Dear Fellows and Members
It is strange how seemingly unrelated events can cast a different but consistent light on to a topic. In making this comment I have global warming in mind.
In 2010 during a voyage towards Alaska along the pacific coast of Canada, the US Department of the Interior issued a map and information about Glacier Bay which is located at the southern end of the Alaskan panhandle. The map described how until 10,000 years ago, continental scale ice sheets came and went many times for seven million years, reaching as far south as the upper Midwest of the United States. The extent of Glacier Bay reached its maximum in about 1750 between Point Carolus and Point Gustavus. By 1794 the ice had receded about nine miles, by 1879 by a further 45 miles and a further eleven miles by 1907. If that is true, what caused the warming of the atmosphere and is it still an influence?
In the Royal Institution, London is the Faraday Museum. One of the displays features the equipment used by the eminent scientist John Tyndall (1820-1893) in his study of the radiative properties of various gases. He constructed the first ratio spectrophotometer which he used to measure the absorptive powers of gases. He discovered in 1861 that water vapour, followed by Carbon Dioxide and Ozone displayed the strongest absorption of radiated heat. Indeed his findings were so striking that he wrote “Without water vapour the Earth’s surface would be held in the iron grip of frost”. Life as we know it may have been impossible.
Whilst travelling in an area of volcanic activity, I learnt that the most abundant gases which are released by volcanoes are water vapour, Carbon Dioxide and Sulphur Dioxide, the volumes of which rise enormously as the gases permeate the magma to reach the surface of the earth and rise tens of miles into the atmosphere. In 1991 the largest eruption of the century blasted more than 8km3 of ash and 20 million tonnes of Sulphur Dioxide from Mount Pinatubo in the Philippines into the stratosphere. This created a haze that girdled the planet, reflected sunlight and lowered the average temperatures worldwide by 0.5 deg C. This is but one of several eruptions in the century, so are they still influencing the climate?
I recall from biology lessons that trees absorb CO2 and release O2 into the atmosphere as part of the photosynthesis process. Should mankind therefore be planting even more trees and re-establishing forests rather than destroying them and particularly in the Amazon area, which for decades has been described as the lungs of the earth?
I would not say that CO2 emissions created by man’s activity are not related to the present concerns for global warming, but there are other factors, some of which are mentioned above, that are significant. The point is that the specialists in engineering, physics, glaciers, volcanoes etc who can give a balanced factual assessment, free of emotion and perception, should have a much more dominant presence in the media, displacing reporters and politicians. Engineers should be particularly courageous to speak out at this time of flooding in the North of England and how to prevent it in the future. The government has pledged billions of pounds for flood defences, which means the study of hydrology, modelling, design of pumping systems, channels and conduits applicable to the areas affected and then manufacturing, project management, commissioning and monitoring. Furthermore engineers have the support of The Duke of Edinburgh who, it is reported today, has stated “The whole of our infrastructure, from sewers to power supplies and communication, everything that wasn’t invented by God is invented by an engineer”. [The Sunday Telegraph, 2 January 2016]. A more supportive approbation will be hard to obtain.
Our next lecture meeting will be on 16 February at the Best Western Marks Tey Hotel, Colchester CO6 1DU and the topic will be "The Nature of Engineering Support for the British Antarctic Survey". I hope to see you there at 730 pm