Hull Geological Society
Holderness and global warming
By Mike Horne FGS
First published in two parts in 1991 in “The Avenues Shopper” (edited by Wilf Moran)
The planet on which we live has for millions of years been in a state of change and remains so today. The continents move around, while animals and plants evolve and become extinct. Previously mankind has been reluctant to show any real interest in these changes, but it now finds itself forced to do so as scientists explain that mankind itself may be accelerating these very changes which hold the key to its own devastation.
The Earth’s climate alternates between “Greenhouse” and “Icehouse” periods. Greenhouse periods are times when there is not sea or land ice. The weather is warmer and the sea levels higher. We are in an Icehouse period at present with glaciers on the land and relatively low sea level. During warm spells it is thought that carbon gases (like carbon dioxide) in the atmosphere influence the temperature, insulating the planet during warm spells.
These changes happen naturally over periods of thousands or millions of years and of course mankind has had no influence in their development. But the word from the scientists is that we may be accidentally speeding them up by upsetting the balance of nature. Nature’s natural mechanism for removing carbon gases from the atmosphere during greenhouse periods is to store carbon in the form of coal, oil and limestone. But man is using these stored carbons as a form of energy and the resulting by-products are carbon gases which trap heat in the atmosphere that would normally escape into space.
This is termed “Global Warming” and as the planet warms up, the land and sea ice will melt and sea levels will rise. These rising sea levels do not spell the end for our planet nor the life on it. Similar changes have happened before in the history of the Earth and it has always recovered – slowly. But the effect of a sea level rise on mankind – the creature that has created these changes – will be devastating. If the ice melts it has been predicted the sea level will rise by thirty metres, causing many highly populated coastal areas to be flooded. The amount of land suitable for food production will be greatly reduced and mankind will be faced with widespread homelessness and famine.
And if global warming continues, what will be the effect on Hull? To understand this we have to understand the history of Holderness.
Before the Ice Age there was no Holderness. The land stopped roughly along a line from Flamborough, through Driffield, Beverley and Cottingham. Hull and Holderness were under the sea. During the Ice Age, the sea level fell and the North Sea dried up. Great glaciers formed and travelled south from Scotland and Scandinavia carrying with them a dirty mixture of clay and rock. As the glaciers melted they dumped this “Boulder Clay” on the top of the land they had covered. Hull is built on a layer of boulder clay about ten metres thick. Boulder Clay is very prone to erosion by the sea and Holderness is being washed way at a rate of about two metres a year. The North Sea is pushing its way back to the original pre-Ice Age cliff line.
So the future for the City of Hull, if Global Warming continues, does not look very good. The sea level will rise as the glaciers continue to melt. A slow rate of sea level rise will lead to a faster rate of erosion of the Boulder Clay cliffs of Holderness. There will be a greater risk of flooding in low-lying areas – the River Hull Tidal Barrage will have to be used more often. Eventually low-lying areas will become permanently flooded and the sea will break over the cliffs, washing away homes and farmland.
The drying out of the clay on which our houses are built will play havoc with their foundations. The drying of the clay will make coastal erosion by the sea much easier - you can test for yourself how a piece of dry clay falls apart when it gets wet.
Is there anything that we can do to slow down or eradicate this nightmare scenario? The good news is yes – we can help the situation. In next month’s “Shopper” I will look at the action we can take as individuals – and more important what we should expect from our governments and our own politicians.
Living with Global Warming
In the last issue we discussed the causes and effects of Global Warming. Since the glaciers started to melt at the end of the last Ice Age (about 10 000 years ago) the sea level has been rising steadily. If the ice melts completely the sea level will rise another thirty metres, flooding low lying coastal regions, including Hull and Holderness.
The global warming and sea level rise is a natural process, but scientists believe that we are speeding up the process by our over-enthusiastic use of fossil fuels. Burning these fuels releases Greenhouse Gasses, which have an insulating effect in the atmosphere.
Can this be stopped? To be honest we probably cannot do much to reverse the natural trend, but we can stop the man-made acceleration of the process. The solution is simple – stop using so much fossil fuel – then perhaps the natural cycles have a chance to recover their equilibrium.
This is not as easy as it sounds. Mankind has an ever increasing population which has an ever increasing demand for energy. What we must do is find ways to reduce our demand for fossil energy. A straightforward way to approach this is to look at everything we do or use in terms of “energy economics”. We must ask “how much does this cost in terms of using fossil energy?” We can do this ourselves every day – we can all make a contribution to stopping the Greenhouse Effect.
We can make sure that we use energy efficiently, by only heating the rooms we are using and by not letting heat escape (insulating our homes properly). We can use energy efficient lighting. We can use our cars less, by walking cycling and using public transport. We can get things repaired when they are faulty, rather than throwing them away and buying new. We can refuse unnecessary packaging in shops and recycle as much “waste” as we can. We can have an organic garden which does not use finite mineral resources (including peat).
But more importantly we must convince our political leaders to do the same. The idea that it is good economics to rapidly use up fossil energy resources because they are cheap and produce short term profits is at the root of the pollution problem. We must convince them to develop and use renewable energy resources – hydroelectric, wave, tidal, solar and wind energy. The idea that we should allow our privatised electricity industry to use natural gas to generate electric power is foolhardy. Yes, it might be a cheap source of power, but such a plan is ecologically unsound. The natural gas resource is limited, so why rush to use it all up? Surely we should limit its use to make it last longer, and use non-polluting energy sources to generate electricity?
We should convince our political leaders that we have to use energy more efficiently with grants and regulations for the insulation of buildings. We must have better public transport. It uses less energy per person so why not make more use of it? We should put more freight back on the railways which are more energy efficient. We should encourage energy efficient farming, which does not depend on using mineral resources to boost profits.
It has to be admitted that all of this will have to be paid for. But if we do not pay for it now we will have to pay for it in the future, and at greater cost – the price of fossil energy will increase as it runs out.
The value of our property will decrease as the dry summers causes subsidence and as flooding starts when the sea rises. The cost of feeding the world’s population will soar as the sea-flooded areas become unsuitable for growing food. Yes – humankind will have to pay for Global Warming in the long term if we do not do something now to slow the process down.
The choice is – are we going to be selfish about this and carry on in our old bad ways because it makes “economic sense” or are we going to stop the pollution to give our children a better future because it makes ecological sense?
Note - Opinions expressed in this article are not necessarily those of the Society.
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