A couple of points of clarification:

1) I never denied climate change. In fact, I believe change is the only thing truly consistent regarding climate. Timeframes being relative and all.

2) I didn't say "greenhouse effect", I said "runaway greenhouse effect".

**brief disclaimer - unlike some of the other prophets that have posted in this thread I don't claim to know the exact truth of climate change vis a vis mankind. Obviously misuse of resources, desertification, deforestation, pollution, corruption of water sources, etc.. are all real problem that must be addressed.

If the issue were addressed properly as unsettled and highly theoretical science then it would be less offensive. Especially if they actually held themselves to an empiric standard.

Link

Quote: Last Monday - on ABC Radio National, of all places - there was a tipping point of a different kind in the debate on climate change. It was a remarkable interview involving the co-host of Counterpoint, Michael Duffy and Jennifer Marohasy, a biologist and senior fellow of Melbourne-based think tank the Institute of Public Affairs. Anyone in public life who takes a position on the greenhouse gas hypothesis will ignore it at their peril.

Duffy asked Marohasy: "Is the Earth stillwarming?"

She replied: "No, actually, there has been cooling, if you take 1998 as your point of reference. If you take 2002 as your point of reference, then temperatures have plateaued. This is certainly not what you'd expect if carbon dioxide is driving temperature because carbon dioxide levels have been increasing but temperatures have actually been coming down over the last 10 years."

Duffy: "Is this a matter of any controversy?"

Marohasy: "Actually, no. The head of the IPCC (Intergovernmental Panel on Climate Change) has actually acknowledged it. He talks about the apparent plateau in temperatures so far this century. So he recognises that in this century, over the past eight years, temperatures have plateaued ... This is not what you'd expect, as I said, because if carbon dioxide is driving temperature then you'd expect that, given carbon dioxide levels have been continuing to increase, temperatures should be going up ... So (it's) very unexpected, not something that's being discussed. It should be being discussed, though, because it's very significant."

Duffy: "It's not only that it's not discussed. We never hear it, do we? Whenever there's any sort of weather event that can be linked into the global warming orthodoxy, it's put on the front page. But a fact like that, which is that global warming stopped a decade ago, is virtually never reported, which is extraordinary."

Not enough years have passed to strongly support an actual plateau trend.

Quote: Original post by nobodynews
And what about things like the ice caps? Are they shrinking at rates that match what has happened historically or not? I know that melting ice caps can probably keep things cooler for longer than they would otherwise, much like ice cubes keep our beverages colder than they would otherwise.

I'm pretty sure that premise is flawed.

Recent news on ice caps, btw: http://www.abc.net.au/news/stories/2009/11/25/2752579.htm

Quote: Original post by Gil Grissom
On a different note, if a single year can screw up the trend so badly that it would make it seem that the temperatures no longer rise, then it's clearly not a good idea to use single years as measurement units. Maybe decades would be better. But then the argument about "eight out of ten warmest years have occured after 2000" wouldn't sound as impressive.

Then the current decade would clearly be the warmest on record.

Didn't high school science teach you to draw the line or curve of best fit?





(see also the Wikipedia article for more sourced graphs, and general info*)

As indicated in the second diagram here, El Nino is considered a major factor in the abnormal 1998 year. In both graphs you should see an upward trend in average temperature, though.

*Featured article, apparently, thus probably an extremely reliable source at the moment.

Quote: Original post by Gil Grissom
Add to this the fact that apparently changing the definition of "global temperature" a bit can change the warmest year from 1998 to 2005. And this is while we are still dealing with something that in principle should be directly measurable, we haven't even started making predictions yet.

Global average temperature is "directly measurable", now? I think NASA would pay good money for your thermometer.

Quote: Original post by LessBread
Deniers are either people paid by polluters to mislead other people, people who have been mislead, people with psychological problems or all of the above.

Also people who think Greens are resurgent Communists, but I suspect they'd be a subset of one of the groups already denoted.

Climate change is currently big political news in Australia. The government is pushing through policy on the Environmental Trading Scheme (ETS), and it's currently tearing our federal opposition apart.

That quote from the ABC still seems to be hiding the main point of temperatures this decade, which is that they're the highest on record. While it's technically accurate to say that temperatures have slightly cooled since 1998, it's dishonest as 1998 was the high point. I'm more compelled by graphs showing the average trend over time than comparisons to any one particular year.

(Note though that this use of single data points isn't limited to one side, and it slightly annoys me when both sides do it. It's dishonest to argue, like leading Aussie politicians did last week, that the then current heatwave was "evidence" of global warming. On it's evidence of a freak heatwave, nothing more. It's a general trend of heatwaves over the course of a decade that's more compelling. Grr.)

That said, I think in an ideal world the climate scientists should be discussing their theories about why the data model seems to be plateauing over the last few years. I'm sure they are, in their own scientific circles. The problem is, as you've pointed out, that the whole debate is now extremely politicised, and any cracks in the theory seem to be jumped on as "evidence" that global warming is a myth. And I agree that I do suspect that this is making some scientists skittish about releasing any info that might lead to ammunition against what they think is broadly correct.

Of course actual discussion here on the theories about climate and why there's a plateau in temperatures are going to be beyond my expertise. [grin] The theory I've heard that makes most sense to my high school chemistry level mixed with more advanced chaos theory understanding is that the Earth has a certain tolerance buffer to temperature changes, but only to a certain extent. While weather is a chaotic system, there's a general stable state around what we'd consider "normal", and the weather patterns in the long term tend to stay around that. The problem is that we're changing the parameters of the system by increasing the CO2 in the atmosphere, and that while the weather will still continue to stay around the normal equilibrium it will start to get more chaotic. The real danger is if the weather gets changed so much it shifts to a new equilibrium, one much different from the one we've built our world around. It's like a marble in an egg carton: if you shake it gently it will rock in one cup, shake it more and it will rock harder still in the same cup, but shake it harder still and it will jump to a new cup.

That's why I'm a little bit concerned about the reports of glaciers melting and oceans warming. To my (limited) understand they sound like buffers, absorbing some of the energy in the system, but there's only so much they can take before the weather shifts.

Quote: Original post by Fenrisulvur
Then the current decade would clearly be the warmest on record.

Surely, but that's much less impressive since it's just one decade -- i.e., just one data point.

Quote: Original post by Fenrisulvur
Didn't high school science teach you to draw the line or curve of best fit?

It also taught us that doing that is not necessarily the smartest thing to do. After all, this "cooling trend" was also obtained by drawing a line of best fit between now and 1998.

Also, I don't think anyone in this thread is denying the fact that Earth is generally warming up. The reason I brought up this "10 year cooling" is that it was mentioned in the starting post and then someone asked what it referred to. But I personally and I think everyone else in this thread do believe that global warming does exist. So the question is not so much whether it exists or not, but rather whether it's caused by anthropogenic greenhouse emissions. The point being that if it's not, then limiting emissions is useless.

Quote: Original post by Fenrisulvur
Global average temperature is "directly measurable", now?

Definitely -- all you need to measure it directly is to have a lot of thermometers in a lot of places on the planet and take readings regularly. So, indeed "measurable".

What you are referring to is probably the fact that despite it being "measurable", it wasn't actually measured since in the past people didn't bother to do it.

Quote: Surely, but that's much less impressive since it's just one decade -- i.e., just one data point.

Pertaining to the other thread, Its been shown that children who have grown up bi or multilingual perform better in intelligence tests that children who only know one language,
perhaps if u had this benefit you wouldnt be writing this and other things

Quote: Original post by zedz
Pertaining to the other thread, Its been shown that children who have grown up bi or multilingual perform better in intelligence tests that children who only know one language,
perhaps if u had this benefit you wouldnt be writing this and other things

So then, three unjustified assumptions, a personal attack and zero pertinent arguments? I think we might have a winner...

Quote: Original post by Gil Grissom
Surely, but that's much less impressive since it's just one decade -- i.e., just one data point.

How is that less impressive*?

The last eight or so decades would show a trend of heating with respect to time, and any other trends would be drowned out by such low-resolution datums.

*"Impressive" is a poor choice of wording - I'd probably coin "ominous".

Quote: Original post by Gil Grissom
It also taught us that doing that is not necessarily the smartest thing to do. After all, this "cooling trend" was also obtained by drawing a line of best fit between now and 1998.

Cherry-picking your data. As LessBread pointed out, any statistician would rubbish the conclusion you'd draw from such methodology.
The upward trend is observable from drawing a curve of best fit for all years in the last century and beyond, excluding none.

Also, did the phrase "El Niño" fail to register? 1998 is known to be abnormal.

Quote: Original post by Gil Grissom
Also, I don't think anyone in this thread is denying the fact that Earth is generally warming up. The reason I brought up this "10 year cooling" is that it was mentioned in the starting post and then someone asked what it referred to. But I personally and I think everyone else in this thread do believe that global warming does exist. So the question is not so much whether it exists or not, but rather whether it's caused by anthropogenic greenhouse emissions. The point being that if it's not, then limiting emissions is useless.

And the causative link between global average temperature and human C02 emissions hasn't been illuminated clearly enough for you by the last few decades of climate science?

I'm more inclined to believe you're just a little under-schooled on the subject, and yet not willing to blindly go with the by-and-large scientific consensus on the matter. Start reading, I guess.

Quote: Original post by Gil Grissom
Definitely -- all you need to measure it directly is to have a lot of thermometers in a lot of places on the planet and take readings regularly. So, indeed "measurable".

Considering the ~500 million km2 surface area of Earth, Surely you can accept the likelihood of major deviations between temperature readings provided by the facilities of two separate organizations - before various extrapolations et al are applied to reach a final estimate. "Directly measurable" is a grossly inappropriate description of the task.

Quote: Original post by Fenrisulvur
How is that less impressive*?

Because it's just one data point. It just sounds less impressive than "eight out of 10 hottest years occured in the last decade".

Quote: Original post by Fenrisulvur
Cherry-picking your data. As LessBread pointed out, any statistician would rubbish the conclusion you'd draw from such methodology.

Hmm, did the phrase "not everything you can do by drawing a best-fit straight line is good; for example..." fail to register?

Quote: Original post by Fenrisulvur
And the causative link between global average temperature and human C02 emissions hasn't been illuminated clearly enough for you by the last few decades of climate science?

Unfortunately, not. And not just for me -- for any scientist. Did you read the technical sections of IPCC reports, for example?

Of course, if you do know of any work that definitively establishes human greenhouse emissions as the cause of global warming, I'd be excited to hear. As would be many climate scientists.

Quote: Original post by Fenrisulvur
I'm more inclined to believe you're just a little under-schooled on the subject, and yet not willing to blindly go with the by-and-large scientific consensus on the matter. Start reading, I guess.

Just to illustrate your own schooling, would you care to estimate the volume of natural greenhouse emissions and sinks?

Quote: Original post by Fenrisulvur
Considering the ~500 million km2 surface area of Earth, Surely you can accept the likelihood of major deviations between temperature readings provided by the facilities of two separate organizations - before various extrapolations et al are applied to reach a final estimate.

I surely can, but again -- the fact that it wasn't measured properly does not mean that it couldn't have been measured properly.

Quote: Original post by Fenrisulvur
"Directly measurable" is a grossly inappropriate description of the task.

On the contrary, "directly measurable" is the only appropriate description of a quantity that can be measured directly.

Quote: Original post by Trapper Zoid
That's why I'm a little bit concerned about the reports of glaciers melting and oceans warming. To my (limited) understand they sound like buffers, absorbing some of the energy in the system, but there's only so much they can take before the weather shifts.

The oceans are a buffer too, and they are filling up.

Study: Oceans' intake of CO2 slowing

Quote:
NEW YORK, Nov. 23 (UPI) -- A U.S. study suggests the Earth's oceans' absorption of man-made carbon dioxide might be slowing.

Researchers at Columbia University's Earth Institute note the world's oceans play a key role in regulating climate by absorbing more than a quarter of the carbon dioxide that humans produce by burning fossil fuels.
...
The researchers estimate the proportion of fossil-fuel emissions absorbed by the oceans since 2000 may have declined by as much as 10 percent due to natural chemical and physical limits on the oceans' ability to absorb carbon.
...

See also Ocean Less Effective At Absorbing Carbon Dioxide Emitted By Human Activity



Here's more current news: East Antarctica, Long Stable, Is Now Losing Ice

Quote:
...
Or at least, that's how things have gone until recently. But a new study in the journal Nature Geoscience suggests that this growth spurt may have come to an end. Starting in about 2006, says lead author Jianli Chen of the Center for Space Research at the University of Texas at Austin, East Antarctica started declining, just like the world's other great ice sheets. "The amount [of decline] right now isn't very big, but the trend is alarming," he says.
...
And now it's happening in East Antarctica as well. The new evidence comes from the Gravity Recovery and Climate Experiment, or GRACE. It's a pair of satellites that circle the planet in tandem, moving slightly closer together or farther apart as they fly over regions of higher or lower local gravity — higher over a mountain range, for example, lower over a crater.
...
As for what's causing East Antarctica to lose ice, it's probably much the same phenomenon as in West Antarctica and Greenland. Warming ocean temperatures are melting or weakening the ice where glaciers flow into the sea, and with less ice grinding on the sea floor, there's less friction. That lets ice from the interior flow seaward more quickly. "If you have ice loss," says Steffen, "it has to do with an increase in ice velocity."
...

[Edited by - LessBread on November 25, 2009 4:37:30 PM]