I'm Jonathan Tompkin from the University of Illinois. This week we're talking about energy. Energy's very important. The modern world runs on energy, and our high standards of living depends on it. We have a problem, though. Most of the energy we get today comes from fossil fuels. And this has two big issues. The first one, as we saw last week, is the use of fossil fuels leads to climate change. And if we want to avoid large scale climate change we probably have to cut back on the amount of fossil fuels that we use. Second problem is, is that fossil fuels are a finite resource. So, if we are talking in the sustainability context, we might wonder, is there enough? And if there is enough, do we have alternative sources of energy like renewable sources of energy that we can use to replace it to meet that need. So, this week we are gonna look at that issue. Do we have enough fossil fuels and what happens if we run out? Is there enough renewable energy and what are our other energy options. Renewable energy sources don't produce carbon dioxide emissions at the same rate as fossil fuels, but right now they're more expensive. As a consequence, they're only a tiny part of our energy portfolio. Can we ramp them up in the future? In fact, most of the renewable energy that we get today, comes from biomass. That's from growing things that we can turn into energy, for example, wood gets burned, in stoves. The problem with this of course is, it takes up a lot of land. And that land has a lot of other potential uses, including, growing food. Diverting Midwest corn crops to biofuel for example, producing ethanol, has driven up corn prices. So, where do we get most of our energy from? As you can see in this pie chart, most come from fossil fuels. Most of the renewable energy is biomass. Renewable energy sources are in principle inexhaustible. If we look at little break out pie chart of renewable energy sources we can see that it's mainly taken up with biomass and hydro power. And not necessarily the first things that we think about, when we think about the new renewable energy sources such as photo voltaic solar power, PV solar or wind power. I mean in a lot of ways out, our goal to reach a new energy future depends on expanding these parts of the pie. Energy use in the world is very unequal. Modern industrial countries us a lot, developing countries use less. If we look at this graph, we can see that countries like Australia or the United States, use much more per person than other places in the world. But being a developed country doesn't mean that you have to use as much as the United States or Australia. For example if we look at Western Europe we can see they use much less. So this suggests that there are other strategies apart from finding new energy sources to reduce our carbon footprint. The United States is a good example of a country that uses almost all conventional power. If we look at this list we can see coal, metrol gas, petrol, nuclear power make up the vast majority of the energy footprint of the country. In fact, only eight percent is what we might call advanced renewable. So countries like the United States which use most of the energy today are the ones that have to make the biggest changes if we're going to move to a renewable energy future. Us renewables are dominated by hydropower. And although there is some scope for increase in amount of hydropower, there's not very much. And, in fact, in a lot of places in the country dams being used for hydropower are being taken out, because they disrupt local ecosystems. For example fish life cycles. So we're not living in a post conventional energy world yet. But there are big trends going on in the background. Firstly, let's look at this example of wind power. Wind power in the United States is growing exponentially. It doubles every three years or so. Looking at trends like this, we can see that wind power could make a much bigger contribution to the grid then it does today. Further more, energy use in many advanced economies is declining. In this case, we can see that we, that the United States uses much less energy for each dollar of GDP. So for each value of production, advanced economies like America don't require as much energy as they did a few decades ago. This means that, even in the United States, one of the most profligate users of energy in the world, has not seen big increases in the amount of energy required to run its advanced economy. In fact, it's been broadly flat for decades. This is despite increases in living standards, and increases in the population. So maybe we're not on a J curve for energy, but we still use a lot. This is a picture of Rotterdam shooting energy into the atmosphere as a memorandum of a previous bombing. And what if fossil fuels do run out in the next few years or decades? Are we in a position were we could switch? We're gonna examine these issues in the next few lectures. And we're gonna start by looking at the, the biggest issue of all, oil. Produced by OCE, Atlas Digital Media, at the University of Illinois Urbana-Champaign.
