Global Climate Change ESS Analysis

Global Climate Change – ESS Analysis

1.) H > L > E > A > B > E > H > A > E

Land use can affect climate in numerous ways, however the human manipulation of earth’s surface is the most direct influence. In the past few centuries by cutting down forests through deforestation and replacing them with pastures and cropland, a larger amount of area has become available to reflect the sun’s rays leading to an increase in the reflection of incoming solar radiation into earth’s atmosphere.

As energy from the sun passes through the atmosphere, 26% is reflected back to space by clouds and atmospheric particles, 19% is absorbed by clouds, gases (ex. Ozone) and particles, and 4% is reflected back to space by Earth’s surface. This leaves 51% of the sun’s radiation actually being absorbed by Earth (Pidwirny, 2006) (see Figure 1). The Earth’s surface then re-radiates the Sun’s energy as infrared radiation. Greenhouse gases in the atmosphere then absorb this infrared radiation, and radiate the energy in all directions (Pidwirny, 2006). This once again heats Earth’s surface, which once again re-radiates the infrared energy (see Figure 2). Greenhouse gases include water vapor, carbon dioxide, and methane, and the warming cycle in which these gases are involved is known as the Greenhouse Effect. The Greenhouse Effect is a naturally occurring process without which life on this planet would not exist (EPA, 2009). Without greenhouse gases in the atmosphere, the average temperature of the Earth would be 60 oF colder. This would drop the average global temperature to about 0oF and render Earth uninhabitable to life as we know it (EPA, 2009).

Human activities, however, have increased the levels of greenhouse gases in the atmosphere and augmented this natural phenomenon. Due mainly to the burning of fossil fuels, the concentration of carbon dioxide in the atmosphere has risen from about 280ppm in pre-industrial times to 386ppm in 2008 (Hofmann, Butler, Tans, 2009). Farm animals, especially cattle, and rice paddies also release large amounts of methane into the atmosphere (UCAR, 2007). Methane concentrations have risen from 700 ppb in pre-industrial times to 1775ppb in 2005 (IPCC, 2007) (see Figure 3). Thanks to this amplified Greenhouse Effect, over the past century average global temperature has risen 1.3oF and will reach an increase of 3oF to 7oF by 2100 if emission of greenhouse gases remain at the current rates (EPA, 2009).

These rising global temperatures have lead to greater rates of evaporation. Total column water vapor has increased 4% since 1970, and similar upward trends have been found in upper-troposphereic specific humidity (IPCC, 2007). Water vapor is a powerful greenhouse gas, and increased water vapor in the atmosphere due to increased evaporation is part of a positive feedback cycle, as increased water vapor leads to increased effects of global warming and greater evaporation (UCAR, 2007). Some scientists believe a negative feedback loop is also possible, as increased evaporation could lead to greater cloud formation. Greater presence of clouds would increase Earth’s albedo, decreasing the amount of solar radiation reaching Earth’s surface via reflection (UCAR, 2007). In this negative-feedback model, increased presence of low-altitude clouds would have a net cooling effect on the earth. Recent research, however, lends more support to a positive-feedback cloud model. Data from the Pacific shows that with increasing temperatures, water vapor rises higher into the atmosphere, thinning low-level clouds. These thinner clouds are less able to reflect solar radiation, and allow more sunlight to reach Earth’s surface (Clement et al, 2009). This positive feedback from increased water vapor in the atmosphere and thinner clouds would further strengthen global warming.

References

Clement, A.C., Burgman, R., Norris, J.R. (2009) Observational and model evidence for positive low-level cloud feedback. Science 325, 460-464.

Hofmann, D.J., Butler, J.H., Tans, P.P. (2009). A new look at atmospheric carbon dioxide. Atmospheric Environment 43(12), 2084-2086

Intergovernmental Panel on Climate Change (IPCC). (2007). Changes in Atmospheric Constituents in Radiative Forcing. Climate Change 2007: The Physical Science Basis. Cambridge University Press: Cambridge, U.K.

Pidwirny, M. (2006). The Greenhouse Effect. Fundamentals of Physical Geography. Retrieved from

United States Environmental Protection Agency (EPA). (2009). Frequently asked questions about Global Warming and Climate Change: Back to basics. Retrieved from http://www.epa.gov/climatechange/downloads/Climate_Basics.pdf

University Corporation for Atmospheric Research (UCAR). (2007). Climate and global change. Windows to the Universe. Retrieved from http://www.windows.ucar.edu/tour/link=/earth/climate/climate.html

2.) L > E > A > E > B > H > B

Volcanic eruptions can enhance global warming by adding carbon dioxide into the atmosphere. The small amount of global warming that comes from volcanic eruptions is offset by the far greater amount of global cooling caused by the particles released into the stratosphere. This is called the haze effect and can lower mean global temperatures. When a volcano erupts, water vapor in the atmosphere combines with the sulfur released from the volcano and forms clouds of sulfuric acid. The droplets in theses clouds can absorb solar radiation and disperse it back into space (like a mirror) and possibly lower the temperature in the troposphere.

There are at least three volcanoes that show a relationship from their massive eruptions to years of cold climate conditions that followed it. The first of this evidence is the 1815 eruption of Mt. Tambora in Indonesia. The cold spring and summer that followed it became known as the “year without a summer.” The United States and Europe were the worst hit, having snowfall in the summer and the advancement of their alpine glaciers advancing to severely low elevations. The second example is of Krakatau which erupted in Indonesia in August 1883. For several months after the eruption of Krakatau, the entire world combated unseasonably cold weather and beautiful sunset and longer than usual twilight. The latter two were due to the spread of aerosols spread thought the atmosphere, specifically in the stratosphere. The last example is of the Mt. Pinatubo eruption in the Philippines in June 1991 which ejected 20 million tons of sulfur dioxide and ash into the atmosphere that circled the earth for roughly three weeks. According to Wolfe (2000) Volcanic eruptions of this magnitude can impact global climate, reducing the amount of solar radiation reaching the Earth's surface, lowering temperatures in the troposphere, and changing atmospheric circulation patterns.

When sunlight warms the ground or the ocean, the heat radiates in the air above it; as the warm air rises, the air in the troposphere is “stirred up” as air pressure and density are less at higher altitudes (Russell, 2009). Air is the warmest at the bottom of the troposphere near ground level. As air moves away from ground level, it becomes colder because an increase in altitude causes lower temperatures. Although greenhouse gases such as water vapor, carbon dioxide, and ozone naturally occurs in the atmosphere to keep the Earth warm, the excess amount of such gases can cause an adverse effect on our planet. As a result of excessive greenhouse gases in the atmosphere, winter and summer temperatures can drastically increase causing warmer weather, rainy winters, and extremely dry summers because the gases trap the excessive heat in the atmosphere. Some factors that influence the excessive amount of carbon dioxide in the atmosphere are the burning of fossil fuels (coal, oil, and natural gas) and the cutting down and burning of trees ( Also, chlorofluorocarbons (CFSs), which are ozone-destroying chemicals, are released into the atmosphere through the use of hairspray cans, fridges, and making foam plastic. The adverse effect of CFSs is that they are dangerous greenhouse gases because small amounts can trap large amounts of heat. Animals and plants are affected by excess greenhouse gases. For example, polar bears are not as healthy as they were twenty years ago and they are thinner because of the increase in Earth’s temperature causes the melting of the ice which causes the loss of their home and food. Also, elephant seal pups are thinner because their food is migrating to cooler waters. ( As stated, “The warming of the atmosphere caused by greenhouse gases is melting glaciers and causing ocean water to warm and expand thermally” ( because when liquids are heated, including the ocean water, it expands-takes up more space. As a result, throughout the world, millions of people and areas of land will be at danger from flooding. Many people will lose their homes and large areas of farmland will be ruined because of floods (

References:

Russell, R. (2009). Windows to the Universe, at http://www.windows.ucar.edu/ at the University Corporation for Atmospheric Research (UCAR): University of Michigan.

Wolfe, J (2000), Volcanoes and Climate Change. Retrieved from http://earthobservatory.nasa.gov/Features/Volcano/

http://www.geology.sdsu.edu/how_volcanoes_work/climate_effects.html

3.) The Gulkana glacier in Alaska is one of three glaciers considered a benchmark by the U S Geological Survey E > H > B > A > H >B > A > B > A > B > E > H

The biggest effect of global warming on earth is the drastic rise in sea level due to the melting of glaciers and ice sheets into the ocean. Recent research has shown that the melting of Greenland’s’ ice sheet alone may be the culprit for the roughly 25 percent rise in sea level in the last 13 years. This rise will directly affect the stability of our coastline. According to Lovgren (2004), the complete melting of Greenland’s ice sheets would raise sea levels an estimated twenty-three feet. According to the nature Conservancy some of the most at-risk ecosystems due to sea level rising are mangroves. Mangroves with little sedimentation and on low relief islands are especially endanger. Mangroves are especially important to the biosphere because they provide a habitat and nursery area for many animals, and also produce oxygen through photosynthesis. In order to photosynthesize, mangroves use sunlight, carbon dioxide and water to produce sugar. Though the process the mangroves like all plants absorbs carbon dioxide and expels oxygen into the atmosphere. If the mangroves die off, there will be less carbon dioxide absorbed, thus increasing the amount of carbon dioxide emitted into the atmosphere. As stated earlier, the more carbon dioxide there is in the atmosphere, the warmer global temperature will become.

As the global climate changes, plants often develop heat stress due to increased atmospheric temperature. When plants are heat stressed, the temperature is so hot that it causes irreversible damage to the plants’ function and or development (Anthony E. Hall). Heat stress not only can occur by high day temperatures in the atmosphere but also high night temperature on these plants. “High temperatures can increase the rate of reproductive development, which shortens the time for photosynthesis to contribute to fruit or seed production” (Anthony E. Hall). There is evidence of damage to plants from both high day and high night temperatures. When there is an increase in global climate, carbon dioxide increases in the atmosphere and one of the outcomes is the amount of rainfall being altered. These factors definitely impact the amount of food produced and how well the plant will grow (ESPERE Association). If there are not sufficient amounts of water the animals and plants in the biosphere will die off.

References:

Environmental Science Published for Everybody Round the Earth (ESPERE)

Hall, Anthony E. “Heat Stress and its Impact” University of California: Department of Botany and Plant Sciences.

Lovgren, S. (2004). Warming to Cause Catastrophic Rise in Sea Level. National Geographic News. Retrieved from

http://www.whoi.edu/seagrant/education/focalpoints/erosion.html

4.) B > L > A > E > B > H > L > E > L > H

According to the Environmental Literacy Council fossil fuels were formed over millions of years by the decomposing remains of plants and animals under immense heat and pressure. This process resulted in the natural fuels that we use for energy like coal, petroleum, and natural gas. Fossil fuels contain large amounts of hydrocarbon and carbon. For over a century these three fossil fuels have generated most of the energy consumed by our growing human population in the past century. In order to release the energy stored in them, fossil fuels must be burned. Unfortunately it is during this process that a variety of particulates like ash, nitrogen, carbon and sulfur dioxide, are released into the atmosphere. They can combine with water vapor in the air to form compounds that form acid rain. The burning of fossil fuels also releases carbon dioxide which many scientists believe are contributing to global climate change, specifically global warming. The rise in atmospheric temperatures has also increased the water temperature of the ocean. These changes in oceanic temperatures have impacted coral reefs around the world.

Coral reefs are extremely complex ecosystems. They support almost 25 percent of all known marine species in the world and are home to many plants, invertebrates and more than 4,000 species of fish. Even though coral reefs grow best in shallow waters (70–85° ), It is possible for soft corals to grow in places with warmer or colder water, but growth rates in these types of conditions are very slow. Despite this, small but prolonged rises in sea temperature caused by global warming can cause coral to discard their symbiotic food producing algae called zooxanthelle through a process called coral bleaching. Not only are coral reefs a nursery area for fish and marine invertebrates, coral reefs act as storm buffers to the coastline protecting it from wave action and erosion. When exposed to the climate, all minerals have different rates of weathering especially when water is present. The weathering of minerals especially carbonates, release more carbon dioxide into the atmosphere which has been proven to increase global warming. The release of carbon dioxide though weathering of the lithosphere can also increase the acidity of the ocean and can slow coral reef growth because it is made out of calcium carbonate. Weathering of minerals can also progress the erosion of land and sedimentation in rivers.

References:

Reibeek, H., & Simmon, R. (2005). Paleoclimatology. Retrieved from http://earthobservatory.nasa.gov/Features/Paleoclimatology/paleoclimatology_intro.php

http://oceanservice.noaa.gov/education/kits/corals/coral07_importance.html

5.) B > E > A > L > H > B

Although some scientists disagree, the Intergovernmental Panel on Climate Change reported that the accelerated warming of earth’s climate, a phenomenon called global warming, is “most likely” the result of increased industrialization and the subsequent greenhouse gas emissions caused by human activity (IPCC, 2007). Green house gases including water vapor, carbon dioxide, methane, nitrous oxide, and ozone occur naturally and help keep the earth reasonably warm, however, the burning of fossil fuels and deforestation have increased the amount of greenhouse gases thus increasing their effectiveness in heating the earth. The more greenhouse gases, the more the planet is warmed, which creates a positive feedback loop because the warmer the planet is, the more greenhouse gases, particularly water vapor, will be created. This increased pattern of global warming has resulted in glacier loss in which the ice melts into the sea, which then causes sea levels to rise. Additionally, the rapid acceleration of global temperatures has accelerated the pace in which the snow-packed mountains and glaciers melt. Therefore, there is less time for snow to accumulate on mountains and thus eventually there is less water each spring. This could be especially devastating for people who live in the Southeastern United States where according to the New York Times, over thirty million people depend upon the Colorado River for water. Not only could this have an effect on human health directly it could also greatly affect the areas agricultural production.

References:

Gertner, J (2007). The Future is Drying Up. New York Times Magazine. Retrieved from: