Introduction
Global Warming is a gradual increase in the overall temperature of the Earth's atmosphere generally attributed to the greenhouse effect. Being a science oriented student and having the experienced first-hand of the effects of Global Warming I feel an obligation to share information about the topic. Global Warming has affected the natural climate of the Caribbean, flipping seasons and attributing to the unpredictable state of the weather. Having a personal connection with farming, the effects it has on agriculture is noticeable. As a student also doing Environmental Sciences this is a major concern academically.
Future endeavours in the farming industry will be greatly affected by the drastic climate changes; causing a shortage in food for the overall nation and Caribbean. Researching the reasons for Global Warming can give us an insight on how to prevent any further increase of the Earth's atmospheric temperature. My reasons for choosing this topic are not only, the personal effect it has on me but that it effects on a global scale. Not only affecting agriculture but also mankind and other living organisms and the existence of Earth as a whole. Global Warming is a well sought after topic, allowing an abundance of information and facts to be at my disposal.
Exposition
Good morning teacher and students, today I'm going to be discussing the topic of global warming. Global warming is the rise in temperature worldwide due to an increase in the emission of greenhouse gases into the atmosphere. It is a change that is believed to be permanently changing the Earth's climate. Even though it is an ongoing debate, it is proved by the scientist that the planet is warming. Some of the challenges faced when doing this internal assessment is that there was too much information available on the selected topic and therefore had to choose information according to which suited my I.A. Another challenge was that the information collected was not mainly for the Caribbean but instead it's what happening in the world globally.
My information was taken from secondary sources. These include the book (Easy Approach to Skills in Geography by Vohn A.M. Rahil) and online articles. This book was published in 2011 which means there is only a three year gap from when this information was taken which impacts on the validity of the information. National Aeronautics and Space Administration (NASA) was started in 1958 as part of the Unite State government. NASA does a lot of different things. They are made up of scientists, engineers and astronauts. Over 18 000 people work for NASA. NASA is well known therefore there information can be trusted to be valid. The administrator of NASA is Charlie Bolden. He has a bachelor's degree in electrical science and a master's degree in system management.
The International Panel on Climate Change (IPCC) is a United Nations Body founded in 1998 which evaluates climate change science. The IPCC assesses research on climate change and synthesis it into major assessment report every 5-7 days there the information taken was recent which impacts on the validity of the information. Daily science is one of the internet's most popular news web sites. Since starting in 1995, the award- winning site has earned the loyalty of students, researchers, healthcare professionals, government agencies, educators and general public around the world. This means that there information is well known around the world which makes it more reliable.
Global warming is caused by an increase in the greenhouse effect .The greenhouse effect is not a bad thing by itself it's what allows Earth to stay warm enough for life to survive. Although it's not a perfect analogy you can think of the Earth sort of like your car sitting out in a parking but on a sunny day. You've probably notice that your car is always hotter on the inside than the outside temperate if it's been sitting there for a while. The suns rays enter thorough your car's windows. Some of the heat from the sun is absorbed by the seats, the dashboard and the carpeting and the floor mats. When those objects release this heat it doesn't all get through the windows. Some is reflected back in. The heat radiated by the seats is a different wavelength than the light of the sun that made it through the windows in the first place. So a certain amount of energy is going in and less energy is going out.
The result is a gradual increase in the temperature inside your car. The greenhouse effect is a little more complicated than your hot car. When the sun's rays hit the earth's atmosphere and the surface of the Earth, approximately 70 percent of the energy stays on the planet, absorbed by land, oceans, plants and other things. The other 30 percent is reflected into the space by the clouds, snow fields and other reflective surfaces (source: NASA.) But even the 30 percent that gets through doesn't stay on Earth forever (otherwise the earth would become a blazing fireball.) The Earth's ocean and land masses eventually radiated heat back out. Some of this heat makes it into space. The rest of it ends up getting absorbed when it hits certain things in the atmosphere, such as carbon dioxide, methane gas and water vapour. After these components in our atmosphere absorb all this heat, they emit energy (also in the form of heat.) The heat that doesn't make it through the Earth's atmosphere keeps the planet warmer than it is in the outer space, because more energy is coming in through the atmosphere than is going out. This is all part of the greenhouse effect that keeps the Earth warm.
The major scientific agencies of the United States including the National Aeronautics and Space Administration (NASA) and the National Oceanic and Atmospheric Administration (NOAA) agree that climate change is occurring and that humans are contributing to it. In 2010 the (National Research Council) concluded that "climate change is occurring is very likely caused by humans and natural systems." According to scientist global warming is the process by which the greenhouse gases absorb thermal radiation; these are then reradiated in all directions. But when some of these radiations come back to the surface and lower atmosphere it causes increase in the average surface temperature leading to global warming. In specific terms, an increase of one or more Celsius degrees in a period of one hundred or two hundred years would be considered global warming. Over the course of a single century an increase of even o.4 degrees Celsius would be significant.
The (IPCC) a group of over 2500 scientist from countries across the world convened in Paris in February, 2007 to compare and advance climate research. When the timeframe is advanced by five years, from 1906 to 2006 the scientists found that the temperature increase was 0.74 degrees Celsius. Carbon dioxide which is a colourless gas has increase in the atmosphere over the past years. According to CDIAC (Carbon dioxide information analysis centre) human activities are contributing to huge amounts of carbon dioxide in the atmosphere, resulting in an overall increase in carbon dioxide concentration. Carbon dioxide absorbs infrared radiation so therefore most of the energy that escapes Earth's atmosphere comes in this form so extra carbon dioxide means more energy absorption and an overall increase in the planets temperature. The world watch reports that carbon emission worldwide has increased from about 1 billion tons in 1900 to about 7 billion tons in 1995. This institute also notes that the average surface temperature of Earth has gone from (14.5 degrees 1860 to 15.3 degrees C in 1980.) The IPCC says that pre-industrial amounts of carbon dioxide in the Earth's atmosphere were about 280 parts per million (ppm) meaning that of every million molecules of dry air, 280 of them were carbon dioxide. In contrast, 2005 levels of carbon dioxide were measured at 379 ppm.
Nitrous oxide is another important greenhouse gas. Although the amount being released by humans' activities are not as great as the amounts of carbon dioxide, nitrous oxide absorbs much more energy than carbon dioxide ( about 230 times as much.) For this reason, efforts to curb greenhouse gas emission have focused on nitrous oxide as well. (Source: Soil Conservation Council of Canada.) The use of large amounts of nitrous fertilizer on crops release nitrous oxide in great quantities and it is also a by-product of combustion.
Methane is a combustible gas, and it is the main component of natural gas. Methane occurs naturally through the decomposition of organic material and is often encountered in the form of "swamp gas." Man-made process produces methane in several ways. These include by extracting it from coals, from large herds of livestock (i.e. digestive gases) from the bacteria in rice paddies and decomposition of garbage in landfills. Methane acts much like carbon dioxide in the atmosphere, absorbing infrared energy and keeping that energy on Earth. The IPCC says that methane concentration in the atmosphere in 2005 was 1774 parts per billion (ppb.) While there isn't as much methane as carbon dioxide in the atmosphere, methane can absorb and emit twenty times more heat than carbon dioxide (source: Hopwood, Nick , Cohen and Jordan.) Large scale venting of methane into the atmosphere (such as from the release of huge chunks of methane ice locked under the oceans) could have created brief periods of intense global warming that led to some of the mass extinctions in the planet's distinct past (source: Discover Magazine.)
We have seen that an average drop of just 5 degrees Celsius over thousands of years can cause an ice age; so what will happen if the Earth's average temperature increases a few degrees in just a few predictions are never perfectly accurate because weather is a complex phenomenon. When it comes to long term climate predictions all we can manage are educated guesses based on our knowledge of climate patterns through history. According to Guardian unlimited glaciers and ice shelves around the world are melting.
The loss of large areas of ice on the surface could accelerate global warming because less of the sun's energy would be reflected away from Earth to begin with. An immediate result of melting glaciers would be a rise in sea levels. Initially the rise in sea levels would only be an inch or two. Even a modest rise in sea levels could cause flooding problems for low-lying coastal areas. However if the West Antarctic Ice Sheet were to melt and collapse into the sea, it would push sea levels up 10 meters (more than 32 feet) and many coastal areas would completely disappear beneath the ocean (source: NASA).
The IPCC estimates that sea levels rose 17 centimetres in the 20th century. Scientist projected rising sea levels to continue through the 21st century, with levels increasing between 7 and 22 inches by 2100. The IPCC did not consider changes in the flow in these projections due to lack of scientific data. Sea levels will likely be greater than the range of projections but we can't be sure by how much until more data can be gathered about the effect of global warming on ice flows. With a rise in the overall temperature of the ocean, ocean- borne storms such as tropical storms and hurricanes which get their fierce and destructive energy from the warm waters they pass over could increase in force.
Are the polar ice caps in danger of melting and causing the oceans to rise? This could happen, but no one knows when and it would happen. The earth's main ice-covered landmass is Antarctica at the South Pole, with about 90 percent of the world's ice and 70 percent of its fresh water. Antarctica is covered with ice an average of 2,133 meters thick. If all of the Antarctic ice melted, sea levels around the world would rise about 61 metres. But the average temperature in Antarctica is -37 degrees Celsius so the ice there is in no danger of melting. In fact, in most parts of the continent it never gets above freezing. At the other end of the world, the North Pole the ice is not nearly as thick as at the South Pole. The ice floats on the Arctic Ocean. If it melted, sea levels would not be affected. There is a significant amount of ice covering Greenland, which would add another 7 meters to oceans if it melted. Because Greenland is closer to the equator than Antarctica, the temperature there are higher, so the ice is more likely to melt.
Scientist form the University of London and Edinburgh say that ice loss in Antarctica and Greenland together contributed approximately 12 percent of the rise in sea levels (source: Science Daily) . But there might be a less dramatic reason that polar ice melting for the higher ocean level the higher the temperature of the water. Water is most dense at 4 degrees Celsius. Above and below this temperature, the density of water decreases (the same weight of water occupies a bigger space). So as the overall temperature of the water increases it naturally expands a little bit making the oceans raise.
Less abrupt changes would occur around the world as average temperature increases. In temperature areas with four seasons the growing season would be longer with more precipitation. This could be beneficial in many ways for these areas. However, less temperate parts of the world would likely see an increase in temperature and a sharp decrease in precipitation, causing long droughts and potentially creating deserts. Because the earth's climate is so complex, no one is really sure how much a change to one region's climate will affect other regions. For example, scientist at the University of Colorado theorizes that the decrease in sea ice in the Arctic could reduce snowfall in Colorado because Arctic cold fronts would be less intense. This could impact everything from farmlands to the ski industry. The most devastating effects and also the hardest to predict, are the effects on world's living organisms. Many ecosystems are very delicate, and the slightest change can kill off several species as well as any other species that depend to them.
Most ecosystems are interconnected, so the chain reaction of effects could be immeasurable. The results could be something like a forest gradually dying off and turning to grassland or entire coral reefs dying. Many species of plants and animals could adapt or move to deal with the shift in climate, but many would become extinct. Some of the ecosystems are already changing drastically due to shift in climate. The University of Alberta reports that much of what was tundra in northern Canada is turning into forest.
They also noticed that the change from tundra to forest isn't linear; instead it seems that the change happens in sudden spurts. The human cost of global warming is hard to quantify. Thousands of lives per year could be lost as the elderly or ill suffer from heat stroke and other heat- related trauma. Poor and underdeveloped nations would suffer the worse effects, since they would not have the financial resources to deal with the problems that come with an increase in temperature. Huge members of people could die from starvation if a decrease in precipitation limits crop growth and from disease if coastal flooding leads to widespread water- borne illness.
The Carnegie Institution estimates that around $5 billion in crops losses per year are due to global warming. Farmers see a decrease of about 40 million metric tons of cereal grains like wheat, barley and corn each year. Scientist discovered that an increase of 1 degree Fahrenheit in average temperate results in a 3 to 5 percent drop in crop yields (source: Science Daily). Heat waves, which are projected to increase under climate change, could directly threaten livestock. A number of states have each reported losses of more than 5,000 animals from just one heat wave. Heat stress affects animals both directly and indirectly. Over time, heat stress can increase vulnerability to disease, reduce fertility, and reduce milk production. Drought may threaten pasture and feed supplies. Drought reduces the amount of quality forage available to grazing livestock. Some areas could experience longer, more intense droughts, resulting from higher summer temperatures and reduced precipitation. For animals that rely on grain, changes in crop production due to drought could also become a problem.
By now you may realise that global warming is slowly destroying the Earth and its natural habitats. If we act fast together we can make a difference!