Merry Christmas folks, to all who are celebrating!

Now, how you celebrate Christmas is an interesting question. I’ve discovered lately how Christmas festivities vary considerably around the world, and are tied to local traditions and culture. What you might assume as a universal Christmas tradition may actually be far from that.

This very day, Dec 25, is not always the most important for Christmas celebrations in some countries. In the Netherlands for example, it is Dec 5 that is important because that’s when children receive gifts from “Sinterklaas”, whose origins are tied to Saint Nicholas. Germans also put up a boot for Saint Nicholas on Dec 5, although they celebrate primarily on Christmas Eve, when the Christ child brings presents.

In Spain, children await Jan 5, the eve of Epiphany, when the three kings bring gifts and sweets. Many towns have parades with the kings Melchior, Caspar and Balthazar, who throw sweets to children.

In Russia, celebrations are held on Jan 7. And in Italy, Christmas really begins on Dec 8, the Day of the Immaculate Conception of Mary.

“Santa Claus”, the popular pot-bellied figure bearing gifts that so often depicts Christmas in popular culture is a relatively modern American creation. He was brought to life by the writer Washington Irving and illustrator Thomas Nast, and later popularised by the Coca-Cola company – no kidding!

Some Christmas traditions are country-specific. An Italian friend told me about her country’s artisanal tradition of presepe, a depiction of a Nativity scene. In many Italian homes, you may not find a tree but you might find a presepe with ornately handcrafted figures. There is a whole street in Naples (the via San Gregorio Armeno) dedicated to this craft. Many churches will also have their own presepe.

Another Italian tradition is to avoid eating meat on la Vigilia, Christmas Eve. The idea, apparently, is to purify one’s body on this holy day. Fish is often eaten instead. In fact, it was common for Christians to abstain from meat on Friday, an observance to mark the death of Jesus on this day. Even now, in Britain, fish and chips is commonly served on Fridays. The idea of temperance in diet is, of course, a feature of many religions.

Now that I’m on this subject, allow me to switch topics. I promised early this year to write about meat in my column, so excuse me while I squeeze this in before the year ends.

If you’re worried about catastrophic climate change in the upcoming “Trumpocene” age, the so-called “age of ignorance”, the simplest single action to take would probably be to eat less meat.

The toll from meat production is staggering – far worse than vehicles, contrary to popular belief. The US Worldwatch Institute says: “The human appetite for animal flesh is a driving force behind virtually every major category of environmental damage now threatening the human future – deforestation, erosion, fresh water scarcity, air and water pollution, climate change, biodiversity loss, social injustice, the destabilisation of communities, and the spread of disease.”

Then there are the serious health effects of a high-meat diet plus the appalling conditions that factory-farmed animals are often kept in.

Beef is particularly detrimental to the planet. Pasture, or crops, has to be grown to feed cows. Beef production requires 160 times more land and releases 11 times more greenhouse gases compared with staple crops such as wheat and rice, according to a 2014 US Academy of Science study. As a CNN presenter says, meat is “the new SUV” (four-wheel drive, referring to such vehicles’ fuel-guzzling and polluting ways).

Unfortunately, governments are failing to act on the issue, in part to avoid potential controversy with a meat-loving public, and also because of a powerful meat industry.

But a growing tide of people are now moving towards eating less meat. In Britain, singer Paul McCartney has led a “Meat-Free Monday” campaign that is backed by many celebrities and that has spread to more than 40 countries.

Former California Governor Arnold Schwarzenegger is also advocating one or two meat-free days a week. The body-builder and Hollywood star disputes the belief that muscle needs meat. “I feel fantastic,” he has said of his new diet.

With movie director James Cameron and NGO WildAid, Schwarzenegger has lent support to the Chinese government in its campaign to reduce meat consumption. His translated campaign videos are being aired in China with the message: “Less meat, less heat, more life.”

So if you’re looking to make a difference in 2017, consider this issue. The personal choice to eat less meat can be so far-reaching – helping control planetary climate change, no less! I’ll leave you with that formidable thought for the year.

See you in 2017, and Happy New Year!

Mangai Balasegaram writes mostly on health, but also delves into anything on being human. She has worked with international public health bodies and has a Masters in public health.