The year you compare against
- 07815720002024
One town, made up Picture a town's chimneys, counted every five years. In 2000 they gave off 100 thousand tonnes. Then 120, then 140, then 110, then 90. In 2024 the count is 95. Is that good news? It depends entirely on which year you hold it against.
- Down, against 201032 in 100Up, against 20206 in 100
The year you compare against is called the baseline. Against 2010, when the town peaked at 140, this year's 95 is down 32 in 100. Against 2020, when it was 90, the same 95 is up 6 in 100. Same chimneys, same year, two true sentences. A cut is a number against a year.
- 07815720002024
The town's 2024 count is 95. Which baseline makes it look best?
2020. It is the most recent.
Not yet. 2020 is the lowest year on the chart. Against 90, this year's 95 reads as a rise. Recent is not the same as flattering.2000. You should always start at the start.
Not yet. Against 2000's 100, the town is down 5 in 100, a small cut. Starting at the start is one honest choice, and not the one that reads best.2010, the peak. Against 140, 95 is a big cut.
Right. The highest year on the chart is the one that makes any later reading look like a cut. Every baseline is a choice, and the peak is the flattering one. Move the baseline year and read what the same 2024 count of 95 becomes. The town is made up; the arithmetic is real.
2000100 thousand tonnes202495 thousand tonnesYear compared against: 2000
Against 2000, when the town gave off 100, this year's 95 is down 5 in 100.
2005120 thousand tonnes202495 thousand tonnesYear compared against: 2005
Against 2005, when the town gave off 120, this year's 95 is down 21 in 100.
2010140 thousand tonnes202495 thousand tonnesYear compared against: 2010
Against 2010, when the town gave off 140, this year's 95 is down 32 in 100.
2015110 thousand tonnes202495 thousand tonnesYear compared against: 2015
Against 2015, when the town gave off 110, this year's 95 is down 14 in 100.
202090 thousand tonnes202495 thousand tonnesYear compared against: 2020
Against 2020, when the town gave off 90, this year's 95 is up 6 in 100.
What does choosing the peak year as the baseline do?
It is always wrong to do.
Not yet. Every baseline is a choice, including the honest ones. What makes a reading misleading is leaving the year out, not which year it is.It makes any later count look like a big cut, without the chimneys doing anything different.
Right. The chimneys gave off 95 in every frame. Only the sentence changed. A baseline at the peak turns an ordinary year into an achievement.Nothing. A cut is a cut.
Not yet. The same 95 read as down 32 in one frame and up 6 in another. The number in the headline is set by the year, not the chimney.Move the control.
- 1990100 UK emissions, 1990 = 100202447 UK emissions, 1990 = 100
The real one. The UK's law counts against 1990. In 2024 the country gave off about 373 million tonnes inside its borders, 53 in 100 below 1990. Say 1990 every time and the number means something. Drop the year and it means whatever the reader assumes.
- 1996826 million tonnes, UK footprint2007984 million tonnes, UK footprint2023699 million tonnes, UK footprint
A second real one, from one table. Defra's count of everything Britons buy, wherever it was made, was 699 million tonnes in 2023. Defra says: 15 in 100 below 1996, the first year it counted. The same table shows 2007 as the peak, 984. Against that, 2023 is 29 in 100 down. Both true. A press release can pick either.
Three years from Defra's table. Tap the one that makes 2023 look like the biggest cut.
Tap the part of the picture that answers it.
1996: 826826 million tonnes2007: 984984 million tonnes2023: 699699 million tonnes2007: 984
Right. The peak. Against 984, 699 is down 29 in 100. The highest bar is always the flattering baseline, whichever table it is in.1996: 826
Not yet. The first year. Against 826, 699 is down 15 in 100, a figure Defra itself gives. Honest, and smaller.2023: 699
Not yet. That is the year being measured. A year cannot be its own baseline; against itself every count is zero change.- 2007984 million tonnes2023699 million tonnes
The footprint was 984 in 2007 and 699 in 2023. The cut against 2007 is about how many in 100?
in 100The gap, divided by the 2007 number.
Right. About 29 in 100. The gap is 285; 285 out of 984 is 29 hundredths. Against 1996 the same 2023 count is 15 in 100 down, because the gap is smaller and the base is smaller. - 2020barely flewNowup 5 in 100
An airline says: emissions up only 5 in 100 since 2020. In 2020 its planes barely flew. What does the 5 in 100 hide?
Nothing. Up 5 is up 5.
Not yet. Up 5 from a floor and up 5 from a normal year are different facts about the same planes. The year is part of the number.That the airline is lying.
Not yet. Every word is true. The thing to notice is the year, not a lie. A baseline is chosen, and the choice is the story.That 2020 was the lowest year it ever had, so 'up 5' from there may be far above 2019.
Right. A baseline at the floor does the opposite of one at the peak: it makes a rise look small. The sentence is true, and the year is doing all the work.
Lesson complete
A cut is never a number on its own. It is a number against a chosen year.