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).
Nuclear Power
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來自 University of Illinois at Urbana-Champaign 的課程
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從本節課中
Energy
In this module, we will look at energy use. We will also consider what the trend of energy use means for the planet, and how we might transition to a more sustainable pattern of use.
與講師見面
Dr. Jonathan TomkinAssociate Director
School of Earth, Society and Environment
I am Jonathan Tomkin from the University of Illinois.
So, if fossil fuels are going to be a problem in the future because they produce
carbon dioxide. What sort of energy sources can we rely on
in the future? Well, there is one source of energy that
doesn't produce very much carbon dioxide and can be scaled up easily to proven
technology and it's nuclear energy. Many countries get a large amount of their
electricity from nuclear energy already. For example, France gets the majority of
its energy in it's electrical grid from nuclear power.
Many countries do not have nuclear power right now, but might in the future.
So, is nuclear power a potential answer to both the challenge of needing more energy
and reducing our carbon footprints? This has been an ongoing debate for a long
time. Nuclear power is cheaper than some other
technologies for producing energy. Not yet as cheap as say coal, but it's
pretty competitive. But there are worries about its
suitability, for widespread use because of both security issues, and also of course
because of the danger of contamination. Operation has been safe in most countries.
In the United States for example which is one of the world's biggest producers of
nuclear power. There's been no recorded deaths in the
operation of a civilian nuclear power plant.
And this contrast, nuclear power with other sorts of power like coal, wind,
whatever. Most energy sources do produce some
accidents or some deaths. Another potential energy of nuclear power
is that one of it's prime sources, uranium, has a widespread distribution and
can be sourced from stable democracies like Canada or Australia.
And so, this reduces its security concerns that we see with some other sources of
energy. And although it's similar in price, in, in
terms of producing electricity per kilowatt hour, to coal or natural gas.
The estimates are a little bit uncertain. And this is because, there's a high risk
associated with catastrophic incidents associated with nuclear power.
A 2010 study by the Japanese government called the Energy White Paper, concluded
that the cost per kilowatt hour was 49 yen for solar, ten to fourteen yen for wind,
and five to six yen for nuclear power. So, compared to other low carbon
technologies, it's much cheaper. Another potential advantage of nuclear
power is that it can be relied on, as a base load throughout the year.
You don't have to wait for the wind to blow or for the sun to shine.
Like the fossil fuels, however, nuclear power is potentially a non-renewable
resource, in that it requires fuel that is mined.
Is there enough uranium in the future? Well, it is true that supplies are finite.
Pessimistic predictions of the amount of high-grade uru-, uranium fuel available
suggest that a peak was actually reached in 1980s.
And other people suggested that we might hit peak uranium around 2035.
It is probable that if the price of power goes up, and so the lower grade uranium
could be used. It would be more expensive to extract but
if the price of electricity was high that would be justified.
That we'd probably have enough nuclear power to see us through the century at
least. And there are other nuclear technologies
that are less widespread that would have much longer lives, potentially.
So called breeder reactors produce their own fuel, for example.
And there are other sorts of reactors, like thorium reactors.
We should also be aware if we're thinking about.
Whether or not we're at peak uranium as the price of uranium might be a way of
measuring that. Uranium prices are relatively high, but
they're not as high as they have been at some points in the past.
So, that's not clear. And of course, the major problem in
nuclear power is, would you like a nuclear power plant in your backyard?
The answer for most people is no. Metaphorically, backyards extend to the
entire community. If no one wants nuclear energy in their
community. And there's actually a term that often
gets used for this, and it's called NIMBY, or not in my back yard, sometimes
nimbyism. The issue with this is, of course, is
that, here in the United States for example, we all use nuclear power.
The lights that are shining on me today are partly the result of nuclear power.
But we don't want to be associated with either the operation of nuclear power
plants or, of course, the waste that gets produced.
So, this creates a tension. We can't produce nuclear power, as an
energy source if we can't operate the plants or store the waste.
So far, advanced economies haven't really found a solution to this NIMBY problem.
Opposition from local groups often prevents the construction of nuclear power
plants, especially new nuclear power plants today.
And of course it's very hard to find places to store the waste.
The United States has no long-term solution for nuclear power storage.
For quite awhile Yucca Mountain was considered as a place to store nuclear
waste. But that plan has been discontinued and
there is currently nothing to replace it. Not in my backyard can be a very
reasonable stance, of course. One of the things we think of when we talk
about nuclear power is the risk of catastrophic failure.
Chernobyl in the Ukraine, experienced a catastrophic failure of one of their
nuclear power plants. Not only did this result in the deaths of
50 workers, and possibly thousands of people throughout Europe, because of
enhanced rates of cancer. But it also required the evacuation of an
entire city. This is an excellent reason not to have a
nuclear power plant in your backyard. More recently, we've seen the Fukushima
Daiichi disaster, where a tsunami, caused by an undersea earthquake, caused the
meltdown of a reactor in coastal Japan. The earthquake and tsunami killed around
20,000 people in Japan. It's not clear exactly how many people
will die because of radiation exposure due to the meltdown of a nuclear plant, but
estimates typically are in the range of around 100.
As a consequence, support for nuclear power in Japan has plummeted, and all but
two of the country's nuclear reactors have been switched off.
So, this leaves us with a problem. If there is no public support for nuclear
power because of the potential risks. Can we find other sources of power that do
not produce carbon dioxide and put us at risk of massive climate change?
That's what we'll look at in the next lecture, the new sources of renewable
energy. Produced by OCE, Atlas Digital Media, at
the University of Illinois Urbana?Champaign.
