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Is global warming a natural phenomenon?

  1. Oct 3, 2004 #1
    is global warming a natural phenomenon? I think it is . But we can enhanced it such as we produce tonnes of carbon dioxide every day, causing the greehouse effect strengthen and finally lead to global warming .
     
  2. jcsd
  3. Oct 5, 2004 #2

    tony873004

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    One thing is for certain. The Earth never has had the exact same temperature year after year, decade after decade, century after century. So with or without mankind, the Earth would still be experiencing either a warming trend or a cooling trend.

    But natural or manmade, is global warming even happening? Astronomy magazine reported last year that the 20th century was not the warmest century of the past 1000 years, but only average.

    If mankind is causing warming, I don't want to ignore it, but I do realize that a group of people who I call "the sky is falling" crowd are eagar to jump onto the global warming bandwagon. This drags down the credibility of the real scientists. This same group of people brought us Y2K, and backed it up with support from computer professionals.

    I'm not trying to claim that global warming is not happening, but if it is, it makes me wonder why:

    The waves at the beach near my house don't break any further inland than they did 30 years ago when I was a small kid. Since the beach gradually slopes to the water, a small difference in sea level makes a huge difference in how far the waves break. A 6 foot difference between low and high tide can make a 600 foot difference in where the waves break. I know this because I got trapped on a small beach with my dogs, when we walked past some rocks, and on our return, the rocks were under water. But returning at a different time during low tide, I've witnessed the waves breaking about 200 yards from these rocks. So even a 1 inch rise in sea level should cause the waves to break an average of ~8 feet further inland.

    A warmer global temperature should raise sea level. As water heats, it expands, and parts of the world where water temperature is teetering around 32 degrees farenheit should be rapidly melting and raising sea level too.

    I also wonder why vegitation is not doing better today than 30 years ago. Greenhouse gardeners heat their greenhouses and pump in extra carbon dioxide to make their plants grow better. If we've really increased C02 levels and temperatures worldwide, the plants should be loving it.

    The highest temperature ever recorded was 136 degrees in Death Valley, California in 1913. If the world is warmer today than back then, you'd expect that the highest temperature ever recorded would have taken place in the 90 or early 2000s.

    I find myself wanting to jump on the global warming bandwagon every time we have a heatwave, or hear of record heatwaves elsewhere (like Europe last year). But then I realize that the world does not seem any warmer to me now that it was when I was a kid. And heat waves happen even in an ice age. Back when wooly mamoths roamed the Earth, there was still one day per century that took the prize of being the hottest day of the century.

    Also, all the consequences of global warming seem to be negative. More violent storms, destruction of habitat... I've even heard one person say that there will be no more coral reefs in 50 years because of global warming. To me this implies that the "sky is falling crowd" has got their teeth sunk deep into this one. If the world were 5 degrees colder on average, and warming up, would these same people be talking about how everything was getting better? I doubt it.

    I've also noticed that every time a large chunck of ice breaks off Antartica or somewhere in the Artic, everybody screams global warming. Haven't large icebergs been dropping into the sea for millions of years? And why is it always ignored when it snows in Antartica's interior, where the fallen snow will stay trapped as water ice for thousands or millions of years, balancing the icebergs that break off.

    Again, I think wheather or not the world is warming, and whether or not mankind is fully or partially responsible is something that should be fully studied. But it is important to seperate the real science from the theories put forth by "sky is falling" crowd.
     
  4. Oct 5, 2004 #3
    The global warming subject is like a really big jigsaw-puzzle.
    And we only have some pieces on the edges.

    There is something changing, if its us or mother nature herself?
    I don't know, guess nobody does.
    What i do know (or more have the feeling) that there are more records broken on the area of rainfall, temperatures and number of violent storms in the last couple of years than in the last 2 decades before.
    Or it might be that ppl notice it more now than they did before, which leads you back to the bandwagon and the "the sky is falling" neurotics.

    Anyway, if mankind has managed to start a proces of warming/cooling.
    Whats to worrie about, if it took us a 100 years to put it into motion, it probably is a moving train now.
    And we're all on it for the ride.
     
  5. Oct 5, 2004 #4
    CO2 in the air causes the greenhouse effect, but it also causes cloud cover, which blocks sunlight and cools. I would be more worried about the wobble effect than emmisons from our factories, when global warming is concerned.
     
  6. Oct 5, 2004 #5

    russ_watters

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    The "greenhouse effect" is a natural phenomena - "global warming" is what humans are adding to it, above and beyond the normal greenhouse effect.
     
  7. Oct 6, 2004 #6
    Both the greenhouse effect and global warming are natural effects. other 'natural' factors, such as sun spots could cause an increase in global temperatures, global warming.
    however, the term 'global warming' is often used as shorthand for anthropogenic global warming (AGW), that is, global warming caused by humans. AGW is a mechanism typically theorized as an increase in atmospheric CO2 (one of the main terrestrial greenhouse gases along with methane, water vapor, ozone) due to fossil fuel consumption that causes more of the sun's energy to be trapped within the atmosphere, thus resulting in higher temperatures in the atmosphere and on land/sea.

    considering the ice ages, volcanoes (mt pinotubo decreased global temps by 0.5C the year after it's most recent eruption), and Andre's clathrate, global tempuratures appear to change dramatically (occasionally) without humans. but that doesn't mean that human's CAN'T noticeably change the global temperatures...but it doesn't mean they CAN, either.
     
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