When you look up zero waste, you're bound to notice tons and tons of pictures of glass jars everywhere.
But what's our obsession with glass? Is it really so much better for the environment than plastic?
Let's start by analyzing every zero waster's beloved material: Glass.
First, it's important to note that glass is endlessly recyclable, back to its original use.
It never loses its quality and purity, no matter how many times it's recycled…. but is it actually being recycled?
Glass bottles are made from all-natural resources, such as sand, soda ash, limestone and recycled glass.
However, it is important to note that we're running out of the sand that's used to make glass in the first place.
Worldwide, we go through 50 billion tons of sand every year. That is twice the amount produced by every river in the world.
Once these raw materials are harvested, they're transported to a batch house where they are inspected and then sent to the furnace for melting where they're heated to 2600 to 2800 degrees Fahrenheit.
Afterwards, they go through a conditioning, forming and finishing process before becoming the final product.
Once the final product is created, it's transported so it can be washed and sterilized, then transported again to stores for sale or use.
Once it comes to its end of life, it's (hopefully) collected and recycled.
Unfortunately, each year only one-third of the roughly 10 million metric tons of glass that Americans throw away is recycled.
The rest goes to a landfill.
When a glass bottle is collected and recycled, it has to begin this process of being transported, going through batch preparation, and everything else that follows again.
emissions + energy:
As you can imagine, this entire process to make glass, especially using virgin materials, takes up a lot of time, energy and resources.
Also, the amount of transporting the glass has to go through adds up too, creating more emissions in the long run.
A lot of the furnaces used to create glass also run on fossil fuels, thus creating a lot of pollution.
The total fossil fuel energy consumed to make glass in North America, primary energy demand (PED), averaged to 16.6 megajoule (MJ) per 1 kilogram (kg) of container glass produced.
The global warming potential (GWP), aka climate change, averaged to 1.25 MJ per 1 kg of container glass produced.
These numbers encompass every stage of the packaging life cycle for glass.
If you're wondering, a megajoule (MJ) is a unit of energy equivalent to one million joules.
A property's gas usage is measured in megajoules and is recorded using a gas meter.
To put the carbon footprint measurements I gave into perspective a little better, 1 liter of gasoline is equal to 34.8 megajoules, High Heating Value (HHV).
In other words, it takes less than a liter of gasoline to make 1 kg of glass.
end of life:
You're probably better off holding onto glass and re-purposing it before you toss it into the recycling bin.
Glass takes a very, very long time to break down.
In fact, it can take a glass bottle one million years to decompose in the environment, possibly even more if it's in a landfill.
Because its life cycle is so long, and because glass doesn't leach any chemicals, it's better to repurpose and reuse it over and over again before recycling it.
Because glass is nonporous and impermeable, there are no interactions between glass packaging and the products inside, resulting in no nasty after taste – ever.
Plus, glass has an almost zero rate of chemical interactions, which ensures that the products inside a glass bottle keep their flavor, strength and aroma.
I guess that's why lots of zero wasters encourage people to save all their empty jars for reuse.
It's great for storing food you get from the bulk food store, leftovers, and homemade cleaning products!