Regents Earth Science


Tuesday, 21 October 2014
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Is Global Warming just a natural cycle? PDF  | Print |  E-mail

         Global warming is a topic that people all over the world have very strong feelings about.  Many tests and research have been done, and we now know more than ever about it..  As our technology increases, we have a better chance of understanding this strange thing that is happening to our planet.  But is global warming a natural process or is it caused by humans? Could it be blamed on our naive knowledge of the planet and how delicate it really is, or could it just be that the planet goes through this process every few thousand years?  Satellite images show that the sea around Antarctica has been rising in the past 20 years.  Scientists have suggested that high amounts of atmospheric carbon dioxide (one of the greenhouse gases) is to blame for around 33 degrees of warming on Earth.  Although, if there were no greenhouse gases, the Earth would be unlivable .  The greenhouse effect is what happens when the energy from the sun is trapped by the Earth’s atmosphere.  Carbon dioxide, water vapor, nitrous oxide, and methane are all gases in the atmosphere that help trap the energy emitted from the sun.  Without all these gases, the Earth could sink to -2 degrees Fahrenheit.

 

Source: http://science.nasa.gov/headlines/images/fidget/greenhouse.GIF 

        There are many reasons that people think global warming could be caused by humans.  For the last century, we have been destroying our natural resources.  Newspaper headlines and magazine articles have many people convinced that global warming is anthropogenic, or human caused.  “What you can say is, yes, carbon dioxide (in the atmosphere) is at levels higher than ever before, and carbon dioxide is a greenhouse gas, so it’s reasonable to say that there’s warming associated with the increase of carbon dioxide.  But you can’t make the leap yet that all the cars in the world have led to what we’re observing in the thinning of the Greenland ice sheet.” said Dr. Waleed Abdalati, the co-author of the paper that proved that Greenland was shrinking.  It is hard to distinguish what is human caused.  “And so you have all these processed mixed together that have been going on for thousands of years, and you’re in the difficult position of trying to separate something very recent from the natural cycle without fully understanding what that natural cycle is.”  Abdalati said.  Recent studies have suggested that eating meat like domestic livestock can affect the planet in a big way.  One of the easiest things you can do to help the planet is to cut down on your intake of meat.  One calorie of animal protein needs ten times as much fossil fuel and carbon dioxide than one calorie of plant protein.  Livestock also produces methane.  The EPA reported that livestock produces the most methane in the U.S.  The U.S. consumes the most meat out of any country in the world.  If everyone would simply cut down on their meat intake and was a little more knowledgeable about our planet, we could dramatically reduce our environmental impact on the world. 

Global warming has been blamed on many different natural causes.  Around 1,000 A.D. until 1950 A.D. there were very large temperature deviations. This has partly been explained by volcanic eruptions and changes in the sun.  Around these times, people did not have the technology to impact the Earth in that way.  There have been warming periods early in the Earth’s history without human influence.  Dr. Krabill, who is the project scientist at NASA’s Wallaps Flight Facility, was part of the team that discovered the thinning of Greenland.  During 1993 and 1994, Krabill’s team took a survey of the altitude of the ice sheets surface on a portion of Greenland using an airborne laser.  In 1998, they repeated their test.  What they found was that the ice sheet lost 51 cubic kilometers.  Another NASA funded study took place where they removed ice cores from glaciers.  “These samples suggested that a natural accumulation of snowfall might be to blame,” said Dr. Mosley-Thompson, a research scientist for Byrd Polar Research Center at the Ohio State University.  Some scientists are also blaming ocean currents.  From 1990-1996, a flux of warm water into the North Atlantic as part of the North Atlantic Oscillation may hold some evidence.  The earth could also be warming as a response to last glacial period around 10,000 years ago.  Global cooling was also a big deal from the 1940’s to the late 1970’s.  Many tests have been performed to try to prove theories about global warming.  Scientists cannot perform experiments on the earth’s atmosphere.  They conduct these experiments in small models under controlled conditions.  They change the conditions to see how things react.  They also run computer simulations of global climate, although it is impossible to create a perfect model of our climate.  “The system is too complex, even the most complex climate model doesn’t get it right”, said Mosley-Thompson.   

 

           This diagram shows the major temperature changes throughout Earth's history

Source: http://science.nasa.gov/headlines/images/fidget/globaltemp.jpg  
 

Tree rings are also a good indicator of past climates.  Dr. Thomas J. Crowley, a geologist at Texas A&M University, found that fluctuations in tree rings matched temperature fluctuations from around 1000 A.D. to 1850 A.D. Fifty percent of the temperature fluctuations that were found in the tree rings were linked to volcanic eruptions and solar intensity. Some Scientists have also used ocean sediment and chemicals trapped in ancient ice. 

            We must be very careful when researching topics like this because there is a lot of misinformation.  One source of such misinformation was a person I encountered by the name of Dr. Fred Singer.  His claim was “I have no connections whatsoever with the tobacco industry, now or in the past.”  Yet, he wrote a letter thanking the Tobacco Institute for $20,000, which was supposed to “support our research and education projects.”  He was also listed on Exxon Mobil’s website as receiving $10,000 in direct funding.  He also received $65,000 more in funding from Exxon Mobil.  Exxon Mobile has also financed think tanks like the Competitive Enterprise Institute, Alexis de Tocqueville Institute and even Dr. Singer’s group.  Then “experts” like Dr. Singer are more than happy to pocket the money.  Why would all these oil and tobacco companies be sponsoring him if he is supposedly writing about how to cut down on pollution and help the environment when these companies are some of the biggest polluters in the world?  Simply to protect their own interests by having "misinformationists" such as Dr. Singer in their pockets.

            “I think that there are many scientists that are still locked into the idea that we have to prove something (about causes of climate change) beyond a reasonable doubt.  I don’t think we necessarily have to do that…that’s the way you approach this type of problem.”   Dr. Crowley said.  Disagreement is unavoidable in this situation.  With so many people, ideas, and opinions, it is hard to tell what the truth actually is.  I think there is more evidence for human influence rather than natural causes. I don’t think that humans are helping the environment and we could be doing a lot more than we are now.  As technology gets better, so will our answers.

By: Savannah King

Bibliography

http://desmogblog.com/no-apology-is-owed-dr-s-fred-singer-and-none-will-be-forthcoming.

 

The link below is not working please go to http://science.nasa.gov/ which is another part of the same site. 

http://science.nasa.gov/headlines/y2000/ast200t_1.htm
                              

http://www.organicconsumers.org/articles/article_7590.cfm



 

 
 




 
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