Materials Cycle
Materials (matter) do not appear or disappear on this planet. What is here is here for good. We call that the 1st Law. Gravity (the natural force that keeps things near the Earth’s surface) also helps keep all the materials here. Considering this and to keep life going, Nature taps the power of this limit by cycling the materials it produces again and again over time—each time finding a use for the different stages the materials go through in the cycle, and each time contributing something to the beauty and the health of the ecosystems upon which our health and our lives depend.
Examples of natural life cycles of materials produced by Nature include rocks, water, trees, plants, food, and nitrogen.
Even the materials manufactured by people have a life cycle. Eventually they will fall apart (we call this the 2nd Law) as they move through the different stages in the materials cycle—but in their case, unless they were designed and made to move through the natural materials cycle like food and plates and paper that can be composted, they will start falling apart in places they can’t be useful. They will not just go “away”. This Unit will help students understand that there is no such thing as away, that materials cycle and that time is a huge factor – perhaps technically-speaking a resource can used again, but how much time does it take to renew– within our lifetimes?
We tend to be a throw-away society. Once we are finished with our stuff, we toss it out as used and/or unwanted. Used or unwanted material can pile up — into our landfills, or even simply in our trash cans or tossed on the street and in our parks and waterways. The all too familiar site of litter – such as snack bags, plastic water bottles and takeout containers to shopping carts and car and truck tires clog our storm drains or contaminate our waterways. Students will explore the many creative, practical, and scientific solutions to this problem from making art out of litter, composting, and changing habits and behaviors altogether.
Creating our own materials cycling system for the things we produce that can’t go into the natural materials cycle can cycle around and around in our own “techno-cycle.” By doing this we are contributing to the beauty and health of the ecosystems that all depend on us, upon which we all depend, and for which we are all responsible.
Renewable and Non-Renewable Resources
A renewable resource, essentially, has an endless supply such as solar energy, wind energy, and geothermal pressure (the sunlight used in solar power and the wind used to power wind turbines replenish themselves). Other resources are considered renewable even though some time or effort must go into [creating conditions for] their renewal (e.g., wood, oxygen, plants and grasses, and fish).
A renewable resource, also known as a flow resource, is a natural resource which will replenish to replace the portion depleted by usage and consumption, either through natural reproduction or other recurring processes in a finite amount of time in a human time scale. [Their supply replenishes naturally or can be sustained]. Wikipedia
Examples of renewable resources include:
- Energy: Windy, tidal, geothermal, solar, hydro-electric, biomass
- Fish Stocks (if not over fished)
- Soil
- Trees and Plants
A nonrenewable resource is a natural substance that cannot be replaced or is not replenish-able with the speed at which it is consumed. It is a finite resource–it doesn’t grow more of itself.
Fossil fuels such as oil, natural gas, and coal are examples of nonrenewable energy resources. Humans constantly draw on the reserves of these substances while the formation of new supplies takes [a really really really long time] eons.
Nonrenewable resources come from the Earth. Humans extract them in gas, liquid, or solid form and then convert them for their use. The reserves of these substances took billions of years to form, and it will take billions of years to replace the supplies used.
Here is a list of examples of non-renewable energy, liquid, and solid resources:
- Fossil fuels (ex. oil, coal, and natural gas)
- Uranium
- Tar Sand
- Steel
- Phosphate
- Aluminum
- Minerals like Rock Crystals (quartz)
- Mercury
- Copper
- Ground and Surface Water
KEY TAKEAWAYS
- A nonrenewable resource is a substance that is being used up more quickly than it can replace itself. Its supply is finite.
- Most fossil fuels, minerals, and metal ores are nonrenewable resources.
- Renewable resources such as solar and wind power and the water cycle are unlimited in supply.
Water is a Resource; Water Cycles; Access is a Human Right
From a technical viewpoint, water is qualified as a renewable natural resource; it has a hydrological cycle (the water cycle) and can recharge from precipitation. (www.WWF.panda.org)
Though, in science, water is considered a renewable resource due to the water cycle, (remember the water cycle (see attached) condensation, precipitation, storm water runoff, infiltration, percolation, ground water re-charge and flow, plant uptake and transpiration, evaporation, water also has properties (traits) of a nonrenewable resource. Water is not replenished like most renewable resources and instead is reused (www.quard.org). We cannot make new water on the planet. We have what we have forever.
As more and more people need access to drinking water, our groundwater and surface water reserves are being used faster than they can replenish themselves in those places.
Ground water is a limited resource. It should not be regarded as an “unlimited” resource. Water conservation should still be a main priority.
We all depend on water as a shared resource.
Humans, plants and animals benefit from the use of water resources. We use water for drinking (we can only go three days without water!), bathing, cooking, cleaning, growing food, agriculture, energy, recreation (swimming, boating, skiing…).
We should all be drinking at least 8 glasses of water each day to stay healthy and fit and hydrated, AND to be able to pay attention better, remember things better, learn better and feel better!
Water is essential to our lives and all life on Earth–so it is important to take care of our water resources.
Since everyone has a right to clean, safe and delicious water, we need to take care of our water resources and make sure everyone has access to them. In Philadelphia, tap water is affordable (compared to bottled water) and accessible to everyone. We are very fortunate to be surrounded by many sources of fresh water.
What is Sustainability?
Sustain-ability: The capability to thrive over time –Human sustainability is the ability for humans and other life (upon which we depend) to flourish on Earth forever
The sustainable use of resources we depend on, means we must find a way to use resources so that they will be renewed, replenished, cycled, recycled, re-used, and re-purposed forever so that current and future generations of people, plants and animals can thrive over time.