Crude estimates

Why is crude oil measured in barrels?

— From medieval times onwards, all sorts of commodities were measured in barrels for convenience, from wine to eels to whale oil. However, standardisation only arrived in fits and starts. Since Richard III’s time, a barrel of wine was defined as 42 ‘wine gallons’, but this wasn’t the same as 42 gallons of water. When the US oil industry started in the mid 19th century, traders adopted the same measure as was used for selling wine. However, in 1824, Britain had standardised a gallon as 20 per cent larger than a wine gallon, the latter of which was renamed a ‘US gallon’. Hence a barrel of oil is only 35 imperial gallons. Because the volume occupied by a liquid depends on temperature, a barrel of oil is further defined as a quantity of oil which fills a barrel at precisely 15.6˚C and one atmosphere of pressure. Why we can’t measure oil by mass – which wouldn’t be weather-dependent – is somewhat puzzling.

Field questions

How much do farmers pay to rent farmland?

Cereals average of £251 per hectare in 2024/25 (was £210 in 2015/16)

General cropping £254 (£256)

Dairy £285 (£214)

Lowland grazing £138 (£130)

Less-favoured area grazing £93 (£85)

Crime and non-crime

How much crime is there according to the police and the Crime Survey for England and Wales (a survey which asks the public for their experience of crime)?

Year
Crime survey
Police recorded  2017/18
10.7m
5.5m 2018/19
11.2m
6.0m 2019/20
10.2m
6.1m 2022/23
8.7m
6.7m 2023/24
8.8m
6.6m 2024/25
9.4m
6.6m

Peopling places

How has the world’s population grown since the late Paul R. Ehrlich wrote his book The Population Bomb in 1968?

Location
1968
2023 World
3.55bn
8.09bn Asia
2.03bn
4.78bn Europe
649m
747m Africa
347m
1.48bn North America
313m
609m South America
183m
433m Oceania
18.7m
45.6m

However, in contrast to his gloomy predictions, global life expectancy has also grown, from 55.6 years in 1968 to 73.2 years in 2023.