Global Warming....

Discussion in 'World affairs' started by mosaix, Jan 11, 2007.

  1.  
    mosaix

    mosaix Active Member

    Joined:
    Feb 13, 2006
    Messages:
    4,724
    Although I have been generally on the side of the 'man made' camp I have always worried that a significant minority (I think) of scientists have had differing views.

    On BBC Radio 4 this afternoon a scientist gave the following info:

    1) Man produces 4 billion tons of carbon dioxide each year.

    2) This is only 7% of the total carbon dioxide produced each year.

    So far so good. The argument has been that this is too little to cause global warming. However:

    3) The remaining 93% of carbon dioxide is in balance not causing an overall annual increase or decrease and the 4 billion tons is extra each year.

    4) Since the start of the industrial revolution the amount of carbon dioxide in the atmosphere has risen from 260ppm to 380ppm (I think it was ppm could have been ppb, either way this is a 46% increase).

    Point 4 seems pretty damning.

    And finally a point that has been quoted to me many times: 'the amount of carbon dioxide produced by man is minuscule compared to that produced by a volcano - mount St Helens for instance'.

    5) Volcanoes produce very little carbon dioxide. They produce lots of sulphides that whilst in the atmosphere actually reflect the suns rays - causing global cooling.

    Any thoughts anyone?
  2.  
    Talysia

    Talysia Lady of Autumn

    Joined:
    Oct 26, 2006
    Messages:
    4,755
    Hmm. I don't think I know enough about this subject to answer your question properly, but it would be interesting to find out how the state of the environment would be if things had gone differently. For example, if we had found a cleaner source of fuel earlier in our development or relied less on fossil fuels, would there be holes in the ozone layer and such? Truly a difficult question to answer for me.
  3.  
    ras'matroi

    ras'matroi New Member

    Joined:
    Mar 20, 2005
    Messages:
    139
    I've read an interesting articleon the effects of global warming and epecially it causing a sea level rise.

    e.g.: The sea level of the Northsea is currently rising 25-30 cm percentury and it gets faster.
    If the sea level rises about 5 meters Half of the Netherlands, some parts of northern Germany and parts of Denmark would be lost to the sea. (Can't see more on the map :mad: )

    This seems really frightening even if it will take a long time until it will rise that high.
  4.  
    Allegra

    Allegra New Member

    Joined:
    Oct 30, 2006
    Messages:
    1,950
  5.  
    Stormpirate

    Stormpirate Sailing the stormy seas..

    Joined:
    Sep 8, 2006
    Messages:
    158
    El Nino has some to do with the warmer year this year. It's not all just global warming.

    As far as the whole in the ozone layer, it's pretty much been there even before humans started in on our actions.
  6.  
    Delvo

    Delvo New Member

    Joined:
    Oct 19, 2006
    Messages:
    452
    Fuel use isn't the culprit behind human-caused ozone depletion. Chlorofluorocarbons are. Since the switch away from those to other kinds of refrigerant and aerosol spray propellant, the ozone layer has been returning to normal.

    Global warming can't possibly be responsible for the lack of a winter this winter because the amounts of "extra" warmth are completely off. Global warming is a matter of how many years or decades it will take to increase a single degree in average temperature, and this winter compared to last winter is more like 20-40 degrees of difference in a single year. It's just another wacky fluctuation. Global warming could be part of it, but no more than a small fraction of one degree of it.
  7.  
    Lenny

    Lenny Edit Ninja In Training

    Joined:
    Jan 11, 2007
    Messages:
    3,741
    There was an interesting report last year about Global Warming and Mars.

    I haven't a clue where the link has got to, but the report was about how Astronomers and Scientists believe that Mars may be experiencing Global Warming - the ice/methane caps on Mars have beebn slowly shrinking over the years.

    Could Global Warming, therefore, be something out of our 'control'?

    There's always been a big thaw after the end of an Ice Age, so it could be perfectly natural.

    But I'll agree that man is contributing to the whole thing, however minutely or massively.
  8.  
    Green

    Green Sick and Tired

    Joined:
    Jun 10, 2005
    Messages:
    808
    I believe that some measurements in 2006 have shown that the hole over the Greenland is larger than ever. I can't remember the source, I'm afraid, but maybe New Scientist. It might have only been a seasonal problem, though.

    As to global warming being out of control... there comes a point in warming where that does happen, though we're not there yet. Once the temperature rises above a certain point and methane reserves stored beneath the oceans (not sure what formed they're stored in, sorry) start to be released into the atmosphere, the problem quickly escalates, since methane is a much worse greenhouse gas than CO2. Many mass extinctions have been caused by this effect in the past.
  9.  
    chrispenycate

    chrispenycate resident pedantissimo Staff Member

    Joined:
    Aug 10, 2005
    Messages:
    6,138
    I believe the methane reserves are beneath icecaps or permafrost layers; methane's not very soluble) And a warm winter could precipitate a positive feedback effect (at least no-one has a mathematical model which proves that it couldn't) If methane is released at an acceptbly low rate (ie, those reserves released over decades) it will disappear; methane only exists in our oxygen-rich atmosphere because it's continuously replenished by biological processes, it "burns" relatively fast (yes, giving carbon dioxide, but that's another side of the question) If jt were released fast, from the Siberian tundra because of one warm winter following several years of permafrost reduction, it could trigger a feedback effect (over a few years, maximum) There again, it might not - climate models just aren't good enough, and information about reserves of methane not accurate enough, for anything better than "interpolation of data" (that's gobbledegook for "a guess").
    While looking at rising sea levels, take a glance at a relief map of Bangladesh. How many bengali refugees?
  10.  
    Rane Longfox

    Rane Longfox Red Rane

    Joined:
    Jul 30, 2004
    Messages:
    2,662
    What people generally fail to realise is that no one knows what causes global warming in the first place. The greenhouse effect is a pretty well researched and documented phenomena, and is caused by CFCs, but it hasn't even been proved that the greenhouse effect has a significant effect on global temperatures anyway.

    Bottom line is, we have no idea what causes global warming, and the most likely answer is that it's a natural phenomenon that we can do nothing about. But that doesn't sound good in news headlines, does it...

    Gosh, I'm getting cynical in my studenthood:eek:
  11.  
    Green

    Green Sick and Tired

    Joined:
    Jun 10, 2005
    Messages:
    808
    You won't find many environmental chemists and climatologists these days who would tell you that the presence of greenhouse gases and human involvement in their production is not linked, with any reasonable doubt, to the increase in global warming. The ones you would find might just have links to anti-global warming lobbies and their related corporations. Not necessarily, but there you go.

    Records from ice digs have shown increased levels of CO2 (and CH4) coinciding with increased global temperatures, indicating levels of the kind of positive feedback mechanism that Chris talks about being present in the past. Now, I'm not saying we're on the verge of a mass extinction, I'm just talking about the presence of such a mechanism in the past.

    PS - Chris, do you mean "extrapolation?"
  12.  
    jackokent

    jackokent Jack of all trades

    Joined:
    Feb 23, 2006
    Messages:
    1,166
    I saw something the other day on TV (and I warn you now I am not in anyway a scientist and have no idea what I am talking about) about a tidal convector. This is powerd by sea water dropping (or something) and creating a big current that drives things like the gulf stream round the British Isles.

    Apparantly all the fresh water from the ice melting and increased flow from of rivers in places like siberia have flooded the convector with fresh water. At some point it will have so much fresh water it will stop. This will be a sudden catastrophy and instead of causeing warming, will cause Northern Europe to freeze. It will then cause dessert conditions in current rain forest areas. The program was basically suggesting the effect of the convector stopping would be as catastrophic as all the other stuff and we are not gearing up for it in any way. Also, they had some chap taking samples and the salinity of the convector has reduced so dramatically and so quickly they were saying it could stop in as little as 20 years.

    I found it all very scarey but don't know if anyone else has any info on this.
  13.  
    Lenny

    Lenny Edit Ninja In Training

    Joined:
    Jan 11, 2007
    Messages:
    3,741
    A year or so ago it was predicted that before the end of the century, the gulf stream will have shifted by 7 degress. It's already moved by about 0.5 degrees.

    It may not sound like much, but it will bring change to Britain especially, with a big freeze, like you said, as well as a different weather system. We'll be seeing many more hurricans and tornadoes than we have been.
  14.  
    Green

    Green Sick and Tired

    Joined:
    Jun 10, 2005
    Messages:
    808
    I think an increase of about 5 degrees globally is mass-extinction time (if my Discovery Channel is telling me the truth), so 0.5 degrees is actually quite a lot.
  15.  
    Lenny

    Lenny Edit Ninja In Training

    Joined:
    Jan 11, 2007
    Messages:
    3,741
    Not heat-wise.

    Movement along the lines of latitude.
  16.  
    Green

    Green Sick and Tired

    Joined:
    Jun 10, 2005
    Messages:
    808
    Ah, right. What kind of impact does 7 degrees latitude have, then (apart from the migration of species)? I have trouble with picturing how much that is :)
  17.  
    Lenny

    Lenny Edit Ninja In Training

    Joined:
    Jan 11, 2007
    Messages:
    3,741
    It's apparently enough to divert the Gulf stream right past England - no more heating for us.

    If the giant ice shelves in Iceland melt, that'll havethe same type of impact... only ten times faster.
  18.  
    jackokent

    jackokent Jack of all trades

    Joined:
    Feb 23, 2006
    Messages:
    1,166
    This program suggests that the climate change will mean that British Isles will be surrounded in sea ice and many rain forests in other side of the plant (for some reason that went way over my head) will vanish because there will be no rainfall there at all.

    The scarey thing was the speed of this thing happenning. They were saying if the flow stopped (which it definately will one day) it will stop suddenly, we'll get no warning and all the other stuff will happen.
  19.  
    Dave

    Dave Wherever I Am, I'm There Staff Member

    Joined:
    Jan 5, 2001
    Messages:
    14,167
    It is ppmv. I think I've posted these links before, but they make it more clear:
    CO2 Trends Mauna Loa 1957-1999
    Mauna Loa is a volcano in Hawaii. High up and not near any local source of pollution. If you look closely at the graph it is not a straight line. It goes up and down every single year. It goes up in the Winter and down in the Summer. Only it always goes up more than it goes down.

    CO2 Trends Law Dome 1008-1999
    Law Dome is in Antarctica and this graph uses ice core samples. In some ways it is even more graphic. The graph becomes exponential in the last few years.

    I first saw these graphs 25 years ago. They had a profound effect on me then, yet nothing has changed in the years since. Even if you still believe there is no global warming, or you think that global warming is unrelated to the level of CO2, you must at least say that such a large scale experiment that we are conducting on the Earth's atmosphere is a bad idea.

    The Earth has had higher levels of CO2 before. But it was a time of more primitive plants and animals, and there have also been countless mass extinctions in the past too.
  20.  
    Green

    Green Sick and Tired

    Joined:
    Jun 10, 2005
    Messages:
    808
    Going off "An Inconvenient Truth," this is due to the fact that the northern hemisphere has a lot more landmass (and, therefore, vegetation) than the southern hemisphere. So when it's winter for the north, more CO2 is given out than when it's winter for the south. And then global warming causes the difference in increase/decrease. Or something.

    Anyway, you probably knew this, but I still think it's fascinating :) People should watch this film/lecture - it is entertaining, if nothing else.

    I am the kind of person that tends towards the "I don't care, where's my local cinema?" attitude, but even I have recently started to worry about global warming. So it must be important :D

    I wish that America (its policies, not necessarily its population) would start to actually do something about its emissions. At least some countries are paving the way, and the UK is getting better, too :)

Share This Page