Global Warming??

Question

I'm a little curious about global warming. I have done a bit of research, but am still wondering: what is the evidence that global warming is happening? Many years ago the the temperature was hotter than it is now...and then it got colder. Couldn't this be just another weather cycle? And if global warming really DOES exist, could it be caused by things other than too much carbon dioxide?

Please and thank you!

Answer 1

I'm a 6th grader at the gifted an talented program. Our group of students have been studying global climate chang for 2 years.GlOBAL WARMING DOESN'T HAVE TO BE THE INCREASE OF THE TEMPERATURE, IT CAN ALSO BE THE DECREASE OF IT!And the increases and decrease happen because of us, humans-we are the one polluting, not reusing ,recycling, and reducing.and we're adding carbon dioxide to the greenhouse effect. Scientists say that we might have another ice age or we could be poisoned by the dangerous layers of gas around us!!! People are cutting down too much trees,which makes it harder for us to breath. We are using up fossil fuels and polluting the world with cars! But, fortunately, there are many ways you can help, including reducing, recycling, and reusing, carpooling, ride a bike, walk. plant trees,and change your lightbulbs into flourescent ones. Remember, the Earth is in YOUR hands!

Go to this website below to visit the works of students who are studying climate change:

www.caminodepaz..org

Answer 2

It is a big lie built by environmentalists and politicians to control more of your life. You are wise to remain skeptical.

Answer 3

In the 1970's we had global cooling caused by:  The burning of fossil fuels.  Now the same language is being used today to promote the idea of global warming.   The carbon in the air supposedly reflected sunlight back into space causing wild winters.

It was the envronmentalists that wanted catalytic converters on all cars to break the exhaust down into carbon dioxide and water.  Now these are seen as the new "poisons"  Better cover up the oceans while we still can so they don't put all that nasty water vapor into the air.  

It's all false, fake, and phoney.  There is no good data to suggest we are warming up the planet.

Did carbon change properties in the last 30 years?  Not likely.  

There is no eveidence of Anthropogenic (man made) global warming.  It's all a big swindle to open the door to economic slavery.

So now global warming is also a decrease in temperatures.  That sounds like George Orwell's News speak.  Left is right and right is wrong.  They really try to brain wash people these days.

Answer 4

This explanation from NASA Director James Hansen pretty much sums it up, including debunking the myth that it's colder (in any meaningful way) now:

http://www.columbia.edu/~jeh1/mailings/2...

Here's a less technical explanation from another group within NASA:

http://earthobservatory.nasa.gov/Study/G...

Q. If Earth has warmed and cooled throughout history, what makes scientists think that humans are causing global warming now?



A.  The main reason that scientists think humans caused warming since 1950 is that none of the natural processes that influence Earth’s climate have changed enough during that time period to explain the warming.

Over the past thousand years, temperatures have been preserved in natural records like tree rings, ice cores, and coral reefs. Many independent estimates of temperatures from these sources show that while global average surface temperatures varied, at no time were they warmer or did they climb more quickly than during the latter half of the 20th century. Three things can alter global temperatures over this short period: changes in the Sun’s activity, volcanic eruptions, and human emissions of greenhouse gases and aerosols.

During the twentieth century, the average amount of energy coming from the Sun either remained constant or increased slightly. (See “Has the Sun been more active in recent years?” for more on that topic.) Major volcanic eruptions temporarily cooled temperatures by pumping reflective gases into the atmosphere. At the same time, the burning of fossil fuels pushed greenhouse gas levels higher than they have been for at least the past 700,000 years. Laboratory experiments have shown that carbon dioxide, methane, and other greenhouse gases absorb and re-radiate infrared energy, or heat, and satellite observations have shown that these gases have the same heat-trapping effect in the atmosphere. The dramatic rate of increase in greenhouse gases during the latter half of the 20th century matches the rate of temperature increase.



Even more telling is the way in which temperatures are rising. If the warming were caused by a more active Sun, then scientists would expect to see warmer temperatures in all layers of the atmosphere. Instead they have observed a warming at the surface and in the lower parts of the atmosphere and a cooling in the upper atmosphere. Something is trapping heat in the lower atmosphere, and that something is greenhouse gases.

Finally, scientists are almost certain that warming during the last 50 years was caused by human activity because models can’t reproduce the observed temperature trend without including a rise in greenhouse gases.

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Answer 5

Global warming, or the gradual increase of world wide temperatures on an annual basis, has much evidence to support its effects on the world as well as its actual existence.  Normal cyclical patterns of global temperature max and mins do not account for the warming we are currently seeing in the world today, as evidenced by the melting ice sheets.  September 1st annual measurements of Arctic ice caps extent has continued to show a drastic decrease in extent of ice remaining after a summer's melt.  This melting is what determines what will be called Multi-Year Ice for the next winter season.  Of course ice extent in the winter can and sometimes will reach new extremes, new maxima, but it is strictly the ice leftover after the summer's melt that determines the extent of global warming on the Arctic environments.  Furthermore, extreme summer temperatures warm ocean waters, assisting in the formation of tropical systems.  Higher ocean water temperatures, stronger storms, i.e. Katrina.  Fact:  Water heats and cools five times slower than land. The time needed to cool the oceans to a point below 80 degrees, which is what is needed to help the formation of these tropical systems is much longer, so the hurricane season can extend further than its normal ending point of November 30th in the Atlantic Ocean, example 2005 hurricane season, when a tropical storm formed on December 30.  To the question of the temperature variations of some years ago, scientists will concede the fact to a much more crude method of recording and calculating global temps as well as promoting the fact of CO2 causing actual global cooling vice warming.  Our understanding of the processes over the years has increased and changed to match this new understanding.  In fact many would say that the non-believers have increased scientists efforts to perfect the proof needed to win this endless debate, and has helped their effort.  Global warming in our time can be link to the Industrial Revolution and man's graduation from foot to car and endless burning of fossil fuels.  This argument does nothing to prove the reasons for a period of warming that occured during the dinosaur period millions of years ago.  This warming period was perhaps caused due to an increase in volcanic activity, releasing CO2, methane and sulphur into the atmosphere.  Gases such as these when released in significant quantities act as greenhouse "covers" over the Earth, trapping solar radiation near the land and warming global temperatures.  I hope this explantion helps.  I am a metorologist working at the National Naval Ice Center, where we track the movement and extent of the polar ice caps.