Never Mind the Bullocks, Here's the Science (25 page)

And who knows? One day soon you may find your local grocer putting health warning stickers on fruit…

A Happy Reader

This is an email sent to me by a Happy Reader.

Dear Dr Kruszelnicki
,

In your article ‘Is grapefruit juice safe?’ in the ‘Good Weekend’ of 20 September 2008 you wrote about the interaction of grapefruit juice with certain medications.

I am 82 years old and have been having a glass of grapefruit juice with my breakfast for the last 30 years. For the last 5 years I have been on Nexium for my hiatus hernia, 20 mg per day.

For the last 2 to 3 years I have developed a most irritating clogged throat every day after breakfast, and it usually lasts for most of the morning and often till later in the day.

Having read your article I thought I ought to try a different juice for breakfast on the days when I take the Nexium – I am now only taking 1 pill every other day – with dramatic results.

The ghastly rasping cough has just about vanished, and as a consequence I am feeling much better. I thought the throat irritation would ultimately end in throat cancer and was really worried. Thank you very much for the information and I am truly grateful for the help and advice you gave in your column.

Best wishes
,

…

References

Bailey, David G., et al., ‘Grapefruit juice-drug interactions’,
British Journal of Clinical Pharmacology
, August 1998, Vol 46, No 2, pp 101-110.

Bailey, David G., et al., ‘Interaction of citrus juices with felodipine and nifedipine,’
The Lancet
, 2 February 1991, pp 268-269.

Bakalar, Nicholas, ‘Experts reveal the secret powers of grapefruit juice’,
The New York Times
, 21 March 2006.

Garg, Santosh K., et al., ‘Effect of grapefruit juice on carbamazepine bioavailability in patients with epilepsy’,
Clinical Pharmacology & Therapeutics
, September 1998, pp 286-288.

Paine, Mary F., et al., ‘A furanocoumarin-free grapefruit juice established furanocoumarins as the mediators of the grapefruit juice-felodipine interaction’,
American Journal of Clinical Nutrition
, May 2006, Vol 83, No 5, pp 1097-1105.

Greenland Greenhouse

The claim by the Climate Change Sceptics is, at face value, kind of reasonable. About 1,000 years ago, they say, the world’s climate was a lot warmer. After all, the Vikings had colonies in Greenland, which must have been given that name because it was green. Then, as the climate changed and Greenland got cold and covered with ice, the Viking colonies died out.

And now it’s warming up again? Well, argue the Climate Change Sceptics, why should we worry, because the Greenland story is proof that the world’s climate is constantly changing.

Viking

There’s a bit of controversy about the origin of the word ‘Viking’.

One claim is that it means a man from the Vik, a huge bay that lies between the mouth of the Göta River in Sweden and Cape Lindesnes in Norway.

But another claim is that it comes from the word
vikingr
, which means ‘pirate’ in an early Scandinavian language.

Yet another claim is that it comes from the old English word
wic
, meaning ‘a fortified trade settlement’.

And yet another claim is that ‘viking’ comes from the Old Norse verb
vika
, meaning ‘to go off.

It’s Not That Simple

Any discussion about Climate Change is complicated. Partly because climate is complicated. Partly because there are natural changes in the climate going on anyhow. And partly because human beings are changing the climate by dumping Greenhouse Gases into the atmosphere.

Whenever you try to make a story easy to understand, there is also the danger of making the story inaccurate.

For example, this story—of Norse people settling Greenland, but then dying when the world cooled down—is a good example of a story that is both simple and wrong.

The real story is actually quite messy, and very interesting.

The Real Story

Eric the Red (or Erik Thorvaldsson), who lived from c. 950-c.1003 AD, was the first Norseman to set up permanent colonies in Greenland.

His parents had violent tendencies. They had to flee Norway and move to western Iceland because of ‘some killing’. Unfortunately, their son, Eric the Red, also had a tendency to get into arguments and kill people. After three such fights and subsequent deaths, he was exiled from Iceland around the year 982 for three years.

He had heard tales of an uninhabited country about 800 km to the west. Two other sailors had been to this country over the previous century. Gunnbjorn Ulfsson (or Ulf-Krakuson) had been driven there by strong winds, while Snaebjorn Glati had tried to colonise this country, but failed.

Eric’s parents were not welcome in Norway, and he was not welcome in Iceland. So he sailed west and found the uninhabited country. He spent the three years of his exile exploring the fairly
inhospitable place. At that time, in 985 AD, the climate in Greenland was roughly similar to what it is today. So the landscape was very similar to what it is today—about 80% ice, 19% bare rock, and just 1% green. But he did find a few locations, at the head of long fjords, that were relatively comfortable in the short summer.

After his three years of exile were up, he returned to Iceland. He realised that he could be a leader in this new country—all he needed was followers. So he called the new land ‘Greenland’. This was because, according to the
Saga of Eric the Red
, ‘people would be more attracted to go there if it had a favourable name’.

There was nothing particularly green about Greenland—this was just Creative Advertising on the part of Eric the Red. His tales of this fertile land succeeded—it certainly helped that there had been a recent famine in Iceland—and he attracted about 500 settlers. They all set off in a fleet of 25 Viking longboats to colonise Greenland. Only 14 of the longboats arrived—the others were lost at sea, or turned back.

Colonising Greenland

Once the colonising fleet arrived, they realised that their new home wasn’t quite as lovely as Eric had told them.

They colonised two main settlements.

The larger one was the Eastern Settlement. Despite its name, it was virtually at the southern tip of Greenland (only 50 km to its west). At its peak in around 1126 AD, it had ‘190 small farms, 12 parish churches, a cathedral, an Augustinian monastery and a Benedictine nunnery’. The peak population was about 2,000 to 4,000 inhabitants.

The smaller one was the Western Settlement. It was situated about 550 km northwest of the Eastern Settlement, and so it was both closer to the North Pole and more inhospitable in winter.
At its peak population of about 1,000 inhabitants, it had ‘90 farms and 4 churches’.

At first, the colonists flourished in this virgin land. From time to time, more colonists arrived from Iceland. Unfortunately, one group of immigrants who arrived in 1002 AD brought a particularly nasty epidemic with them. It killed many colonists, including Eric the Red himself in 1003 AD.

King Trick

In the 11th century, the Viking King Magnus Barelegs used the lightness of his beautiful longships to trick the King of Scotland.

The King of Scotland had made a treaty with King Magnus, that Magnus could have all of the land that he could sail his ship around. The King of Scotland had realised that there was no point in trying to hang onto all the islands off the Scottish coast, because he could not defend them.

In Scotland, the Kintyre Peninsula is 65 km long, with a very narrow neck. So King Magnus sailed up to this narrow neck, and while sitting at the rudder of his light but strong dragon ship, was dragged across the narrow strip of land. Legally and cunningly, he claimed the Peninsula of Kintyre.

Problems—1

The colonists also had to contend with hostile locals, the Inuit. In one single battle, the Norse settlers lost 2% of the adult males. In today’s terms, that would equate to 100,000 Australian male deaths.

They also had major problems with trade. In 1349-1350, the Black Death swept through Norway, their major and only legal
trading partner. It killed about half the Norwegian population. Norway virtually abandoned the colonists, the last official Norwegian ship visiting in 1368. From 1368 until the ultimate downfall of the colonies around 1450, only four other ships visited—in 1381, 1382, 1385 and 1406. It was illegal for private ships to visit, so they each claimed to have been blown off course and caught in heavy fog.

The Greenlanders also created major environmental problems for themselves. Only 1% of the landscape was green. The tiny amounts of soil that were present had been built up over millions of years.

The colonists didn’t treat their new home gently—they caused massive soil erosion through a combination of overgrazing, tree lopping for ships, pasture and firewood, and reckless management. For example, to cover the roof and walls of one large house, they used some four hectares of turf, which could otherwise have been used for growing crops or raising livestock. The first settlers had a diet that was 80% based on land agriculture (which was very environmentally costly), and only 20% came from the surrounding sea. By the 1300s, when they were on their last legs, they had changed their diet so that about 65% of it came from the ocean. However, by this time, their numbers were too small to survive.

By the end, they were reduced to eating the flesh off the tiny foot bones of rabbits and small birds.

Greenland, You’re Warming to It

Once the colonising fleet arrived in Greenland, they realised that their new home wasn’t quite as lovely as they had been told.

They colonised two main settlements.

The larger one was the Eastern Settlement. Despite its name, it was virtually at the southern tip of Greenland (only 50 kilometres to its west).

At its peak around 1126 AD, it had ‘190 small farms, 12 parish churches, a cathedral, an Augustinian monastery and a Benedictine nunnery’. The peak population was around 2,000 to 4,000 inhabitants.

Problems—2

And yes, besides the very hostile neighbours and the self-inflicted environmental problems, the climate did change after the colonists arrived in 985 AD. There were several sets of cold years in the 1300s, followed by the Little Ice Age in the 1400s. This caused many ocean icebergs, which greatly hampered ocean travel.

Ice core analyses tell us that between 800 and 1300 AD, the climate in Greenland was similar to what it is today, or perhaps slightly warmer. This period is called the Medieval Warm Period. According to Jared Diamond, author of
Collapse: How Societies Choose to Fail or Survive
, ‘Around 1300 though, the climate in the North Atlantic began to get cooler and more variable from year to year, ushering in a cold period termed the Little Ice Age that lasted into the 1800s. By around 1420, the Little Ice Age was in full swing, and the increased summer drift ice between Greenland, Iceland and Norway ended ship communication between the Greenland Norse and the outside world.’

The last inhabitants of the more northern settlement (the Western Settlement) died around 1350 AD. A traveller from the Eastern Settlement visited it and found it to be empty of life.

The last records that we have of the Eastern Settlement are from Thorstein Olafsson, the captain of the ship that visited in 1406. He appeared to be content to stay there for four years. He reported three events—witchcraft, insanity and a marriage. In 1407, a man was burnt at the stake for using witchcraft to attempt the seduction of a woman named Steinunn. Then Steinunn went insane. Finally, in 1408, Captain Olafsson married a Greenland woman. He left Greenland in 1410.

So yes, the Norse colonists had to contend with Climate Change. But previous cold snaps before the 1300s had not forced them to extinction, and some warm periods in the 1400s did not save them.

Survival

The colonists also had to deal with aggressive neighbours, loss of trade, environmental problems so huge that they could not feed themselves, and poor responses to those problems (e.g. eating beef instead of fish). In fact, it’s amazing that they survived so long.

Even today, Greenland survives only with massive subsidies from Denmark, and from fishing licence payments. The true story of the Greenland colonists is far more complicated than ‘it got cold and they died’. After all, the Inuit not only survived during this entire period, but also flourished, and are still there today. ‘When later European explorers began visiting Greenland in the late 1500s, they were immediately amazed at the speed and maneuverability of kayaks and commented on the Inuit appearing to be half fish, darting around in the water much faster than any European boat could travel.’