Originally posted by traderonwallst
OH...OK...I gotcha. 50 years worth of data and you can eliminate the sun. I gotcha.

Well, we have about that much for direct data of irradiance. But we have sunspot data going back much longer. They both say the same thing - high activity in the early 20th century, which reached a plateau around 1940-50. If we're going to blame the sun, we need it to be doing the right thing.

Also, to believe that global warming exists means you believe we will never see cooling again. Can I assume that you DO believe that???? Because if you honestly believe cooling will never again occur, I know you are too forgone to continue having this conversation with you, while at the same time if you do agree we will see cooling again, you fall into the trap of believing its cycles.

Trader, you can be frustrating - I've already explained this in the other thread. There's only so much CO2 we can emit, at some point we will run out of fossil fuels. So, when our emissions start to dwindle, at some point after that, CO2 levels might return to some lower level. It will be on the order of hundreds, if not thousands of years. As the biosphere can only remove it so fast. For example, it took 80,000 years during the PETM. But it probably won't be that long, for numerous reasons.

So, essentially, this idea of warming forever is a strawman of the science.

I guess the safe answer would be not to answer.

That's a bit unfair, I've answered almost anything you've asked.

I would prefer that this thread was related to the video though. The other thread is more solar related.

[edit on 14-2-2008 by melatonin]

Originally posted by DINSTAAR
It can not be determined that Co2 or heat cause or effect each other either way.

This was established over 100 years ago. CO2 as a molecule absorbs longwave radiation. In the atmosphere, this process leads to the greenhouse effect from various greenhouse gases.

Check out the work of Tyndall, Fourier, and Arrhenius, which laid the basis for later scientists.

With the information that we have we can determine that one of these three things must be correct, and that we do not have enough information to prove any.

1. Co2 levels in our atmosphere cause warming
2. Warming causes Co2 levels to rise. (and cooling, lower respectively)

Both of these are true. CO2 is a GHG, and so causes warming by radiative forcing. Warming of oceans reduces the solubility of gases in solution.

Both are readily demonstrated in the lab.

The video contains some of this information, especially the historical stuff about CO2 and the greenhouse effect. It might be a good idea for people to actually watch the video before commenting, it might help.

[edit on 14-2-2008 by melatonin]

A few quick points:

On CO2 warming being proven in a lab...well yes, the effects of CO2 in isolation are well known. What is not well known is the dynamic reactions of the global system to changes in CO2 and their effects on temperature. The GCM's rely on positive feedbacks and heavy aerosol cooling to track past temps, and these feedbacks havent really been demonstrated as being a scientific fact. There is considerable uncertainty on the sign of various feedbacks, let alone quantifying the effect.

Secondly, on the sun's role. It is a mistake to take the effects of solar irradiance, plot against temperature, and say there is no correlation and be done with it. The cause and effect is far more complex than that. Fact is, no one can say for sure that the sun is NOT the cause of climatic variation. Svaalgard argues for a higher solar sensitivity than present in most GCM's.

On falling solar activity, have a look at the work of Svensmark. He is putting together a reasonable case for the sun's electromagnetic field having a large effect on climate through its modulation of cosmic rays. Experiments in the lab appear to show that cosmic rays are important in seeding clouds, which in turn cause a cooling effect due to their effect on the earth's albeldo (note that GCM's usually assume a positive feedback on cloud cover). A fall in solar activity leads to an increase in cosmic rays, and hence an increase in cloud cover.

Lastly, to demostrate that CO2 is the causative factor, you need to be reasonably sure of the natural variation and then demonstrate that CO2 is driving the temperature above and beyond that natural variation. Multiproxy studies have established that the current warm period cant reasonably be distinguished from prior warm periods in the last 1000 years (Moberg, Loehle and McCulloch). So there is a lack of evidence that the current warming is unprecented to begin with. Additionally, there is generally a low understanding of many of the natural variances that can affect climate. This is noted by the IPCC in its reports (for example, aerosols are designated as having a low understanding, yet they are required to explain the cooling period last century as well as pulling back the current GCM's from dramatically overprojecting future temperatures).

In short, i think it is nonsense to say that the science is settled, since we have no idea what is driving the climate. The consensus is argued by a realtively small group of climate scientists, and a rather large group of environmentalists and other with vested interests.

Arguing consensus in science is for those who do not have the required scientific evidence to support their case. The science is never settled, and to argue that it is, and there is no point in debating further, is to try and shut down the scientific method.

Originally posted by Long Lance
Melatonin

Hello

i am quite tired to see threads where what some people like to call a discussion does not go so well, get simply ignored. it seems as if being a proponent of GW makes people skip opposing views, reinforcing the impression that a belief system is at work.

Not sure of the point here.

that said, i'm going to use a few previously written passages from the 'call for evidence thread' to supplement this post, for efficiency's sake, but before i do that, let me ask you why

Americans

and by that i believe you mean residents of the USA are singled out?

That was the title of the talk given by Oreskes - an American historian of science. Don't shoot the messenger. Indeed, it's not just an american issue, down-under has a decent denial industry, and to some extent, so does europe. But it is well-organised and funded in the US.

along Traderonwallstreet's line of thinking, how do you explain climate variations in the past? do you think they would never happen again and if so, why?

Probably the same way you would.

I don't think I said that because human effects are currently significant, this negates natural variations. They both exist concurrently. I don't get why people think that it must either be all human, or all natural. Binary thinking is rather a tad too simplistic.

do you believe that human effort could halt climate develeopment here and now and if so, would it be desireable?

Not too sure what you mean by 'climate development'.

The Sahara is believed to have once sported vegetation and even a human population, but their austere and, compared to today, primitive lifestyle seems not to have saved their environment from climate change. the same goes for Viking settlers in Greenland of course. (although in the latter case, it can be argued that planet-killing SUVs might have improved their lot by melting these advancing glaciers /jk)

if climate changes on its own, it follows, the question doesn't just reduce to 'what can we do to save the planet', but 'how do we control its weather patterns', a preposterous proposition and a losing one at that. so, to put it bluntly, in order to do the impossible, we are supposed to try harder and harder, because someone said the world would come to an end if we didn't, while there's ample evidence that similar or worse (than projected for this century) climate variations did not have that predicted result.

I don't think the planet needs saving, it will do alright on its own - just like it has for 4.6 million years. What we do need to account for is how our behaviour will impact on human society and wider ecology.

Rapid climate changes are not a good thing (c.f., PETM). I think I mentioned somewhere a while back - if the changes happened over a period of thousands of years (e.g., a 4'C rise), I think we'd adapt well. But the same change in a hundred or so? Not so well.

finally, tell me exactly how much effort you would be willing to (force people to) commit in order to halt climate development.

Ah. Ok, so when you say climate development you mean natural variations? For example, ice-ages?

Well, firstly, you are mixing two issues. We can easily halt one effect on climate, that's our emissions and destructive behaviour. We just reduce our impact. Of course, that's not as easy as I make it, but it's our actions that led to this particular situation.

From the other perspective, ice-ages and such like. Well, I don't really know. That's something we'd need to discuss together as a species. Current estimates are of the order of thousands of years, but lets just say it was in ten years that we enter a new ice-age. What should we do? Again, I don't know. I'm not sure interfering with the natural cycle would be a good thing, as we tend to mess up when we act in such ways. I suppose it would depend on the rate of change - a 4'C drop over thousands of years would not be as bad as a 4'C drop over 100 years.

But it wouldn't be my decision. However, this is not the same issue as reducing the impact of our current behaviour.

Originally posted by zvezdar
A few quick points:

On CO2 warming being proven in a lab...well yes, the effects of CO2 in isolation are well known. What is not well known is the dynamic reactions of the global system to changes in CO2 and their effects on temperature. The GCM's rely on positive feedbacks and heavy aerosol cooling to track past temps, and these feedbacks havent really been demonstrated as being a scientific fact. There is considerable uncertainty on the sign of various feedbacks, let alone quantifying the effect.

And so CO2 also warms climate, unless you can show why the physics of a CO2 molecule in the lab is different than one in the atmosphere. I'm sure you wouldn't play the same game with water vapour (e.g., it warms in the lab, but maybe not in the atmosphere, heh).

No need to obfuscate. The extent of GHG-induced warming is the issue here. So, when someone says CO2 cannot cause warming, they are wrong, no? As this is the sort of arguments people make, repeatedly.

I agree that the extent of feedbacks are more uncertain, but we have climate sensitivity measures from other methods apart from modelling. And lest we forget, the uncertainty goes both ways

Secondly, on the sun's role. It is a mistake to take the effects of solar irradiance, plot against temperature, and say there is no correlation and be done with it. The cause and effect is far more complex than that. Fact is, no one can say for sure that the sun is NOT the cause of climatic variation. Svaalgard argues for a higher solar sensitivity than present in most GCM's.

OK, great. Unless we can show how fairly constant, and possibly falling, solar irradiance can force temperatures upwards, it's not really an issue. Then you need to explain how a solar irradiance explanation actually leads to a cooling stratosphere and a night-time waming bias - GHG warming can do so easily enough.

There is actually a fairly good fit for solar activity prior to about 1970. But, yeah, Svalgaard now suggests either higher sensitivity to solar variations or just minimal impact from solar sources for a few hundred years (which is not the first time I recall hearing that) - but the way you interpreted his ideas is quite telling. Svalgaard actually appears to favour that it was of minimal impact.

Anyway, still doesn't negate GHG physics.

On falling solar activity, have a look at the work of Svensmark. He is putting together a reasonable case for the sun's electromagnetic field having a large effect on climate through its modulation of cosmic rays. Experiments in the lab appear to show that cosmic rays are important in seeding clouds, which in turn cause a cooling effect due to their effect on the earth's albeldo (note that GCM's usually assume a positive feedback on cloud cover). A fall in solar activity leads to an increase in cosmic rays, and hence an increase in cloud cover.

Yes, Svensmark and his 'magical' cosmic rays (Ignore the magical bit, it's a carry-over from earlier discussions).

But, again, cosmic rays appear to be going nowhere (as they correlate strongly to solar variations). And even if they were, you would still have to ignore the very basic physics underpinning GHGs.

Neither solar irradiance or cosmic rays provide a coherent explanation of the observations.

Lastly, to demostrate that CO2 is the causative factor, you need to be reasonably sure of the natural variation and then demonstrate that CO2 is driving the temperature above and beyond that natural variation. Multiproxy studies have established that the current warm period cant reasonably be distinguished from prior warm periods in the last 1000 years (Moberg, Loehle and McCulloch).

I'm not sure we do. If we know that CO2 is a GHG, that GHGs alter radiative balance resulting in warming, and that CO2 levels are increasing. Then it is fairly easy to place some warming at the feet of CO2, especially as such an explanation has been producing verified predictions.

Exactly how much is a different question. Even if the baseline for the last 300 years was 2'C lower than we are compared to 1000 years ago, we could apply the same approach.

So there is a lack of evidence that the current warming is unprecented to begin with.

So, we now switch to 'unprecedented', heh. Again, as before, a different question. CO2 could still be a causative factor and not be leading to unprecedented warming.

Additionally, there is generally a low understanding of many of the natural variances that can affect climate. This is noted by the IPCC in its reports (for example, aerosols are designated as having a low understanding, yet they are required to explain the cooling period last century as well as pulling back the current GCM's from dramatically overprojecting future temperatures).

Well, scientists were well-equipped to assess the aerosol impact of Pinatubo. You're just depending on what has been called the 'phlogiston theory' for climate - hoping for some other unknown factor to explain warming when we have a well-established explanation already. Might as well blame it on pixies.

When you can overturn the very basic physics underpinning GHGs, then we might ignore this mechanism. A mechanism that has good explanatory power.

In short, i think it is nonsense to say that the science is settled, since we have no idea what is driving the climate. The consensus is argued by a realtively small group of climate scientists, and a rather large group of environmentalists and other with vested interests.

Arguing consensus in science is for those who do not have the required scientific evidence to support their case. The science is never settled, and to argue that it is, and there is no point in debating further, is to try and shut down the scientific method.

No idea? Heh. If you say so. No-one is shutting down the scientific method, you just need to get out there an collect data. It's what the scientific method requires.

But, settled in what way? Settled that GHGs can cause warming? Yes, settled as a settled science can be, no? Just like it's pretty much settled that the earth orbits the sun.

Settled in every aspect? No. No science will never be settled once and for all. However, you're just playing the FUD game - uncertainty, exotic pixie theory, doubt. Rinse. wash, repeat.

When all those CO2 molecules continuously find their way into the atmosphere and do their bendy wobble thing - a bendy wobble thing we understand very well

[edit on 19-2-2008 by melatonin]

Let's just assume that GW is fact. That man-made CO2 emissions are raising the atmospheric concentrations above what is 'normal' and 'natural' and as a result, the average temperature of the planet is increasing and will cause drastic climactic catastrophies.

Assuming this is true, would the wise solution be a) to raise taxes, implement a commerce-based system to tax those who produce CO2, force people to spend their tme and money on a myriad of proposed projects to reduce the amount of CO2, or b) scrub the CO2 from the atmosphere?

I say (b). But that hasn't even been put forward as a solution by anyone I have heard. Instead, we have a carbon footprint cap and trade system, basically a way to allow CO2 production as long as someone (the government) gets paid for the privilege, a demand that newer, more expensive technologies are used under penalty of law, and cries for additional taxes.

Want to convince me that this is a problem? Show me someone who is trying to solve it rather than milk it. Until then, I will not believe. I will continue to 'deny ignorance'.

TheRedneck

Originally posted by Long Lance
no, sorry, but we can't easily change our impact on the planet. most CO2 reduction plans are usually expensive, over-optimistic and most of the time biased in favor of cosmetic advantages, which look good on paper but aren't viable on any usable scale.

I think I did sort of accept that it wouldn't be so easy in the next sentence. However, we survived for thousands of years without pumping billions of tonnes of CO2. So, the human race won't die out by reducing CO2 emissions. Indeed, we won't die out with dwindling fossil fuels either.

You can do it anyway you like, but our impact needs to be reduced. Alternatively, you can just deny the science because the consequences don't suit you (ABE: like the post above), or maybe just accept the science and think 'frack it'.

TBH, I couldn't give a fig. I care more about science than our own myopic behaviour. Luckily, the people who matter are at least making some positive grumblings, but whether they do anything worthwhile is another question. You can ramble about costs etc, but we have seen oil prices rise 300% over the last few years, and still we sit in our homes watching inane gameshows - economies never collapsed. And they won't with positive action to mitigate climate change.

Like a big fat dude sitting on his ass, stuffing his face with big-macs with the doctors warning of impending diabetes and heart disease ringing in his ears, he just can't get past the lovely positive feeling of a greasy fat burger to see, or care about, the consequences of his behaviour.

iow, is rate of change the only issue you have with today's climate?

Well, I think if we see it purely from an adaptation POV, then the rate of change is important. However, the extent of warming shouldn't be ignored either.

[edit on 19-2-2008 by melatonin]

Being an American myself, I can tell you why this is. We are very skeptical of everything, we need it to be in our hands with a pamphlet explaining it for us to completely 100% grasp and agree to a concept. Otherwise, it's Yes vs. No an answer which nobody can completely agree on.

While global warming has had a huge uprise in scientific evidence, we don't understand our planet anymore than we understand the universe. The planet is warming up, and it probably is because of Co2 emissions but it could also be because of unknown changes in the universe and our atmosphere which modern science cannot yet measure and understand.

The real problem is that nobody knows, and we are all scared of the worst. The educated more so than the less educated (most often Americans are less educated). We all love our planet and don't want our species to become extinct for obvious reasons, so we fight for what we believe will fix our fate on the planet. It is chickens running with our heads cut off in a direction unannounced to us. Scientists are just doing the best they can with what they have got.

While all signs point to Yes on global warming, there could be an uncountable amount of factors. We are doomed to become extinct at one point or another, and most of us don't like to admit it.

Originally posted by melatonin

You can do it anyway you like, but our impact needs to be reduced. Alternatively, you can just deny the science because the consequences don't suit you (ABE: like the post above), or maybe just accept the science and think 'frack it'.

I think there's a demon in my keyboard. Here I though I posted on the inability of the present proposals to make a serious impact and called for an answer as to why more logical plans are not forthcoming. instead I must have posted something about not liking consequences...

My apologies. I think maybe I'll try re-reading a dictionary. I hate it when they change the language...

TheRedneck