Many Scientists Have Concluded That Human Activities
Introduction
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 are throwing our natural greenhouse gas effect out of balance (Norby & Luo, 2004:282). Basically, we are surrounded by a blanket of air called the atmosphere which has kept the temperature on earth just right for centuries (Climate and Society).
Just as the glass in a greenhouse holds the suns warmth inside, so the atmosphere traps the suns heat near the earths surface and keeps the earth warm. We call this the natural greenhouse effect because it makes the earth a perfect planet for growing and living things. Because of this blanket, for hundreds of years the earths atmosphere has changed very little. It has kept the right temperature for plants, animal and humans to survive quite comfortably (Norby & Luo, 2004:282). Greenhouse gasses are both natural and manmade. These gasses are Carbon Dioxide, Methane, Chlorofluorocarbons (CFC’s) and Nitrous Oxide (Miller, 2005:475).
This following essay will detail various human activities as well as other forces that are affecting the natural greenhouse gas effect. Furthermore, it will address the issue of global warming as well as outline some of the many consequences of global warming. Global Temperatures 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 (Juery Rohrer, 2007).
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(Miller, 2005:475). The clearing of land contributes to the build up of CO2 by reducing the rate at which the gas is removed from the atmosphere or by the decomposition of dead vegetation (Juery Rohrer, 2007) The emissions of CO2 have been dramatically increased within the last 50 years and are still increasing by almost 3% each year, see graph below:
Graph 1 (Juery Rohrer, 2007) The carbon dioxide is released to the atmosphere where it remains for 100 to 200 years. This leads to an increasing concentration of carbon dioxide in our atmosphere, which in turn causes the average temperature on Earth to rise (Miller, 2005:475) (see graph on next page). Graph 2 (Juery Rohrer, 2007) 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 by the sun (Norby & Luo, 2004:282).
But the vast majority of climatologists believe that increases in the sun’s energy have contributed only slightly to recent warming. Global Warming 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 (McCright & Dunlap, 2000:517). 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 (McCright & Dunlap, 2000:517) .
Some details of the damaging effects include:
- Harm to ocean life
Through global warming, the surface waters of the oceans could become warmer, increasing the stress on ocean ecosystems, such as coral reefs. High water temperatures can cause a damaging process called coral bleaching. When corals bleach, they expel the algae that give them their colour and nourishment. The corals turn white and, unless the water temperature cools, they die. Added warmth also helps spread diseases that affect sea creatures. 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. Conclusion Human activity definitely have had a noticeable and documented effect on the steady rise in global temperatures, but there are also arguably other factors that contribute to overall global warming. Either way the argument should not be about who or what to blame for global warming but rather how to slow it down and repair the damage that is being done.
Reference list
- Juery Rohrer. (2007). Time for change. Retrieved April 12 2010 from http://timeforchange. org/CO2-cause-of-global-warming
- McCright, A,M. , & Dunlap, R,E. (2000). Challeging global warming as a social problem: An alalysis of the conservative movements counter-claim. Journal of Social Problems, 47(4), 500-522.
- Climate and Society. The earth institute. Retrieved April 12 2010 from http://www. earthinstitute. columbia. edu/about/about. html Miller, G,T,JR. (2005).
- Living in the Environment, 14th ed, Thomson Brooks/Cole. Norby,R,J. , & Luo, Y. (2004). Evaluating ecosystems responses to rising atmospheric CO2 and global warming in a multi-factor world. New Phytologist, 162(2), 281-293.
