Humanities 11 Episode 9
fresh water - solutions
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global warming's threats to Canada
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rainforest deforestation (cause and effects)
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water quality (human impact and impact on humans)
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CFC's
..., Chlorinated Fluorocarbons are chemicals that break down the ozone layer. Often used as refrigerants.
sustainable development
..., Development that balances current human well-being and economic advancement with resource management for the benefit of future generations.
reforestation
..., The process by which trees are planted to re-establish trees that have been cut down in a forest land
permafrost
A permanently frozen layer of soil, usually found in tundra of the arctic or high mountains
PH levels
..., a measure of relative acidity of a solution, ranging in value from 0(most acidic) to 14(most basic). Potential hydrogen and refers to the concentration of hydrogen ions (H+), 0-7 Acidic, 7 pure water, 7-14 basic
old growth forests
..., forests free from disturbance for long enough (generally 150 to 200 years) to have mature trees, physical conditions, species diversity, and other characteristics of equilibrium ecosystems
Brundtland Commission
.Named for the prime minister of Norway. The UN established the World Commission on Environment and Development, which investigated the state of the world's environment and proposed solutions in a 1987 document, "Our Common Future" ..., Where the call for sustainability came from; two key concepts: "needs" in particular the essential needs of the world's poor, to which overriding priority should be given, and the idea of limitation imposed by the state of technology and social organization on the environments ability to meet present and future needs
acid rain (cause and effects)
Acid rain is rain consisting of water droplets that are unusually acidic because of atmospheric pollution - most notably the excessive amounts of sulfur and nitrogen released by cars and industrial processes. Acid rain is also called acid deposition because this term includes other forms of acidic precipitation such as snow. Acidic deposition occurs in two ways: wet and dry. Wet deposition is any form of precipitation that removes acids from the atmosphere and deposits them on the Earth's surface. Dry deposition polluting particles and gases stick to the ground via dust and smoke in the absence of precipitation. This form of deposition is dangerous however because precipitation can eventually wash pollutants into streams, lakes, and rivers. Acidity itself is determined based on the pH level of the water droplets. PH is the scale measuring the amount of acid in the water and liquid. The pH scale ranges from 0 to 14 with lower pH being more acidic while a high pH is alkaline; seven is neutral. Normal rain water is slightly acidic and has a pH range of 5.3-6.0. Acid deposition is anything below that scale. It is also important to note that the pH scale is logarithmic and each whole number on the scale represents a 10-fold change. Today, acid deposition is present in the northeastern United States, southeastern Canada, and much of Europe including portions of Sweden, Norway, and Germany. In addition, parts of South Asia, South Africa, Sri Lanka, and Southern India are all in danger of being impacted by acid deposition in the future. Causes and History of Acid Rain Acid deposition can occur via natural sources like volcanoes but it is mainly caused by the release of sulfur dioxide and nitrogen oxide during fossil fuel combustion. When these gases are discharged into the atmosphere they react with the water, oxygen, and other gases already present there to form sulfuric acid, ammonium nitrate, and nitric acid. These acids then disperse over large areas because of wind patterns and fall back to the ground as acid rain or other forms of precipitation. The gases responsible for acid deposition are normally a byproduct of electric power generation and the burning of coal. As such, it began entering the atmosphere in large amounts during the Industrial Revolution and was first discovered by a Scottish chemist, Robert Angus Smith, in 1852. In that year, he discovered the relationship between acid rain and atmospheric pollution in Manchester, England. Although it was discovered in the 1800s, acid deposition did not gain significant public attention until the 1960s and the term acid rain was coined in 1972. Public attention further increased in the 1970s when the New York Times published reports about problems occurring in the Hubbard Brook Experimental Forest in New Hampshire. Effects of Acid Rain After studying the Hubbard Brook Forest and other areas today, there are several important impacts of acid deposition on both natural and man-made environments. Aquatic settings are the most clearly impacted by acid deposition though because acidic precipitation falls directly into them. Both dry and wet deposition also runs off of forests, fields, and roads and flows into lakes, rivers, and streams. As this acidic liquid flows into larger bodies of water, it is diluted but over time, acids can accrue and lower the overall pH of the body. Acid deposition also causes clay soils to release aluminum and magnesium further lowering the pH in some areas. If the pH of a lake drops below 4.8, its plants and animals risk death and it is estimated that around 50,000 lakes in the United States and Canada have a pH below normal (about 5.3 for water). Several hundred of these have a pH too low to support any aquatic life. Aside from aquatic bodies, acid deposition can significantly impact forests. As acid rain falls on trees, it can make them lose their leaves, damage their bark, and stunt their growth. By damaging these parts of the tree, it makes them vulnerable to disease, extreme weather, and insects. Acid falling on a forest's soil is also harmful because it disrupts soil nutrients, kills microorganisms in the soil, and can sometimes cause a calcium deficiency. Trees at high altitudes are also susceptible to problems induced by acidic cloud cover as the moisture in the clouds blankets them. Damage to forests by acid rain is seen all over the world, but the most advanced cases are in Eastern Europe. It's estimated that in Germany and Poland, half of the forests are damaged, while 30% in Switzerland have been affected. Finally, acid deposition also has an impact on architecture and art because of its ability to corrode certain materials. As acid lands on buildings (especially those constructed with limestone) it reacts with minerals in the stones sometimes causing it to disintegrate and wash away. Acid deposition can also corrode modern buildings, cars, railroad tracks, airplanes, steel bridges, and pipes above and below ground. What's Being Done? Because of these problems and the adverse effects air pollution has on human health, a number of steps are being taken to reduce sulfur and nitrogen emissions. Most notably, many governments are now requiring energy producers to clean smoke stacks by using scrubbers which trap pollutants before they are released into the atmosphere and catalytic converters in cars to reduce their emissions. Additionally, alternative energy sources are gaining more prominence today and funding is being given to the restoration of ecosystems damaged by acid rain worldwide.
aquifers
An aquifer is is an underground layer of rock that allows water to flow through it. If the flow of water is stopped by a layer of impermeable rock, the aquifer holds underground water supplies ( ground water).
global warming causes
Causes of Global Warming Global warming is basically a change in the climatic conditions of the Earth, brought about by a considerable rise in the near-surface temperature of the planet. A number of factors have been contributing to this rise in the average global temperature - either directly or indirectly, right from the time the planet came into existence. It is the alarming rate at which the temperature has been rising over the last few decades that has put the scientific fraternity on its toes, and the desperate measures to find out what is causing the global temperature to rise at this rate, hints at this very fact. Global warming, and the resulting climate change, can be caused by natural as well as man-made factors (anthropogenic factors, to be precise). The natural factors causing this sudden warming of the planet include the greenhouse effect, solar activity, volcanic emissions, orbital forcing (slow tilting of the Earth's axis), etc. The anthropogenic causes, on the other hand, include various human activities - right from breathing (respiration), to the use of vehicles and various industrial processes, which add to the greenhouse effect and cause the Earth to become warm. Greenhouse Effect The greenhouse effect is said to be the most crucial factor contributing to global warming. It refers to the process wherein the radiations coming from the Sun are trapped by the greenhouse gases within the atmosphere of the Earth, which in turn causes the temperature near the Earth's surface to soar. The greenhouse gases in question here, include carbon dioxide, carbon monoxide, methane, chlorofluorocarbons (CFCs), water vapor, etc. It is believed that the greenhouse effect has increased the Earth's temperature by somewhere around 24 percent, with carbon dioxide contributing to about 12 percent of the greenhouse effect, water vapor contributing around 36 percent, methane 5 to 10 percent, and Ozone making around 3 to 7 percent to the same. Solar Variation The changes in the amount of radiant energy emitted by the Sun, i.e. solar variation, is said to be yet another reason of global warming. This solar variation has been correlated with the changes in the Earth's climate and temperature. The solar variation theory states that the amount of solar radiation has been increasing with time. If the proponents of this theory are to be believed, the Sun has been gaining strength, and is at its strongest since the last sixty odd years. And thus, it is believed that the Sun may now be acting as a cause of global warming. Sunspots Sunspots are also said to be a cause or catalyst for global warming. Recent reports suggest that the number of sunspots in an area directly affects the amount of time taken by that region to cool down. The Sun is the main source of energy to the Earth. The Earth absorbs about 70 percent of the solar flux, which - in turn increases the temperature of the Earth's atmosphere, land and oceans. Human Activities It isn't quite a coincidence that global warming and industrialization seem to go hand in hand, and that becomes obvious as you compare the industrialization and temperature rise trends over the last few decades. Even scientists acknowledge that rapid industrialization, wherein we have opted for quite a few shortcuts, has contributed to the increase of global warming today. Humans had started contributing to global warming some 8000 years ago with the start of agriculture, wherein deforestation to clear land for farming resulted in a significant rise in the amount of carbon dioxide in the atmosphere. A prominent greenhouse gas, methane is released in the atmosphere as a part of the digestive process in cattle and other ruminating animals. Scientists are of the opinion that bad practices in industries result in release of various greenhouse gases which eventually trap the Sun's radiations in the atmosphere, and contribute to global warming. Though the use of household appliances which release chlorofluorocarbons (CFCs) in the atmosphere has come down now, it was at its peak in the 90s and caused irreversible damage to the atmosphere. Other than cattle, methane also exists in plenty beneath the Earth's crust, and the release of methane during mining indirectly contributes to rising temperature on the planet. Other than deforestation, humankind has also contributed to global warming by using fossil fuels, which emit carbon dioxide and other such harmful gases. While all the natural factors do come into play when it comes to global warming, one has to understand that they are necessary in maintaining the right balance on the Earth. Had it not been for all these natural occurrences, the entire planet would have had been a cold desert resembling the continent of Antarctica. In fact, some scientists are of the opinion that human life would have been impossible on the planet in the absence of greenhouse effect (human activities excluded), because the average temperature of the planet would be around 27°C in that case. Read more at Buzzle: http://www.buzzle.com/articles/what-causes-global-warming.html
ozone layer depletion (cause and effects)
Causes of Ozone Depletion Ozone is a triatomic form of oxygen (O3), found in the Earth's atmosphere. A combination of low temperatures, elevated chlorine and bromine concentrations in the upper stratosphere are responsible for the destruction of ozone. The production and emission of chlorofluorocarbons (CFCs), is the leading cause of ozone layer depletion. CFC's accounts for almost 80% of the total depletion of ozone. Other ozone-depleting substances (ODS), include hydrochlorofluorocarbons (HCFCs), and volatile organic compounds (VOCs). These are often found in vehicle emissions, byproducts of industrial processes, refrigerants, and aerosols. ODS are relatively stable in the lower atmosphere of the Earth, but in the stratosphere, they are exposed to ultraviolet radiation and thus, they break down to release a free chlorine atom. This free chlorine atom reacts with an ozone molecule (O3), and forms chlorine monoxide (ClO), and a molecule of oxygen. Now, ClO reacts with an ozone molecule to form a chlorine atom, and two molecules of oxygen. The free chlorine molecule again reacts with ozone to form chlorine monoxide. The process continues, and this results in the depletion of the ozone layer. Possible Effects of Ozone Depletion As ozone depletes in the stratosphere, it forms a 'hole' in the layer. This hole enables harmful ultraviolet rays to enter the Earth's atmosphere. Ultraviolet rays of the Sun are associated with a number of health-related, and environmental issues. Let us take a look at how ozone depletion affects different life forms. Impact on Humans Skin cancer: Exposure to ultraviolet rays poses an increased risk of developing several types of skin cancers, including malignant melanoma, basal and squamous cell carcinoma. Eye damage: Direct exposure to UV radiations can result in photokeratitis (snow blindness), and cataracts. Immune system damage: Effects of UV rays include impairment of the immune system. Increased exposure to UV rays weakens the response of the immune system. Accelerated aging of skin: Constant exposure to UV radiation can cause photo allergy, which results in the outbreak of rash in fair-skinned people. Other effects: Ozone chemicals can cause difficulty in breathing, chest pain, throat irritation, and hamper lung functioning. Effects on Amphibians Ozone depletion is listed as one of the causes for the declining numbers of amphibian species. Ozone depletion affects many species of amphibians at every stage of their life cycle. Some of the effects are mentioned below. Hampers growth and development in larvae Changes behavior and habits Causes deformities in some species Decreases immunity. Some species have become more vulnerable to diseases and death Retinal damage and blindness in some species Effects on Marine Ecosystems In particular, plankton (phytoplankton and bacterioplankton) are threatened by increased UV radiation. Marine phytoplankton play a fundamental role in both the food chain as well as the oceanic carbon cycle. Plankton play an important role in converting atmospheric carbon dioxide into oxygen. Ultraviolet rays can influence the survival rates of these microscopic organisms, by affecting their orientation and mobility. This eventually disturbs and affects the entire ecosystem. Impact on Plants In some species of plants, UV radiation can alter the time of flowering, as well as the number of flowers. Plant growth can be directly affected by UV-B radiation. Despite mechanisms to reduce or repair these effects, physiological and developmental processes of plants are affected. Another observation is an increase in the ozone present in the lower atmosphere due to the decrease in the ozone in the stratosphere. Ozone present in the lower atmosphere is mainly regarded as a pollutant and a greenhouse gas, that can contribute to global warming and climate change. However, studies have pointed out that the lifespan of lower atmospheric ozone is quite less, compared to stratospheric ozone. At the same time, increase in the level of ozone in the lower atmosphere can enhance the ability of sunlight to synthesize vitamin D, which can be regarded as an important beneficial effect of ozone layer depletion. Growing concern for ozone depletion led to the adoption of the Montreal Protocol in 1987, in order to reduce and control industrial emission of chlorofluorocarbons (CFCs). Such international agreements have succeeded to a great extent in reducing the emission of these compounds. However, more cooperation and understanding among all the countries of the world is required to mitigate the problem. You too can do your bit to save the ozone. Use/buy more recycled products, save energy, take public transport, and, most importantly, spread awareness. Our individual efforts can go a long way in saving the Earth's blanket. Read more at Buzzle: http://www.buzzle.com/articles/ozone-layer-depletion-effects-and-causes-of-ozone-depletion.html
global warming effects
Effects of Global Warming Changes in the Global Sea Level As the temperature will increase, the ice cover on the planet will start melting. The water from these melting glaciers will end up in the oceans, which will lead to a rise in the sea level. Over the last century, sea levels have increased by 4 to 8 inches, and by 2100, it's expected to increase to 35 inches. An additional 2 degree rise in global temperature will lead to the complete melting of the Greenland ice cap, which will cause the sea level to rise by 5 to 6 meters. Such a rise will cause many of the low lying areas, such as the US Gulf Coast and Bangladesh, as well as islands, such as Lakswadweep, to submerge underwater. If the whole of the Antarctic ice sheet melts, the global sea level is expected to rise by 10.5 meters. Drastic Changes in Climate Patterns Global warming will alter the climatic patterns of the planet. As far as precipitation is concerned, it will increase in equatorial, polar and sub-polar reasons, and decrease in subtropics. This change in precipitation pattern will trigger a drought in some regions, while floods in other regions. Warming of the atmosphere will increase the temperature of ocean waters, which will continue being warm for a few centuries. Warm water will lead to frequent natural disasters like hurricanes. Overall, the planet will experience extreme weather conditions, characterized by flood and droughts, heat waves and cold waves, and extreme storms like cyclones and tornadoes. Widespread Extinction of Flora and Fauna A rise in global temperature will also hamper the rich biodiversity of various ecosystems. According to the Intergovernmental Panel on (IPCC), an increase in global temperature by 1.5 to 2.5 degrees will make 20 to 30 percent of species vulnerable to extinction, while a rise of about 3.5 degrees will make 40 to 70 percent species vulnerable to extinction. Climate change will result in loss of habitat for many animal species like polar bears and tropical frogs. More importantly, any change in the climate patterns will seriously affect the migration patterns of various bird species. Irregular patterns of precipitation will affect animals and humans alike. Effects on Us Humans In case of humans, global warming will affect our food and water supplies as well as our health conditions. Changes in precipitation will affect basic necessities such as agriculture, power production etc. Increase in the temperature of ocean waters will hamper fisheries. The sudden change in climate patterns will have a hazardous effect on the human body which won't be able to endure the extreme conditions, a hint of which can be seen in form of frequent heat waves and cold waves. Increase in natural calamities such as storms, will lead to heavy human casualties. Infectious diseases will rise to a great extent as disease transmitting insects will adapt to wet, hot conditions. Many people will die of malnutrition as food production will decrease due to frequent droughts and floods. Many people argue that global warming is a slow process, and will take centuries for all these devastating effects to take place. These people ignore the fact that the rate at which we are contributing to this hazard has also increased, and is expected to rise at a faster rate in the future. We have already done enough of damage, and hence it's high time we understand the global warming causes, effects and the future repercussions and work out some solutions at the earliest. We may not live to face its dreaded consequences, but our future generations surely will. Read more at Buzzle: http://www.buzzle.com/articles/global-warming-causes-and-effects.html
genetically modified foods
GMO: An organism whose genetic material has been altered through some genetic engineering technology or technique; also known as a transgenic organism
Rachel Carson's "Silent Spring" (p. 422 + 435)
Silent Spring is an environmental science book written by Rachel Carson and published by Houghton Mifflin on September 27, 1962.[1] The book documented the detrimental effects on the environment—particularly on birds—of the indiscriminate use of pesticides. Carson accused the chemical industry of spreading disinformation and public officials of accepting industry claims unquestioningly. In the late 1950s, Carson turned her attention to conservation, especially environmental problems that she believed were caused by synthetic pesticides. The result was Silent Spring (1962), which brought environmental concerns to the American public. Silent Spring was met with fierce opposition by chemical companies, but it spurred a reversal in national pesticide policy, led to a nationwide ban on DDT for agricultural uses,[2] and inspired an environmental movement that led to the creation of the U.S. Environmental Protection Agency. ( from wikipedia)
Montreal Protocol (p. 431)
The Montreal Protocol on Substances that Deplete the Ozone Layer (a protocol to the Vienna Convention for the Protection of the Ozone Layer) is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances that are responsible for ozone depletion. The treaty was opened for signature on September 16th, 1987, and entered into force on January 1st, 1989, followed by a first meeting in Helsinki, May 1989. Since then, it has undergone seven revisions, in 1990 (London), 1991 (Nairobi), 1992 (Copenhagen), 1993 (Bangkok), 1995 (Vienna), 1997 (Montreal), and 1999 (Beijing). As a result of the international agreement, the ozone hole in Antarctica is slowly recovering. Climate projections indicate that the ozone layer will return to 1980 levels between 2050 and 2070. Due to its widespread adoption and implementation it has been hailed as an example of exceptional international co-operation, with Kofi Annan quoted as saying that "perhaps the single most successful international agreement to date has been the Montreal Protocol".[1] The two ozone treaties have been ratified by 197 parties, which includes 196 states and the European Union,[2] making them the first universally ratified treaties in United Nations history.[3]
biosphere
The are of Earth that supports life. It consists of two parts : the atmosphere, the thing layers of gases and water vapour that surround the Earth; and the lithosphere, or Earth's crust, the layer on which we live. From wikipedia: The biosphere is the global sum of all ecosystems. It can also be termed the zone of life on Earth, a closed system (apart from solar and cosmic radiation and heat from the interior of the Earth), and largely self-regulating.[1] By the most general biophysiological definition, the biosphere is the global ecological system integrating all living beings and their relationships, including their interaction with the elements of the lithosphere, hydrosphere, and atmosphere.
boreal forests
The coniferous or needle=leaf forest that lies between the treeless tundra and the mixed deciduous and coniferous forest to the south.
biodiversity
The variety of living forms or species on the planet.
groundwater
Underground water that is store in aquifers. An aquifer is is an underground layer of rock that allows water to flow through it. If the flow of water is stopped by a layer of impermeable rock, the aquifer holds underground water supplies.
desertification/soil degradation (cause and effects)
What Causes Desertification? -Overgrazing Overgrazing was not as large of a problem long ago because animals would move in response to rainfall. People would move with the animals so it prevented overgrazing in such areas. Now, humans have a steady food supply so they do not have to move about. Therefore, people use fences to keep their animals in one place which causes overgrazing. (Desertification, 2001) -Farming of Average Land Farming of average land is causing desertification worldwide. Farmers are clearing average land, and using it which takes away the richness in the soil. People should let the average land replenish itself before farming. (Desertification, 2005) -Destruction of Plants in Dry Regions Destruction of plants in dry regions is causing desertification to occur. People are cutting down tress to use them as a source of fuel. Once all these trees are cut down there is nothing to protect the soil. Therefore, it turns to dust and is blown away by the wind. (Desertification, 2005) -Incorrect Irrigation in Arid Regions Causes a Build Up of Salt in the Soil Incorrect irrigation is commonly used in poorer areas. Farmers are using canal irrigation and other poor techniques because of the lack of water. This type of irrigation causes a build up of salt in the soil. (Desertification, 2005) The Effects Of Desertification -Soil becomes less usable The soil can be blown away by wind or washed away rain. Nutrients in the soil can be removed by wind or water. Salt can build up in the soil which makes it harder for plant growth. -Vegetation is Lacked or Damaged Loosened soil may bury plants or leave their roots exposed. Also, when overgrazing occurs, plant species may be lost. -Causes Famine Places that have war and poverty are most likely to have famine occur. Drought and poor land management contribute to famine. -Food Loss The soil is not suited for growing food; therefore the amount of food being made will decline. If the population is growing, this will cause economic problems and starvation. -People near Affected Areas Desertification can cause flooding, poor water quality, dust storms, and pollution. All of these effects can hurt people living near an affected region. (The Facts of Desertification and United Nations Convention to Combat Desertification, 2000)
Kyoto Protocol
establishes legally binding commitments for the reduction of four greenhouse gases (carbon dioxide, methane, nitrous oxide, sulfur hexafluoride), and two groups of gases (hydrofluorocarbons and perfluorocarbons) Took place in Rio De Janeiro in 1992
