As the world's expanding population burns large quantities of fossil fuels and simultaneously cuts down large expanses of fore
As the world's expanding population burns large quantities of fossil fuels and simultaneously cuts down large expanses of forests worldwide, the concentrations of CO2 and other greenhouse gases are building up in the atmosphere. "The green house effect is the (imperfect) analogy used to explain the atmospheric phenomenon that keeps our planet warm enough to sustain life." There is mounting evidence that this shift in Earth's atmosphere will lead to global changes and potentially major climatic disruptions . The major concern is not that the greenhouse effect is real;"we wouldn't be here if it wasn't." It's that it "may be exacerbated by anthropogenic increases in the effective gasses, threatening a disruption to the equilibrium between incoming and outgoing energy, and a resulting average global warming." From 1880 to today, by many measurements, the global average temperature has increased by 0.5 Degrees Celsius. Human and ecological systems are already vulnerable to a range of environmental pressures, including climate extremes and variability. Global warming is likely to amplify the effects of other pressures and to disrupt our lives in numerous ways. "Melting icebergs and expanding oceans may cause floods." The Intergovernmental Panel on Climate Change (IPCC) predicts
The world's drylands, contrary to popular misconceptions of being barren unproductive land, contain some of the most valuable
The world's drylands, contrary to popular misconceptions of being barren unproductive land, contain some of the most valuable and vital ecosystems on the planet. These dryland environments have surprising diversity and resiliency, supporting over two billion people, approximately thirty-five percent of the global population (UNEP, 2003). In fact, approximately seventy percent of Africans depend directly on drylands for their daily livelihood (UNEP, 2003). However, these precious and crucial areas are at a crossroad, endangered and threatened by the devastating process of desertification. There are over one hundred definitions for the term 'desertification', however the most widely used and current definition is as follows: desertification refers to the land degradation in arid, semi-arid and dry sub-humid regions due to human activities and climate variations, often leading to the permanent loss of soil productivity and the thinning out of the vegetative cover (UNCCD, 2003). It is important to note that desertification is not the expansion and contraction of deserts or hyper-arid territories, which grow and decrease both naturally and cyclically. French ecologist Louis Lavauden first used the term desertification in 1927 and French botanist Andre Aubreville, when witnessing the land degradation occurring in North and West Africa in 1949 popularized this term (Dregne,
Evaluate the arguments for and against the use of GM crops in developing countries. Which do you support and why?
Social and Political theory Evaluate the arguments for and against the use of GM crops in developing countries. Which do you support and why? One of the major causes for debate in recent years has been the argument over whether or not genetically engineering or genetically 'modifying' crops is a just practice. Genetic engineering refers to the methods that make it possible to change the pattern in genetic material. Changing the pattern of the DNA molecules may make it possible to change countless characteristics in the living organism. This ability to modify an organism's genetic makeup has innumerable uses for researchers trying to understand the basic biology of plants and animals, including humans. In applied plant science, the research is helping the development of agricultural crops that are better for the environment and for consumers. However, are they fulfilling this aim? Are GM products really safer for the consumer and for the surrounding environment? There are many apparent strengths and weaknesses to genetically modifying crops, all of which can be divided up into certain aspects. For example, what are the consequences of GM crops upon; health, the environment, society/culture and the economy. It is mainly within these areas that the essay will examine these strengths and weaknesses. It is the opinion of this essay that although there are definitely potential
"What may cause sea levels to rise? How might rising sea levels pose significant problems for human populations? How might these negative effects be addressed?
Extended Writing - Geography "What may cause sea levels to rise? How might rising sea levels pose significant problems for human populations? How might these negative effects be addressed? Rising sea levels are one of the effects of global warming and this is a major problem that our world faces today. Briefly global warming is a greenhouse effect on the Earth that is linked to deforestation and an increase in industrial gas emissions into the air. Rising sea levels are caused by polar ice caps in Antarctica and Arctic melting from the warmer temperatures due to global warming. Rising sea levels pose a major problem for large populations living on the coast and this can cause a massive movement of refugees looking to live in-land or in other countries. Many scientists around the world are working on a solution for the problem, but several scientists are contradicting each other on various topics. The main cause of rising sea levels is major melting of mountain glaciers in Antarctica. Ideas as to a possible sea-level rise are estimated at "up to 100 centimetres over the next 100 years". The Pew Centre on Global Climate Change ('PCGCC') have stated that sea levels have risen 25 centimetres in the last 100 years and they say they will rise another 50 centimetres in the next 100 years. The effects on coasts if sea levels were to rise are mass erosion of beaches; major
The Mesolithic era.
The last Ice Age ended 10,000 radiocarbon years ago and saw the beginning of the Mesolithic period (Mithen, 1999). In Europe, the Mesolithic era was a transitional time between the ice ages and post-glacial environments and hunter-gatherers and farming societies. Europe entered into a period of intense climatic change; temperatures increased, ice-sheets retreated and sea levels rose. Much of the European landscape changed from periglacial tundra to deciduous woodland. The proliferation of plant-life, and subsequently wildlife, forced the people of the Mesolithic to adapt to this new and unpredictable environment. Archaeological investigation shows the development and adaptations that occurred throughout the region, but as with today, post-glacial Europe was a vast area with variances in culture and environment that have led to a great diversity in the sites and artefacts that are discovered. The establishment of forest led to differences in the type and patterns of game available for hunting. Whereas Upper Palaeolithic bands hunted predictable migratory game such as reindeer their Mesolithic successors had to create new subsistence strategies to deal with the multitude of species that faced them (Fagan, 2001). Legge and Rowley-Conwy (In Pryor, 2003) provides evidence of the variety in Mesolithic diets by analysing animal bones found at Starr Carr. They showed that wild
To what extent is Climate Change caused by Human Activity?
To what extent is Climate Change caused by Human Activity? Palaeoclimatic records have allowed scientists to determine that the last 2 million years climate has fluctuated between periods of warmth and cold. Global average surface temperatures have fluctuated by as much as 5°C between the two climatic regimes. In the longer term i.e. the last 50 million years the Earth has become much colder. The size of the ice caps has repeatedly grown and shrunk every 100,000 years. (Figures UNFCCC 2001). At present we may be coming towards the end of the latest warmer interglacial period, although mankind's alteration of the atmosphere through greenhouse gas pollution makes predicting the long term future of our global climate difficult. Climate change refers to the average state of the climate, where climate is taken to mean 'the mean weather over an extended period of time in a specific location' (Earth Under Siege 1997) or its variability, this being the level of persistence over an extended period of time, typically decades or centuries. Climate change is caused by a number of factors, these include natural internal processes or external forcings, as well as the possibility of these changes resulting from human activities; 'Anthropogenic' changes in a specific location. (Government of India, Ministry of Environment & Forests) The very nature of the question implies that climate
Floodplains - Any watershed begins with small trickles of water.
Any watershed begins with small trickles of water. These small trickles gather and form larger streams, which gradually grow from brooks to creeks to rivers. As the volume of water increases in the stream channel, the stream channel has a greater cross-sectional area (there is an increase in stream size - width, depth, velocity, and flow volume). As the river reaches the flat land around the base of the hill, the river will begin to meander. This slows the progress of certain areas of the river and speeds up others, meaning that one side is often eroded while the other is deposited - forming a floodplain. A floodplain is a mostly flat area of land bordering a river that is subjected to periodic flooding. It is made up of silts and sands, which have been deposited over many years by the river. Whilst some deposition takes place within the river channel, the bulk of the sediment is deposited when the river floods. The reason for this is that as the river spreads over its floodplain, there is a sudden increase in both the wetted perimeter and the hydraulic radius. This results in an increase in friction, causing a decrease in velocity and the deposition of material previously held in suspension. The heaviest sediment will be deposited closest to the river, thus forming what is known as levees. A prominent slope known as the bluff line often marks the edge of the
Types of Pollution
Types of Pollution The 2 main types of pollution on discussion here are namely land pollution and air pollution Land Pollution Pollution occurs when people dispose of their waste on the land. The disposal of non-biodegradable and toxic waste in landfills may result in numerous problems. Firstly, when it rains, rain water may seep through the soil and waste, dissolving and carrying away with it, harmful substances that pollute the soil, groundwater and any nearby streams. Moreover, when the waste in the landfill decomposes under heat and pressure of the soil above, they would release poisonous fumes such as methane. Many buildings in America and Europe are sited on such land. Hence, an excavation of the ground may result inn the release of these fumes into the atmosphere, killing people, animals and plants nearby. Moreover, the land above the landfill is filled with pockets of gas and this makes the land very unstable. Subsidence may occur at any time and this makes the land dangerous to live on. examples of such land include: * Love Canal, New York, USA * Portsmouth, England Moreover, with a growing population on Earth, land is becoming scarcer and there may not be enough land to be used as landfills in the future. Air Pollution Introduction: Of all types of pollution, air pollution is one of the most insidious and one of the most difficult to do anything about. It
Natural Hazards - This report will look at the floods that occurred along the Yangtze River, and Dongting lake, China, August 2002. Floods are very common within China's provinces.
Natural Hazards Floods in china, august 2002. This report will look at the floods that occurred along the Yangtze River, and Dongting lake, China, August 2002. Floods are very common within China's provinces. This report will analyse the causes of this catastrophic flood that occurred earlier this year in China. "Water levels along 1,829 kilometers (1,136 miles) of the 2,819-kilometer lake (Dongting) have surpassed warning marks, the official Xinhua news agency reported" (http://www.cnn.com/2002/WORLD/asiapcf/east/08/22/china.lake/) Frequent heavy rainfalls in early and mid June, one month earlier than usual, led to landslides and mountain floods and caused severe damage and property loss in large parts of China. Although there were no floods along the major rivers, there were flash floods, landslides and mudflows, which resulted in high casualties. This report will be a factual account of what hapend in these provinces. River and coastal flooding are the most frequently occurring natural disaster and are increasing in occurrence more rapidly than any other disaster. Urbanization and deforestation reduce the capability of the earth to hold excess water. As asphalt expands and open spaces disappear, it takes less rain to flood communities as water running over the pavement collects quickly and easily disrupts storm drain systems. Those areas that are most at risk include
Discuss a range of geomorphological techniques we can use to determine the rate and magnitude of slope movement.
"Discuss a range of geomorphological techniques we can use to determine the rate and magnitude of slope movement." To discuss the question, we must first identify what slope movement is. Also known as "mass wasting (sometimes called mass movement) it encompasses a broad array of processes whereby earth material is transported down a slope by the force of gravity. It is related closely to weathering, which is the breakdown of minerals or rocks at or near Earth's surface through physical, chemical, or biological processes, and to erosion, the transport of material through a variety of agents, most of them flowing media, such as air or water" (Gale's science of Everyday Things). Slope movement therefore is movement of the land which has become unstable. Instability of the land can be caused by many environmental and human impacts such as weathering and structural changes to the landscape. The condition of slope movement is that of the gravitational force of the land exceeding the resisting force, thus leading to incipient failure within the slope. This therefore leads to movement. After the initial failure of the slope, movement occurs within the land which maybe significant or unnoticeable depending on the rate of the mass movement. Landslides for instance, are movements of a very high speed thus are very dramatic movements of land, which have immediate and delayed