Hai.... I'm Rozita
Glaciers and Glacial Warming, Receding Glaciers
The largest implication of this loss of glaciers is not the change in scenery, but the fact that the seasonal melt water from glaciers, especially in Asia and South America, is the life support for billions of people. Large cities like Lima get much of their water from glaciers.
In other parts of the world, glacier water keeps streams cool and full for salmon and other important wildlife. And as more and more water reaches the ocean, it is increasing sea level at a faster rate --- which threatens every coastal city and shoreline. New scientific projections show at least a three foot (one meter) rise in ocean levels by the end of this century, part of which is also due to the expansion of warming sea water.
This will inundate rice fields and estuaries that feed billions, and push into the heart of the worlds largest cities --- and make each storm a threat of more devastating waves and surges.
Sunday, November 8, 2009
Posted by ROZITA Norhanah bt Abd Wahab at 5:31 AM 0 comments
Hai.... I am Norhana. I want to discuss about:
The impact of global warming
Thousands of icebergs float off the coast of the Antarctic Peninsula after 1,250 square miles (3,240 square kilometers) of the Larsen B ice shelf disintegrated in 2002. The area of the ice was larger than the state of Rhode Island or the nation of Luxembourg. Antarctic ice shelves have been shrinking since the early 1970's because of climate warming in the region. Image credit: NASA/Earth Observatory
Continued global warming could have many damaging effects. It might harm plants and animals that live in the sea. It could also force animals and plants on land to move to new habitats. Weather patterns could change, causing flooding, drought, and an increase in damaging storms. Global warming could melt enough polar ice to raise the sea level. In certain parts of the world, human disease could spread, and crop yields could decline.
Changes of habitat
Widespread shifts might occur in the natural habitats of animals and plants. Many species would have difficulty surviving in the regions they now inhabit. For example, many flowering plants will not bloom without a sufficient period of winter cold. And human occupation has altered the landscape in ways that would make new habitats hard to reach or unavailable altogether.
Weather damage
Extreme weather conditions might become more frequent and therefore more damaging. Changes in rainfall patterns could increase both flooding and drought in some areas. More hurricanes and other tropical storms might occur, and they could become more powerful.
Rising sea level
Continued global warming might, over centuries, melt large amounts of ice from a vast sheet that covers most of West Antarctica. As a result, the sea level would rise throughout the world. Many coastal areas would experience flooding, erosion, a loss of wetlands, and an entry of seawater into freshwater areas. High sea levels would submerge some coastal cities, small island nations, and other inhabited regions.
Threats to human health
Tropical diseases, such as malaria and dengue, might spread to larger regions. Longer-lasting and more intense heat waves could cause more deaths and illnesses. Floods and droughts could increase hunger and malnutrition.
Changes in crop yields
Canada and parts of Russia might benefit from an increase in crop yields. But any increases in yields could be more than offset by decreases caused by drought and higher temperatures -- particularly if the amount of warming were more than a few degrees Celsius. Yields in the tropics might fall disastrously because temperatures there are already almost as high as many crop plants can tolerate.
Limited global warming
Climatologists are studying ways to limit global warming. Two key methods would be (1) limiting CO2 emissions and (2) carbon sequestration -- either preventing carbon dioxide from entering the atmosphere or removing CO2 already there.
Limiting CO2 emissions
Two effective techniques for limiting CO2 emissions would be (1) to replace fossil fuels with energy sources that do not emit CO2, and (2) to use fossil fuels more efficiently.
Alternative energy sources that do not emit CO2 include the wind, sunlight, nuclear energy, and underground steam. Devices known as wind turbines can convert wind energy to electric energy. Solar cells can convert sunlight to electric energy, and various devices can convert solar energy to useful heat. Geothermal power plants convert energy in underground steam to electric energy.
Alternative sources of energy are more expensive to use than fossil fuels. However, increased research into their use would almost certainly reduce their cost.
Carbon sequestration could take two forms: (1) underground or underwater storage and storage in living plants.
Underground or underwater storage would involve injecting industrial emissions of CO2 into underground geologic formations or the ocean. Suitable underground formations include natural reservoirs of oil and gas from which most of the oil or gas has been removed. Pumping CO2 into a reservoir would have the added benefit of making it easier to remove the remaining oil or gas. The value of that product could offset the cost of sequestration. Deep deposits of salt or coal could also be suitable.
The oceans could store much CO2. However, scientists have not yet determined the environmental impacts of using the ocean for carbon sequestration.
Storage in living plants
Green plants absorb CO2 from the atmosphere as they grow. They combine carbon from CO2 with hydrogen to make simple sugars, which they store in their tissues. After plants die, their bodies decay and release CO2. Ecosystems with abundant plant life, such as forests and even cropland, could tie up much carbon. However, future generations of people would have to keep the ecosystems intact. Otherwise, the sequestered carbon would re-enter the atmosphere as CO2.
Posted by ROZITA Norhanah bt Abd Wahab at 12:01 AM 0 comments
Saturday, November 7, 2009
Hello.... I'm Rozita...
Causes of global warming
Climatologists (scientists who study climate) have analyzed the global warming that has occurred since the late 1800's. A majority of climatologists have concluded that human activities are responsible for most of the warming. Human activities contribute to global warming by enhancing Earth's natural greenhouse effect. The greenhouse effect warms Earth's surface through a complex process involving sunlight, gases, and particles in the atmosphere. Gases that trap heat in the atmosphere are known as greenhouse gases.
The main human activities that contribute to global warming are the burning of fossil fuels (coal, oil, and natural gas) and the clearing of land. Most of the burning occurs in automobiles, in factories, and in electric power plants that provide energy for houses and office buildings. The burning of fossil fuels creates carbon dioxide, whose chemical formula is CO2. CO2 is a greenhouse gas that slows the escape of heat into space. Trees and other plants remove CO2 from the air during photosynthesis, the process they use to produce food. The clearing of land contributes to the buildup of CO2 by reducing the rate at which the gas is removed from the atmosphere or by the decomposition of dead vegetation.
A small number of scientists argue that the increase in greenhouse gases has not made a measurable difference in the temperature. They say that natural processes could have caused global warming. Those processes include increases in the energy emitted (given off) by the sun. But the vast majority of climatologists believe that increases in the sun's energy have contributed only slightly to recent warming.
Posted by ROZITA Norhanah bt Abd Wahab at 11:52 PM 0 comments
Friday, November 6, 2009
Hai... I'm Rozita.
SIGNS OF GLOBAL WARMING
Canada
- Canadadian Rockies-tree stumps were exposed for the first time in 2500 years as glaciers receded.
- Polar bears reproductive success has been reduced.
Greenland and Scandinivia
- Rapid retreat and loss of ice mass.
- 15% of Arctic tundra has melted.
- by 2080 the sea ice is expected to disappear during summer.
South Americans
- Andes, Peru and Chile : widespread retread of mountain glaciers.
- Brazil and Argentina : heavy rain created mudslides and flood, killing thousands of people.
Posted by ROZITA Norhanah bt Abd Wahab at 7:35 PM 0 comments
Warning signs from all over the world....
I'am Rozita. I want to discuss about the warning signs of global warming...
USA
- The Arapaho glacier (Colorado) has thinned by 40 meters, since 1960
- Flowers in Washington DC blommed 4.5 days earlier.
- Hurricane Katrina created massive flooding in New Orlens in 2005.
- Mosquitoes have undergone genetic adaptation to warmer temperatures.
- Alaskan glaciers have retreated and thinned, temperature increase of 3-4°C since 1950 has resulted in the permafrost melting.
Posted by ROZITA Norhanah bt Abd Wahab at 7:22 PM 0 comments
Signs of global warming
I'm Rozita.... Global Warming means...
extreme weather events, weather related disasters, glacier retreats, threatened coastal areas, increased ocean acidity,heat waves, and changing animal and plant behaviour are signs of global warming.The warming phenomena is most likely contributed by human activities.
Posted by ROZITA Norhanah bt Abd Wahab at 7:13 PM 0 comments