Glaciers are melting, mercury’s edging up. Don’t plant any palm trees — but this warm spell may change your life
LOOKS LIKE we’re in for a warm spell.
This forecast laughs at the December blizzard which may now be wailing in the weather. stripping round your door. It scorns the friendly testimony of the remarkable Indian summer most of Canada enjoyed until a few weeks ago. It’s concerned with nothing so fleeting as today’s weather.
Signs are multiplying that the climate of the world’s Northern Hemisphere, and perhaps the whole earth, is becoming warmer. This warm spell is marked by a climb in temperat ure of only a few degrees in average temperatures over a period of many years nothing you’d notice in your daily glance at the thermometer on your front porch. Yet t he change is rapid enough to affect the lives of millions of people.
Whether or not wild life can exist, land be farmed and man make a living from the soil over areas of hundreds of thousands of square miles, may be decided by a rise or a drop of even a few degrees in average temperature. Forests have risen from peat bogs due to similar slight climat ic shifts in ages past .
In few countries could the coming of such a warm spell mean more than in Canada, where most of t he population lives within 100 miles of its southern border. Agricultural pioneers have in recent years pushed farther north in Ontario and Manitoba, and in the Peace River section of If. C., to show that farming is possible in great areas of the Dominion formerly considered unprofitable wilderness. A gradual but steady edging up of the climatologist’s temperature charts could mean the difference between success and failure for such ventures and might greatly boost the potent ial population which this country can support.
You might wear more summer-weight suits, fewer tweeds—and our clothing industry thus be
altered. You might prefer your holidays in June or September, rather than the hot test summer months — and our tourist season be lengthened. Your garden’s life, your farming technique or other business program all these factors in your life might come in for modification to meet the demands of an even slightly warmer climat e.
What’s the evidence to back up this long-range “clear-and-warmer” forecast for Canada?
Science bases its warmer climate forecast on a phenomenon which can be easily observed by the summer tourist in the Rockies. Driving by sightseeing bus to almost any of t he famous glaciers, t he vacationist can himself see unmistakable evidence that these great frozen rivers of ice, although still “flowing” inch by inch down the mountain valleys, have been steadily shrinking in size, or retreating, for many years.
Pushed slowly but inevitably down the mountain slopes by the weight of its own tremendous mass, a glacier builds up ahead and to either side of it, huge moraines hillocks of earth, stone and rubble, scraped up from the valley floor. And today in place after place the lower limits of the glaciers can be seen to have fallen back from moraines established years before.
This evidence is revealed even more strikingly to the eyes of Canadian scientists exploring by air many previously unknown ice fields and glaciers in the Yukon and Alaska. They haven’t yet attempted to interpret these findings. But what they have learned does bear out the discoveries of a famed Swedish scientist. Dr. Hans Ahlmann of Stockholm University’s Geographical Institute, who has conducted similar studies of the glaciers of Northern Europe, Iceland and Greenland.
Dr. Ahlmann believes that the melting of the glaciers is part of a general warming up of the climate of the Northern Hemisphere and perhaps of the whole world. Not only is the warmth increasing,
but the increase has speeded up greatly in the last few years. The depths of the oceans themselves are being affected. Dr. Ahlmann reports, and suggests that this and ot her factors may disturb the forces affecting the world’s climate.
What Makes Weather?
fMJMATE is a complex structure depending ^ on many things . . . heat from the sun, moving masses of ocean water, the scarred and broken surface of the continents, and the swiftly flowing air currents of the atmosphere ... all in delicate balance. It seems remarkable that, our climate remains as constant as it does, yet we do know that, slow tidal waves of change have completely altered the earth’s climate from age to age.
One such change which literally enveloped much of the earth like a flood tide— a frozen flood—was the Pleistocene Ice Age, which lasted for nearly a million years. The Northern Hemisphere grew colder and colder as snow and rain froze on the mountaintops and glaciers grew larger and larger. One great icecap cent ring in Norway and Denmark spread out over Russia, Germany and Holland until it covered the North Sea and overlapped the east, coast of Britain. Similar ice sheets reached out to cover almost all Canada and push down into the Mississippi Valley.
Four glacial tides flowed
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gradually south in this period, until the great ice age began its final withdrawal some 50,000 years ago. That the withdrawal is not yet complete is witnessed hy the remaining mountain glaciers and polar ice caps.
But between such climatic tidal waves come “brief” periods of fluctuation which by comparison are mere ripples. If of little account in measuring the physical history of the world, these lesser changes are of much more immediate interest to mankind because they take place in the span of a few hundred years.
The first ripple in our climate within
the age of civilized man came about 6000 B.C., when a prevailing warm, moist climate in the Northern Hemisphere gave way to a drier climate. It was this change which produced oak forests in what had been peat bogs, as shown by excavations in Scandinavia and the British Isles. Within another 2.000 years the dry period gave way in turn to a moist, cold climate; there Was heavy rainfall in North America from 700 B.C. to 400 A.D., followed again by a dry era lasting some 800 years. A miniature ice age in the northern half of the world lasted from 1600 A.D. until comparatively recent years. During that period the remnants of the Pleistocene icecap and the great mountain glaciers began to expand again. In Iceland, districts which had
been farmed during the era of the country’s independence (870-1264) were covered with ice for the next 600 years.
What causes these lesser shifts in climate is a mystery—the mystery of the balance struck between heat, air and moisture, and the forces which may at any time begin to upset and alter their relation. It was in an attempt to find some of the answers that Dr. Ahlmann, one of the world’s foremost climatologists, led four expeditions between 1931 and 1940 to study the glaciers in their relation to climate in the arctic north of Scandinavia, the islands of Spitzbergen, Iceland and Greenland.
Glaciers are the geologists’ frozen history books. A cross-section of a glacier, cut away to a depth of 1,000 feet, may provide a calendar dating hack 3,000 years. Studying such an ice wall, layer by layer, the scientist can tell with considerable precision how much rain or snow fell during a season and how temperatures varied. But there’s a more important reason for turning to glaciers in climate research.
As far as is known, the total amount of moisture on the earth’s surface does not vary -but. is constantly evaporating from oceans and lakes and bodies of ice and constantly being redistributed and falling again as snow or rain. Glaciers are the world’s great water reservoirs, so immense in capacity that, their melting can raise the level ot oceans. Odd as it seems at first glance, the scientist, also considers them reservoirs of heat, for although cold by normal standards the ice masses are a long way from the absolute zero ( -459.6 deg. F.) that marks complete absence of heat.
Dr. Ahlmann and his party set out to determine three things: whether the arctic glaciers were growing or shrinking; whether precipitation or temperature was the chief factor in their size
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since a glacier’s growth depends on the amount of rain or snow that falls on it and its decline on the heat which it receives: and whether this heat was received chiefly from the sun’s rays or from warm air currents wafted into the area from elsewhere.
All the glaciers Dr. Ahlmann examined were shrinking. He established by measurements that prevailing air temperatures had more influence on a glacier’s size than precipitation. And, of paramount importance, he determined that shrinkage was due far less to the sun’s rays than to the heat received from circulating air.
These findings may not seem sensational. But. dovetailed with much previous information they form a rather surprising picture of our climate of today.
The Northern Hemisphere, and possibly other parts of the world as well, seems to be approaching the end of a miniature “ice age” which set in about 200 years ago. Dr. Ahlmann sees remarkable changes in the climatic situation in the last 30 years.
Glaciers are melting. Probably as a direct result, oceans are increasing in
depth. So far the increase seems infinitesimal — around a millimetre a year, for several decades. But the glaciers are only part of the picture. An estimated 90r4 of all the water stored on land in the form of ice and snow is in the Antarctic and the inland ice sheet of Greenland, which is virtually a continent in itself.
If the same mysterious factors which are causing glaciers to melt should affect these other vast masses of ice, Dr. Ahlmann calculates that the oceans would rise enough to inundate permanently, in our time, coastal settlements all over the world.
New Acres for Siberia
The melting of the glaciers is part of a general warming in climate, Dr. Ahlmann believes. In Norway end Spitzbergen, average temperatures have increased more since 1850 than at any time in the last 200 years, ln Spitzbergen, in the period from 1931 to 1938, the February temperature averaged eight degrees above that for the period from 1911 to 1920. Over Denmark, warm, humid west and northwest winds have increased greatly in frequency and intensity since 1873. A similar change has taken place in England.
In Siberia, where much of the earth is frozen the year round, the southern limit of this frozen area has been moving northward several miles every year, making new country habitable. Siberia is a land of untold natural resources. The “liberation” of terrain through thawing means that this latent wealth can be more fully exploited. This in turn implies that not only will the area itself attract population, but that the population potential for the whole of Russia may be boosted.
Iceland farmers are again working land that was under ice for six centuries. Finland’s growing season has been noticeably lengthened. Due to cold, Norway’s birch forests had only two good seed years from 1875 to 1915: now, nearly every year is a good seed year and the once dwindling forests are expanding.
In the Russian sector of the arctic seas, the last 20 years have brought a marked decrease in the amount of drift ice, greatly facilitating navigation. The shipping season from the West Spitzbergen coal fields has lengt hened in the last 40 years from 95 days to 203 days a year. Off southwestern Greenland, cod have migrated 600 miles northward in the last 29 years, boosting the annual fish catch in some fishing grounds from 150 tons to as much as 13,000 tons.
There are indications that this warmer trend extends even into the tropics, according to Dr. Aldmann’s studies. On the mountains of East Africa the glaciers are also receding. Lake Victoria has fallen seven feet in the last years and other sizeable African lakes now only have water part of the year and some have dried up entirely.
Canadian Reports Agree
Lack of anything like complete and accurate meteorological charts, for any but the most recent years past, is one of the scientists’ great problems in trying to plumb the mysteries of climate. But, after a 1946 survey, the United States Weather Bureau concluded that the climate throughout the whole world grew steadily warmer for half a century or more, prior to 1940. A slight downward dip since that time is suggested by U. S. figures. Worldwide figures have not yet been added to the chart and the American climate experts state that it is impossible yet to judge whether the recent dip is a
revereal of the 50-year trend or merely a short-term upset.
Canadian meteorological charts reflect the same steady rise as found elsewhere. If you study the jagged lint of a graph recording the mean annual temperatures for Toronto since 1841 you’ll find that the average temperature for the past 105 years was 45.1 degrees F. Only nine times in the 47 years prior to 1889 did the mean temperature for any one year rise above that average while only nine times in the 58 years since 1889 has the mean temperature for any one year failed to rise above the average. The actual increase is very slight, of coursebarely t hree degrees difference between the averages of the first and last decades of the 105-year period.
The Winnipeg temperature graph can he traced hack only 73 years, for which the average thermometer reading was 35.2 degrees F. Only four times in the 27 years prior to 1900 did the mean temperature for any one year climb above the average, while only 10 times in the subsequent 46 years has it failed to better the average.
But the Canadian climatologist hastily adds a warning.
“You can’t accept the records from two places as evidence that Canada’s climate is getting warmer,” he tells you, “even though scattered records from certain other inland points seem to bear out these figures. Only recently have accurate records been kept for the whole Dominion and Canada is such a young country that even those we have, such as the Winnipeg and Toronto figures, go back only 50 to 100 years. As far as a study of climate is concerned it’s like trying to measure the growth of a forest by walking around its fringe.”
Our Glaciers Shrink
Evidence from Canadian glaciers, however, bears out Dr. Ahlmann’s findings.
“Nearly all glaciers studied seem to be in a general state of decrease,” says Dr. Hugh S. Bostock, a member of the geological survey of Canada’s Department of Mines and Resources. “A number of glaciers are known to have made advances sometime between 100 and 300 years ago. Most of these have been receding since then, although a few advanced their fronts for short periods in the last few years.”
Aerial photographic surveys in recent years have revealed many glaciers for the first time. In such photographs, the lower parts of the glaciers of the Coast Mountains are seen to be bordered by broad belts bare of vegetation between the ice and the well-defined margin of the forest.
“The position of the forest margin marks the extreme limit of the glaciers’ advances of the last 300 years,” Bostock explains, “and the bare border testifies to the rapidity of the general recession that has followed.”
Canada’s best-known glaciers are those in the popular Banff and -Jasper vacation areas, but these are relatively small compared to those in the lessaccessible parts of the northern coast and St. Elias Mountains, where icefields stretching for 80 to 150 miles have been plotted.
Sixteen miles off the Alaska Highway, where it is crossed by Slim’s River, lies the foot of the Kaskawulsh Glacier. This glacier gathers its ice from t ributaries reaching more than 30 miles to the mountain ice fields. Its lower end is five miles wide and the water that boils up from its base tumbles into two different rivers, one of which flows 1,400 miles to the Bering Sea, and the other 140 miles to the Gulf of Alaska. An arc-shaped moraine,
on which grow scattered spruce trees, lies between a quarter mile and a mile beyond the base of the glacier.
When R. G. McConnell of the Canadian Geological Survey visited the glacier in 1898 he judged that the position of the moraine indicated an advance which had ceased about 100 years before. Today there are signs of a small and short-lived advance since that time, but the ice of the lower end of the glacier now is wasting away.
The $64-billion question in this great climate quiz is: how far will the warming process go and when will it stop?
A change in average temperature of as little as two degrees does not mean much in climates near the equator where the temperature is fairly stable. But, in a zone like North America, where temperatures vary widely in winter and summer, a two-degree difference in average would affect the clothes people wore, the sort of houses they lived in, the kind of life they led, the kind of business they engaged in. It might make all the difference in whether a man was a factory worker or a farmer. California’s billion-dollar annual tourist business hangs on peculiarities of temperature which in statistics seem negligible. A slight warming of Canada’s climate, although it might take several generations to make itself felt, could in time have spectacular consequences. Areas now wilderness might turn into fertile farmlands, and the subarctic zone, now productive only of scrub, might become a lumber empire. Will all this happen?
Scientists are still seeking the answer. Their first concern is whether the change represents just a transfer of warmth for the southern latitudes of the earth to the north, or whether the “warming” is taking place in both regions. If the whole earth is growing warmer the cause might lie in factors beyond the earth itself, such as conditions in our solar system, or the earth’s movement in relation to the sun.
Research in these vital questions is being accelerated in two ways. Once more expeditions are free to go forth to gather data. The second Byrd expedition to the Antarctic already has gleaned some postwar information about climate and a number of universities and scientific institutions in both America and Europe are organizing climate-research expeditions for the near future. U. N.’s scientific section, by helping to integrate research and findings, may speed progress in this field.
We cannot be sure today whether we are on the verge of another great “warm age” of the sort that has encouraged human advances intermittently in the past; or whether we are merely in the course of a minor cyclical change in climate which may soon reverse itself.
It is certain, however, that we are on the threshold of an unprecedented opportunity to fathom one of the most important factors in the life of mankind, if