BIOSOLIDS AS A FERTILIZER...THAT’S GROSS! OR IS IT?

In other parts of the world, biosolids (human waste) from sewage treatment plants are treated and used as sustainable agricultural fertilizer. Research the pros and cons of this method and take a stand as to whether this can be a realistic alternative to our current agricultural practices. Who are the potential stakeholders in this issue? Are we influenced by the Western view of human waste as an unsanitary and disgusting nuisance?

What are biosolids?
Biosolids, also known as sludge, is the organic by-product of sewage water treatment. They contain essential plant nutrients and organic matter, which allows it to be recycled and used as a fertilizer.

Pros
There are many benefits that come along with using biosolids as fertilizer. Sewage biosolids are rich in nitrogen and phosphorus, as well as important micro-nutrients such as copper, iron and zinc. These micro nutrients make biosolids a good fertilizer because it allows the pants to grow and the soil to be rich. Sewage biosolids are particularly good for growing crops such as corn, soy beans and canola. They also improve pasture. This in turn reduces the need for commercial fertilizers that can have harmful chemicals, reduces production costs and does wonders for the soil. Biosolids, as mentioned before, improve the fertility of the soil, enhance the soil structure, moisture retention and reduce the chance of soil erosion and runoff.
Not only do biosolids help the crops and soil, but it also helps the farmers. Instead of purchasing micro-nutrients, nitrogen, phosphorus and other resources needed to grow their plants; farmers can save money by using biosolids that naturally come with all those things. An additional benefit is that by using biosolids on agricultural lands, municipalities are able to recycle a treatment process by-product in a cost effective manner. Lastly, society in general gets to reap the benefits. As a result of biosolids as fertilizers, reduced pressure of costs to provide sewage treatment, revitalizing used up soil resources and keeping farmers in business are rewarded to society.

Cons
Although there are many obvious benefits from using biosolids as land fertilizers, there are still concerns surrounding the process. One small example is the public concern for the odor of biosolids. One other example is the concern about contaminants in biosolids. Many studies have identified heavy metals, organic pollutants and pesticides in many samples of biosolids. Also, although metals such as zinc and copper are necessary for plant growth, some metals in large quantities can cause problems with animal health and plant growth. Biosolids also contain nitrogen and phosphorus, which in excess can move into groundwater or surface water causing problems for animals. There are also concerns surrounding the amount of pathogens in biosolids. Pathogens are infectious agents, or germs, that cause disease to its host.

Regulations
There are many steps to be taken and requirements to be fulfilled before sewage biosolids are allowed to be used for land application. One of the many examples is the regulations and protocols under the Nutrient Management Act. This act describes the standards that must be fulfilled in order to use sewage biosolids as a land fertilizer.
• Government approval of the treatment processes
• Laboratory analysis of the sewage biosolids
• Receiving soils to ensure that they meet the standards
• Government approval of the fields that receive sewage biosolids and the application procedure
• Government certification and licensing of persons involved in preparation and land application
• Detailed record-keeping

Conclusion
I think that sewage biosolids is a realistic alternative to current agricultural practices. Personally, I think that the benefits of sewage biosolids outweigh the disadvantages. Yes, there are risks, but what doesn’t come with risks. Using biosolids as a land fertilizer is not only better for the land, but for society as well. It allows farmers to stay in business and make a living and helps society. Although there are many concerns surrounding this subject, I think it is a safe method. There are many steps that go into using biosolids as a fertilizer. There are tests, licenses, certificates, approvals and standards that must be met. They are only permitted to be used a fertilizer if it is proven that it is safe and does not contain any contaminants and pathogens. Therefore, I think sewage biosolids should be used as fertilizer. Although it may seem unsanitary or disgusting to use biosolids as fertilizer, we have to look past the first thing that comes to mind and actually think about the benefits.

www.atlantawatershed.org/glossary/glossary.htm
http://www.omafra.gov.on.ca/english/nm/nasm/sewbiobroch.htm#1
http://www.durhamsap.ca/works.asp?nr=departments/works/sewer/biosolids/biosolids1.htm&setFooter=/includes/biosolidsFooter.inc
http://pubs.caes.uga.edu/caespubs/pubcd/SB27/SB27.html

The Importance of Technology

EVALUATE THE IMPORTANCE OF VARIOUS TECHNOLOGIES, INCLUDING CANADIAN CONTRIBUTIONS, TO OUR UNDERSTANDING OF THE INTERNAL BODY SYSTEMS (DIGESTIVE, CIRCULATORY OR RESPIRATORY)



Everything must start somewhere. This is true with everything around us. The flowers we see outside started form a seed. The buildings we see outside started out as a drawing. Even us, we started out as a tiny embryo. Like these examples, medicine and the understanding we have of our bodies today, would not even be close if it wasn’t for the invention of simple technologies. If it wasn’t for the first X-ray machine, or the discovery of many medicines, where would we be today? As a result of the developing technologies over centuries, people, such as doctors, have a better understanding of what is going on inside our bodies and are able to help take care of them.

One of the important technologies developed to help understand how our bodies work is the X-Ray machine. It was discovered around 1895, when Wilhelm Conrad Röntgen discovered an image produced from his cathode ray generator. Röntgen investigated further and discovered that the rays were created on contact between the cathode ray and the inside of the vacuum tube, they were no repelled by magnetic
fields and could penetrate many kinds of matter. About a week later, Röntgen took a X-ray photograph of his wife’s hand which clearly revealed her bones, and revealed it to the public. They were shocked and it generated scientific interest in the new form of radiation. He named this new discovery X-radiation, X standing for unknown. X-ray technology has helped the medical world in a number of ways. An X-ray is able to pin point a problem where as something else may miss it. Also, it is a quick way for doctors to see what they are dealing with. For example, when a broken bone is in question, an X-ray is the easiest and fastest way for doctors to locate, view and assess broken bones, sprains or torn muscles.

Another very important contribution to the world of medicine is the development of “Cat scanning” (Computed Axial Tomography), also known as Computed Tomography (CT) imaging. The CT was invented in 1972 by a British engineer named Godfrey Hounsfield and by a South African physicist named Allan Cormack. CAT scans are special X-rays that produce sectional images of the body. These images allow the radiologist, to look inside the body similarly how we would look inside a loaf of bread. CT scans takes pictures of “slices” of the body so that doctors can look right into the area they need to. CT scans are often sued for evaluating the brain, neck, spine, chest, abdomen and pelvis. Since its development, CT scanning has made wonderful improvements in efficiency and patient comfort.

However not all the important medical technology invented were machines. This device is now one of the most commonly used tools for doctors, but it used to be a new and exciting invention. The stethoscope was invented in 1816 by a young physician named, Rene Theophile Hyacinthe Laennec. The stethoscope is a medical device used to listen to the internal sounds of the body. It is often sued to listen to lung and heart sounds and is also used to listen to blood flow in arteries and veins. Before this invention, a doctor would simply put their ear on the patient’s body and listen for the sounds. Laennec‘s modesty ultimately led to the invention. He was embarrassed to place his ear on the female patient’s chest, so he rolled up paper to listen and discovered it was very clear and amplified. He used his woodturning skills to make the first official stethoscope, which was made from wood.

One of the greatest contributions to medicine came from Canada. The first is the breakthrough was the discovery of insulin. In 1921, At the University of Toronto, Dr. Frederick Banting and medical student, Charles Best, made a pancreatic extract which they hoped would put an end to the epidemic of diabetes. They tied a string around the pancreases duct and several weeks later found that the cells had died and been absorbed but thousands of islets were left behind. They isolated them and produced isletin which became known as, insulin. The men managed to test it on dogs with diabetes. They discovered the insulin actually manage to keep the dog alive, because it helped regulate the dog’s blood sugar levels. In 1922, the insulin was tested on a 14 year old, Leonard Thompson, who lay dying at the hospital of diabetes. After his first injection, he suffered an allergic reaction. Therefore, the scientists worked hard to improve the insulin. Fortunately, after the second injection on Leonardo Thomson, the results were wonderful. Banting and his team soon when distributed the insulin to children lying in comas and dying throughout the hospital. Children soon began awaking from comas and it became known as one of medicines most dramatic moments. Banting and Best’s work was privately published but soon after a company offered to produce large quantities of the insulin. In 1923, Banting was awarded the Nobel Prize in Physiology or Medicine.

The inventions and discoveries I have described in this blog are only a tiny portion of the various technologies that have contributed to our understanding of the human body and its internal systems. The importance of these technologies is immense and without them we would be nowhere close to where we are today. Without the discovery of anesthesia, where would we be in terms of surgery today? Would be able to perform complicated surgeries such as a quadruple bypass or a heart transplant? If it wasn’t for the discovery of insulin, would people be able to survive with diabetes? The answer to all these questions is no. The various technologies developed over centuries and centuries is reason why we are able to do all these complicated surgeries and survive things that were once epidemics. Also, technologies are still developing. Everyday scientists and researchers get closer to finding cures for incurable diseases and it is all thanks to the advancements in medical technologies.

http://www.imaginis.com/ct-scan/history.asp
http://inventors.about.com/od/xyzstartinventions/a/x-ray.htm
http://www.ehow.com/facts_5456183_invention-stethoscope.html

How Do You Know When You Have Gone Too Far?

Artificial selection has resulted in plants that are more-disease resistant, cows that produce more milk, and racehorses that run faster. One must wonder what will come next. Under what circumstances should humans be artificially selecting plants or animals?

What is Artificial Selection?

First of all, what is artificial selection? According to an online dictionary, artificial selection, also known as selective breeding, describes deliberate breeding for certain traits, or combinations of traits. The term was developed by Charles Darwin, to distinguish it from natural selection. In natural selection, the environment is like a filter which only a few variations can pass through where as in artificial selection, humans favor specific traits.

Natural selection vs. Artificial Selection

Natural selection plays a very important role in evolution. In this process of natural selection, only the organism that are best adapted to their environment will survive and pass on their genetic characteristics to the next generation. Organisms that are not adapting as well to the physical and biological changes in the environment are eliminated.

One example of natural selection is the color of the Gypsy Moths in England. It is a good example of how when there is a quick change in the environment, a species has the ability to adapt. When an industrial revolution took place, industrial factories, such as coal factories, emitted massive amounts of pollutants into the air. There was so much pollution that the skies we dark during the day, as if it was night. The original color of the gypsy moths was light gray. This allowed them to blend in with the trees, which had light gray bark, protecting them from predators. However, when the change in the environment occurred, their camouflage no longer helped them. The tree bark became darker because of the pollution. Now those few dark gray gypsy moths were now at an advantage and the light gray ones were eaten by predators. As a result, through adaptation and natural selection, the gypsy moth was able to slowly change it light gray color to a dark gray color.

Artificial selection is when we “humans” take on the role as the “environmental pressure” causing the organism to adapt. It is pretty easy to accomplish. First, a specific plant or animal is chosen because of its specific heritable genetic trait that is desired. The plant or animal is then bred with another of its kind with a similar trait. This results in offspring that have a higher potential to display the desired trait. This cycle can be repeated over and over again with the offspring until the desired trait is achieved.

One major example of artificial selection is the breeding of dogs. All the domestic dogs we see today, although very different in appearance, from Chihuahua to the Great Dane, all belong to the same species, Canis domesticus. They all originated from the same ancestor, the wolf. However, thanks to artificial selection, we were able to select certain traits, and created a variety of dogs that differ in appearance and behavior. Dogs such as the Dachshunds and Greyhounds both descend from the same ancestral wild dogs. However, both breeds of dogs were created by artificial selection. In the Dachshunds’ case, the process resulted in low and elongated bodies. For the Greyhounds, the process resulted in swiftness in running.

Another example is artificial selection in plants. Early farmers cultivated many well known vegetables from Brassica oleracea, which is wild cabbage. By artificially selecting for certain traits, common vegetables such as cabbage, broccoli, cauliflower and Brussels sprouts are all descendants of the wild cabbage. For example, broccoli was bred by selecting for large flower stalks. Brussels sprouts were created by artificially selecting for large bud size.

Advantages of Artificial Selection

Sooner or later, artificial selection is going to play a major role in our lives. There are many benefits that can come from this. Using artificial selection, disease can be prevented. All that needs to be done is to detect the people, animals or plants that are more likely to carry hereditary diseases and eliminating them. People, such as breeders of animals and plants, are looking to create organism that will have desirable characteristics. These include high crop yield, resistance to disease, high growth rate and many other characteristics that will benefit not only the organism, but humans in the long run. The process of artificial selection has made it possible for our species to increase the effectiveness of the animals and plants we breed. Using artificial selection we can create cows that produce more milk, crops that are more disease resistant, chickens that produce more eggs and even racehorses that run faster. How can these not considered benefits of artificial selection? With crops that are more disease resistant, cows that produce more milk and chickens that produce more eggs, businesses can expand and improve. They will be able to sell more, make more money, which benefits the economy and society as a whole. Another advantage of artificial selection is its efficiency. Artificial is way more convenient and efficient than natural selection. Natural selection happens naturally, over time. It can even take as long as a few thousand years for it to occur. Artificial selection can be done whenever needed, easily and quickly.

Disadvantages of Artificial Selection

Although there are many major advantages of artificial selection, it still has its many disadvantages. One of the dangers that can arise from artificial selection is inbred offspring. Some of the traits that are desired are so rare that they exist only between one or two families. When the trait happens to be recessive, two members of the same family line may have to breed together in order for the trait to be expressed. In animals, this can cause genetic defects and many other serious problems. For example, Dairy cattle are bred in order to produce more milk. However, some family lines can suffer from increased infections and fertility problems. Persian cats are bred for their particularly flat faces. Unfortunately, they often develop respiratory problems and can have trouble eating. Not only does artificial selection take a negative toll on the heath of the animals, but it takes a negative toll on our world’s diversity. If every animal was created by choosing only the desirable traits, there would be no diversity. It can also permanently eliminate many of the unwanted genes from the gene pool. To humans, many desirable traits are considered those who affect the appearance of the animal. They do not care about the genes that will help them adapt and survive. If all of the organisms had the same “desirable” traits, then one major change in the environment could wipe them out completely. The wipe out of a species would then throw the world’s ecosystems out of balance.

Conclusion

Now that we have covered the advantages and disadvantages of artificial selection, there is only one question left to ask. Is it ethical? If humans can already “design” what kind of animals and plants exist in the world, how much further can they go? The answer is, much further. As discussed in a previous topic, humans have already started “designing” their own babies. Just like choosing whether a cow will produce more milk or a plant will resist disease, humans can choose if their babies will be disease free and have blue eyes. Under what circumstances should humans be artificially selecting plants and animals, if any? Although there are many advantages, as I mentioned before, I still think it is ethically wrong to be artificially creating plants and animals. Humans are choosing to overlook the disadvantages and focus on the advantages. However, these disadvantages will become a major problem in the future. The main purpose of artificial selection is to produce offspring with a higher chance of carrying desirable traits. However, the measures taken to do this are actually causing the offspring to suffer. They are now developing genetic mutations and defects, because of problems such as inbreeding. The point was to create perfect animals and plants, but they are becoming less and less perfect. It kind of defeats the whole purpose of artificial selection.

There was a time when the world was mysterious and everything was left up to chance and nature. Today, science has taken over. Technology has overruled the mystery and might of nature. The world is slowly becoming like a factory, where everything is made the same. Soon there will be no more variety and diversity. The beauty of nature and out planet is slowly fading away.

Natural and Artificial Selection: Mechanism of Evolution: Biological Change in Wild & Domestic Animals http://geneticsevolution.suite101.com/article.cfm/natural_and_artificial_selection#ixzz0d6gTS9Xi

http://www.brighthub.com/science/genetics/articles/47262.aspx#ixzz0d6bpKfuZ

http://www.mnsu.edu/emuseum/biology/evolution/genetics/naturalselection.html

http://en.wikipedia.org/wiki/Common_descent#Wild_cabbage

Natural and Artificial Selection: Mechanism of Evolution: Biological Change in Wild & Domestic Animals http://geneticsevolution.suite101.com/article.cfm/natural_and_artificial_selection#ixzz0d6ZMc7gs

http://wiki.answers.com/Q/Advantages_and_disadvantages_of_selective_breeding

I'd Like to Order One Baby...Blue Eyes and Blond Hair Please.

Imagine a world where everyone looked like the same. Imagine everywhere you looked, the people looked like they came out of a magazine? Well soon we won't need to imagine, because technology is developing and becoming more advanced everyday. Soon, it may become reality.

What is it?

The term, “designer baby” refers to a baby whose genetic make up has been artificially selected by genetic engineering combined with in vitro fertilization to ensure the presence or absence of certain genes or characteristics. In order to do this, processes like in vitro fertilization (IVF) and pre-implantation genetic diagnosis (PGD) are required. In vitro fertilization is the process by which egg cells are fertilized outside the womb. The fertilized egg, or zygote, is then placed inside the uterus, hopefully establishing a successful pregnancy. Pre-implantation genetic diagnosis refers to procedures done on an embryo before it is implanted into the uterus. It screens the embryo for any genetic conditions that could later lead to a disease. PGD can be offered for three major groups of diseases which are sex linked disorders, single gene defects or chromosomal disorders. Embryos that are free of any mutations are implanted in the uterus and the ones that do have mutations are simply discarded. This procedure makes it highly likely that a baby will be born free of diseases and disorders. However, PGD is not only used for screening for disorders but can also be used for sex selection. The embryos resulting from IVF can also be genetically tested for X or Y chromosomes. The embryos of the desired sex are then implanted.

Although at the moment, modifying are or selecting are children's genes has mostly been for medical purposes, in the future it could be used for cosmetic purposes. The future is not far ahead because as I said PGD is already being used for sex selection. It is possible that soon PGD can be used to select your child's hair colour, eye colour, their abilities, intelligence and so much more. The big question is, are the research in genetic processes getting to out of hand? First let's examine the benefits and disadvantages of “designer babies”.

Advantages

One main advantage of “designer” babies is that they can be used to help save lives. Like I said before, using methods such as IVF and PGD can be used to screen embryos for any genetic conditions that could lead to harm for the baby. It can reduce a baby's chance of being born with serious illnesses such as Down Syndrome, Huntington's disease, cystic fibrosis and rare blood disorders. Couples with a history of genetic disorders choose to use these procedures to ensure their child is born well and healthy. Couples may also use this procedure in order to save the life of one of their other children. For example, if they have a child with a rare blood disorder, they can “design” a child that is healthy. The healthy child then becomes a donor increasing the sick child's chance of survival. One of the reasons people find that PGD is the way to go is because the screening is done on the embryo before implantation. Many women, who are already pregnant and find out that their baby has genetic condition decide to terminate their pregnancy. Pre-implantation genetic diagnosis finds the problem before the pregnancy is technically established. It helps some people avoid the psychological and physical trauma that comes along with having an abortion.

Disadvantages

There are many advantages to “designer babies”, but those advantages come along with many disadvantages. Firstly, PGD is not successful 100% of the time. One of the reasons is that the sample form the embryo that is tested is so small, it cannot be screened for every possible genetic problem. There can also be the problem of a misdiagnosis. Basically PGD, does not guarantee a successful pregnancy or a healthy baby. The embryo can also be damaged when removing the sample cell. However, one of the major problems is the ethical implications.

Ethical Implications

The problem is that procedure such as PGD are now being taken to far. They are not only used for medical purposes or to save someone's life, but for cosmetic purposes. At first there was sex selection and now it is possible it can go as far as choosing your child's abilities. There are many reasons people find the idea of PGD and “designer babies” wrong. For example, some couples may use PGD to help save the life of one of their other children. People find this ethically wrong because it seems like the child is being created just so it can be used for something else. It reduces the child to an object being made to benefit someone else. Another major problem is the fact that embryos who are found with genetic conditions are discarded. Like I said before, people may use PGD to avoid having to possibly terminate their pregnancy later on. However, many may find PGD to be wrong on moral and religious grounds. It is basically the same thing as an abortion. Many people, such as pro-life groups believe that even though it is an embryo it is still a living human being. Discarding a embryo is the exact same thing as having an abortion. It is still killing the innocent. All those embryos that have ever been discarded may have grown up to be an amazing and life changing person. There are many debates arguing that the embryos have the right to not be genetically modified. People retaliate by saying the parents have the right to do whatever they want to their unborn children. However, the fact is that that embryo is still a person. How would we feel if someone could do whatever they wanted to us and we had no say in the matter. Why should our rights be different from theirs. Another ethical issue is the fact that people may be able to choose the way their children look and act. In i way, humans have begun to take the role of God. Many people believe that they were created in God's image and that God had his reasons for it. Unfortunately it will soon become, we were created in the way our parents and society think is beautiful because science made it possible. There are many social implications that come along with this issue. If it becomes possible to choose eye and hair colour, the IQ and abilities of our children, there will soon be a different kind of race of humans. It will be like a super race, where they are considered superior and look down and frown upon those who have not been genetically modified. Society will also be greatly divided into the rich and the poor. Assuming that these procedure will be expensive, it will be the rich who can be beautiful and protected from disease and disabilities. It will be the poor that have to suffer from disease and disabilities and the discrimination that will come along with it. Those who are “different” will be considered worthless. It is similar to the time of Hitler. Hitler and his Nazi's set out to create a “super” race or a perfect human race by eliminating those of certain ethnic background, those with diseases and those with disabilities. Hitler's desire for perfection led to a mass genocide and is one of the most horrific time sin history. What is to say, that won't happen again?

If everyone looked the same, where would be the magic in the world? If everyone looked, acted and had the same abilities, there would be no diversity. If parents could choose how smart their children would be, would there only be doctors and lawyers in the world? Would everyone have a place in the world? Humans are not just clothes that you can design and throw away if you don't like it. We cannot start all over if we don't like the design. These are lives we are dealing with nature we are messing with.


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

http://singularityhub.com/2009/02/25/designer-babies-like-it-or-not-here-they-come/

http://www.actionbioscience.org/biotech/agar.html

http://www.buzzle.com/articles/pros-and-cons-of-designer-babies.html

http://www.spiked-online.com/Articles/00000006DD57.htm

http://www.humansfuture.org/genetic_engineering_designer_babies.php.htm\

http://www.revolutionhealth.com/conditions/reproductive-health/infertility/art/pgd

Humans…stewards of the world?

Many scientists believe that humans are the most invasive species, because humans can greatly change and environment and impact living things that live there. There is no doubt that human intervention has, in some situations, positively affected the biodiversity of our ecosystems. However, that is not true in many cases. I am choosing to talk about global warming. I will talk about how humans have helped create global warming and how it is affecting the biodiversity and living things of our planet.

Global warming is the increase in the earth’s atmospheric and oceanic temperatures which has occurred due to an increase in the greenhouse effect resulting especially form pollution. All climate scientists believe that it is a fact that the earth’s temperature is gradually increasing. Temperatures have increased, on average, by one degree Fahrenheit. Although this sounds insignificant, this small increase has already had a immense impact on the environment and will continue to do so for a long time. Scientists have determined a number of factors that has caused global warming. Of course, some of them are natural, but the majority of causes are man made. These are known as greenhouse gases.

What are greenhouse gases? Greenhouse gases trap heat from the sun within the earth’s atmosphere. As a result of this, earth’s surface and atmosphere are heated. The main contributor to greenhouse gases is carbon dioxide. Carbon dioxide can be released into the atmosphere in many ways such as, burning fossil fuels in factories, cars, coal plants and many others. Methane is another contributor to greenhouse gases. It is actually 20 times more potent than carbon dioxide as a greenhouse gas. It can be released from agriculture, fertilizers, industrial gases and many other sources. It is not only the big businesses that contribute to this problem. Each one of us makes a big contribution to the greenhouse gases found in the atmosphere by using luxuries such as air conditioning and heaters and driving our cars.

Another major cause of global warming it the size of our population. The increase in our population leads to an obvious increase of fossil fuel usage for energy, transportation and power. Also, all these people need food. This leads to an increase in deforestation for agriculture. This is a problem because us humans breathe out carbon dioxide and the trees which convert that into oxygen are slowly disappearing little by little. The increase in population can also lead to an increase in cattle/livestock who are actually large contributors to greenhouse gases. Their feces or manure is another source of methane.

Global warming has already had several effects on our planet and will continue to do so. One of these affects is the increase and spread of infectious diseases. As northern countries warm and winters grow milder, many infectious and disease causing insects, bacteria, viruses and fungi will be able to move into new areas and harm diverse species such as lions, snails, butterflies and humans. Disease carrying insects and bacteria that were once barred from certain areas due to severe seasonal chills can now invade. For example, mosquitoes now move up mountainsides and infect animals that were once protected by temperatures. Also, the rise in temperatures will also speed up the melting of glaciers and polar ice caps. Average temperatures in the Arctic region have risen twice as fast and the ice is getting thinner, melting and then breaking. For example, the largest single block of ice in the Arctic, called the Ward Hunt Ice Shelf, had been around for 300 years. However, in 200 it started to crack and within two years split all the way through and is now breaking into pieces. As a result of melting polar ice caps and glaciers, the sea level will also rise. This can in turn cause many more problems. Not only do the melting glaciers and ice caps cause the sea level to rise, but it also poses a threat of throwing global ecosystem out of balance. Ice caps are fresh water and when they melt, they desalinate the ocean. The desalinization of the gulf current will screw up the ocean currents, which are supposed to regulate temperatures. Global warming also has a huge impact on animals and plants. The increase in global temperatures are disrupting ecosystems and pushing species that cannot adapt to the brink of extinction. It is estimated that around 1 million species could become extinct by 2050 if this continues. For example, polar bears are drowning because they have to swim longer distances to find ice floes. It is predicted that two thirds of the world’s polar bear population will be extinct by mid-century due to melting polar ice caps.

Humans have made many great and positive impacts on the world and its ecosystems. However, as you can see, we humans have also negatively impacted the planet we live on and all its living things. Due to our carelessness and misuse of the world’s resources, we have put our planet in peril. We have disrupted ecosystems, helped diseases grow and endangered the lives of many species of animals and plants. Many scientists believe that humans are the stewards of the world because we van greatly change an environment and impact living things that reside there. However, but isn’t being a steward taking care of things and making sure everything runs smoothly and well? I think we humans need to prove that we can be stewards of the world by making a change, taking care of our planet and by stopping global warming.

My References:
http://www.nrdc.org/globalWarming/fcons/fcons4.asp
http://www.nrdc.org/globalwarming/qthinice.asp
http://www.howstuffworks.com/question473.htm
http://www.cbsnews.com/stories/2002/06/20/tech/main512920.shtml
http://www.culturekiosque.com/nouveau/news/global_warming_spreads_disease.html
http://www.environmentalgraffiti.com/sciencetech/5-deadliest-effects-of-global-warming/276
http://ready2beat.com/educational/what-are-main-causes-global-warming
http://timeforchange.org/cause-and-effect-for-global-warming