Give me your opinions about global warming

[SkepticLance]

Swansont said :

 

Sunspots can't cause warming for only those 30 years and then not at other times.

 

Correct. If we look back in time, we see the correlation between sunspot activity and temperature holds true, with provision for variations due to other factors, for 1000 years. The classic example is the Maunder Minimum (meaning few or no sunspots) 'coinciding' with the central and coldest part of the Little Ice Age.

 

1veedo said :

 

Because the data indicates CO2 is responsible for ~half of the temperature increase during the first half of the century.

 

In this, you are certainly consistent. However, you have simply quoted authority. I have shown in published graphs that the correlation with sunspots is much better than any with CO2 increase.

 

Dak said :

 

quantify 'minor and quite unexceptional'. the CO2 had, after all, been steadily increasing for decades by 1910.

 

All is relative. The CO2 increase from 1880 to 1910 was minor and unexceptional compared to the much greater increases after that time, and especially from the late 1980's onwards.

 

as for sunspots increase to their highest level in 8,000 years, the graph shows a higher frequency in 1850-1910, and 1940-2000. iow, the period we're talking about has the lowest frequency of the dates represented on the graph.

 

Sunspots are at a relatively low level in 1910, and by 1940 have reached an exceptionally high level. 8,000 year high refers to the last 70 years, according to New Scientist.

 

 

 

If you deny this simple fact, you belong with Homer Simpson and the Doh brigade.

 

no need for ad-homs.

 

No need to get defensive, either. You at least admit to the facts.

[swansont]

Swansont said :

 

Sunspots can't cause warming for only those 30 years and then not at other times.

 

Correct. If we look back in time, we see the correlation between sunspot activity and temperature holds true, with provision for variations due to other factors, for 1000 years. The classic example is the Maunder Minimum (meaning few or no sunspots) 'coinciding' with the central and coldest part of the Little Ice Age.

 

 

But, as I believe you've said before, this time it's different, and we're focused on very recent history. The last ~100 years does not show correlation over all of that span. Since we know that solar activity should and does have an effect, what is left is quantifying the other factors that must be present.

[1veedo]

In this, you are certainly consistent. However, you have simply quoted authority. I have shown in published graphs that the correlation with sunspots is much better than any with CO2 increase.

There's a difference between authority and evidence. What I have is evidence to back up my claim. What evidence, aka published peer-review, do you have to support your claim?

 

You have to understand that the climate is much more complicated than what you're making it out to be. There isn't always one dominant factor at work. Eg first solar then aerosols (mid-century cooling) then CO2 (past 30 years). Climate scientists model temperature based on the amount of energy coming into and out of the planet. This energy is measured in radiative forcing or W/m^2. You can break down what factors are increasing the total energy of the planet and what factors are decreasing the total energy -- a hotter sun or more CO2 increase the amount of energy coming into the Earth and sulfur decreases this. Whenever you add these factors together and get the total energy influx you can then model ("predict") what the temperature is going to do.

 

Eg the positive forcing from CO2 is present throughout the entire century not just the latter half and you can calculate the total temperature increase just from CO2 even during periods of cooling (eg the CO2 is stopping temperatures from dropping as far as is the case of mid-century cooling)

 

In the case of early-century warming (1900 to 1950) we have the solar contribution at .35 W/m^2 and, when calculating the energy required to raise the Earth's temperature during this period, Lean et al found that this .35 represented 40% of the net warming effect (ie we're not counting any negative forcing here, just the positive forcing that is required to outweigh the negative and cause a temperature increase equal to the total area under the temperature curve from 1900 to 1950).

[SkepticLance]

Swansont said :

 

But, as I believe you've said before, this time it's different, and we're focused on very recent history. The last ~100 years does not show correlation over all of that span.

 

That is correct. I have not been arguing against that point. I have simply said that sunspot activity correlates better to warming for the period 1910 to 1940 than does greenhouse gas.

 

1veedo said :

 

You have to understand that the climate is much more complicated than what you're making it out to be. There isn't always one dominant factor at work.

 

Again you put words in my mouth. As I said only a post or two back, climate is multi-factorial. However, greenhouse gas increase in the early part of the 20th Century was minor compared to what we saw a few decades later, and the correlation with warming was much stronger with sunspot activity, until 1940.

 

1veedo also said

 

the positive forcing from CO2 is present throughout the entire century not just the latter half

 

That is undoubtedly correct, since CO2 is increasing throughout. However, the impact for the period in terms of warming is clearly lower than the impact of whatever is happening in the sun when sunspot activity is high, at least until 1940.

[swansont]

Swansont said :

 

But, as I believe you've said before, this time it's different, and we're focused on very recent history. The last ~100 years does not show correlation over all of that span.

 

That is correct. I have not been arguing against that point. I have simply said that sunspot activity correlates better to warming for the period 1910 to 1940 than does greenhouse gas.

 

I don't think anyone is denying that the correlation exists. The error, however, would be in the contention that you can then say that solar is the (major) cause of the warming during this period. ("solar activity was the prime driver of global warming from 1900 to 1940, which is correct, and is clearly and demonstrably correct from the data") because if solar caused warming then, why does sunspot activity anti-correlate from ~1942-1955, and 1870-1880? From 1880-1910, where sunspot is ~ flat, the temperature decreases; all of this span has a constant increase in CO2. Obviously, there are other factors in play (which does not rule out the correlation being completely coincidental and acausal, but I don't think anyone would advance that hypothesis), and if you haven't accounted for and quantified them, then such a conclusion as you make isn't scientifically defensible.

[SkepticLance]

swansont

 

This is the closest we have come to agreement, which means something is finally going right.

 

I have said all along that global warming is multi-factorial. The correlation from 1910 to 1940 is strongest with sunspot activity. You are correct in saying that is not the case with every decade or several decades over the past few centuries. It seems that other factors have a stronger relative effect at those times.

[swansont]

swansont

 

This is the closest we have come to agreement, which means something is finally going right.

 

I have said all along that global warming is multi-factorial. The correlation from 1910 to 1940 is strongest with sunspot activity. You are correct in saying that is not the case with every decade or several decades over the past few centuries. It seems that other factors have a stronger relative effect at those times.

 

(emphasis added)

 

No. The statement that there is correlation does not validly lead into the bolded statement. Not from the graph to which you referred, which does not quantify the temperature contributions.

[SkepticLance]

swansont

You are a stubborn cuss. I just agreed with you!

 

Tell me, if the variations in correlation at different times in history do not reflect a relative change in the influence of the various factors driving global warming/cooling, then what do they reflect?

[1veedo]

They do refelct change in the influence of various factors driving global warming. However the conclusion that the sun was the primary influence (~greater than 75%) is still erroneous. You're just beating around the bush here. Your last two or three posts, actually, have been red herrings.

 

Example: "greenhouse gas increase in the early part of the 20th Century was minor compared to what we saw a few decades later"

 

This is true but it does not follow that greenhouse gases were insignificant in the early part of the 20th century because of it. It's just a fact that I brought up a long time ago.

 

Instead of beating around the bush and tip toeing around the issue at hand why don't you address the basic fact that cumulative solar forcing between 1900 and 1950 was ~.35W/m^2, equivalent to about 40% of the total energy required for degrees C under the curve, integral from 1900 to 1950 of T(year).

 

You are very close to the truth, SkepticLance, but being close doesn't quite cut it.

[SkepticLance]

1veedo

 

You still have not addressed the fact that greenhouse gas increase 1880 to 1910, which was almost exactly the same as greenhouse gas increase 1910 to 1940, led to totally different results.

 

It is very obvious to me that another factor drove those very different results in terms of warming/cooling. And that other factor must have been far more potent over those years than greenhouse gas increase, since it totally swamped the greenhouse gas effect. We do not have to guess. As I pointed out many times, the data is some kind of solar activity, as shown in changes in sunspot activity.

[swansont]

swansont

You are a stubborn cuss. I just agreed with you!

 

Tell me, if the variations in correlation at different times in history do not reflect a relative change in the influence of the various factors driving global warming/cooling, then what do they reflect?

 

You said you agreed, but from your statement, it's not clear that you really do.

 

You cannot conclude, from that graph, how much of an effect solar has, or even how much CO2 has.

[SkepticLance]

To swansont

 

One of the themes you (plural, as in my debate opponents) have mentioned several times is quantifying influences. I do not believe we can do that with any accuracy. I have seen figures calculated by IPCC which are very much at odds with the raw data. This makes me cautious about believing those results.

 

There are two extreme views in the global warming debate, and both extremes appear to be willing to be dishonest to put their views across.

 

As I said earlier, Dr. Stephen Schneider (global warming catastrophist) once admitted in an interview to exaggerating data to make people more aware of harmful consequences. IPCC made the statement that 90% of global warming over the past 50 years is due to greenhouse gases. Since the first 20 years of that 50 year period were actually global cooling, that is a very dishonest and misleading statement.

 

As a result, I do not simply accept what global warming enthusiasts, or global warming deniers say, as being true. I am only interested in data. I distrust the results of complex calculations, and generally assume they are likely to be in error. I believe the sorry record of deceit on both sides of this argument makes my suspicious attitude quite justified.

[1veedo]

Climate science works completely different than you think it does. I've explained the very basics a couple times now on the specific issue of temperature change (more energy=higher temperatures, less energy=lower temperatures; it's fairly intuitive) but you keep thinking the climate works in a completely different way than it does. Your version of how the climate behaves is not reflective of how it actually behave in reality as scientists know it does.

 

You are right that the sun had a much larger effect during this time and that CO2 had less of an effect, and this is obvious from the graphs, but you're makign some very elementary mystakes here. For one both the sun and CO2 lag their effects on temperature. When analyzing sunspots we know from historical data which you can actually see graphed that more sunspots means higher temperatures around 10 years in the future. CO2 lags a few years as well and to make things more complicated it also cumulates in the atmosphere (eg current warming is "caused" by all the CO2 released over the period ~1900 to today, depending on if you accept CO2 stays in the atmosphere for 200years, 50years, or somewhere in between -- 1800~1950, which is something I think scientists are still trying to figure out). So you cant even look at sunspots, CO2 levels, and temperature linearly, which is exactly what you're trying to do!

I distrust the results of complex calculations, and generally assume they are likely to be in error.

So basically you distrust science and this is why you're posting at scienceforums.net.

 

You do realize that the data you are looking at on wikipedia has actually gone through "complex calculations?" You cant represent everything with just the raw data. Global temperatures are a good example of this. Although it seems pretty strait froward even ground temperature readings have to be averaged out and weighed specifically for proximity with other stations, and the ones located in cities have to knock off a few degrees. How satellites know the temperature is even more complex: http://scienceforums.net/forum/showthread.php?t=27104

 

And your solar cycles are smoothed, probably 11 years (not necessarily the most "complex" of calculations), so even the most basic data (count the number of spots on the sun, kiddies!) has gone through some calculations before being graphed. And how do we know sunspots correlate with solar irradaice? A bit of complex calculations again, represented here,

 

[SkepticLance]

1veedo said :

 

So basically you distrust science and this is why you're posting at scienceforums.net.

 

When we get into debate, simplification of our views is something we all must do to get a point across. If we could not do that, we would all have to take about ten years hard work, and the equivalent of a Ph.D. thesis to complete an argument.

 

Science, at its most basic, is set upon the foundation of objectively derived empirical evidence. This is where I start. This is where we should all start.

 

When we 'manipulate' the data, we introduce potential for error. The more we manipulate data, the higher the probability that significant error will creep in. Certain basic calculations are needed, as you pointed out. Thus, averaging temperatures to get a global temperature change, is a simple manipulation of the data, which is needed. As you also pointed out, a simple calculation on sunspot numbers is needed to show a trend in that parameter.

 

These simple calculations are unlikely to introduce much error. It is when we go into more complex manipulations of the data that the potential for substantial error increases. It is these calculations that I most distrust.

 

I trust that this expansion of my views from the original simplified statement will allow some extra understanding.

[1veedo]

When we 'manipulate' the data, we introduce potential for error. The more we manipulate data, the higher the probability that significant error will creep in.

There's this thing in science called the scientific method. What scientists do every day is look at data to find casual relationships between different variables, create models -- otherwise known as theories --, and test these models to see if what they predict is in accord with what actually happens. It doesn't matter how complex these models actually are; what matters is whether or not these models can make accurate predictions.

Thus, averaging temperatures to get a global temperature change, is a simple manipulation

Measuring surface temperature isn't even as simple as "averaging." There is a lot of work behind this. Some areas of the planet, just as an example, have a lot more stations than others. Eg we have very little data about Antarctica but other parts of the world are very dense with reading stations. Scientists also feed in water temperatures because, seeing as water makes up over 70% of our planet, water temperatures are a much better indicator of what global temperatures are actually doing. Just something as simple as getting the temperature of the Earth is extremely complicated.

 

So complicated in fact that scientists (and weather forecaster) are now using satellites to tract temperature trends. This is actually easier than the former method and at the same time the basic data that the satellites gather goes through a lot of manipulated.

 

Let me give you a physics problem to illustrate how you can manipulate data and get data that's even more useful. Say you want to figure out the composition of a star. How do you think you could do this? Well we happen to know that all hot gases emit their own individual spectra. So you could take in basic electromagnetic data from a star, which is almost useless without complex manipulation, and use it to identify the composition of elements in the star. This is in fact known as spectroscopy and I'm sure astronomers find the data gathered from this process very useful.

 

 

I assume you read the rest of my post though? Or would you be committing another red herring? Although the issue about scientists being able actually conduct science by manipulating data and figuring things out is interesting in and of itself, the main area of interest was your misrepresentation of the climate system.

[SkepticLance]

1veedo

 

I have not misrepresented the climate system. My statement that 1910 to 1940 temperature rise correlates more closely with sunspot activity than with greenhouse gas increase is totally correct.

 

And there is a very big difference between computer climate models of the entire world, and the method used to estimate average global temperature in any one year. Even the latter is not without controversy. The more complex the manipulation of data, the more likely to introduce significant error. If you have an appreciation of reality, you will admit this simple fact.

[1veedo]

I have not misrepresented the climate system. My statement that 1910 to 1940 temperature rise correlates more closely with sunspot activity than with greenhouse gas increase is totally correct.

So you have completed your red herring even when I called you on it. Good job. Do you have any intent on actually addressing my post or are you still trying your old tactic of tip toeing around the issue at hand?

And there is a very big difference between computer climate models of the entire world, and the method used to estimate average global temperature in any one year. Even the latter is not without controversy. The more complex the manipulation of data, the more likely to introduce significant error. If you have an appreciation of reality, you will admit this simple fact.

Well yes, naturally, but what this boils down to is an argument from incredulity, which is a logical fallacy. Scientists are a lot smarter than you think they are. Many times scienitsts manipulate data to make it less error prone, as is the case of spectroscopy. I'm not sure what they do but when analyzing a particular star they have to separate the incoming waves at peaks and troughs to get the significant wavelengths, from which they can figure out what elements are in the star. If they just took the raw data and applied it directly the results would be extremely error prone, to the point that it's completely useless.

 

You can apply this to basic entropy. The more complex something is the more it can actually do. For example a computer program only 100 lines might not be able to do much but a program 1000 lines might be able to do more. Why? Because it's more complex. And it is more error prone but assuming the complexity is applied constructively, as is the case in science, the complexity is a good thing. Occam's Razor only applies when all things are considered equal.

 

But all this aside there is no justification for finding it hard to believe that scientists cant figure things out. How do you think you explain something as complex as electromagnetism? Through simple calculations and basic theories that fall short of the phenomenon? Or through calculations and concepts complex enough to describe the phenomenon? Equally so can be applied to calculus. There are many things you cant do with basic algebra that are then possible through calculus, which is inherently much more mathematics. Although more complex math means you are more prone to error this does not guarantee that you actually make these errors. And in the case of science, scientists publish their work to peer-review so essentially you have hundreds, if not thousands, of people going over your work to find any errors you could have made. This is just basic science and whether you like it or not this is how science works. If you don't like it then it brings us back to square one again with you arrogantly thinking that you're smarter then all of the thousands of scientists across the planet.

[SkepticLance]

Actually, I have no illusions about being smarter than thousands of scientists. There are thousands of scientists who, like me, are sceptical of the global warming catastrophist's predictions. This includes hundreds of climate scientists.

 

On the complexity of global climate computer models. The people constructing such models are still working on them with some urgency. Why? Because they are seriously imperfect. It has been noted on a number of occasions that such models cannot predict cloud formation properly, and cannot predict what different cloud formations will do to global temperature. This point is one that has been made strongly by those climate scientists who are sceptical of the more extreme predictions of the catastrophe enthusiasts.

 

So, in spite of the protests, global computer climate models are seriously imperfect.

[fattyjwoods]

i think that the major countries are making global warming go way faster. Countries like USA, Russia, China are really making a lot of CO2 and stuff like that. You might have heard about how Tony Blair trying to get an agreement out of Bush to lower carbon rates but apart from that nobody seems to care. Bush justs keeeps on rejecting blair's and other enviromental organisations pleas to slow down global warming. do u guys think Bus and Putin and other major carbon producing countries are screwing up our childrens/grandchildrens/great-grandchildren's future. i absoulutely think so

[Reaper]

Actually, I have no illusions about being smarter than thousands of scientists.

 

What basis do you have for this belief? And in what kind of intelligence? If you are talking about being informed on global warming data, then that does not appear to be the case.

 

There are thousands of scientists who' date=' like me, are sceptical of the global warming catastrophist's predictions. This includes hundreds of climate scientists.

[/quote']

 

Thousands? Hundreds? The list of skeptics who were scientists numbered less than 100, from what I found. And then there are some are organizations, but there isn't a lot of details on them. But the one thing that caught my eye was the American Association of Petroleum Geologists, as they are the only professional organization skeptical about the climate change. Of course, not all in the organization are scientists. Here is the list, courtesy of Wikipedia:D. I think your claim is off by a significant amount. Of course, wikipedia is not the most reliable source, so if you have info that contradicts this, please let us know.

 

List: http://en.wikipedia.org/wiki/Category:Global_warming_skeptics

 

 

On the complexity of global climate computer models. The people constructing such models are still working on them with some urgency. Why? Because they are seriously imperfect. It has been noted on a number of occasions that such models cannot predict cloud formation properly, and cannot predict what different cloud formations will do to global temperature. This point is one that has been made strongly by those climate scientists who are sceptical of the more extreme predictions of the catastrophe enthusiasts.

 

Actually, you will find that computer models about weather and climate patterns are very accurate. Yes, it is true that the calculations involved are very complex (think millions of calculations and thousands of parameters), but its complexity does not mean that there will be more errors. Our computers are very sophisticated. A lot of the mathematical theories and equations used include Chaos Theory, if you ever read up on the subject. For example, basic weather patterns can be reliably predicted up to a week. Many of the equations used for basic weather patterns are also applied to climate.

 

Also, the climate models that are used to predict global climate, particularly those used by NASA and the ICPP, are based on physics, not statistics as is commonly believed. Here is a basic info about how climate models work and how they are used: http://www.logicalscience.com/skeptic_arguments/models-dont-work.html

 

Many of the predictions about global climate change made in the past were very accurate. You will find some examples of such in the link provided. Just beware, the title is misleading, but it does a good job smashing the claim that data from the computers are error prone.

 

So, in spite of the protests, global computer climate models are seriously imperfect.

 

So, in conclusion, global computer models are accurate, in spite of your claims. If you want me to provide info and data on just how accurate, just ask me . I didn't include a lot of info because it can easily take up more than a page.

[SkepticLance]

Lockheed said :

 

The list of skeptics who were scientists numbered less than 100, from what I found.

 

I would be incredibly startled if you could find a list of every global warming sceptic. However, maybe you are indeed a worker of total miracles. I am aware of six climate scientists here in New Zealand who are sceptics. If this is a fair sample (and I know the number is too small), then the number of similar sceptics in the USA alone is more like 500.

 

Even if the rather simplistic calculation I just used is out by a massive error factor, the number of climate scientists who retain significant scepticism would be in the hundreds.

 

Remember, I am talking of sceptics - not deniers. To be a sceptic, you just need to withhold belief of some aspects of the current paradigm, not all. That describes my own view. As I have said before, I accept that the world is warming, and that human activity is a prime causal factor. It is just some of the more extreme interpretations that I query.

 

Such as the way some of you guys stick to your belief that greenhouse gases were the prime driver of warming/cooling even before they had risen to a level where they could have much impact. That is an extreme belief. Other factors have been more potent drivers, as shown by the data.

 

Your statement on the accuracy of climate models is just that - a statement. It seems that every month I read about some new discovery that causes modellers to go back to their computers to factor in something else that had not been there earlier. If the models are so bloody accurate, why are they constantly changing them?

[1veedo]

Thousands? Hundreds? The list of skeptics who were scientists numbered less than 100, from what I found. And then there are some are organizations, but there isn't a lot of details on them. But the one thing that caught my eye was the American Association of Petroleum Geologists, as they are the only professional organization skeptical about the climate change. Of course, not all in the organization are scientists. Here is the list, courtesy of Wikipedia. I think your claim is off by a significant amount. Of course, wikipedia is not the most reliable source, so if you have info that contradicts this, please let us know.

 

List: http://en.wikipedia.org/wiki/Categor...rming_skeptics

Actually the American Association of Petroleum Geologists is changing their position on global warming.

 

"As of May 2007, the AAPG is in the process of updating its statement, in part because "the current policy statement is not supported by a significant number of our members and prospective members." A proposed statement makes no claim that recent global warming is or is not primarily anthropogenic."

 

The original statement was put into place by the union. The actual members -- otherwise known as scientists -- seem to want a different statement.

 

I would be incredibly startled if you could find a list of every global warming sceptic. However' date=' maybe you are indeed a worker of total miracles. I am aware of six climate scientists here in New Zealand who are sceptics. If this is a fair sample (and I know the number is too small), then the number of similar sceptics in the USA alone is more like 500.[/quote']Yes, six in New Zealand. That's wonderful. But Lockheed has clearly proven that the list is only in the hundreds, compared to tens of thousands of climate scientists who agree otherwise. You can find a few dozen biologists that disagree with evolution as well, but the scientific consensus is still that evolution is real.

Remember, I am talking of sceptics - not deniers. To be a sceptic, you just need to withhold belief of some aspects of the current paradigm, not all. That describes my own view. As I have said before, I accept that the world is warming, and that human activity is a prime causal factor. It is just some of the more extreme interpretations that I query.

You mean the media? Try to avoid using straw men here. The vast majority of scientists are going to disagree about some things. It is you in reality who are denying things. Climate models ARE accurate and as long as you hold the position that they aren't you are denying the science.

Your statement on the accuracy of climate models is just that - a statement. It seems that every month I read about some new discovery that causes modellers to go back to their computers to factor in something else that had not been there earlier. If the models are so bloody accurate, why are they constantly changing them?

Climate models have had the big things factored in for a very long time. Sense greenhouse gases at the moment have the overwhelmingly largest effect on the climate, modeling the increase in ghgs in and of itself yeilds very accurate models. Now we're dealing with smaller things like cloud albedo, contrails (which recent research seems to indicate have a warming effect of +.1W/m^2, instead of what was once believed to be slightly negative), etc, which combined have a close to 0 net influence on the temperature. This doesn't mean previous models are inherently inaccurate because we're talking about minute changes here. The first computer climate model in 1988 only factored CO2 increase, a steady irradiance from the sun, and predicted one volcanic eruption around 1990 but 20 years latter, according to NASA, the model is "right on the money." This model then only measured CO2, solar irradiance, and particulates/sulfurs. Today we're accounting for a whole range of factors, all of which are orders of magnitude less important then the above three.

[SkepticLance]

1veedo said :

 

But Lockheed has clearly proven that the list is only in the hundreds, compared to tens of thousands of climate scientists who agree otherwise.

 

If you look back at my earlier entry, you will find that is all I claimed. If you agree with me, why are you arguing?

 

 

The vast majority of scientists are going to disagree about some things. It is you in reality who are denying things. Climate models ARE accurate and as long as you hold the position that they aren't you are denying the science.

 

Here is a reference to the fact that cloud effects are not even now understood, and may change models when they are better understood.

 

http://www.economist.com/science/displaystory.cfm?story_id=9433721

 

Climate models are still a work in development. It is premature to claim accuracy, especially over a period of decades.

 

And 1veedo, please try to avoid describing every argument you disagree with as a straw man. It is getting tedious.

[1veedo]

Well please stop the logical fallacies.

Here is a reference to the fact that cloud effects are not even now understood, and may change models when they are better understood.

 

http://www.economist.com/science/dis...ory_id=9433721

 

Climate models are still a work in development. It is premature to claim accuracy, especially over a period of decades.

 

And 1veedo, please try to avoid describing every argument you disagree with as a straw man. It is getting tedious.

Depending on what model you use it could be as much as -1.5W/m^2 or as little as -.5. So we're getting roughly a +/- 1 error margin compared to other smaller factors in the positive range. This factor is also an anthropogenic one caused by industry aerosols so whether or not cloud albedo proves to have a large effect or a smaller effect depends on what we as humans do in the future. We have the same problem with ghg emissions as well -- temperatures could rise anywhere between 1.8 to 4C this century depending on which path society decides to take. The 1.8 to 4C range is any combination of high aerosol / low ghg and high ghg / low aerosol. This is hardly the problem of climatologists and more the problem of economists and government air quality employees to predict. We're not even sure how much we're putting out today, so how do you expect us to predict accurately how much we're going to put out in the future?

 

Volcanoes also put out particulates (aerosols) but this effect is already averaged based on previous eruptions, but because of their random nature tend to add future uncertainty. They release much fewer aerosols then humans do, however.

 

See my above post for more information, you must have missed it.

Climate models have had the big things factored in for a very long time. Sense greenhouse gases at the moment have the overwhelmingly largest effect on the climate, modeling the increase in ghgs in and of itself yeilds very accurate models. Now we're dealing with smaller things like cloud albedo, contrails (which recent research seems to indicate have a warming effect of +.1W/m^2, instead of what was once believed to be slightly negative), etc, which combined have a close to 0 net influence on the temperature. This doesn't mean previous models are inherently inaccurate because we're talking about minute changes here. The first computer climate model in 1988 only factored CO2 increase, a steady irradiance from the sun, and predicted one volcanic eruption around 1990 but 20 years latter, according to NASA, the model is "right on the money." This model then only measured CO2, solar irradiance, and particulates/sulfurs. Today we're accounting for a whole range of factors, all of which are orders of magnitude less important then the above three.

Note that aerosols in this case is referring to the direct effect of particulate pollution, and not cloud albedo caused by aerosols.

[ParanoiA]

I have heard it stated, repeatedly, by Rush that precipitation is not factored in these models. Is that true? I'm sure that's twisted logic on some level, but wanted to ask.

 

Also, they were talking about this article yesterday. This is an attack on media, not science. Although, it does expose the tendency of humans to be obsessed with doomsday scenarios with climate change.

 

Why was the science wrong then, but correct now?

 

This is what I was getting at many moons ago when I was told to read this and read that. It doesn't matter what I read, because it's written by scientists doing work that I only partially understand on a very elementary level - so it still comes down to "believing" one side or the other.