This course introduces the academic approach of Sustainability and explores how today’s human societies can endure in the face of global change, ecosystem degradation and resource limitations. The course focuses on key knowledge areas of sustainability theory and practice, including population, ecosystems, global change, energy, agriculture, water, environmental economics and policy, ethics, and cultural history. This subject is of vital importance, seeking as it does to uncover the principles of the long-term welfare of all the peoples of the planet. As sustainability is a cross-disciplinary field of study, this foundation requires intellectual breadth: as I describe it in the class text, understanding our motivations requires the humanities, measuring the challenges of sustainability requires knowledge of the sciences (both natural and social), and building solutions requires technical insight into systems (such as provided by engineering, planning, and management).
Measuring Sustainability: The Future, Part 1
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從本節課中
Measuring Sustainability
In this module, we will examine what tools are available to measure sustainability. Finally, I will make some predictions on global sustainability for the 21st century, based on the models we have spoken about in this course and the trends that have been observed in the early part of this century.
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Dr. Jonathan TomkinAssociate Director
School of Earth, Society and Environment
I'm Jonathan Tomkin from the University of Illinois.
This is the last lecture in this series. I'm going to be using this opportunity to
try and sketch out what the twenty-first century might look like in terms of
sustainability. Where are we headed?
Well, in the very first week I discussed the concept of growth curves and how that
there are some J growth curves and S growth curves.
J growth curves inevitably lead to a crash because whatever the current capacity is,
they always blow straight past it. Whereas, S growth curves can asymptote
toward a steady state towards that current capacity.
So, we might ask ourselves then if we're thinking about sustainability in the
twenty-first century, which of these two patterns we're more likely to be on.
Well, let's look at some real growth curves then.
This is from the United States. Energy use is flat, carbon dioxide
emissions are down, car trouble is down. Thanks to a transfer from coal to gas,
carbon dioxide emissions have dropped even as the price of energy is decreased.
Air pollution, like sulphur dioxide, is way down.
All this is despite the higher population and affluence as measured by GDP.
Note that this is not the prediction of an IPAT analysis.
Is this the whole story however? In some ways, the world is on two tracks.
There's the developed world track and the developing world track.
Developed world countries use lots of resources but at a static and sometimes
declining rate. In some cases, the amount of absolute
increase is zero. Japan's population, in fact, is predicted
to be a third lower in 50 years. And so, we could predict that Japan will be using
less resources then than it does now. These observations about developing world
have led to some new ideas. One of these is de-materialization.
This is the process by which less materials are used to deliver the same
function, Comparing electric file of a textbook
versus an actual physical book. This is an observed trend in the developed
world causing more efficient or even shared.
We see plenty of examples in this course of increased efficiencies,
There's better use of energy than there used to be in the past. And, there's less
use of water now in the United States than there was in the 1980's.
One estimate suggests that between 1980 and 2005, a French consumer enjoyed 50%
more affluence, but used only ten percent more energy.
So, this isn't just restricted to the United States, this is something that we
see in most developed economies. This isn't just a theory,
There are lots of other observations that line up with observe, with this idea.
Some commentators have spoken about peak oil but there is also peak travel, peak
steel, peak stuff. Take farmland in the United States.
We use less farmland now in the United States than we have in the last few
decades. In fact, peak farmland occurred in the
1950's. In fact, we use a comparable amount of
farmland as we did as at the start of the twentieth century.
The population of the United States has grown from 80 million to 300 million in
that time. I spoke previously about peak vehicle
travel in the United States. This isn't just restricted to the United
States, this is seen in many other countries as well, where it's been
observed in Britain, Germany, France, Japan.
From 2005 to 2008, every year in the United States, the amount of vehicle miles
traveled per person dropped. As of 2008, the average American is
driving about the same distance as they did in 1998.
We have this other idea of peak stuff. Beyond some point of consumption, people
stop buying new things. Maybe they don't have the space for it or
they don't have the need for more material objects in their, in their houses or in
their lives. The British environmentalist Chris
Goodall, for example, argues that people in the United Kingdom are actually
consuming less material goods now than they were in the 1990's.
According to data from the UK Office of National Statistics, the total material
requirement peaked at 2.17 billion tons in 2001 and has fallen by four%..
But in 2007, even though GDP rose over that period, so people were more affluent
but they had less things, they had less material things.
And, of course, material things have an impact on the environment.
Water use is down, travel and car ownership use is down, metal and paper use
is down, calorie consumption is down, and meat eat, eating is falling in the United
Kingdom. So, this is not the sort of trends that we
would associate with a J curve growth, an exponential growth.
This is true elsewhere as well. It's been observed in the US and Germany.
A good example of this, is that the amount of material going to landfills in the
United States is less now that it was in the past.
This is sometimes described as an environmental Kuznets curve.
In this case, the hypothesis is that as countries get wealthier they move through
a transition from when the began when they're poor, little pollutants are made.
And as they grow richer, more and more pollution is created.
But then past a certain threshold point, the amount of pollutants actually
decreases. So, if countries can transition from being
poor to being rich, they can move from being low polluting to high polluting and
back to low polluting. There are some different sets of data that
back this up. One famous example is sulfur dioxide.
As the United States got wealthier through the twentieth century, the amount of
sulfur dioxide emitted by American industry increased, but it peaked at
mid-century. Then,
Due to environmental laws and the concerns of individuals, it was decreasing all the
way through to today and it's continued to drop into the twenty-first century.
This is actually not just being observed in the United States.
Sulfur Dioxide emissions follow the same pattern all around the world.
There's this idea that if you have around $5,000 per person in per capita income,
you have a peak in sulfur dioxide production. And as you get wealthier than
that, the amount of sulfur dioxide that, that country produce actually starts to
fall again. We can apply this environmental Kuznets
curve to other environmental issues. One idea too, might be that we talked
about population. And it appears that population growth occurs in this narrow
band between wealthy and poor countries, as the country transitions to a more
developed state. This curve is controversial, however.
Notice how it is really empirical, It's based on observation not on
underlying theoretical concerns. It could be that it's not so much that
it's an increase in wealth that makes the environmental impact come down, but just
the passage of time. Of course, in the United States, we saw a
growth in wealth at the same time as the twentieth century progressed.
It could just be that as people became more enlightened, or technology improved,
or people became more socially aware of environmental issues, that there was the
demand to drop these emissions. And so, it's not actually to do with
wealth so much as a process of time. Another real concern is that it appears
that the environmental Kuznets curve doesn't apply to all environmental
variables. Let's think about calorie consumption, for
example, as we get wealthier that increases at a slower rate but it still
increases. More seriously, we might worry about
things like carbon dioxide production because that changes the nature of the
climate. That appears to increase at a slower and
slower rate but, nevertheless, still increase as countries become wealthier.
So, instead of seeing the curve bend back over, the curve remains quite flat and so
even wealthy countries are very polluting. In fact, the wealthier the country is, the
carbon dioxide the more it pollutes. Another good example might be steel
production. Steel production is showing no signs of a
Kuzenets curve right now. This could be due to building growth in
countries like China, but nevertheless, even developed countries like the United
States is still using a lot of steel. So, it could just be that the impact of
increase wealth, instead of moving down towards lower emissions, in another way
just reached a steady state. So, very wealthy countries are no worse
for the environment than merely wealthy countries.
Critics of peak stuff actually see these sorts of arguments as determinative.
They take the observation that developed countries use so much resources that any
talk about a dematerialization is overselling the case.
And that there might be a slight decrease or might be a slight change,
But really the rate is so high that this change is immaterial.
And there's another reason to think there won't be a universal Kuznets curve for the
twenty-first century. As we saw in the population module,
Most of the growth in the twenty-first century is going to happen in developing
countries. So, these are countries that have not
reached that point where they might start to decrease their levels of consumption.
Developed world countries use far more resources per person that the rate of
change in that growth is much lower than for developing countries.
So, developing countries are using less resources, but those resources are being
used at a growing rate. Perhaps, there is a hopeful side to this,
however. Developing countries needn't go through
the same development process that the industrialized countries of today had to
go through to reach their current state. They can leap straight into more efficient
developed technologies. Famously, many African countries aren't
installing fixed telephone wires, for example,
They moved straight to mobile phones. Other examples could include inproved
developments of farmland utilization. It's been estimated that if the
productivity of the world's farmers on an average basis was raised to the current
level of farmers in Iowa. A world of ten billion people could be fed
an American diet on about half the farm land being used now.
That's to show the incredible difference in yields and efficiency between the very
peak farmers and the world average. So, if we can use these sorts of
technologies and spread them to these quickly developing, quickly growing
developing countries, then we might be able to avoid some of the worse impacts of
industrialization. Another thing that I would add is that
this all appears to be somewhat organic, In a sense the system seems to run itself.
If we think about the twentieth century, we can see a history of world wars, other
disasters including flu pandemics, and social economic upheavals including the
Great Depression. All of these events, no matter how large
they were, no, did little more than slow down the trend lines that were established
for the countries that were developing through the twentieth century.
So, we might expect barring some global level catastrophe that these trends will
continue. We might have a recession, we might have a
local war, but in all of these cases, the trend line for the twentieth century
suggests that the twenty-first century's progress will just occur naturally from
the system itself. Produced by OCE, Atlas Digital Media at
the University of Illinois, Urbana-Champaign
