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