity generated by the plant,
even without considering the waste problem.
But these "everyday" risks pale into insignificance by comparison
to fossil fuels, which according to the 1000-tonne rule are
currently killing about 10 million future people worldwide every year.
Having appreciated the massive pros and cons of fossil fuels, the
challenge now is to radically change how we generate and use energy. We
need to maintain what we have achieved in terms of human quality of
life and longevity for future generations.
The importance of honesty
The right to life of today's children and
future generations is clearly more important than today's economic
wellbeing. Agreement on this point is almost universal, given that
hardly anyone would dare to publicly contradict it. If we are honest
about that, big changes are
urgently necessary.
At
the "macro" (national/corporate) level,
all extraction and burning of fossil fuels must be slowed and stopped
as quickly as possible. Entire economic systems
including energy, transport, and
agriculture need to be reconstructed to completely avoid fossil fuels,
deforestation, and other unsustainable practices. That could take
decades, so we have to start now. The 1000-tonne rule
implies that we need to move even faster than 5% per year. The optimal transition rate is as fast as
possible without
causing even more deaths.
At
the "micro" (individual) level, if we are to stop indirectly killing
future people, we must completely stop flying
and driving, and drastically reduce meat consumption, to approach a sustainable
personal carbon footprint of about 2 tonnes CO2 per year. That is
the amount of CO2 that
trees and other plants on land and in the oceans
are currently sustainably absorbing by photosynthesis, divided
by global population.
We
must also increase the global rate of
photosynthesis by stopping deforestation and promoting reforestation
(as well as implementing geoengineering solutions, provided the
benefits are clearly greater than the dangers),
and take appropriate measures to curb global population growth. But
even if such projects are very successful, and
regardless of what happens in the political/corporate domain, the
average person will still have to drastically reduce personal emissions.
The macro
and the micro levels are equally important. To have any hope of
achieving the 1.5°C
target, we must combine them. Each motivates the other.
To those who say we "cannot" change the system in this way
or we "cannot" stop flying, driving, and eating meat, there is an
easy answer: Tell the truth. We can do these things, and we know it.
Humans can do many things. We can also kill millions of future people
and risk the extermination of humanity, if we want. The question is,
what do we want?
The
statements in italics are not necessarily political demands or value
judgments. They can be regarded merely as logical conclusions that
follow directly from widely accepted facts and values. In general, we
are free to
choose between honesty and denial (or between caring or
not caring about children and future generations). If everyone agreed
to
be consistently honest (or to care), implementation of the statements
in italics (or
something similar) would be inevitable. Again, this is not necessary a
political claim or value judgment, but merely a logical conclusion. Is
dishonesty the only thing standing in our way?
Responding rationally and
constructively
Many people feel overwhelmed by these ideas. The temptation to either
panic or deny is understandable. How can
we break free from extreme reactions and develop a rational,
constructive response?
One
idea is to consider our economic situation in its geographic and
historic context. Many of us are living in luxury —
at least, relative to most other
humans on the planet today or at any time in history. Our
luxurious lifestyles have been achieved at the expense of the natural
environment, upon which our children and future generations will depend
for
their survival. Future generations will miss out on many of the
luxuries that today's middle class takes for granted. The climate
crisis is a reminder that it is time to
tighten our belts and give back.
Another
approach is to apply ideas from the social sciences —
psychology and sociology.
As we open our hearts and minds to climate change and its probable
future consequences, our first response might be depression —
a
combination of sadness and powerlessness. This is a rational and honest
response, and it helps us to appraise our situation. But we also need
to act, which is motivated by a different
kind of emotion. Rewards and punishments play an important role;
they should be proximate in time and space to the corresponding actions. Personal
climate action can include taking advantage of our
freedom of speech, working constructively
with like-minded soulmates on practical solutions, focusing on the
positive aspects
of a low-carbon lifestyle, and empathizing with children and young
people everywhere. In this way, we
can create social rewards for ourselves that motivate further
action. We feel liberated, which helps us to promote healthy,
honest, realistic, constructive public discourses and social
representations of climate change. To promote large-scale
behavioral change, we need to think about
rewards and punishments that can appropriately be applied to large
numbers of people. Economically, these might involve subsidies and
taxes. Legally, they might involve jail sentences or financial
compensation for damages. Socially, personal identity is a powerful
motivator. People are motivated to change by the desire to
belong: doing what is currently cool, identifying with a new
movement, getting positive feedback from others, finding new friends
and social circles.
The
talk will draw on diverse academic disciplines including
physics, chemistry, biology, ethics (philosophy), psychology,
sociology, medicine, economics, law, and political science. It will be
accessible for experts in all disciplines and all concerned
citizens, regardless of academic background.
Abstract.
Greenhouse-gas
emissions are indirectly causing future deaths by multiple mechanisms.
For example, reduced food and water supplies will exacerbate hunger,
disease, violence, and migration. How will
anthropogenic global warming (AGW) affect global mortality due to
poverty around and beyond 2100? Roughly how much burned fossil carbon
corresponds to one future death? What are the ethical, legal,
psychological, medical, political, economic implications?
Predicted death tolls are crucial for
policy formulation, but uncertainty increases with temporal distance
from the present and estimates may be psychologically biased. Order-of-magnitude
estimates can be made by comparing literature from
diverse relevant disciplines. The carbon budget for 2°C AGW
(roughly 1012 tonnes of carbon) will indirectly cause
roughly 109
future premature deaths (10% of projected maximum global population),
spread over one to two centuries. This zeroth-order prediction is
relative and in addition to existing preventable death rates. It lies
between likely best- and worst-case scenarios of 3 x 108 and
3 x 109,
corresponding to plus/minus one standard deviation on a logarithmic
scale in a Gaussian probability distribution. It implies that one
future premature death is caused every time roughly 1000 (300 to 3000)
tonnes of carbon are burned; therefore, any fossil-fuel project that
burns millions of tons of carbon is probably indirectly killing
thousands of future people. The prediction may be considered valid,
accounting for multiple indirect links between AGW and death rates in a
top-down approach, but unreliable
due e.g. to the uncertainty of
climate change feedback and interactions between physical, biological,
social, and political climate impacts (e.g., ecological cascade
effects, co-extinction). Given universal agreement about the value of
human lives, a death toll of this unprecedented magnitude must be
avoided at all costs. As a clear political message, the
“1000-tonne rule” can be used to defend human rights,
especially in developing countries, and to clarify that climate change
is primarily a human rights issue.
Biography. Richard Parncutt
studied at the University of Melbourne and the University of New
England
(Armidale, NSW). He has a BSc with
honours in physics and an interdisciplinary PhD in
psychology, music and physics. His other research addresses the
perception and
cognition of musical structure, music performance, the origins of
tonality and music, and musicological interdisciplinarity (more).
He
now lives in Graz, Austria (more). In
2018, he organized an innovative multi-location semi-virtual conference
(more)
to reduce academic carbon footprints (more).
Reference
Nolt, J. (2011). How harmful are the average American's greenhouse gas
emissions? Ethics, Policy and
Environment, 14(1), 3-10. The opinions
expressed on
this page are the
authors' personal
opinions. Suggestions
for improving or extending the content
are
welcome at parncutt@gmx.at.