Scientists for a long time have been predicting vast and rapid global warming, many of these predictions have not materialised, at least not on the same scale as was first predicted. When considered on a time scale of many thousands of years, the earth should be going into a cold period in its natural cycle of climatic change. The question is what effect is the global warming having on this? Moreover, is it actually detrimental at all? Global warming has been predicted on the basis that throughout history temperature and carbon dioxide in the atmosphere have been directly linked.
It is not known which causes which, but, carbon dioxide emissions have increased rapidly in the last century or so. Could this increase cause a rise in temperature? The theory behind global warming is that CO2 (carbon dioxide) is a greenhouse gas, letting in short wave heat radiation into the earth’s atmosphere and preventing long wave radiation from escaping, thus acting as an insulator around the earth. When the theory was first produced massive temperature rises were predicted (several degrees), enough to have massive detrimental effects on the earths natural cycles.
In reality, a rise has been observed, but not on the sort of scale predicted, this rise is still big and rapid none the less. Effects of global warming could be more complicated than one would also think. At first impression, a warmer climate may seem an attractive proposition; in fact, it could cause cooling in some areas. For Example, The UK has a warmer climate than that of a country on the same latitude as it (i. e. Canada). This is due to the warm flow of current from the Atlantic conveyor (or as its more commonly known ” the gulf stream” ).
A warmer climate could turn this off; the past effect of the Atlantic conveyor being switched off has been an ice age in much of northern Europe. Dramatic changes in the earth’s circulatory patterns would also be observed if such climatic change were to take place. For example, a reduced temperature gradient between the poles and the equator. This in turn would cause a reduction in the force of the Hadley cell. The polar and subtropical jet streams, thus affecting the climate of the middle latitudes; the change may also affect the number and types of Rosby Waves.
A northward shift in the ITCZ may also be observed due to an increased warming of the northern hemisphere. These changes are big, but on a survival scale, not huge. It would be possible for us to adapt to even fairly drastic temperature rises. Food could still be produced and for some of the world at least, productivity would increase, cancelling out those areas where it had dropped. Could Global cooling be more of a threat? Closer to home other effects would be observed:- Environment Example of impact Consequences Landscape Disappearance Of glaciers.
Reduction in tourism and winter sports Hydrological In areas of erratic or irregular rainfall-wetlands shrink-rivers shrink and dry up, effects on water supplier eg. Underground aquifers Also effects on irrigation, hydroelectric power, navigation. Water companies have to improve engineering to cope with imbalance of supply and demand. Maritime Changes in sea temperature and position of ocean currents Changes in location of wildlife, implications for fish stocks and shoal location. Fishing industry disrupted. Meteorological Increased storms and strength of hurricanes.
Damage to areas not used to storms eg. UK Regional weather Interior locations- drier summers, reduction in soil moisture, colder winters. Maritime locations eg. UK- higher temperatures, longer summers, wetter winters Effects not predictable until more observations and records can be gathered Vegetation Distribution of flora and fauna will shift to different latitudes. Species vulnerable to change may become extinct, eg great raft spider (Great Britain) Spread of pests. New varieties growth abled in new countries.
Human health Increase in a range of tropical diseases e. malaria and cholera As temperatures rise Increased death rate in some parts of the world. Incr4ased pressure on medical services. Through climatic research such as ice core data and Varves, it has been possible to build up an accurate record of the earth’s climate over thousands of years. The natural cycle is over an approximate period of 10,000 years, with alternate warm and cool periods. Time The effects of global cooling could be huge. Looking back at past records of ice ages, much of the northern, and some of the southern hemispheres were completely covered by the ice sheet.
This caused people to gradually move south and north respectively, as the ice sheets retreated 10,000 years later, to return from the direction they came. I feel we have to bear in mind that the population of the world at that time would be far far less than it is currently. For the population of the UK to fit into southern Britain and move over to France may be more feasible due to improvements in transport and communications, but with decreased food-producing land, could the remaining land support such populations?
Currently we are producing too much food to feed ourselves so this also may be feasible. It may also be much easier to survive in colder conditions now with improvements in technology and transport, however the effects on peoples lives would be huge, even if they didn’t have to move. At the current time, we are long overdue to go into a cold period (for the U. K, this is an ice age. ) One explanation for us not entering into this cool period is the cancelling out of the natural cooling of the earth by global warming.
Bearing in mind the regularity and consistency of the warm and cool periods in the earth’s history, it may be presumciuous to assume that we are not entering, or are going to enter this cold period. The reliability of records is very good and using the past as a predictor of the future, it would seem inevitable that we will enter a period of extreme cooling. When we consider this compared with our statement: – “Global cooling is both more likely and more likely to have more disastrous effects than global warming. It would seem that, with our limited knowledge of global warming, global cooling might indeed be more likely.
Considering the severity of the effects of each of our scenarios, I feel it would also be, potentially more disastrous if global cooling were to take place. Indeed, if the scale of global warming were as predicted in early scientific research, then maybe the effects of each of the scenarios would be on similar scales, and global warming could yet turn out to be much bigger than we realise. Certainly, the levels of CO2 have increased sufficiently, as illustrated by my graph. However, I feel that without more knowledge of global warming it is near impossible to predict the outcomes.
It is also near impossible to predict how people will react to such event. For example if the time period is long or short, will people be able to adapt? Maybe they could and maybe our levels of technology could help us achieve such a feat. To make a decision relies on knowledge of both factors, and as long as we only have reliable knowledge of one of the factors then it is impossible to predict whether the effects would be more disastrous. If we go on current data and knowledge then global cooling looks like being more disastrous.