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Let’s see if we can get a handle on why precisely the issue of global warming and climate change has come so much to the fore in recent years. Without having to pass a judgment on what is being claimed, perhaps we can get a better understanding on where so many scientists and politicians are coming from.
I remember while at school in the early seventies how we were being warned that the earth was being dangerously cooled. For more than thirty years temperatures across the world were falling. Packed ice was thickening in Iceland and changes in migrational patterns were being observed widely. So, thirty years hence, where is the new ice age? Has London yet been buried in snow? By the end of the seventies global temperatures were on the up again and no more seemed to be heard.
I can recall the harsh winter of 1962/3 and my family has a photograph of a milk float surrounded by deep snow outside our window. During the eighties I always seemed to wear wellington boots to work for at least a few weeks in the winter. Since then I have never had the cause to do so. We all know how the Thames in London used to ice over and people could ice skate on it as shown in the paintings of Pieter Bruegel. The last time that was to happen was in 1813.
Everyone can agree that the climate is constantly changing. Modern scientific methods of calculating temperatures from the past from tree rings to ice cores give us masses of new information. In the 1980s scientists observed how surface temperatures were once again rising quickly and the headlines were soon full of ‘the greenhouse effect’ and ‘global warming’.
The part played by the earth’s atmosphere in trapping the heat radiated by the sun and stopping it bouncing back into space is called ‘the greenhouse effect’. Only some gases would contribute to this effect, the most important of which is water vapour, responsible for 95% of the vital ‘greenhouse’ protection. Nitrogen and oxygen are at zero, CFCs at a little more than this, nitrous oxide and methane at less than 1%, and carbon dioxide (CO2) at 3.62%.
It is important to realise that CO2 only makes up 0.04% of all the gases in the earth’s atmosphere yet is crucial for life on the planet. A little less than 200 billion tons of CO2 enters our atmosphere each year, with only 3% coming from human activity e.g. from burning fossil fuels. By comparison, 57% is given off by the oceans and 38% is emitted by animals, us included. Plants then absorb CO2 by photosynthesis turning it into oxygen to sustain all animal life.
Scientists would generally agree that for thousands and thousands of years before the Industrial Revolution the levels of CO2 had not risen above 280 parts per million in the atmosphere. The burning of fossil fuels by man led to a theory that too much CO2 was building up in the atmosphere, greater than the amount the oceans and plants could deal with. The earth’s natural regulatory system was being thrown out of kilter. Within decades the waters would rise after the ice melts, deserts would expand and temperatures would rise and rise. The phenomenon of global warming was upon us.
At this stage of our understanding of the global warming story, we have reached the end of the 1980s. Suddenly, the phenomenon was the accepted truth and was even assumed as self-evident. Scientists were ‘overwhelmingly’ at one on this. The United Nations set up an intergovernmental panel on climate change (the IPCC) in 1988. At the same time a senate committee in the USA debated the question, chaired by Al Gore. Greenpeace and Friends of the Earth were delighted to find their environmental issues going up the agenda. Huge amounts of public money were now being pumped into research on global warming.
So, calls were soon to be made to drastically reduce the human production of CO2 in order to stabilise the concentration of CO2 in the atmosphere. Or face an increase which would be greater than any in the last ten thousand years, it was claimed. Only dramatic action would suffice. The future of our children is at stake. But critics would say that computer models were not adequately taking into account natural variations. Were predictions based on firm science? Or were these just the arguments of the oil and tobacco industries trying hard to galvanize popular opinion away from global warming realities?
By the mid nineties the headlines would concentrate on the balance of evidence tipping towards proof that humans were influencing the rapid rate of global warming. Any uncertainties over the role played by natural variations in the climate took second place. New political fallout comes about at the time of the Kyoto Protocol of 1997. Would efforts to restrict CO2 emissions prevent the Third World’s economic growth and thus stop them from catching up with the developed world? With the economies of India and China growing so fast, with heavy industry at the fore, wouldn’t they soon be major CO2 contributors?
The shift which resulted from Kyoto was one away from the use of fossil fuels like coal, gas and oil towards ‘renewable’ energy sources which did not emit greenhouse gases, like solar, wave, wind and hydro power. Awkwardly for many, nuclear power is ‘carbon free’. However, opposition focussed on the toxic waste. Overall, though, Kyoto brought a global consensus that the planet needed saving urgently. Yet, even if all the emissions targets set were reached, by 2050 the temperatures around the world would only reduce by 0.05oC.
Were scientists the world over really agreed that we were not just seeing natural variations in temperatures which were cyclical over a very long period of time? Did human intervention suddenly cause a dramatic rise? Weren’t glaciers always retreating and advancing? Whatever the answers are, the prevailing orthodoxy on global warming is such that few politicians will challenge it. Can man actually do anything to avert a ‘catastrophe’? Would cutting back on all man-made greenhouse gases stop the danger?
That the earth had warmed over the course of the twentieth century is generally agreed upon scientifically. Equally, there is consensus that the level of CO2 in the atmosphere has risen in two hundred years from 280 ppm to over 380 ppm. The rise in the latter coincides with the industrial activity of man. So, if man suddenly puts this into reverse, would it do anything to affect the former – would global warming reverse too? Had not the accepted ‘Medieval Warming’ period come without a rise in CO2?
There is the sun, and there is the cloud covering of planet earth. Greenhouse gases make it harder for heat from the earth to escape back to space. But what is the main source of that heat that warms the earth if not the sun? Dark patches can be spotted on the surface of the sun, associated with magnetic activity, and usually over 1,300 are recorded annually. At the height of the ‘Little Ice Age’ in the seventeen century only 50 or so were recorded. An Austrian physicist, Victor Hess, won a Noble prize in 1936 for discovering ‘cosmic rays’ bombarding the earth from exploded stars. It was subsequently discovered that sunspot activity caused ‘solar winds’ throughout the solar system which determined how many of these cosmic particles reached the earth. When the magnetic force from the sunspots is intense, cosmic rays are deflected from the earth and when low, many more get through.
More recently it was seen how the cosmic rays relate to the cloud cover in the lower atmosphere, so central to the global climate patterns. In 1991 two Danish scientists discovered how throughout the twentieth century there was a big increase in sunspot activity. Soon after, others saw how the extent of cloud was related to the intensity of cosmic rays hitting the earth. We are now on another path which does not see CO2 as the only cause of climate change. Research in 2005 concluded that the more cosmic rays enter the earth’s atmosphere, the more clouds are likely to form and cool the earth. The more solar radiation deflects the rays, the less clouds are able to form and the more temperature rises.
Could the activity of the sun be the real culprit? Or is it indeed man who tips the balance?
Stop the globe - I want to get off!
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