BRETT LUCAS TRINITY COLLEGE L6 SCIENCE GEOGRAPHY CLIMATE CHANGE: NATURE OR NEGLIGENCE The climate of our world is changing, but why? There is a great debate going on in the scientific community on whether our current climate change crisis is a natural occurrence over millions of years – as what has happened on the planet of Mars – or this natural process is being accelerated by man’s negligence. But first we must establish what is climate change? Climate Change is a long-term shift in the statistics of weather (taken from weather. gov October 2007 article on Climate Change).
Throughout our planets long history our climate has changed between hot and cold in each time period from the Precambrian period to today. The Earth’s climate has always been considered dynamic with changes occurring through a natural cycle. What we are all concerned about here on earth is whether the changes that have happened today have been accelerated because of man’s living trends. Scientists from classrooms to NASA specialists study climate change, and evidence such as tree rings, pollen samples, ice cores and sea sediments provide vital information.
Scientists have all agreed that causes of climatic change are of two types – those that are due to natural causes and those that are created by the main inhibitors of earth, Man. Natural Causes Continental Drift This has been happening on our planet from the beginning of time, which is caused by the continuous movement of our tectonic plates. The proof of our theory is that the western side of Africa and the eastern side of South America seems to be able to fit like a jigsaw puzzle and they have similar fossils.
In the past all of the continents formed a massive super continent called Pangaea. When the continent separated it caused great changes to the earth’s ocean current pattern, therefore causing a the fresh and salt water cycle to be off balance thus affecting our planet’s climate. Volcanoes During volcanic eruptions large volumes of greenhouse gases (sulphur dioxide (SO2), water vapour, dust, and ash) are dispersed into the earth’s atmosphere. These gases trap heat from exiting the atmosphere after the earth has absorbed what it can from the Sun.
For example, in April 1991 Mount Pintoba in the Philippines erupted emitting tonnes of gases into the atmosphere. The volcano in its eruption destroys natural life on the land surface with its lava. When the volcano is an undersea volcano it can displace great amounts of water during an eruption especially when the undersea volcano creates an island, which can further affect the ocean currents. The Earth’s Tilt The earth, which is tilted at an angle of 23. 5° to the perpendicular plane of its orbital path, makes a full orbit around the sun in one year.
For half of the year the northern hemisphere is tilted towards sun, which is summer for the North Pole (6 months of daylight). In the other half the northern hemisphere is tilted away from the sun therefore the North Pole will have winter (6 months of darkness). If there was no tilt, there wouldn’t have been any seasons. If the tilt was more the summers and winters would have been intensified whilst if the tilt was less, the summers would have been cooler and the winters would have been warmer. Greenhouse Effect
The greenhouse effect occurs when heat energy from the sun enters the earth’s atmosphere and most is being absorbed by the earth. The reflected heat energy rays is sent back into the atmosphere but most is then stopped by the greenhouse gases (such as water vapour, carbon dioxide, methane, nitrous oxide and chlorofluorocarbons) which keep most of the reflected heat energy from escaping and reflecting it back down to earth with more heat energy from the sun. With this continuous action the earth’s surface temperature will rise. Ocean Currents
The world’s oceans are major components in the climate system. They cover approximately 71% of the earth and absorb about twice as much of the sun’s radiation as the atmosphere or the land surface. The ocean current moves heat around the earth (which is about same as the atmosphere). Winds push horizontally against the sea surface and drive ocean current patterns. Ocean currents influence certain parts of the world more than others. For example the Humboldt Current that flows along the coastline of Peru directly affects the coast off of Peru and other adjoining regions.
The El Nino in the Pacific Ocean affects the climatic conditions all over the world due to the ocean currents. Ocean currents can affect places that share the same latitude in Europe and North America. Any of these phenomena can have an impact on the climate, as is believed to have happened at the end of the last Ice – Age, about 14000 years ago. Human Causes Use of Oil, Coal and Natural Gas With the dawn of the Industrial Revolution in the 19th Century, we saw the large-scale use of fossil fuels (such as Oil, Natural Gas, and Coal) for industrial activities (factories, electricity).
These activities created jobs and over the years people moved from rural areas to cities. In the present day we use these fossil fuels on a much larger scale to power almost every thing, which in turn let out millions of tonnes of carbon dioxide each day increasing the amount of greenhouse gases in the atmosphere, which creates more heat coming down to the earth, melting our polar ice capes and raising sea levels. Further heated seas will increase the number and intensity of hurricanes and other climatic natural disasters around the world (for example hurricane Ivan which hit the country of Grenada in 2004).
How we all contribute Every Day All of us in our daily routines contribute our bit to this change in climate. For example: * Electricity is the main source of power in urban areas. All our gadgets run on electricity generated mainly from thermal power plants. These power plants run on fossil fuels. * Cars, buses, trains, aircraft and trucks are the most common ways of transportation for goods and people in and out of cities. These means of transport need to be powered to move therefore its usually powered by petrol or diesel. Large quantities of waste are generated in the form of plastics that remain in the environment for many years and cause damage. * Many trees are destroyed to facilitate the high demand for paper, which is being used in our work at school and offices. Trees are also destroyed for timber. With the continuous destruction of our forest this will increase the carbon dioxide levels in the atmosphere. * With our global population increasing at a rapid rate, we will need food to feed this population.
Therefore more farms will be needed for the growing of the food, thus more fertilizers being used to grow the crops better. Due to the high use of fertilizers large amounts of nitrous oxide is emitted into the atmosphere adding to the amount of greenhouse gasses in the atmosphere. Global Warming This is I caused by man’s intense use of the earth’s resources creating a high above normal greenhouse gas levels. These high levels of greenhouse gases are warming up the earth and depleting our ozone layer.
A hole has been formed over Antarctica, which was caused by global warming. This hole is allowing more sunlight to enter the earth’s atmosphere thus melting our polar ice caps and raising our sea levels (the sea is rising at a rate of 3. 33mm per year – NASA). With the warming up of the earth the sea will also be warmed thus creating stronger hurricanes and longer hurricane seasons. Conclusion There is no doubt that the earth in its own natural evolution would have created significant occurrences of climatic change.
Thing such as continental drift, volcanoes, the earth’s tilt, the greenhouse effect and ocean currents are all parts of the natural order. We know scientifically that the earths has been around for millions of years and there is no definitive time when these natural causes would have impacted climate change to the point where earth would have deteriorated to a stage similar to the planet Mars. What is clear though is that the impact of man’s lifestyle has negatively affected climate change to the point where the destruction of earth is now in the foreseeable future.
Governments of nations around the world, advised by scientist have now embarked on programs to decelerate the speed of climatic change by developing green engineering – which is the design, commercialization, and use of processes and products that are feasible and economical while minimizing the generation of pollution at the source and risk to human health and the environment. Green engineering embraces the concept that decisions to protect human health and the nvironment can have the greatest impact and cost effectiveness when applied early to the design and development phase of a process or product. (United States Environmental Agency) Man must now act to determine the survival of Earth Existence. Bibliography 1Climate InstituteClimate. org 2Causes of Climate ChangePhysical Geography. net 3Global Climate ChangeNational Aeronautics and Space Administration 4Causes of Climate Change 5Geography for ASEditor – Clive Hart 6Geography – An Integrated ApproachDavid Waugh