Thread: Climate change
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Old 03-06-2007, 21:30   #36
simon simon is offline
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Join Date: Jun 2003
Location: England
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Originally Posted by Argos View Post
Congratulations! You are the first to call the authors deniers. Nobody denies global warming. They made their study for the time between 1850 to 2000 (the time of publication was 2001) and because they used averaging techniques for the graph, they skipped the first and last ten years to avoid unreal artefacts. I don't know what you have to complain there.
It wasn't to avoid 'unreal artefacts', but because the pattern they were claiming can't be seen after 1980. The pattern of warming after 1980 is what needs to be explained. It's acknowledged that solar activity has had an influence on temperatures in the past and that was the traditional explanation for most temperature changes. But solar activity can't explain the pattern of warming since 1980 and so can't explain the 0.6C warming we've seen in the last 30 years, which is the main evidence that global warming is happening.


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You're right, big mistake, obviously I got lost during converting units. Thanks for clearing *embarrassed*
After I caught you making such an elementary error, I'm surprised you still have the nerve to claim that you know more about this than me. Nobody who is at all familiar with the issue or scientific units would claim that human carbon dioxide emissions are only 1/1000th of what they really are and use that to claim that CO2 emissions from volcanoes are greater. It reveals that you're just a big mouth with no real knowledge of this subject.

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Well, I oversimplified a bit. The average of the last 50 years would be 1.5 ppm - in reality the slope of the accumulation increases constantly, but this can be seen since the last 'little ice-age' at the end of the 16th century. Whatever is the reason, it has to be in the past, not the present.
The ice-core record shows that the atmospheric CO2 concentration was fairly constant around 280ppm until about 1800, since which it has increased increasingly rapidly.

Here are some graphs of what has happened over recent centuries.

And here are graphs and commentary about the last 650,000 years. The CO2 concentration was always between 180ppm (in the depths of the coldest ice ages) and 300ppm (in the warmest interglacials). Since 1800, though, the concentration has increased from 280ppm (which had been pretty stable for the last 10,000 years of this interglacial) to 380ppm in 2006.

The increase can be tied to the Industrial Revolution because that's when it started, it has been accelerating as human carbon dioxide emissions have been increasing and because the isotopic ratio shows that most of the additional carbon came from fossil sources, rather than somewhere in the biosphere.

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The colonization of Australia is a good example, that adaption from species of cool temperate climate to a much hotter climate is not a big problem. You can easily plant most of your plants at home in UK into a tropical country without serious trouble, whereas to transplant in arctical regions it's often very difficult, if not impossible. The main adaption problem is competition, which is dramatically increased in tropical regions, not so much the climate.
Rabbits and sheep aren't an ecosystem. Some temperate species can make the transition, but a lot can't. Your view certainly isn't shared by the experts. This paper from the journal Nature estimates that 15-37% of a representative sample of species are at risk of extinction from expected global warming by 2050.


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As for the speed of temperature increase, here is a quote from the NCDC on abrupt climatic changes in the past:

For reference

"During a brief period called the Younger Dryas, after temperatures in most of the Northern
Hemisphere had begun to warm from the last ice age, they rapidly returned to near-glacial
conditions. After about 1,000 years, they abruptly warmed again, with temperatures in Greenland warming by eight degrees Celsius (+14°F) in a decade. By comparison, the change in the global mean annual temperature over the last 140 years has been less than 1°C..."
That's describing a change in Greenland. The Younger Dryas event most affected the North Atlantic region and was centred on Greenland. What's more, changes in temperatures near the poles tend to be much greater than the global average - that's why we get ice ages with relatively small changes in global average temperatures. For example, Alaska has warmed by 6C in the last 30 years while the global average increase has been 0.6C. An additional 1.3C increase in global temperatures will probably trigger the complete and irreversible melting of the Greenland ice sheet.

Even so, the start of the Younger Dryas was rather unpleasant. At exactly the same time most of the large animals in North America went extinct and the human hunter-gatherers who lived there (the Clovis people) were wiped out.

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We can't blame everything on industrial revolution and exploitation of natural ressources.
We can, because the isotopic ratio shows that the additional CO2 in the atmosphere since 1800 is overwhelmingly from the burning of fossil fuels.

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Things we see now, have happened numerous times before.
There has been nothing like such a rapid and large change in CO2 concentrations in the 650,000 years of the ice-core record.

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The predictions of climate models are based on small data sets with significant lack of data for the oceans (currents, salinity, acidity, vertical distribution of their values and influence of it's biomass), the formation and energy balance of clouds (serious research begun only recently) and turbulances in the atmosphere are studied not well enough to come to firm conclusions about the future. At least nice mathematical playing around!
Don't believe what you read on propaganda websites that tell you that volcanic carbon emissions are greater than human emissions. The models do deal with oceans and clouds. There is an enormous mass of scientific evidence which has convinced nearly all the world's scientists. That's why they're raising the alarm.

Last edited by simon; 03-06-2007 at 22:16.
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