Global Warming: A Classic Case of Alarmism

This is a Guest Post by Dr David Evans

The big temperature picture. Graph and insight from Dr Syun Akasofu
(2009 International Conference on Climate Change, New York, March 2009).

The global temperature has been rising at a steady trend rate of 0.5°C per century since the end of the little ice age in the 1700s (when the Thames River would freeze over every winter). On top of the trend are oscillations that last about thirty years in each direction:

1882 – 1910    Cooling
1910 – 1944    Warming
1944 – 1975    Cooling
1975 – 2001    Warming

In 2009 we are where the green arrow points, with temperature leveling off. The pattern suggests that the world has entered a period of slight cooling until about 2030.

There was a cooling scare in the early 1970s at the end of the last cooling phase. The current global warming alarm is based on the last warming oscillation, from 1975 to 2001. The IPCC predictions simply extrapolated the last warming as if it would last forever, a textbook case of alarmism. However the last warming period ended after the usual thirty years or so, and the global temperature is now definitely tracking below the IPCC predictions.

The IPCC blames human emissions of carbon dioxide for the last warming. But by general consensus human emissions of carbon dioxide have only been large enough to be significant since 1940—yet the warming trend was in place for well over a century before that. And there was a cooling period from 1940 to 1975, despite human emissions of carbon dioxide. And there has been no warming since 2001, despite record human emissions of carbon dioxide.

There is no actual evidence that carbon dioxide emissions are causing global warming. Note that computer models are just concatenations of calculations you could do on a hand-held calculator, so they are theoretical and cannot be part of any evidence. Although the models contain some well-established science, they also contain a myriad of implicit and explicit assumptions, guesses, and gross approximations—mistakes in any of which can invalidate the model outputs.

The pattern suggests that the world has entered a period of slight cooling until about 2030

Furthermore, the missing hotspot in the atmospheric warming pattern observed during the last warming period proves that (1) the IPCC climate theory is fundamentally broken, and (2) to the extent that their theory correctly predicts the warming signature of increased carbon dioxide, we know that carbon dioxide definitely did not cause the recent warming (see here for my full explanation of the missing signature. The alarmists keep very quiet about the missing hotspot.

No one knows for sure what caused the little ice age or for how many more centuries the slow warming trend will continue. It has been warmer than the present for much of the 10 thousand years since the last big ice age: it was a little warmer for a few centuries in the medieval warm period around 1100 (when Greenland was settled for grazing) and also during the Roman-Climate Optimum at the time of the Roman Empire (when grapes grew in Scotland), and at least 1°C warmer for much of the Holocene Climate Optimum (4 to 8 thousand years ago).

Addendum

Measuring the global temperature is only reliably done by satellites, which circle the world 24/7 measuring the temperature over large swathes of land and ocean. But satellite temperature records only go back to 1979. Before that, the further back you go the more unreliable the temperature record gets. We have decent land thermometer records back to 1880, and some thermometer records back to the middle of the 1700s. Prior to that we rely on temperature proxies, such as ice cores, tree rings, ocean sediments, or snow lines.

The powerpoint and audio from Dr Akasofu’s presentation at The International Climate Change Conference 2009 can be downloaded here.

Dr Akasofu published a paper explaining the above graph last week (thank you to Rick Werme).

The Cooling World
Newsweek, April 28, 1975

There are ominous signs that the Earth's weather patterns have begun to change dramatically and that these changes may portend a drastic decline in food production– with serious political implications for just about every nation on Earth. The drop in food output could begin quite soon, perhaps only 10 years from now. The regions destined to feel its impact are the great wheat-producing lands of Canada and the U.S.S.R. in the North, along with a number of marginally self- sufficient tropical areas – parts of India, Pakistan, Bangladesh, Indochina and Indonesia – where the growing season is dependent upon the rains brought by the monsoon.

The evidence in support of these predictions has now begun to accumulate so massively that meteorologists are hard-pressed to keep up with it. In England, farmers have seen their growing season decline by about two weeks since 1950, with a resultant overall loss in grain production estimated at up to 100,000 tons annually. During the same time, the average temperature around the equator has risen by a fraction of a degree – a fraction that in some areas can mean drought and desolation. Last April, in the most devastating outbreak of tornadoes ever recorded, 148 twisters killed more than 300 people and caused half a billion dollars' worth of damage in 13 U.S. states.

To scientists, these seemingly disparate incidents represent the advance signs of fundamental changes in the world's weather. The central fact is that after three quarters of a century of extraordinarily mild conditions, the earth's climate seems to be cooling down. Meteorologists disagree about the cause and extent of the cooling trend, as well as over its specific impact on local weather conditions. But they are almost unanimous in the view that the trend will reduce agricultural productivity for the rest of the century. If the climatic change is as profound as some of the pessimists fear, the resulting famines could be catastrophic.

"A major climatic change would force economic and social adjustments on a worldwide scale," warns a recent report by the National Academy of Sciences, "because the global patterns of food production and population that have evolved are implicitly dependent on the climate of the present century."

A survey completed last year by Dr. Murray Mitchell of the National Oceanic and Atmospheric Administration reveals a drop of half a degree in average ground temperatures in the Northern Hemisphere between 1945 and 1968. According to George Kukla of Columbia University, satellite photos indicated a sudden, large increase in Northern Hemisphere snow cover in the winter of 1971-72. And a study released last month by two NOAA scientists notes that the amount of sunshine reaching the ground in the continental U.S. diminished by 1.3% between 1964 and 1972.

To the layman, the relatively small changes in temperature and sunshine can be highly misleading. Reid Bryson of the University of Wisconsin points out that the Earth's average temperature during the great Ice Ages was only about seven degrees lower than during its warmest eras – and that the present decline has taken the planet about a sixth of the way toward the Ice Age average. Others regard the cooling as a reversion to the "little ice age" conditions that brought bitter winters to much of Europe and northern America between 1600 and 1900 – years when the Thames used to freeze so solidly that Londoners roasted oxen on the ice and when iceboats sailed the Hudson River almost as far south as New York City.

Just what causes the onset of major and minor ice ages remains a mystery. "Our knowledge of the mechanisms of climatic change is at least as fragmentary as our data," concedes the National Academy of Sciences report. "Not only are the basic scientific questions largely unanswered, but in many cases we do not yet know enough to pose the key questions."

Meteorologists think that they can forecast the short-term results of the return to the norm of the last century. They begin by noting the slight drop in overall temperature that produces large numbers of pressure centers in the upper atmosphere. These break up the smooth flow of westerly winds over temperate areas. The stagnant air produced in this way causes an increase in extremes of local weather such as droughts, floods, extended dry spells, long freezes, delayed monsoons and even local temperature increases – all of which have a direct impact on food supplies.

"The world's food-producing system," warns Dr. James D. McQuigg of NOAA's Center for Climatic and Environmental Assessment, "is much more sensitive to the weather variable than it was even five years ago." Furthermore, the growth of world population and creation of new national boundaries make it impossible for starving peoples to migrate from their devastated fields, as they did during past famines.

Climatologists are pessimistic that political leaders will take any positive action to compensate for the climatic change, or even to allay its effects. They concede that some of the more spectacular solutions proposed, such as melting the Arctic ice cap by covering it with black soot or diverting arctic rivers, might create problems far greater than those they solve. But the scientists see few signs that government leaders anywhere are even prepared to take the simple measures of stockpiling food or of introducing the variables of climatic uncertainty into economic projections of future food supplies. The longer the planners delay, the more difficult will they find it to cope with climatic change once the results become grim reality.

[end]

The Cooling World:
http://denisdutton.com/cooling_world.htm

Original Newsweek article with scary maps and graphs:
http://denisdutton.com/newsweek_coolingworld.pdf

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