Santa Claus and reindeer© Kaisa Siren/Rex Shutterstock

My nephew asked an interesting question the other day. “Why does Father Christmas feed his reindeers with carrots?”

This is a good point. With cereal prices in the doldrums, shouldn’t Santa be using British-grown oats instead?

Time sits heavily on my hands once we have finished the winter ploughing and, since I’m a farmer and love nothing more than doing pointless paperwork, I’ve actually calculated the impact of this. You may have to squint at my mathematics.

Matthew is the managing director of Naylor Flowers Ltd, a South Lincolnshire business which grows cut flowers and potatoes for supermarkets. Matthew is a Nuffield Scholar

There are two billion children in the world. Santa is famously less generous with Muslim, Hindu, Jewish and Buddhist children so his customer base is mostly the 378 million Christian children.

If we knock off 5% for the “naughty” ones and allow for houses containing more than one child, we are looking at about 90m homes.

Assuming that these are evenly distributed around the earth, he covers 75m miles on Christmas Eve.

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The different time zones around the world give him 31 hours of night time, so the task isn’t quite as daunting as it first appears; it’s only 820 visits a second.

If we allow him a half-hour comfort break at South Mimms services to have a wee and a Twix then he’s left with roughly 1/1,000th of a second to park, hop out of the sleigh, jump down the chimney, fill the stockings, glug the sherry, get back up the chimney and move on to the next house.

I estimate that this requires a speed of 650 miles a second or 3,000 times the speed of sound. For comparison, Roger Bannister travels at 0.005 miles a second when he’s in a hurry.

The Ulysses space probe pootles along at 27.4 miles a second.

A conventional reindeer can only run at 15 miles/hour so clearly the AHDB could learn a thing or two about genetic improvement from the Lapland breeding programme.

Let’s now think about sleigh payload.

Assuming that each child gets about 1kg of gifts, the sleigh carries nearly 400,000t.

That’s not counting Santa who, let’s be honest here, is carrying a few extra pounds himself.

This means the sleigh is four times larger than the QE2. Luckily, at 650 miles a second, he should be capable of outrunning the Vehicle and Operator Services Agency inspectors.

Anyway, Santa has enough problems already. The centrifugal forces will be 17,500 times greater than normal gravity. This would be painful even for a man who has just drunk 75m glasses of sherry.

So this gives us the information to calculate his fuel consumption and I can tell you that Santa isn’t going to get away with a £35 tax disc, nor will he get a Christmas card from George Monbiot.

“Anyway, Santa has enough problems already. The centrifugal forces will be 17,500 times greater than normal gravity. This would be painful even for a man who has just drunk 75m glasses of sherry”

So, 353,000t traveling at 650 miles a second will burn roughly 14 quintillion Joules of energy a second. Readers who drive Nissan Navaras will be nodding sympathetically here.

Oats are about 2% fat and 66% carbohydrates, four times more energy that you get in a carrot.

If there are 17MJ of contained energy in the carbs and 37MJ in the fat (and assuming the reindeers’ energy conversion is 40% efficient) then Santa would be feeding 77 trillion tonnes of oats a second.

These are rough figures, let’s call it 80 trillion. Could you imagine the positive impact on the cereal trade?

I hope that this festive season you can think of a less fanciful reason to feel some optimism for the year ahead. Hopefully 2016 will be a year of perfect weather, good yields, high demand and record prices.

Or is that stretching your imagination a bit too far?