I've heard that scientists are recently trying to hide the fact that the earth is actually cooling down;

I hope this is not the case.That would indeed be very disappointing, but not the first time it happened. Scientists are human too, but they need to hold themselves to a higher standard.

I think many scientists are looking at the situation from a cautious point of view. The question of whether the build up of CO2 can trigger a positive feedback effect is a critical one, and one that has not been proven true, nor false. How much CO2 can be added without consequences? Double? Triple? ... There must be a limit. If we don't know where it is, it makes sense to err on the side of caution.

The bottom line is that we don't know the answer, and the only way to find out the answer for sure is to cross the line. Do we really want to do that? It's not like we can fix it, like replacing blown speakers. Should we stick the microphone in front of the speaker and just keep turning that CO2 knob without forethought? Once the speakers blow, it's too late. If there is any group that can understand the ideas of positive and negative feedback, and the damaging consequences of runaway effects with positive feedback, it should be those of us here.

 

I think many scientists are looking at the situation from a cautious point of view. The question of whether the build up of CO2 can trigger a positive feedback effect is a critical one, and one that has not been proven true, nor false. How much CO2 can be added without consequences? Double? Triple? ... There must be a limit. If we don't know where it is, it makes sense to err on the side of caution.

How can you be sure the atmosphere was not actually depleted in CO2 relative to its "best" (or other relative term) state. How do you define normal, best, target or any other relative word for atmospheric CO2? Maybe we should add CO2 to avoid consequences of continued depletion?

The point is, there was a strong suspicion of intentional publication bias and throttling of any dissent that didn't agree with the political dogma championed by Al Gore. Now, with discovery of the hidden e-mails, it is no longer just a suspicion but clear evidence of a conspiracy that needs to be thoroughly and openly investigated.

John

 

Now, with discovery of the hidden e-mails

The world has come to a pretty pass when someone as level headed and unexcitable as JohnP talks about conspiracy.

I haven't heard about the Emails have you a link please?

 

I wish I had a link to the e-mails per se, but I don't. Here is a link to a current news item about them, though.

http://www.foxnews.com/story/0,2933,578486,00.html

John

 

How can you be sure the atmosphere was not actually depleted in CO2 relative to its "best" (or other relative term) state.

I guess we can't be sure of that. However, we can be sure that we are not currently in a runaway greenhouse effect.

How do you define normal, best, target or any other relative word for atmospheric CO2?

The issue isn't whether it is normal, but whether the concentration is high enough to trigger positive feedback by some mechanism.

Maybe we should add CO2 to avoid consequences of continued depletion?

Is there evidence of continued depletion? My understanding is it is on a steady rise since it is now 30-40 % higher than at the start of the industrial revolution. Anyway, even if you think adding CO2 has benefits, how do you know when to stop?

The point is, there was a strong suspicion of intentional publication bias and throttling of any dissent that didn't agree with the political dogma championed by Al Gore. Now, with discovery of the hidden e-mails, it is no longer just a suspicion but clear evidence of a conspiracy that needs to be thoroughly and openly investigated.

That could be true. I'm against McCarthyism in any form. I'm not surprised when politicians do such things, but as I said, I hope scientists rise to a higher level. We should be clear and truthful about what is known and unknown. Unfortunately, the problem is that the most critical issue is unknown. That is, we don't know if a positive feedback is possible, and if it is, we don't know what the limit is.

 

Is there evidence of continued depletion? My understanding is it is on a steady rise since it is now 30-40 % higher than at the start of the industrial revolution. Anyway, even if you think adding CO2 has benefits, how do you know when to stop?

One has to plot CO2 levels over a greater period that 200 years plus or minus. I have read that the past 7 to 10 years have shown no increase in temps or at least nowhere near the expected increase from CO2. How is that explained?

For me, any statistical analysis of correlation must consider both potential benefits and risks (i.e., be two-tailed), unless one can make an awfully strong argument that it should be one-tailed. If there is a correlation, then one must also prove cause and effect. Neither seems to have been done in the political frenzy over CO2.

John

 

One has to plot CO2 levels over a greater period that 200 years plus or minus. I have read that the past 7 to 10 years have shown no increase in temps or at least nowhere near the expected increase from CO2. How is that explained?

It's hard to explain it, but there are many possibilities. Two are the following.

1. CO2 levels currently have very minor effect on the temperature due to controlling negative feedback effects.
2. CO2 levels have strong effects, but they are presently being masked by other strong counteracting natural or man-made effects.

In either of these cases, there can still loom a disaster if a threshold is crossed into a positive feedback regime. Temperature data are unclear, but it is clear that CO2 levels are rising (quickly by earth standards) and will continue to rise for hundreds of years based on current expectations. The bottom line is that the situation is completely uncertain and we don't understand it, yet we are turning the crank strongly in one direction. So, effort to curb CO2 buildup is a cautious move. To me, it just seems prudent to keep things in check as much as possible. There is no way we can stop the increase, but we can slow it down while we try to understand the real science.

For me, any statistical analysis of correlation must consider both potential benefits and risks (i.e., be two-tailed), unless one can make an awfully strong argument that it should be one-tailed. If there is a correlation, then one must also prove cause and effect. Neither seems to have been done in the political frenzy over CO2.

Well, there is a strong argument that maybe it should be biased in favor of risks. In nature, change rarely brings benefits, and more often brings disaster, to species well adapted to their environment. Most benefits of change comes to species not firmly rooted in a good niche. I'll make the point I've made before. The earth, and life on earth will be just fine no matter what we do. The only risk is to ourselves. Of course, humans are very adaptable and even the worst case is not likely to spell our ultimate doom, but survival and comfort are very different things.

However, I agree that taking action should not include lying, faking data, playing political games etc. We should also consider any harmful human costs to being overly aggressive in trying to slow the CO2 buildup. There is some evidence that shows we are not presently on the brink of disaster; so, our actions should not be panic-stricken over-compensations. A little common sense goes a long way here.

As a technologist, I'm really excited that we are now finally seriously looking at other energy production methods. I also like to see that people are capable of making changes if needed. If there are people being deliberately deceptive, I'm disappointed by that. Hopefully those people are dealt with so the bull-crap can be swept out and the real science can take the stage.

 

Try googling global dimming. The particulates we send up also have an effect.

 

I had listened to an interesting report on the relationships between large scale carbonizing of vegetation (forest fires) to that of extint dinosaurs. The jest of the report was that evidence of larger scale forest fires weren't detected in the prehistoric record until after the dissappearance of the dinasaurs, predominately herbivoires. This then lead to adaptaion of vegetation to take advantage of the evolving climate.

As I indicated previously, stagnation of climate is not good, and our ability to exsist is dependant on the rate of change. Global warming/ cooling at any rate within anyone's current models, is a non issue. It's when the earth awakes, that we'll be vulnerable, and will reduce our current concerns irrellavent.

 

There are a lot of bad things that can happen on earth, some we can do something about, some not. The Yellowstone caldera volcano is overdue, though on the time scales it operates on a thousand years isn't much. When it goes so does the USA, and the rest of the world will loose a significant chunk of population. Not too much we can do about that. An asteroid we might have a chance at though.

 

An asteroid we might have a chance at though.

A big enough asteroid could nearly sterilize the earth of life. Microbes and deep water ocean life would probably survive, and evolution would go through the greatest "reboot" in history. This has happened already a couple of times in earth's history, but never with the complexity of life we have now.

Even the caldera scenario could wipe out human life. We are not as powerful as we sometimes like to think. An event like that would wipe out the world's food chain and colapse the entire ecosystem. Again, life would survive and adapt, but I wouldn't bet on the humans being part of the new-world order.

If humans are to be sure of surviving for millions of years beyond the present time, we should migrate into space at some point. Mars will likely be tera-formed thousands of years in the future, and a colony there will be a good way to protect our species from extinction. Even better will be finding earth-like planets in other solar systems. Our technology can only protect us so much. There are forces in nature that can not be combated directly. At some point running is the only option. Moving some of us off-planet will not be an easy thing to do, but it is within the capability of human beings for sure, if we are given enough time.

 

A big enough asteroid could nearly sterilize the earth of life. Microbes and deep water ocean life would probably survive, and evolution would go through the greatest "reboot" in history. This has happened already a couple of times in earth's history, but never with the complexity of life we have now.

Whilst is is now fairly well established that the dinosaurs were wiped out by the Mexican asteroid, the end Permian mass extinction was by far the greatest and has yet to be satisfactorily explained. At this time an ecosystem of complexity rivalling our own was anihilated.

 

Whilst is is now fairly well established that the dinosaurs were wiped out by the Mexican asteroid, the end Permian mass extinction was by far the greatest and has yet to be satisfactorily explained. At this time an ecosystem of complexity rivalling our own was anihilated.

Yes, true. It certainly rivaled our own. It really comes down to how complexity is defined.

My own personal view is that we now have greater complexity with the establishment of mammal life. Mammals are the most developed energy utilizing forms of life that have evolved, as far as we know. And, hand in hand with that is the development of the human brain, which in my view, is the most complex and amazing thing that has ever evolved on our planet.,

 

And, hand in hand with that is the development of the human brain, which in my view, is the most complex and amazing thing that has ever evolved on our planet.,

Playing devil's advocate, this from one of the said mammals with the amazing brain. A squid might want to argue this point, or perhaps an ET with a bigger database of what's out there. We could be as common as life.

The numbers I was hearing from the global dimming were pretty amazing, I don't know if they can be taken seriously or not. In some parts of the world 10% decrease in solar energy hitting the surface of the earth. The amount of light is large enough this is not life threatening, but the argument I was hearing on the PBS show is it may have been offsetting the greenhouse gas effects somewhat. Just another variable in a very large system.

 

Yes, true. It certainly rivaled our own. It really comes down to how complexity is defined.

My own personal view is that we now have greater complexity with the establishment of mammal life. Mammals are the most developed energy utilizing forms of life that have evolved, as far as we know.

I get uncomfortable with such statements, because it is tempting to equate "complexity" with our place in evolution. As we know, bacteria do more with less than we mammals do. Perhaps, they are the more highly evolved life form?

I also question whether mammals are the most efficient energy utilizers. I think it is easier to defend the concept that most current species are equally highly evolved.

In reality, I am willing to give an edge to humans for smarts, but I am much less certain we have an edge in terms of survival. Numerous other vertebrates and insects have survived and adapted over the eons relatively unchanged.

John

 

I also question whether mammals are the most efficient energy utilizers.

You should question that, but I never said they are the most efficient. It's not a question of efficiency that I was raising. I don't actually know how to define efficiency in this context. And, once it is defined, I'm sure that mammals are NOT the most efficient because we waste a tremendous amount of heat energy as warm blooded creatures.

Rather, my point is about the complex systems that need to be in place for warm-blooded energy production systems to function properly. Mammals have the greatest capacity for power output for use in muscle action or brain power. The speed of the cheetah and the intellectual creations of man are good examples of what the energy production system of a mammal are capable of allowing.

I'm no expert in this field, but it is known that evolution has produced several abrupt, large and discrete leaps in energy utilization. The first simple creature used ambient thermal energy, then plants developed a huge advantage with the use of solar power, simple animals then adapted to steal the chemically stored energy from plants. Reptiles are very limited because they can not fully control their metabolism and depend on external heat sources. Dinosaurs and birds do (or did ) better and attained a higher metabolic output. But, warm blooded mammals can utilize energy by regulating body temperature at a optimized point. There is a definable measure of complexity here in terms of the feedback systems and other mechanisms that need to be in place to generate greater and greater power. There is a cost, but also major benefits that come with warm-blooded metabolism.

I think it is easier to defend the concept that most current species are equally highly evolved.

That strikes me as a very difficult concept to defend. First you have to define what it means to be "highly evolved". Then, you have to convince us that the millions of species on earth are all equal. Then you have to explain that, even though we only have identified about 2 million of the 10 to 100 million species believed to exist currently, the other much larger unknown segment also obeys your law. That seems unlikely, but feel free to make your arguments. I'm eager to learn if you can actually do this.

 

A squid might want to argue this point, or perhaps an ET with a bigger database of what's out there.

Well, the squid can't argue, so I win that one. However, when ET shows up, I'm sure he will win; hands (or whatever he has) down.

 

Oh, I don't know. I picked squids because they have relatively large brains, and could easily use color and shapes as a communication medium. Octopus love puzzles, and solving them. Intelligence to us is tool using, but there may be other standards.

Only reason what I say is vaguely possible is we still have a lot of research to do. We've only found where giant squid come from in the last 5 or less years.

 

Oh, I don't know. I picked squids because they have relatively large brains, and could easily use color and shapes as a communication medium.

Well, I was just joking around. Squids are definitely a good example to pick. They would seem to be at the high end of the scale in the Mollusca Phylum. Even though that Phylum is considered to be "less advanced" in the sense that Chordata and Anthropoda "rule the world", so to speak; there is probably no other non-Chordata or non-Anthropoda species as advanced as the giant squid.

It's also interesting that even though these two Phyla dominate the world, all the 19 or so other "more primitive" animal Phyla that have evolved in the past still have living species to represent them today. Some species are just very effective at filling their niche, and the giant squid is one of them. Is it because they are simple and well adapted; or, is it because they have adapted by developing complexities that we don't understand? Who can say?

I agree that you can't really make comparisons without clear standards and definitions. This is why I accepted studiot's comment about the Permian life complexity and was clear to state that my comment about "complexity" of mammals, and the human brain is a personal opinion. There are clear cases where you can say one thing is more complex than another. For example. A man is more complex than a virus for sure, and probably also more complex than a one cell organism. He is also probably more complex than plants, or worms or squid or even fish, and maybe even dogs. However, at some point you can't prove any of these statements, and can make counter arguments. This all boils down to the inability to define words clearly. Since we can't even agree on the definition of life itself, it's not likely we can agree on a definition for complexity of life.

 

I assumed you were talking about the complexity of the whole system, not one individual species.