Global Warming and Other Bollocks. Stanley Feldman
warmth, acquired during the day, is prevented from being dissipated into space at night. The proponents of the theory of anthropogenic global warming (i.e. global warming caused by humans) point out that, as a result of this effect, increasing the amount of greenhouse gases in the atmosphere will reduce the amount of heat dissipated into space at night and therefore, over time, it is likely to cause the earth’s temperature to rise.
Arrhenius failed to persuade the climatologists of his era of the significance of his theory. The wood burning in Sweden did not produce the warm winters he forecast. His predictions, based on the greenhouse-gas effect of CO2, turned out to be wrong. The theory did not explain the recurrent swings in temperature that have occurred since the Earth was born. It failed to answer the question of why, in the not-too-distant past, his Scandinavian ancestors had been able to live, farm and colonise Greenland and the frozen north of his country but had been forced to abandon their settlements due to the encroaching ice in the 16th and 17th centuries, without evidence to suggest there had been any reduction in the atmosphere’s CO2 concentration. It seemed more likely, to the climatologists, that the explanation lay with the small deviation that occurs in the axis of Earth as it circles the sun and the flattening of its slightly elliptical circuit, the so-called Milankovitch effects.
A new ice age?
In 1938, a British scientist, G S (Guy) Callendar, drew attention to the potential beneficial effect on the agriculture and farming of a rise in temperature as a result of an increase in CO2 in the atmosphere, but his views were largely ignored. His predictions were based on the observations of Dr Keeling’s team of scientists on the CO2 content of the atmosphere at the top of a mountain in Hawaii. They had demonstrated that the level of CO2 in the atmosphere in the Pacific was slowly rising each year. Callendar’s words went unheeded as, in spite of his prediction of a warmer world, it was followed by a 35-year period, from 1940 to 1975, of progressively colder times. Before we accept that an increase in CO2 causes warming of the planet, the fall in temperature that occurred in this period in spite of a documented incremental rise in CO2 must be explained.
It is almost certain that the levels of atmospheric CO2 would have increased rapidly during World War II and the post-war reconstruction period, and that this should have caused a rise in temperature due to the greenhouse-gas effect. But the temperatures actually fell by 0.3–0.4ºC. The effect was sufficiently worrying for climatologists, at that time, to warn of the advent of a new ice age.
STANLEY FELDMAN
DOGMA
Greenhouse gases are all the fault of human activity.
ANYONE LYING ON an English beach enjoying the summer sunshine could be excused for jumping to the conclusion that it was the occasional cloud that obscures the sun that causes their world to cool. They are probably right. Under cloudless skies the temperature drops dramatically the moment the sun sets or one moves from the sunshine into the shade, although the CO2 levels do not change.
When one listens to the weather forecast, it is clear that it is the cloud cover that determines whether the sun will shine and the weather will warm up. It is the amount of energy in the water molecules that make up the clouds that determines whether or not a particular wind will warm us up or cool us down. It would be nonsense to consider the effect of gases in the atmosphere on Earth’s temperature without accepting a major role for these clouds, especially those at the lower levels. To concentrate solely on the CO2 ignores the fact that many different processes are involved in determining the planet’s temperature.
There is one principal source of heat, and that is the sun; it far exceeds any other influence on the global temperature. Nevertheless, significant but comparatively small amounts of geothermal energy are constantly being released from the molten mass in the depths of the Earth. This energy warms areas of the oceans, through the hydrothermal vents of underwater volcanoes, and the land where the Earth’s crust is sufficiently thin to allow thermal warming, as in, for example, Arizona, Iceland, New Zealand and Antarctica. However, their global contribution of energy is tiny.
There is good evidence that the sun’s heat varies from time to time and that this is related to magnetic activity and sunspots. There is strong correlation between the number and frequency of these changes and the sun’s energy output. When there are a lot of sunspots the energy is reduced and the temperature, not only of Earth but of other planets such as Jupiter and Mars, falls slightly. Sunspots affect not only the amount of heat given off by the sun but also the amount of cosmic bombardment from outer space, due to their strong magnetic effect.
The mean temperature on Earth depends upon how much of the sun’s energy reaches the surface of our planet when the sun shines and how much of this heat is lost from the Earth when it gets dark. There is no doubt that this is affected by the atmosphere.
Over the past century, solar irradiance has increased, which in itself would account for a 0.2ºC rise in surface temperature if no other mechanism existed to affect the transfer of this energy from the sun to the Earth. However, various factors in the atmosphere affect this process.
The most obvious is the effect of the clouds.
The importance of water
Clouds are composed of water vapour and droplets; the higher the concentration of water droplets, the darker and more thunderous are the clouds. By and large the lower the clouds, the higher the concentration of water droplets. When a cloud appears to obscure the sun it does so by reflecting the sun’s energy, including that in the visible spectrum, back into space, so that its light fails to reach us on Earth. This reflective action depends largely on the concentration of water as droplets. Because molecules of water also absorb the warming, shorter-wave, infrared energy, we also lose much of the sun’s heat when it is cloudy.
The water molecules in the clouds also affect the surface temperature of the Earth in their role as a greenhouse gas. They blanket over the Earth and prevent the escape of infrared energy from its surface, stopping it cooling. That is why cloudy nights are much warmer and balmier than clear nights. On cloudless nights the temperatures tend to drop rapidly once the sun sets as the atmosphere lacks the greenhouse effect of the water in the clouds. It is evident on these occasions that our comfort depends to a much greater extent on the water in the atmosphere than it does on CO2.
We are coming to realise that clouds themselves, especially their disposition and composition, are also affected by solar activity, although the contribution this makes to the temperature of our planet is difficult to quantify.
The concentration of water in the atmosphere varies. Even on a ‘dry day’ the air we breathe is moist and the air we exhale is saturated. If one looks at the amount of ice deposited in the freezer compartment of a refrigerator it is evident that the air in the refrigerator, which may have appeared to have been dry, in fact contained a lot of water, some of which was deposited as ice when it was trapped inside the refrigerator when the temperature fell.
Greenhouse gases, like carbon dioxide and water, merely store part of the energy that originated in the sun. They absorb some of the energy that radiates from the sun when it shines and from the Earth after it has been warmed by the sun. At night CO2 and water vapour act together as a blanket over the Earth, minimising the loss of heat as the atmospheric temperature begins to fall.
The effects of the various components involved in determining the Earth’s temperature are difficult to separate quantitatively. The overall effect of the clouds is especially difficult to measure, as it varies enormously from time to time and from place to place. Its effect on the sun’s energy depends upon whether it is present as a vapour or as droplets. If all the water in the atmosphere acted effectively as a greenhouse gas it would