Forum

 
  Back to OzPolitic.com   Welcome, Guest. Please Login or Register
  Forum Home Album HelpSearch Recent Rules LoginRegister  
 

Pages: 1 2 3 ... 16
Send Topic Print
Climate Change Debate (Read 26342 times)
pjb05
Gold Member
*****
Offline


OzPolitic

Posts: 1404
Gender: male
Climate Change Debate
Mar 22nd, 2008 at 6:21pm
 
Quote:
Climate models of today are considerably more accurate than those of the early 80's, but the interesting thing is that using some of the earliest models, we can predict what has happened over the last 20 years or so - with no iteration involved. Long term climate is largely deterministic, whereas short-term weather is stochastic. 

There are some natural influences of course, and the biggest errors are related to polar effects, aerosols and cloud albedo modelling. There are also cyclical effects such the Southern Oscillation Index and the effects of large explosive volcanoes, such as Mt Pinatabo. La Nina episodes such as the one we are currently experiencing generally have a short-term global cooling effect, as do explosive volcanoes.

- but the biggest single factor that we can't model is the response of mankind. How quickly can we curb emissions and develop alternative energy sources? The latest IPCC synthesis reports provides us with a range of possible scenarios.


These models still rely on making assumptions about processes that aren't fully understood, eg the role of clouds and water vapour. 
Back to top
« Last Edit: Mar 22nd, 2008 at 10:18pm by N/A »  
 
IP Logged
 
Musician35
Ex Member


Re: Renewable Energy Sources
Reply #1 - Mar 22nd, 2008 at 6:41pm
 
Could you explain further what you mean? There are feedbacks that are not fully accounted for, but generally these are all positive feedbacks.

If you mean that the IPCC synthesis report for 2007 is inaccurate due to political pressure, mainly from China, I agree with you.

I know one climatologist personally, and from what he says, the IPCC report was not even discussed in much depth in Bali, because it was woefully understating the reality.

Even though the IPCC Third Assessment Report (WG1- 2001) was much more conservative than AR4 last year, the real situation is much worse.
Back to top
 
 
IP Logged
 
pjb05
Gold Member
*****
Offline


OzPolitic

Posts: 1404
Gender: male
Re: Renewable Energy Sources
Reply #2 - Mar 22nd, 2008 at 7:08pm
 
Quote:
Could you explain further what you mean? There are feedbacks that are not fully accounted for, but generally these are all positive feedbacks.

If you mean that the IPCC synthesis report for 2007 is inaccurate due to political pressure, mainly from China, I agree with you.

I know one climatologist personally, and from what he says, the IPCC report was not even discussed in much depth in Bali, because it was woefully understating the reality.

Even though the IPCC Third Assessment Report (WG1- 2001) was much more conservative than AR4 last year, the real situation is much worse.  


They are assumed to be positive feedbacks, but whether we know enough to be sure this is the case is another matter. If these assumptions are wrong then all the modeling and predictions become invalid.
Back to top
 
 
IP Logged
 
freediver
Gold Member
*****
Offline


www.ozpolitic.com

Posts: 53355
At my desk.
Re: Renewable Energy Sources
Reply #3 - Mar 22nd, 2008 at 7:11pm
 
PJ I didn't say you can't draw a line around it. I even conceded that you could. It's the conclusion you draw from that which doesn't hold water.

Not only is it senseless to claim that because you are a small part of a big problem and a small part of a big solution that you might as well not bother, but in Australia's case the implications of our choice are far stronger than for any other group of 20 million people, because we are a welathy western country with the highest per cpaita emissions. Refusing to particpate in the global solution will have a far greater impact that our population alone would suggest.
Back to top
 

People who can't distinguish between etymology and entomology bug me in ways I cannot put into words.
WWW  
IP Logged
 
freediver
Gold Member
*****
Offline


www.ozpolitic.com

Posts: 53355
At my desk.
Re: Renewable Energy Sources
Reply #4 - Mar 22nd, 2008 at 7:13pm
 
pjb05 wrote on Mar 22nd, 2008 at 7:08pm:
They are assumed to be positive feedbacks, but whether we know enough to be sure this is the case is another matter. If these assumptions are wrong then all the modeling and predictions become invalid.


Of course they are positive feedbacks. You don't need a degree to understand that reduced snow cov er will add to the heating effect.
Back to top
 

People who can't distinguish between etymology and entomology bug me in ways I cannot put into words.
WWW  
IP Logged
 
pjb05
Gold Member
*****
Offline


OzPolitic

Posts: 1404
Gender: male
Re: Renewable Energy Sources
Reply #5 - Mar 22nd, 2008 at 7:36pm
 
freediver wrote on Mar 22nd, 2008 at 7:11pm:
PJ I didn't say you can't draw a line around it. I even conceded that you could. It's the conclusion you draw from that which doesn't hold water.

Not only is it senseless to claim that because you are a small part of a big problem and a small part of a big solution that you might as well not bother, but in Australia's case the implications of our choice are far stronger than for any other group of 20 million people, because we are a welathy western country with the highest per cpaita emissions. Refusing to particpate in the global solution will have a far greater impact that our population alone would suggest.


Its total emissions that count - not per captia of a small country, if man made global warming really is a problem. Trying to slash our high per capita emissions will have huge consequences for our economy and quality of life and is not the easy fix you seem to make out.  
Back to top
 
 
IP Logged
 
freediver
Gold Member
*****
Offline


www.ozpolitic.com

Posts: 53355
At my desk.
Re: Renewable Energy Sources
Reply #6 - Mar 22nd, 2008 at 7:52pm
 
You aren't making any sense PJ. Sure, it's the total emissions that count. But If you insist that we make small contribution then you also have to accept that the cost of reducing our emissions is equally small - probably smaller given our relative profligate waste. Otherwise you are just being selfish and hypocritical. It's a fairly simple concept. Any group of 20 million people could make the same argument. We all have to do our part, not try to pretend we are a special case because you can draw a smaller circle around us.
Back to top
 

People who can't distinguish between etymology and entomology bug me in ways I cannot put into words.
WWW  
IP Logged
 
pjb05
Gold Member
*****
Offline


OzPolitic

Posts: 1404
Gender: male
Re: Renewable Energy Sources
Reply #7 - Mar 22nd, 2008 at 8:07pm
 
freediver wrote on Mar 22nd, 2008 at 7:52pm:
You aren't making any sense PJ. Sure, it's the total emissions that count. But If you insist that we make small contribution then you also have to accept that the cost of reducing our emissions is equally small - probably smaller given our relative profligate waste. Otherwise you are just being selfish and hypocritical. It's a fairly simple concept. Any group of 20 million people could make the same argument. We all have to do our part, not try to pretend we are a special case because you can draw a smaller circle around us.


No it won't be equally small. We are a small part of the world economy, just we are a small part of the world's emissions. But to slash our emissions won't be a small cost to us as a nation.

How do you propose we do it? All you seem to be proposing is a tax on carbon. That won't magically reduce our emissions. Deep cuts are a huge ask and I don't think renewables are up to it. Clean coal or nuclear might but really requires governments to mandate the technology and large capital investments.
Back to top
 
 
IP Logged
 
Musician35
Ex Member


Re: Renewable Energy Sources
Reply #8 - Mar 22nd, 2008 at 8:15pm
 
First of all, I'd like to discuss this if possible in a non adversarial way. I think we'll achieve more understanding by talking through the issues.

The science behind climate change is extremely subtle, and it took me a good 5 years for me to understand all the implications of it myself, however some very basic principles apply.

The feedbacks I'm talking about are not crucial to the fact that Global Warming is happening and that it is largely anthropogenic. We've gone way beyond that in our understanding.

Sure there are skeptics, and I think I've read just about every argument presented, and looked at counter arguments by climate scientists and counter - counter arguments etc.

Having gone through this process in detail, I am convinced that Climate Change poses a real threat - not all of it due to temperature increase or rising sea levels alone.

I think the most old and infirm of the Australian population could probably outrun sea level change.  Some of the other intangibles include salination of coastal aquifers, reduction in the calcification rates of certain crucial marine organisms, such as coccolithophorids and corals.
The pH of sea water has already decreased globally by 0.1 from 8.3 to 8.2. We can very accurately predict the rate of calcification based on Seawater pH, and we can predict Seawater pH change very accurately from atmospheric pH.  A recent paper in December last year showed that a level of 450ppm was likely to cause extinction of the vast majority of coral species in the world today. This level is projected to occur around 2050. That's not very far off.

The melting of tropical glaciers is likely to have far ranging consequences for water supplies in highly populated countries like India and China, and will affect local weather patterns including monsoons.

PJ - The point you make about global emissions is correct, and I also agree that we need to take into account economic factors. We can't make huge technological shifts while we're bankrupt.  Clean coal may well have a role to play in the near future, but nobody to date has actually costed this out.
Back to top
 
 
IP Logged
 
pjb05
Gold Member
*****
Offline


OzPolitic

Posts: 1404
Gender: male
Re: Renewable Energy Sources
Reply #9 - Mar 22nd, 2008 at 8:43pm
 
Regarding CO2 and ocean pH I found this blog which raises some interesting points:


1). This confirms that the alarmists are feeling the heat badly. First, the woeful rebutall by Environmental Defense and Michael Oppenheimer to the Senate Report and now this. They know they are losing the scientific debate badly nowadays, so they are openly admitting that a change in tactics is required. Nothing like changing the rules of the debate when you find yourself being clobbered.

2). It remains that since 1850, the total of human emissions (even including those from land use changes) consists of about 500 billion metric tons of carbon. According to the models, about 45% of that has remained in the air, the rest going 50/50 to the oceans and land. So this means that approximately 138 billion metric tons of carbon have gone into the ocean. According to the models.

Now, the ocean's reservoir of carbon stands at around 40,000 billion metric tons, the vast majority of which is dissolved in the lower depths, where pressure and coldness promotes absorption of far more CO2. Warmer surface waters tend more easily to release it.


So here are two things to consider.

A). Assume that the preindustrial surface ocean contained 1030 minus 138, or 892 billion metric tons. Following that proportion, the present surface ocean would seemingly be 15% more rich in CO2. Given that the ocean is a complex buffer solution, resisting pH changes, can a 15% increase of CO2 actually bring about the 0.1 pH change that is claimed? This question goes to the heart of the issue. (By the way, a 0.1 pH change represents a 26% increase of hydrogen ions.)

B). If it turns out that a 15% increase cannot bring about such a change, yet the 0.1 pH change is true, then consider thermohaline currents. To me it seems very reasonable to suppose that a warming ocean would circulate heat to the lower depths and thus release some of the CO2 dissolved there. This would rise up into the surface waters and necessarily influence the pH. It is entirely possible, then, that to the extent pH changes ARE real, they originate not from the sky but from the ocean below.

Just as Gore and others have the CO2/Temperature relationship backwards, prevailing assumptions about ocean acidification may be backwards too.

3). The most recent posting at CO2Science.org on this suggests that the extra CO2 stimulates biological growth in the upper ocean, which in turn is known to increase pH. So, maybe there is a biological negative feedback that helps stabilize ocean pH values?

4). According to Anthoni, whom I've cited before:

The most important limiting factor in aquatic ecosystem is the dearth of hydrogen ions (H+), which has also been overlooked. The more acidic the water, the higher biological productivity becomes, and the denser the amount of life. In the sea this is borne out by the observed fact that highly productive upwelling areas are more acidic. In other words, acidic seas are a good thing.

Bottom line, this is a confusing topic. But it does seem safe to say that how organisms use the pH that's available to them is not to be found or predicted in chemical calculations alone. I think Marc is right on target, then, that the ocean acidification issue should not be given a free pass. My own observations lead me to suspect that the present model of CO2 distribution is flat wrong. For instance, if the preindustrial ocean had nearly the same carbon content as the present one, fine, let's grant it around 40,000 GtC. But then the preindustrial atmosphere weighed 590 GtC compared to our 815. The partial pressure exerted by that preindustrial atmosphere being much less, the ability of the ocean to hold onto CO2 would have to have been correspondingly less too - in which case its carbon content could NOT have been 40,000 GtC. In short, the preindustrial ocean should have been degassing CO2 in response to the relative vacuum above it.

But if on the other hand we say, no, the preindustrial ocean was colder, so it held onto CO2 better - then we admit that the present ocean, being warmer, should be discharging CO2. And this point ties into Lance Endersbee's analysis, which shows atmospheric CO2 rising as a function of ocean temperature. But where, anywhere within the IPCC model, does it attribute rising atmospheric CO2 levels to a warming ocean? Nowhere. In fact it makes the ocean a passive sink rather than an active source. As a sink, yes, it should be getting more acidic. But as a source - CO2 upwelling from warming reservoirs below - surface waters would ALSO become more acidic. That's my point.



Back to top
 
 
IP Logged
 
pjb05
Gold Member
*****
Offline


OzPolitic

Posts: 1404
Gender: male
Re: Renewable Energy Sources
Reply #10 - Mar 22nd, 2008 at 8:50pm
 
Here's a study which suggests higher CO2 levels will increase phytoplankton growth:

Global warming: Oceans could absorb far more CO2, says study
Nov 11, 2007

PARIS (AFP)  The ocean's plankton can suck up far more airborne carbon dioxide (CO2) than previously realised, although the marine ecoystem may suffer damage if this happens, a new study into global warming says.

The sea has soaked up nearly half of the CO2 that has been emitted by fossil fuels since the start of the Industrial Revolution.

The gas dissolves into surface waters and is then transported around the oceans.

But a key role is played by plant micro-organisms called phytoplankton, which take in the dissolved gas at the ocean's sunlit surface as part of the process of photosynthesis. This plankton dies and eventually sinks to the ocean floor, thus storing the carbon for potentially millions of years.

One of the big questions is how much more of CO2 the sea can absorb.

If, like a saturated sponge, the oceans cannot take up any more, atmospheric concentrations of CO2, the principal greenhouse gas, would sharply rise and stoke global warming.

Another concern is that rising levels of dissolved CO2 also causes acidification of seawater. Wildlife such as coral, which secretes a skeletal structure, are known to be affected by acidification but the impact on other marine species is largely unknown.

In an innovative experiment reported on Sunday in Nature, researchers closed off part of Raune fjord in southern Norway to see how plankton reacted to different levels of CO2.

They used nine large enclosed tanks of seawater that were exposed to CO2 concentrations likely to prevail over the next 150 years.

These three levels were today's concentrations of CO2; double that concentration, to simulate the air in 2100; and triple, replicating the air in 2150).

To feed the plankton, the researchers added nutrients to simulate food usually brought up by ocean currents and upwelling, and then monitored plankton levels over the next 24 days.

The investigators found that, the higher the CO2 level, the more the plankton bloomed.

The organisms were able to gobble up to 39 percent more dissolved carbon compared with today, but did not need any additional nutrients to achieve this.

The findings "underscore the importance of biologically-driven feedbacks in the ocean to global change," say the authors, led by Ulf Riebesell of the Liebniz Institute of Marine Sciences in Kiel, Germany.

The paper, though, warns that taking the carbon out of the air and placing it into the sea could cause problems.

Algal blooms could inflict oxygen depletion in some parts of the ocean while rising carbon levels may cause an imbalance in primary nutrients, with implications that could ripple across the marine food web.

Supporters of so-called geo-engineering -- unconventional projects aimed at easing global warming -- have been closely looking at plankton, seeing in it fantastic potential as a carbon sponge.

Their schemes entail sowing the sea with iron filings and other nutrients to encourage plankton growth and thus suck up more of the atmospheric CO2.

Mainstream scientists say such experiments are unjustified, given the uncertainty surrounding the environmental impact and the many knowledge gaps that persist about ocean topography and currents.
Back to top
 
 
IP Logged
 
Musician35
Ex Member


Re: Renewable Energy Sources
Reply #11 - Mar 22nd, 2008 at 9:55pm
 
Do you actually understand what is being said here, or are you just cutting and pasting?

You've cut and pasted quite a lot of details. Would you understand enough if I were to rebutt every point made, or would I be wasting my time because you don't understand the science?

You also neglected to show the source:

http://awesternheart.blogspot.com/2008/01/greenies-getting-rattled-now.html

The most amusing part of the commentary was this:

"Just as Gore and others have the CO2/Temperature relationship backwards, prevailing assumptions about ocean acidification may be backwards too."

Gore as in Al Gore? The famous politician? He isn't even a climate scientist, he's basically a messenger. In fact I very much doubt if Al Gore understands very much of what he says.

Point 2 is totally misleading. The "models" that it refer to is a single diagram taken from the IPCC   Working Group I report in 2001. It isn't actually a model, it's a simple diagram showing a snapshot of the global carbon fluxes in 2001. He then assumes that this model has been valid since 1850!

Point 4 is almost as entertaining as his Al Gore Remark. First he makes an assumption that the carbon content of the oceans in 1850 was 40,000 Gigatons, then later he states that this assumption (which he made himself) could not possibly be correct. What's he trying to say here?

The purpose of his post is basically to muddy the waters. Of course the actual mechanism for ocean pH reduction is complex, but the root cause for all the mechanisms proposed by all the workers cited is a combination of increased CO2 emissions, reduction of carbon sinks and some increase in temperature.   
Back to top
« Last Edit: Mar 22nd, 2008 at 10:34pm by N/A »  
 
IP Logged
 
Musician35
Ex Member


Re: Renewable Energy Sources
Reply #12 - Mar 22nd, 2008 at 10:09pm
 
pjb05 wrote on Mar 22nd, 2008 at 8:50pm:
Here's a study which suggests higher CO2 levels will increase phytoplankton growth:


(First of all I promise not to cut and paste, except from my own articles.)

Fine. We need studies like that to fine-tune our understanding of the process. So far nothing that you have said so far has denied the fact that the Ocean pH is falling.  I mentioned calcification earlier. That refers to the reliance on marine organisms to deposit calcium carbonate from sea water.

OK, the obvious organisms that are being affected by ocean acidification include corals, crustaceans and even some tiny plant-like creatures called coccolithophores which form calcium carbonate skeletons and drive a pump, essentially, where CO2 is absorbed by the ocean. They too are under threat. In the Southern Ocean, coccolithophores have been shown to be responsible for up to 30% of the CO2 absorption.

Then there are increasing cases of very interesting new diseases in crabs and lobsters which are basically caused because things are not calcifying anymore, and they're not calcifying at a rate that keeps up with the processes that take away that calcium carbonate.

Fish have a single crystal of calcium carbonate beneath their brain. They're called otiliths, and they're used for balance. Basically fish can't survive without them.

Otiliths grow during the lifetime of the fish if the conditions are right for the deposition of calcium carbonate. As the pH decreases, the rate of calcification also decreases.

It's not the absolute values that are important, rather the rate of change, and the somewhat different conditions that exist today compared with the past. We're talking extremely high human population, an almost unprecedented rate of change in atmospheric CO2 which is demonstratively derived from fossil fuels (from the isotope ratios) and we're talking about changes that are happening too fast for ecosystems to adapt.

I'll elaborate further, but first let's put temperature rise in some kind of perspective.

The most recent work on grain for example yields indicates that the small amount of warming that has already occurred has reduced what the yields are today over what they would have been just based on technological change. In other words the yields haven't been going down but they haven't been going up as fast as they might have because of the problems of crop varieties having thermal limits on them, particularly the world's feeding base which of course are those three famous grains- Wheat Rice and Corn.

Taking rice as an example - it's within two or three degrees of its limit over most of Asia.

http://news.bbc.co.uk/1/hi/sci/tech/1645590.stm

What this is all about is averting human disasters. We currently have 6.77 billion people and counting. It's all very well to talk about the geological past, mass extinctions included, but the important issue is the here and now. What will be the effects on the staple foods now - fish stocks, rice, wheat and corn?

Of course, we should be able to breed new strains that will be able to do just great when the planet is 6°C or 7°C hotter. There are actually such seed banks, but what you do with seed banks is that you select organisms for storage attributes not for their ability to reproduce under new climatic conditions. The only way to save the genetic diversity of crops is to keep planting them out in diverse circumstances and diverse strains and subsidise farmers to grow less productive ones so you have the diversity safe.

However, they're not doing that - they're not even thinking about it over most of the world.

Times have changed since the beginning of the Eocene, and even since the medieval period.

- like the fact that we have 6.77 billion people instead of 150 Million during Medieval times, or the fact that we now have 1/100 of the Tropical rainforest that we did then, and that fish stocks are down by 99% on Viking days. The buffering effect of 'Gaia' has certainly declined considerably since the peak of the Eemian interglacial, 125,000 years ago, when global temperatures were higher than today and sea levels were some 4-6 metres higher. The current atmospheric carbon dioxide is now 383 ppm compared with a peak of 225ppm at the height of the Eemian.

The last time we had 383 ppm CO2 in the atmosphere was just after the Paleocene Eocene Thermal Maximum (PETM). Now that makes for some very interesting reading.
Back to top
« Last Edit: Mar 22nd, 2008 at 10:23pm by N/A »  
 
IP Logged
 
pjb05
Gold Member
*****
Offline


OzPolitic

Posts: 1404
Gender: male
Re: Renewable Energy Sources
Reply #13 - Mar 23rd, 2008 at 12:02pm
 
Do you actually understand what is being said here, or are you just cutting and pasting?

You've cut and pasted quite a lot of details. Would you understand enough if I were to rebutt every point made, or would I be wasting my time because you don't understand the science?

Now thats not very nice. I thought you said you wanted to discuss the issues in a reasonable non-adversarial way? What's actually wrong with cutting and pasting? I'm not a published climate scientist and I suspect neither are you. We have to refer to the work of others. 

You also neglected to show the source:

http://awesternheart.blogspot.com/2008/01/greenies-getting-rattled-now.html

I said it was a blog.

The most amusing part of the commentary was this:

"Just as Gore and others have the CO2/Temperature relationship backwards, prevailing assumptions about ocean acidification may be backwards too."

Gore as in Al Gore? The famous politician? He isn't even a climate scientist, he's basically a messenger. In fact I very much doubt if Al Gore understands very much of what he says.

Actually he studied environmental science at uni, he barely scraped through with a pass I heard. In any case what is wrong with countering/ questioning his claims? Given that he is at the forefront of the global warming campaign its quite an admission to say he doesn't understand much of what he says!

Point 2 is totally misleading. The "models" that it refer to is a single diagram taken from the IPCC   Working Group I report in 2001. It isn't actually a model, it's a simple diagram showing a snapshot of the global carbon fluxes in 2001. He then assumes that this model has been valid since 1850!

Point 4 is almost as entertaining as his Al Gore Remark. First he makes an assumption that the carbon content of the oceans in 1850 was 40,000 Gigatons, then later he states that this assumption (which he made himself) could not possibly be correct. What's he trying to say here?

The purpose of his post is basically to muddy the waters. Of course the actual mechanism for ocean pH reduction is complex, but the root cause for all the mechanisms proposed by all the workers cited is a combination of increased CO2 emissions, reduction of carbon sinks and some increase in temperature.  

He said that increase in temperature migh be a cause of lower ocean PH. That doesn't mean that the increase in temperature is man made. The other points highlight the complexities and possible negative feedbacks. You call this 'muddying the waters'.   

Back to top
 
 
IP Logged
 
Musician35
Ex Member


Re: Climate Change Debate
Reply #14 - Mar 23rd, 2008 at 1:23pm
 
First of all, I don't defer to Al Gore for my information, and the very fact that he is a political figure is unhelpful because it polarises opinion about party lines. This is not some leftish plot. We're talking about measurable increases in atmospheric carbon dioxide - around 30% since industrialisation which have led to measurable increases in Global temperatures in line with Arrhenius Equation predictions.

Quote:
He said that increase in temperature might be a cause of lower ocean PH. That doesn't mean that the increase in temperature is man made. The other points highlight the complexities and possible negative feedbacks. You call this 'muddying the waters'. 


That may be what he's trying to say, but he shows a very rudimentary understanding of the relationship between seawater pH and atmospheric CO2 concentration. These people take research totally out of context. The researchers involved take pains to point out that  their findings do not deny that anthropogenic global warming is taking place.

If you don't accept that the observed temperature increase is man made, what do you attribute it to?
Back to top
 
 
IP Logged
 
Pages: 1 2 3 ... 16
Send Topic Print