Basic science: understanding numbers
Basic science: understanding numbers

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Basic science: understanding numbers

1.1 Water, water everywhere

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NARRATOR 1
Bottled water is ubiquitous in our daily lives. Every year in the UK, we each consume some 70 litres of purchased bottled water, whether it's fizzy, mineral, or just purified tap water under a different name.
The market for bottled water in the UK alone has grown to over 2 billion litres a year. Worth over a billions pounds in 2003, by 2008, the market had more than doubled.
NARRATOR 2
In China, market growth has been even more spectacular. From a relatively tiny 400 million litres in 1991, to over 15 billion litres in 2007. Growing income levels, particularly in urban China, are leading to changing consumer behaviour. While most rural people still drink boiled water, the majority of urbanites now drink bottled water. Most people have water dispensers in their apartments and offices, and smaller bottles of water are on sale everywhere, from cities to the smallest villages.
NARRATOR 1
Worldwide consumption is estimated at over 155 billion litres a year-- enough water to fill 62,000 Olympic swimming pools.
NARRATOR 2
That's amazing for a product that didn't really exist 30 years ago. But there's more to bottled water the meets the eye.
NARRATOR 1
A bottle of water is a plastic bottle, a plastic lid, a label, some water from a specified source, and quite a bit of embodied energy, besides. Let's start with the water. Where does it originate?
NARRATOR 2
Every bottle carries a date code stamp from the production facility where it was bottled. This code shows the best before date as well as the production lot code of the process batch when it was bottled along with many other thousands of bottles which were filled during that shift. The water may have come from a glacier or been filtered through rocks over thousands of years, but now it's likely to be extracted from a well, spring, lake, or in some cases, a tap, all of which involves energy consumption for pumping, filtering, and so on.
NARRATOR 1
After bottling, it travels to a warehouse, and then on to wherever you might have bought it. By this time, a simple bottle of water may have traveled over 1,000 kilometres and taken on a lot more embodied energy.
NARRATOR 2
The lid, bottle, and label are all derived from petroleum, which we see as plastics. The bottle might be PET or some other plastic. The lid is made of another type of plastic, and the label is made of a kind of heat-sensitive shrink plastic. Producing a kilo of virgin PET releases about three kilogrammes of CO2 into the atmosphere.
NARRATOR 1
The newly filled bottles get packaged in plastic, piled on a pallet, wrapped in shrink wrap-- more plastic, about five kilogrammes worth-- and lifted by a compressed gas forklift truck to the edge of the factory site. Each of these processes adds more embodied energy and releases more CO2.
NARRATOR 2
The long distance delivery gets made by truck, train, boat, or even plane to a big warehouse, and ultimately, onto another truck to whatever retail outfit you purchase it from. The bottle of water is now about 18 days old, even though the water itself is much, much older.
NARRATOR 1
Eventually, this bottle of water gets into your house, and maybe you even put it in your fridge to cool it down. By now, it has accumulated some serious mileage and has a big carbon footprint.
NARRATOR 2
Of course, you may drive a hybrid car, so that reduced the energy consumption a little bit it, didn't it? Well, not really. Most of the embodied energy in a bottle of water is due to transporting the water.
NARRATOR 1
Take a major brand of bottled alpine water, for example, which is exported all over the world. You can imagine that transport accounts for most of the final total of its energy footprint. When one bottle of alpine water gets to China, where it's become a popular prestige product, it's released some 250 grammes of CO2 in its travels. About 95 grammes is from the plastic manufacture in China, another five grammes or so for the empty bottle's trip from China to Europe, and another 150 grammes for shipping the full bottle back to China.
NARRATOR 2
So then you drank it. It was cold, clean, crisp, and ever so fresh. But so is tap water, once you cool it down a bit. But it's not the same, say your guests. And it's still not the end of the road for the empty bottle.
NARRATOR 1
Up to this point, there's enough oil used in the production process of bottled water in the UK to heat 32,000 homes for a year. Quite an opportunity cost for a product that you don't really need, and another 45,000 tonnes of CO2 released into the atmosphere.
NARRATOR 2
But that's still not the whole story. You may reuse a few bottles. We're always refilling them. But reusing them continuously isn't a great idea, as toxins eventually leach out of the plastic.
NARRATOR 1
Most end up in the wheelie bin, destination either landfill-- a finite resource which is rapidly becoming exhausted, is unsustainable, costly, and where the empty bottles will stay buried for millennia or increasingly, they will be sent for incineration, leading to more pollution and more CO2.
NARRATOR 2
Even if you're conscientious and recyclable your bottle, only about one in four water bottles actually end up being recycled, and quite possibly being crushed and chipped and making their way back to China for rebirth as furnishings, fleeces, and other plastic stuff.
NARRATOR 1
But sadly, all too many bottles never really die. They somehow end up in the sea, floating around until they are washed up on a beach somewhere for you to moan about on your holiday.
NARRATOR 2
Bottled water--
NARRATOR 1
Who needs it?
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In this video, the issues surrounding bottled water are discussed along with many, many, MANY numbers.

The video also makes some assertions about contamination of bottled water by PET in plastic bottles, which were raised as a possible danger to health a few years ago. However, no convincing scientific evidence has been produced to prove this effect. We’ve left the section on plastics in the video because it’s important to understand that science advances by testing hypotheses. This is a process which includes scientific study and debate, and can take several years, during which time scare stories continue to circulate. The Cancer Research UK website has a good explanation of the situation concerning the plastic bottles [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)] .

As you watch the video, focus on how important the numbers are to the story that the narrators are conveying. How do the narrators try to help the viewer to comprehend the numbers?

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