Video Transcript
In this video, we will learn about how we use the Earth’s resources. We’ll learn about the difference between finite and renewable resources and what it means to use the Earth’s resources sustainably. We’ll also take a look at an example of how science can be used to create more sustainable resources by comparing biofuels to fossil fuels.
Take a look around you. What’s everything in the room that you are in is made of? Maybe you’re taking notes on a piece of paper with a pencil. If your pencil has a wood body, then both the pencil and the paper ultimately came from trees. Maybe you’ve a snack nearby like a piece of fruit, which is obviously some kind of plant that was grown. Maybe you’re sitting at a desk that’s made of metal or plastic. What about your clothes? What are they made of? Maybe cotton. How is the device that you’re watching this video on powered? Is it powered by battery, which contain various metals, or is it plugged into an outlet using electricity that may be generated by burning coal from wind power or nuclear power? And what makes up the room you’re in? Maybe it’s concrete or plaster. And what about the last time you rode in a vehicle? What powered it? Was it fossil fuels like gasoline or diesel?
Everything we use and interact with on a daily basis from the food we eat to the building materials that we use to construct our homes and furniture to the fuel that we use to generate electricity, heat our homes, and power our vehicles ultimately comes from the Earth. We humans are totally reliant on the Earth’s resources to make everything that we interact with. We can divide Earth’s resources into two main categories: renewable resources and finite resources. Renewable resources are resources that can either be used over and over again or they’re replaced quickly by the environment. Examples of renewable resources are the air, soil, and plants. Even though we use resources like these all the time, we don’t have to worry about running out of them.
Finite resources, also called nonrenewable resources on the other hand, are resources that cannot be replaced quickly enough to keep up with the rate of consumption. Because of this, we’ll eventually run out of them if our rate of consumption doesn’t change. An example of a finite resource is fossil fuels like crude oil, coal, and natural gas. Fossil fuels are created when there are large deposits of dead organic matter, like plankton or plants, that are compressed over a very long period of time. For example, 10 feet of solid vegetation that’s compressed and heated over millions of years creates one foot of coal. But we go through that amount of coal to generate electricity much faster than the millions of years that it took to create it. So though fossil fuels are continuously being formed by the Earth, we’re going through them at a faster rate than they’re being formed. So we’ll eventually run out of them, unless our rate of consumption changes.
Another example of a finite resource are metals. Metals are present in large amounts in the Earth’s crust, but only a certain amount of those deposits can be accessed easily by humans. And we use these metals all the time as building materials and things like batteries and solar cells. And the metal uranium mined from uranium ore is needed to power nuclear reactors. Though most metals are plentiful in the Earth’s crust, we’ll eventually run out of them, making them a finite resource. The last example of a finite resource that we’ll look at is limestone. Limestone is created from things like decomposed shells and coral. Limestone is used in the steel-making process. It’s used to create building materials like concrete and plaster, and it’s also used for decoration. And though limestone is being constantly created as marine organisms decompose, this process takes time, making limestone a finite resource.
There’s also lots of resources that can be finite or renewable depending on how we use them. One example of this is trees. We use wood quite frequently, and of course trees grow back over time. But if the rate that we’re chopping down trees for wood is faster than the rate that the trees are able to grow back, then it will lead to deforestation. But we can combat this by making sure that we’re not chopping down too many trees and that we are replanting forests. Another example of a resource like this is animals. Animals, of course, will replenish their numbers over time. But we still need to be careful about how we’re using animals as a resource. For example, there are quite literally plenty of fish in the sea. But if we aren’t careful about our fishing practices on an industrial scale, we might not be able to eat fish as food in the future.
A final example of a resource like this that we’ll look at is fresh water. In many areas, fresh water comes from aquifers, which are large underground deposits of fresh water. These aquifers are slowly recharged over time as groundwater runs into the aquifer. We pump these aquifers both for drinking water and to water crops. And unfortunately, these aquifers are often being pumped at a faster rate than they recharge. This means the areas where aquifers are being used to water crops will either no longer be able to grow crops or they’ll have to find a new way to provide water.
Now resources like these can be renewable as long as they’re used sustainably. What exactly does that mean? Sustainability or sustainable development is often defined as being able to meet the needs of the current generation without compromising the ability of future generations to meet their needs. So sustainability is future focused. Sustainability is also different from being environmentally friendly or environmentalism. While the environment is an aspect of sustainability, making sure that we’re using the resources that we get from the Earth in a responsible way and maintaining the ecosystems that provide those resources, being able to distribute those resources in a way that all people are able to meet their needs, and doing so in a way that’s economically feasible is also part of sustainability. So if we come up with some new technology or way of doing things that’s extremely good for the environment but is ultimately too expensive so that people and businesses can’t afford it, then it’s not a sustainable alternative.
One way that science is directly involved with helping us use Earth’s resources more sustainably is in the creation of new man-made resources. A man-made or synthetic resource is what we get when we use a natural resource from the Earth and use it to make something new. For example, we get paper from the pulp of certain trees. We can refine ore to get pure metals. And there’s many valuable chemicals in crude oil that we use to make various kinds of plastics. Man-made resources have largely replaced natural resources in a lot of products since they often provide sustainable alternatives. For example, tires used to be made from rubber that’s harvested from rubber trees. Now, tires are almost entirely made of synthetic rubber, which is created from crude oil. This alternative is quicker to make, it’s much cheaper, and it doesn’t require cutting down rubber trees.
Herbal remedies have almost entirely been replaced by pharmaceuticals. Clothing used to be made entirely of natural fibers like cotton, wool, and silk. Many clothes now are created with synthetic fibers like acrylic, nylon, polyester, and spandex. These synthetic fibers are ultimately derived from crude oil. Synthetic fibers generally don’t take as much water or resources to produce, which makes them much cheaper compared to natural fibers. Some synthetic fibers can also offer a number of advantages compared to natural fibers like increased stain resistance and being waterproof. Man-made resources have also changed what we build our homes and other buildings with. Instead of using primarily wood and stone, we now use materials like plaster and concrete, which are far cheaper.
Many of these man-made resources were originally created in a chemistry lab, like pharmaceuticals and synthetic fibers. Man-made resources can often provide a sustainable and sometimes renewable alternative to finite natural resources. But of course, they have their pros and their cons. Let’s explore this further using the example of biofuels. Biofuels is a very active area of research. There’s lots of work being done in creating new ways to obtain biofuels and making other ways much more efficient. There’s work being done in creating biofuels from fungi and in capturing the methane that’s released from waste. But the most common way to obtain biofuels currently is by using biomass, which is matter derived from plants.
One way to use this biomass is to get the oils from plants and use that to create biodiesel. The other way is to use the sugars from plants and use that to create ethanol. Really, any plant matter could be used to create either biodiesel or ethanol for fuel, from yard clippings to growing things like soy, corn, or sugar cane. Growing soy plants is usually used in the creation of biodiesel since plants like that give off a lot of oil. And corn is often used in creating ethanol, since it’s a very starchy plant that is able to grow extremely quickly and easily. So the biofuels on the market today are going to be made of ethanol or plant oils. Fossil fuels, on the other hand, are a mixture of hydrocarbons, compounds that contain hydrogen and carbon. Whether we use biofuels or fossil fuels, when we burn them for energy, they’ll react with oxygen and form carbon dioxide and water.
So let’s dig in to the advantages and disadvantages of using biofuels compared to using fossil fuels. The biggest advantage of using biofuels over fossil fuels is that biofuels are a renewable resource. Since biofuels come from plants, as long as we grow the plants that we use to create biofuels in a sustainable way, we’ll always be able to grow more plants to create more fuel, and we won’t run out of the resources we need to create biofuels. Another huge advantage of biofuels is that they’re carbon neutral. Well, both biofuels and fossil fuels produce carbon dioxide when they’re burned. When we grow the plants that we use to create biofuels, they need carbon dioxide to grow, so there’s no net change in the amount of carbon dioxide.
Another advantage of using biofuels is that we’d be able to conserve our crude oil supply. This is important because crude oil is a valuable source of chemicals to create all kinds of things, not just fuels. Biofuels also have fewer emissions of other gases when they’re burned. For example, sulfur dioxide is released when fossil fuels are burned, which contributes to acid rain. And finally, there will be less transportation involved in using biofuels. Crude oil can only be mined in specific places, but plants can be grown anywhere.
But biofuels do have their disadvantages, the first one being that it takes space to grow all these crops that we’ll use to create biofuels. This space could not only destroy natural habitats, but it could also be used to grow crops for food. It also requires water and other resources to grow these crops, and it takes energy to process the crops into fuel. And the yield for fuel that we obtain from growing these plants is not currently that great, although this is an active area of research and there have been huge advances in this field in recent years. And finally, we wouldn’t be able to make a switch from fossil fuels to biofuels today even if we wanted to, since not all vehicles are able to use biofuels.
So as we can see, biofuels provide huge advantages over fossil fuels primarily because they are a renewable alternative to a finite resource. But there are a number of disadvantages that we need to keep in mind if we want to switch to using biofuels as a sustainable alternative to fossil fuels.
So to sum up what we covered in this video, we use the Earth’s resources for everything, food, shelter, fuel that we use to warm our homes and to generate electricity and power our vehicles. We can divide Earth’s resources into renewable resources, which are resources that can be repeatedly used or quickly replaced, and finite resources, which are resources that cannot be replaced fast enough to keep up with our rate of consumption. The creation of new man-made resources can provide a sustainable or even renewable alternative to the use of finite resources. We discussed an example of this with biofuels, which are a renewable alternative to fossil fuels.
