Opinion: The climage is non-linear

Here are two interesting facts. One is that the winter temperatures in the Arctic this year were the highest ever recorded. On two days in February, it was actually warmer at the North Pole than it was in Zurich, Switzerland. At one location in Greenland, the temperature rose to 36 degrees C higher than the usual average for that time of year.

The other interesting fact, revealed last month in two articles in Nature, one of the world’s leading scientific journals, is that the Gulf Stream is slowing down. In fact, it is now moving more slowly that at any time in the past 1,600 years (which is as far back as studies have gone). This could be very bad news for Western Europe.

The difficulty comes in figuring out what these facts mean – if they mean anything at all, and are not just random variations of an unusually extreme kind. And this is the point in the discussion at which you start to hear the climate scientists use the word ‘non-linear’ all the time.

Most people think of global warming as a smooth, gradual process. It might end up doing a lot of damage, but it will sort of creep up on you, not smack you in the face. Unfortunately, that is not how climate change has proceeded in many past cases of warming or cooling.

The change can be abrupt and quite extreme – and once it has happened, it becomes the new normal, perhaps for a very long time. Like many complex systems, the climate is non-linear: it stays the same for a long time, and then suddenly some ‘tipping point’ is reached, and the whole thing flips into a different configuration.

Now, the warming in the Arctic is not non-linear. It’s a trend that has been continuous for decades, although it has accelerated greatly in recent years: the amount of sea-ice coverage at the point of maximum freeze-up, in late March, has been far lower in 2015-18 than ever before.

The focus of concern for the moment, however, is on what the warming is doing to the Greenland ice-cap. This ice is on land, and when it melts it raises the sea-level. More importantly for the near term may be the fact that it is putting a large volume of fresh water into the northern North Atlantic Ocean.

That may be part of what is slowing the Gulf Stream down. It’s a surface current of warm water from the tropics that travels at an average speed of six km per hour, contains as much water as there is in all the world’s rivers, and moves it all the way up to the seas between Iceland and Norway. Then the water cools off, drops to the bottom, and returns southwards as a deep-water cold current.

The Gulf Stream helps keep north-western Europe warm: England is at the same latitude as Labrador, but the average temperature is more than 10 degrees C higher. Norway, with 5 million people, is about the same latitude as southern Greenland (pop. 50,000). But the Gulf Stream has stopped entirely a number of times in the distant past, sometimes for centuries.

To be more precise, it stops going so far north: it ‘overturns’, dives to the bottom and heads back south long before it reaches the latitude of European countries like Ireland, Britain and Norway. And when it has done that in the past, the average temperature in those countries dropped by up to 10 degrees C.

There is reason to suspect that what was happening in these incidents was that a global warming trend was melting a lot of cool fresh water into the northern seas and blocking the Gulf Stream from getting so far north. So is that about to happen again? Nobody knows, but according to the latest studies the Gulf Stream has already slowed by 15 per cent in the past 50-150 years.

When it shut down in the past it was abrupt and fast: non-linear, in other words. The 15 per cent slowdown is not necessarily an indicator that the whole northern branch of the current is on the brink of shutting down. But then again, it might be.

Gwynne Dyer’s new book, ‘Growing Pains: The Future of Democracy (and Work)’, was published last month by Scribe in Canada, the United States, the United Kingdom, Australia, New Zealand.

Just Posted

Central Alberta school divisions to support rural students through agreement

Wolf Creek to bring Enhanced Learning Model courses to Clearview schools

WATCH: Red Deer Catholic students re-envision a local wetland for school project

Father Henri Voisin Grade 3 teacher introduces ‘real-life’-based education

Manslaughter charge stayed against Maskwacis man

Man was accused of manslaughter in connection with the death of his mother in 2015

Red Deer Mounties make numerous arrests over the past two weeks

Over the past two weeks, Red Deer RCMP have made a number… Continue reading

Leslieville Elks’ new hall rising from the ashes

Leslieville Elks Lodge grateful for outpouring of support

WATCH: Red Deer Catholic students re-envision a local wetland for school project

Father Henri Voisin Grade 3 teacher introduces ‘real-life’-based education

Charges dropped against Alberta property owner in rural shooting

OKOTOKS, Alta. — All charges have been dropped against a man accused… Continue reading

China blocks John Oliver on social media after scathing show

BEIJING — A popular Chinese social media site is censoring discussion of… Continue reading

Most Red Deer Advocate readers would call police when witnessing a crime

An overwhelming number of Advocate readers would call the police if they… Continue reading

So much TV, so little summer: Amy Adams, Kevin Hart, Dr. Pol

LOS ANGELES — The fall television season is months away but that’s… Continue reading

BlackBerry Q1 revenue, adjusted earnings beat estimates but stock falls

TORONTO — BlackBerry Ltd. shares sank almost 10 per cent to their… Continue reading

OPEC countries to pump more oil to contain price increase

VIENNA — The countries of the OPEC cartel agreed on Friday to… Continue reading

Man sentenced for Edson triple murder

EDMONTON — An Alberta man who fatally shot three people has been… Continue reading

‘Hot Dog Water’ seller in Vancouver gets laughs, sales with savvy marketing

VANCOUVER — A Vancouver man who sold bottles of “Hot Dog Water”… Continue reading

Most Read


Five-day delivery plus unlimited digital access for $185 for 260 issues (must live in delivery area to qualify) Unlimited Digital Access 99 cents for the first four weeks and then only $15 per month Five-day delivery plus unlimited digital access for $15 a month