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Author: Jensen Morgan

This lesson provides an overview of energy and different sources of energy.

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Source: Earth PD Tesla Coil CC Wind Farm CC Solar Panel CC Biomass CC Oil Rig CC Coal Plant CC Natural gas plant CC World Energy PD Carbon Emissions CC U.S. Energy History PD World Energy Use CC

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Hi, I'm Jensen Morgan. We're going to talk about some great concepts in environmental science. Today's topic is energy so let's get started.

We're going to talk about energy, its sources, fossil fuels, carbon footprint, and how energy use has changed over time.

Energy is used in almost every facet of modern life-- to run our cars. Heat our homes. Clean and transport water. Light our buildings. Power our electronics. And manufacture our products.

Energy is defined as work that can be done by a fuel source. Fuel sources can vary and the form of energy they take can as well. Energy can be thermal, mechanical, or even chemical, though, a large portion of what is used by humans is in the form of electric energy which powers houses, businesses, and various industries. Different fuel sources provide different amounts of energy in their various forms.

Energy sources are split into two main categories-- nonrenewable and renewable. 88.5% of energy used by humans comes from nonrenewable sources, while renewable ones take up the remaining 11.5%.

Renewable energy is considered renewable because it can be replaced in a reasonable human lifespan-- meaning months, years, or decades. Or is simply an unlimited supply. Of US renewables, biomass and ethanol produce 50% of renewable energy generated. Hydroelectric provides 27.5%, wind 17%, photovoltaics 3%, and geothermal 2.5%.

At 88.5%, nonrenewable provide the vast majority of energy used in the US. Nonrenewable energy sources are those that cannot be replaced in the normal human lifespan. Most renewables take thousands to millions of years to form so for human purposes, there is a finite supply.

Natural gas-- which is used for heating and transportation and which the US is the largest producer globally-- makes up 39% of the US nonrenewable energy mix.

Oil is the largest source of energy in the US, even if it is not the largest utilized. It makes up 21.5% of the nonrenewable energy mix, and is used for heating and transportation, as well.

Coal consumption provides 27.5% of nonrenewable energy, primarily for electricity in the home and in industry.

The remaining 12% is made up by nuclear power plants, which uses a rare form of uranium to provide electricity for homes and industry.

The majority of US energy and, therefore, nonrenewable energy, comes from fossil fuels which are most often oil, natural gas, and coal. Fossil fuels are sought after for their energy dense nature and their originally easy accessibility, hence why they quickly became the world's prime energy sources once discovered.

They provide energy for transportation in cars, buses, trucks, boats, and airplanes, as well as electricity to power homes, industries, and businesses. And heating for the same end uses.

Despite being only 5% of the world's population, the US consumes approximately 20% of the world's energy. This graph shows energy intensity globally through kilograms of oil equivalent-- a standard measure of the amount of energy that can be extracted from one kilogram of crude oil. The lighter the country's color, the higher the energy intensity.

As you can see. While the US is one of the highest in energy intensity. Its population is only 5% of the worlds.

Carbon footprint is a tool used to measure the amount of greenhouse gases produced by a source, whether it is a person, a product, a company, or a country. Carbon footprint assessments are tools used to increase awareness of impacts at an individual, organizational, or product level.

Greenhouse gases are of interest because of their capacity to accelerate and exacerbate climate change.

Carbon footprint actually is just a part of ecological footprint calculations and can be used as an indicator of sustainable energy use. This map here shows the average amount of carbon dioxide emissions by country per year. You can see that the US and China are by far the biggest producers.

When talking about energy, it is important to highlight how its use has changed in quantity over time. In this graph here, you can see that US energy use has dramatically increased since the 1700s. The graph follows the rise of the Industrial Revolution. As technology use has increased, so has the need for electricity and other forms of energy.

This graph of global energy consumption looks quite similar. It also follows the rise of the Industrial Revolution, causing increased technology use and electric energy needs, resulting in increased energy consumption.

Now let's have a recap. Today, we talked about energy. Its two main categories of renewable and nonrenewable sources. The energy mixes of each. The nature of fossil fuels, carbon footprint, and how energy use has changed over time in the US and worldwide.

Well, that's all for this tutorial. I look forward to seeing you next time. Bye.