Energy and economics

There is absolutely no doubt that the climate is changing rapidly, showing as a general warming of the earth’s surface and oceans, accompanied by more disruptive weather patterns. It is only recently that there has been the realisation by almost all governments that there will be devastating consequences and that the usual short-term outlook of politicians must be set aside. The resulting Paris agreement (rejected by the United States) sets targets for the reduction of greenhouse gas emissions, with the aim of limiting the warming this century to below 2 degrees above pre-industrial levels. This level of warming will still result in major impacts such as uncertain food production and sea level rise resulting in the flooding of low coastal areas around the world. The cause of this warming is the enhanced greenhouse effect brought about mainly by an increased percentage of carbon dioxide in the atmosphere. This has increased from 280 parts per million (ppm) during the 10,000 years before the mid eighteenth century, before the start of the industrial revolution, to 407ppm today. Much of this carbon dioxide comes from the burning of fossil fuels, oil, gas and coal, so called because they are derived from huge amounts of plant material which were laid down over 300 million years ago. All organic matter contains carbon as part of its chemical make-up, fossil fuels are organic, being derived from plants, when fossil fuels are burnt, carbon is given off in combination with oxygen, as the gas carbon dioxide or CO2. We use gas, oil and coal directly for heating and transportation, but also indirectly through electricity generation. Coal and gas power stations are only 35-40% efficient, that is, 60-65% of the heat energy of the coal or gas is lost in the generating process. Another 10% is lost in transmission, through resistances in the cables and transformers, leaving only about 30% of the energy available to the end user, whether industrial or domestic. A modern car or truck engine will have an efficiency of between 30 and 45%. Driving 10,000 miles in an average modern car will emit around two and a half tons of carbon dioxide to the atmosphere. An electric car using electricity generated from fossil fuels will use slightly more fossil fuel than a car using petrol or diesel, so there is only a reduction in CO2 production if the electricity is generated from renewables. In addition, electrical generation capacity would have to increase by about 25% to meet transport needs if most petrol and diesel vehicles were to be replaced by electric vehicles. We need to look at our overall energy usage, for example, a 60watt incandescent light bulb will waste 98% of energy input as heat, meaning that only 2% of the fuel used. A low energy(fluorescent) bulb of equivalent light output will use around 20% of the energy and an LED light will use about 10%. An average household will produce around seven tons of carbon dioxide a year just from lighting when using incandescent bulbs, reducing to just over three quarters of a ton from LED lighting. Every time you use your tumble drier, you put about three kilograms of CO2 into the atmosphere, from the generation of the electricity used. Fridges and freezers use most energy in the house, after tumble driers and they vary greatly in efficiency, an A two star appliance using half the power of an A rated appliance. That all gives a little bit of background on the subject, so what must we do to reduce the devastating impacts of climate change? Simple really, first; produce most of the energy we use from renewables such as wind, solar, tidal and hydro. Second; reduce our energy demand. If you haven’t already done so, have solar panels fitted to your roof and sign up to an electricity supplier which only supplies power from renewables. Reduce your car journeys, use your bike and legs more. Don’t use aeroplanes. Get rid of your tumble drier. Switch off everything not in use. Don’t use chest freezers, only fridge freezers. Buy the most efficient appliances available. Buy food produced as locally as possible. This list could go on, but think for yourself what could be done. Last but certainly not least; don’t buy stuff. Industrial processes are the greatest producers of carbon dioxide (and other pollutants) and they are mostly producing things we don’t need, the latest fashions in clothes or fitted kitchens, the latest car or computer, throwaway packaging or throwaway presents. Opt out of the consumer society. Economists will have you believe that economic growth is vital, so why is this? Trading (in anything) creates wealth, or at any rate it puts more money in circulation, whoever the beneficiaries are. Gross Domestic Product (GDP) is used as an indicator of the amount of economic activity, or trading, which is taking place, yet it doesn’t indicate whether this activity is beneficial to us or not. The following scenario is not essentially different from buying any item that is not really needed. For example, if we fill a large oil tanker with oil from one of our small oilfields, then send it up the east coast to the Grangemouth refinery, but on the way, it’s satnav sends it crashing into Flamborough Head, this will be a boost to our GDP. We will have to produce more oil to replace that lost. We will have to produce another tanker to replace the wrecked one, keeping the shipyards busy. We will have a major salvage operation employing lots of people and equipment. We will need lots of clean up chemicals, people and equipment to deal with the pollution. And a better satnav. by Alan Tharrat

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