Friday, November 19, 2010

Atmosphere and Change

Welcome to an Informative Site all about the Atmosphere!


The goal of this website is to provide information about the atmospheric system, the energy balance, and the changes occurring as a result of human interaction.
The Energy Balance on Earth


·            Everything on earth depends on energy from the sun although just a small part of the suns energy reaches the earth. Incoming Solar Radiation or Insolation arrives in the form a shortwave radiation. The shortwave radiation is created by the immense heat of the sun and the nuclear reactions that occur although the sun creates other types of radiation too. The shortwave radiation manly arrives in the form of ultraviolet radiation.
·            The shortwave radiation is absorbed by the earth in many ways and it is converted into heat or infrared radiation (longwave radiation).


 




·            The energy of the sun is dispersed in different ways as it hits the earth. 23% of incoming solar radiation is absorbed in the atmosphere Clouds are poor absorbers of energy and reflect most of the radiation back into space. The earths surface absorbs 46% of insolation and reflects only 6%

·         Once the shortwave radiation is absorbed and converted into infrared radiation, the Earth has mechanisms to keep that heat in. This is known as the Green House effect and the heat is absorbed by what we call Green House Gases. These gases absorb and keep heat much better and longer than other gases but the heat will eventually be released back into space
    •   The predominant gases are
      • water vapor
      • CO2
      • Methane
        There are other gases but their impact is small in comparison

Insolation also varies greatly upon latitude. The more South or North we go, the less insolation there is because…
·                       The suns rays are spread out over a larger area near the poles
·                       The suns rays also must travel through more air, so more of the shortwave radiation is reflected back into space.
·                       Since the angle of the rays hitting the earth is far from 90 degrees near the poles, more radiation is reflect than if the rays contacted the earth at exactly 90 degrees



Another factor that affects insolation is albedo. Albedo is term that describes the reflectivity of any object, on a scale of 0 – 1. 1 represents the complete reflection of all electromagnetic radiation and 0 indication the complete absorption. Darker colours have lower albedos while lighter colours have higher albedos. For example, asphalt and concrete have low albedos and absorb a lot of radiation, while snow and ice have high albedos, reflecting almost 80% of radiation.

The reason the poles are not colder than they are is because the heat from the equator moves to the poles heating them up. This creates the pressure and wind systems on our planet. Without the green house effect our planet would be 33 degrees Celsius cooler.

Human Changes to the Balance of Incoming Energy

Changes in insolation occur naturally and the climate of the Earth is always changing. This is the reason for the previous ice-ages and in fact could be the cause of the changing global climate that the world is experiencing today. However it cannot be denied that humans are changing the energy balance of Earth by changing the Earths albedo, the ozone layer and the composition of green house gases.

Humans have made the natural albedo of the earth lower in many places because of the urbanization of the Earth. Cities and roads are built with mainly concrete which has a lower albedo than most natural things. This change is making the Earth retain more heat than normal through absorption. In cities an Urban Heat Island effect takes place because there are so many objects that have a low albedo. This unnatural effect causes cities to be hotter than they should be.
An example of the effect is Tokyo which has surpassed the surrounding temperatures due to it's lower albedo.

Global temperature is rising also because of the destruction of the Ozone Layer. The ozone layer is in the stratosphere, about 10-17km above the surface. The ozone layer is a layer of O3 molecules that protect the Earth. The ozone molecules help to absorb UV radiation and stop it from reaching the surface. This cools our planet and protects us from the harmful affects of UV radiation. (sunburns, cancer and other medical problems) How ever humans have been depleting the ozone layer by destroy the ozone molecules with CFC's (Chloro-floro-carbons). CFCs detach a oxygen molecule from the ozone creating O2 .  The destruction of the ozone shows itself in the form of wholes that appear near the poles. Here the UV radiation is much more dangerous and is affecting many countries especially Australia. However, due to the Montreal protocol, the release of CFC's around the world has been limited severely.

The temperature of the Earth is rising due to the composition of the atmosphere, in particular the increase of carbon dioxide (CO2). In the past we can see that the amount of  carbon in the air has a direct affect on the temperature of the world.


In the last 150 years there has been a rise of 1degree. Although it seems small it can upset ecosystem and atmospheric systems all over the world.

The Causes and Consequences of Global Climate Change

"People tend to focus on the here and now. The problem is that, once global warming is something that most people can feel in the course of their daily lives, it will be too late to prevent much larger, potentially catastrophic change"
 Elizabeth Kolbert

There many natural and man-made causes of global climate change. Some of the obvious and most talked about are: industrialization, agriculture, emissions from transportation and deforestation, just to name a few. These factors among others are not only polluting the atmosphere but also are the main, man made, cause of global climate change.



Since the start of the industrial revolution, humans have been polluting the atmosphere with toxic gases and emissions that are released from large factories and other plants. From the beginning of time, the earth has naturally released and captured carbon dioxide (CO2) but in the past 200 years or so, the impact of these factories and industrialization started to cause a slow but noticeable rise in not only carbon dioxide levels but also methane (CH4) and nitrous oxide (N2O). These levels are at the highest they have ever been and there is no evidence of them slowing down any time soon. The industrial revolution may be to blame for the start of the rise in emission levels and temperatures but in the past 200 years, many different factors have contributed to the change, and humans have done nothing but make matters worse by polluting more and more everyday.

    Another factor in causing global climate change is deforestation and forest fires. Trees are very important when it comes to storing carbon dioxide. They soak up the carbon dioxide in the atmosphere are release oxygen, however, the reason they contribute to the warming is when they are cut down they release all the stored carbon dioxide back into the atmosphere. Forest fires have a far worse impact on the environment because as well as releasing all the stored carbon dioxide within the tree, they release harmful carbon particles and debris from the massive fires.

    The obvious cause and the most advertised problem that humans made and continue to worsen are the emissions from cars, trucks, trains, buses and every other vehicle know to man. All of these modes of transportation emit CO2 and other gases into the atmosphere not matter how ‘fuel efficient’ or hybrid the cars are. Yes, those cars are better than ordinary cars in regards to emissions; however, they are still contributing to global climate change. Car companies are getting bigger and bigger and many say that the emissions from cars are one of the largest negative factors on climate change, and matters are only getting worse. Car companies are developing relatively inexpensive cars for massive markets such as China and India. Both countries are growing rapidly, and more and more people are able to purchase a vehicle. This can be a huge negative impact if the two largest countries in the world start polluting like the countries in the west.


The global climate change that has occurred has had some major consequences on the environment. These environmental consequences can also lead to other problems that effect standard of living, economic situation and poverty, nutrition and other factors.

Due to the increase in temperature there are more frequent and more severe droughts taking place. These droughts can easily ruin a harvest. With the harvest ruined many people will be forced to migrate in search of better growing conditions and areas with water. In Africa many people who would be living on one dollar a day will be adversely effected by the destruction of the harvest, which they expected to sell. The graph below illustrates the effect that the destruction of harvest is having on LEDC’s like Niger and Nigeria. Due to the droughts in 2009 food became quite scarce. This forced people to migrate, uprooting their families and creating all the problems that come with migration, in search of employment, markets and food centers so they can get something, however small, to eat.

 The consequences of climate change are severe. In Africa it is expected by the IPCC that between 75 and 250 million people will have been exposed to increase water shortages due to climate change by 2020. These droughts could also lead to conflict over water resources as water becomes more scarce. This conflict would become more evident especially between places, which share the same water source, such as two countries that share the same underground aquifer. In many cases one country has accused the other of stealing the water, this accusation usually leads to an increase in the tension and a progression of the conflict.



As storms become more frequent the consequences that come with these storms become more exaggerated. Tropical storms are more frequent than ever due to the global climate change, which means that lightning strike, more frequent flooding and storm surges which all come with problems of their own. As the number of lightning strikes has increased the number of lightning related fires has too, destroying homes, businesses and a large amount of vegetation and crops. As floods become more prevalent around the world so too does water contamination. These supplies of water lead directly to people who drink the water causing breakouts of cholera, diarrhoea and other water-borne diseases. In many countries around the world these diseases can easily cause death. In the case of diarrohea people attempt to hydrate themselves after contracting it. Unfortunately by doing so they actually ingest more of the contaminated water and make their condition worse. Storm surges have caused many people to migrate form low-lying areas. The salt water that is in the sea is incredibly detrimental to crops and farmland, and the increase in tropical storms has caused widespread saltwater contamination. As the salt water contaminates the clean water mass devastation of farmland has occurred and has forced much migration around the world.

On top of this, the polar ice-caps near the North Pole are rapidly retreating and sea levels are rising. The warming of the climate has started to melt the ice caps which are an essential part of many ecosystems, especially in Canada. Although the melting ice caps put freshwater into the oceans, they are not the cause for rising sea levels. The sea is rising due to thermal expansion of water as the general temperature of the oceans rises. The rising oceans have severe impacts on low-lying communities and cities. New Orleans as well as many coastal parts of Florida are very vulnerable to a rise in sea level, and they will receive wide spread flooding if sea levels continue to rise.


Further Reading

http://www.un.org/apps/news/story.asp?NewsID=21429&Cr=climate&Cr1=change

This link gives the Intergovernmental Panel on Climate Change (IPCC) report review as well as the import facts and estimates of global climate change from the report.

http://unfccc.int/kyoto_protocol/items/2830.php

This link gives information on the actions that are being taken by current governments to stop climate change and limit pollution.


http://en.wikipedia.org/wiki/Insolation

This link provides a different explanation of insolation as well as other diagrams for further understanding. Wikipedia is also a good resource for researching other topics mentioned on this blog.

http://www.climate.org/topics/international-action/thailand.htm

This is a link to a case study of the effect of climate change on Thailand now and in the future. It is mainly concerned around the affects the changing climate can have on the agriculture of Thailand. Thailand is also considered to be the "rice bowl" of the world.

http://www.carbonfootprint.com/minimisecfp.html

This link will bring you to a website with tips to lower your personal impact on the environment so that we can all live in a better world.