Water Trivia – or not so trivial

Water Trivia – or not so trivial

Q1. As a percentage, how much of our oceans have been explored?

A1. 5%. Interestingly, my reaction to this figure is that it seems surprisingly large. Considering that there are parts of western Europe that went unmapped until the twentieth century, and there are parts of the Pacific Ocean with no exposed land for a thousand miles (Point Nemo, between New Zealand and Chile: 48°52.6′S 123°23.6′W), 5% sounds like quite a lot to me. However, no definition is offered about what 'explored' actually means.

Q2. What is the average water use of a washing machine cycle?

A2. Officially, 90 litres. I also know this from my own measurements. The amount does not sound unreasonable. On the other hand, the standalone rinse cycle uses a considerable amount of water. By way of contrast, the dishwasher is remarkably frugal. 

Q3. Is it true that a million tonnes of plastic enters the oceans every year.

A3. No. The figure is between 8 - 13 million tonnes per annum.

Q4. The daily drinking water requirement per person is 2 - 4 litres. According to the UN, how many litres of water, on average, does it take to produce one person's daily food?

A4. 1,000 - 5,000 litres. Of course, this has to vary between economically-developed and economically-developing countries. It puts into the shade the 150 litres people in the UK each use purely domestically every day.

Q5. How many litres of water does it take to produce 2 slices of bread?

A5. 109 litres. Whilst I do not doubt this figure, I should be interested to see a breakdown of how that water is consumed: farming, transport, milling, baking.