Humans have less impact on climate?

[a_unique_person]

They are exclusive or not , depending on the time scale we look at.
At any instant, temperature is going up or down. But what value is an instant if we are talking about the next century?

My point is just that while there is evidence that global warming is happening on the sort of timescale we might be interested in politically- 20-100 years, I have still seen no unequivocal proof that it is being caused by human activity.
(As opposed to being part of a natural cycle).
Nor do we have a reliable prediction for the 100-1000 year scale. It would be ironic indeed if we attempted intervention now which resulted in another Younger Dryas by the 24th century.

The rate is important. The changes due to the end of the last ice age. The temperature rose by 5C in 10,000 to 20,000 years, we are talking about such a change happening to the earth now in 200 or so years. The difference in the order of magnitude is huge.

Asking for unequivocal proof reminds me of creationists denying the evidence for evolution. Sure, there are gaps, but so much evidence is there, does it really matter?

 

[a_unique_person]

Don't ask me. You're the one bringing up "evidence" and "papers".

As for scientists... I was speaking of the collective group "scientists". So... those scientists.




If one side promotes an argument that there is consensus, when there isn't, they are myth making. C'mon, at least try. This is all very straight forward.

First of all prove you claim, before making the logical conclusion.

Are you telling me you've never come across a qualified scientist that doesn't agree with the alleged "consensus view" on climate change?

Here's Some

-Gumboot

If you want to see some links to science behind AGW, courtesy of varwoche http://www.internationalskeptics.com/forums/showthread.php?postid=1976047#post1976047 .

From your link

The Earth is not warming

Since 2001, no climate scientists have expressed skepticism that warming, of the magnitude described by the IPCC, has occurred.

So for a start, there is not just consensus, it is unanimous, the climate has been warming.

The list of scientists is quite small, displayed on that link. Follow the links provided by Varwoche, you will see the work of hundreds of scientists researching the area.

 

[Meadmaker]

The Herald Sun's Andrew Bolt ran a story about the lack of consensus and was subject to the full force of the ABC's fury. Here and here and here for more background.

I read the story, and looked up some of the cited authors.

I only spent half an hour or so. It's hardly an exhaustive search. However, what I found did not contradict Gore's claims regarding scientific research.

Gore's movie has been described, appropriately, as "alarmist". It seems that there is no consensus that the degree of alarm is justified. There is considerable doubt about the extent of global warming caused by humans, and about the consequences of that warming. I'll keep looking as time allows, but on the basic question of whether or not human induced global warming is occurring, nothing I saw from the sources cited in the article makes me question that there is a consensus about the basic science.

There's lots of debate about appropriate policy to pursue, but on the basic question of whether the phenomenon is real, there seems to be none.

 

[skeptifem]

It's not a majority, its the preponderance of evidence collected scientifically.

so you're saying its the majority of the evidence being in favor of AGW that makes it a consensus? that doesnt challenge what i have said.


also- about the experts disagreeing- I know that people have posted petitions from people skeptical of AGW in threads you have started about it, some of the people signing them worked on ipcc. there is a link in the wiki someone posted earlier, under 'global warming controversy'.

 

[DeviousB]

The two fields where most effort seems to be focused at the moment are attribution and sensitivity.

Attribution is the question of how much of the observed warming is caused by natural and anthropogenic changes to climate forcings. Despite a (healthy) variety of opinions on attribution, the published science is either neutral on attribution, or supportive of a significant anthropogenic contribution.

Sensitivity is the question of how large an effect on the world's climate both the observed and predicted changes will have. The scientific consensus, i.e. the consensus of the science, is that we might expect between a 1.5 and 4.5 Celsius rise in GMST in response to a doubling of atmospheric CO₂.

 

[DeviousB]

also- about the experts disagreeing- I know that people have posted petitions from people skeptical of AGW in threads you have started about it, some of the people signing them worked on ipcc.

Experts can disagree all they want (and do). If they can't produce the science to back up their objections it is just an opinion.

 

[Soapy Sam]

The rate is important. The changes due to the end of the last ice age. The temperature rose by 5C in 10,000 to 20,000 years, we are talking about such a change happening to the earth now in 200 or so years. The difference in the order of magnitude is huge.

Asking for unequivocal proof reminds me of creationists denying the evidence for evolution. Sure, there are gaps, but so much evidence is there, does it really matter?

IMO, yes, the evidence does matter. As does the rate. If the Greenland ice shelf melts next year, a large volume of water at 0 Celsius will enter the North Atlantic. The effect on northern hemisphere weather , ice pack formation, current direction , deep water circulation and albedo would be dramatic. But in which direction? If the same melt takes 100 years would the effect be different? I think it would.

Note the comments on timings on this graph- here-http://www.fettes.com/Cairngorms/Loch%20Lomond%20Stadial.htm

It's evident that the change from glacial to comparitively mild conditions can occur on the order of a human lifetime. I doubt that we can pin any of the several Late Devensian fluctuations on human activity. Perfectly natural temperature variation can be as large as any we are seeing today. (We should also keep in mind that temperature is not the only important variable. Relative lengths of seasons and many other factors affect global average climate).

Yes, AUP, my opinion is that it really does matter whether we have all the facts or not. The evidence which accumulates annually shows that glacial / interglacial transitions are a great deal faster and more complex than we thought.

I repeat that this is no reason for energy profligacy or scientific complacency. But I do not share your confidence that we have the data yet.

Sphenisc-
The Ice ages may have been a freakishly improbable event, from which we are returning to a long term norm. The reason the dinosaurs did so well through the Mesozoic and insects so well in the Carboniferous may also have been climatic stability- but it was not the climate we are used to.
H.sap is an Ice Age mammal, but one which has thrived as the world has warmed after the ice. If it warms more, I suspect we will continue to thrive,long term, by adapting. Or we will not. Adapting on the basis of the wrong theory could be just as unfortunate as doing nothing. Or not. Damned hard to tell. I'm just not so wholly convinced as some that we know enough.

I'm interested in the causes of climate change. If terraforming or planetary engineering is starting here and now, I think it best that we know what we are about, but I confess I don't think of climate change in terms of "solvability", I see it as an opportunity for adaptation. But if you prefer to hold change back, you need to know why it happens.

Climate change will continue to affect all life on Earth, as it always has. For some, increased temperature will be advantageous, for some not. By "solvable" do you mean preservation of the status quo, with prairie wheatlands dominating global grain supply, or had you something else in mind? I mean - is it the climate you want to save, or the politics and culture derived from it? (The two are not the same, though intimately related).

I'm afraid I have to bow out of the discussion,people. I have bags to pack, flights to catch and a well to drill. I hope to check in after a few days.

SS.

 

[Meadmaker]

To answer SS, I don't really want an opportunity to adapt. If forced to adapt, that's ok. I guess we will. However, I don't see any need to force adaptation here. The climate status quo works. Let's not fix it.

In my search, I've seen a lot of discussion of how climate change might actually be good for us. I'm sure that's true, but I don't see any need to take the chance if we don't have to.

 

[DeviousB]

I doubt that we can pin any of the several Late Devensian fluctuations on human activity.

That won't stop someone trying!

 

[CapelDodger]

Since about 20,000 BP, the trend has been upward, except for a major reversal between 12 and 10,000 BP when we had glaciers all over the place again.

20ky BP the world was at a glacial maximum. Since then it's moved into an interglacial, just as it has before, due to regular cycles in Earth's orbit and inclinitation to the Sun. These cycles have nothing to do with the rapid warming that's going on now. The normal pattern for an interglacial is to start warm and gradually cool.

Since then, it's been getting warmer, except for a period from about 1300 to the mid 19th century, when it went down again.

From 10ky BP until 1900 the world gradually cooled. Which is to say, it didn't get warmer, you've been misinformed about that. (There's a lot of misinformation out there, not all of it deliberate.) Since 1900 warming has driven the temperature higher than it's ever been in this interglacial (except possibly during the period between the end of major glaciation and the Younger Dryas (12 to 11ky BP). To characterise 99 centuries of cooling followed by one century of warming as a "warming period" is nonsensical.

Interglacials are typically begin warm and gradually cool until a new glaciation kicks in. This interglacial was following that typical path until the last century. It's path now is not typical at all.

 

[a_unique_person]

so you're saying its the majority of the evidence being in favor of AGW that makes it a consensus? that doesnt challenge what i have said.

A consensus you are talk about is a matter of opinion. This is not just a matter of opinion, it is the result of scientific research. Read the links that Varwoche has collected on actual scientific research, by hundreds of scientists.

also- about the experts disagreeing- I know that people have posted petitions from people skeptical of AGW in threads you have started about it, some of the people signing them worked on ipcc. there is a link in the wiki someone posted earlier, under 'global warming controversy'.

There are about 20 scientists who question anthropogenic global warming, there are hundreds who don't. It's like the old scientific debates about the dangers of smoking and creationists. I can find you scientists who believe in creationism, and the tobacco companies could always find scientists who didn't believe smoking caused any harm.

 

[Schneibster]

"However, Julian Morris, executive director of the International Policy Network, urged governments to be cautious. "There needs to be better data before billions of pounds are spent on policy measures that may have little impact," he said."

I guess I'm unclear on whether he means, "We shouldn't be spending billions of pounds (dollars, for the US members) on policy measures," or "We shouldn't enact policy measures without investigating how effective they will be." I'd tend toward the second view, absent any other information; IOW, let's not just go running off to "do something" if the "something" won't make a difference; let's pick some "somethings" that will make a difference. OTOH, if he means the first, then I would have to disagree with that assessment, merely on the grounds that if we don't do something, it's going to be really, really expensive.

 

[skeptifem]

A consensus you are talk about is a matter of opinion. This is not just a matter of opinion, it is the result of scientific research. Read the links that Varwoche has collected on actual scientific research, by hundreds of scientists.

I was asking why it matters if it is a consensus, i asked if a majority somehow made it correct. you said the preponderance of the data is what matters (which boils down to majority again, just not in people but in research). I am not getting anywhere in this discussion by having you restate your opinion. So lets just forget it. a consensus points to truth in your opinion, but not mine. perhaps that should be a whole different thread all together.

There are about 20 scientists who question anthropogenic global warming, there are hundreds who don't. It's like the old scientific debates about the dangers of smoking and creationists. I can find you scientists who believe in creationism, and the tobacco companies could always find scientists who didn't believe smoking caused any harm.

evidence of there being about 20 scientists who question?

To me both sides have good points. I do not see why it has to be so black and white. Perhaps both are somewhat right. It seems like the science behind global climate is not very old or very well understood, so I am going to wait awhile to make a judgement. Alternative fuel sources are a good idea in many practical ways so I am all for pursuing that.

 

[Iamme]

Here is a link to an article in the "Telegraph:"

http://www.telegraph.co.uk/news/mai...AVCBQUIV0?xml=/news/2006/12/10/nclimate10.xml

"The report paints a bleak picture for future generations unless greenhouse gas emissions are reduced. It predicts that the climate will warm by 0.2 C a decade for the next two decades if emissions continue at current levels."

It seems to me that due to population increases and the fact more countries are becoming more heavily industrialized, that the amounts of emissions should be going up EXPONENTIALLY by decade.

 

[a_unique_person]

I was asking why it matters if it is a consensus, i asked if a majority somehow made it correct. you said the preponderance of the data is what matters (which boils down to majority again, just not in people but in research). I am not getting anywhere in this discussion by having you restate your opinion. So lets just forget it. a consensus points to truth in your opinion, but not mine. perhaps that should be a whole different thread all together.

You miss the point. This is not just opinion. It is scientific research, following the tried and proven scientific method. That means it is, as much as is humanely possible, not opinion, but objective fact. No one in the list of AGW deniers denies the world is warming, for example, that is demonstrated beyond doubt. The deniers are only denying there is a human component to it, that is, the degree to which CO2 is responsible for the measured warming.

evidence of there being about 20 scientists who question?

To me both sides have good points. I do not see why it has to be so black and white. Perhaps both are somewhat right. It seems like the science behind global climate is not very old or very well understood, so I am going to wait awhile to make a judgement. Alternative fuel sources are a good idea in many practical ways so I am all for pursuing that.

It has to be black and white because if the CO2 is responsible for the current warming phase, it means the temperature will continue to rise for a hundreds of years, causing drastic changes to the climate.

 

[Meadmaker]

There are about 20 scientists who question anthropogenic global warming, ...

Are they publishing in scientific journals?

 

[Meadmaker]

It has to be black and white because if the CO2 is responsible for the current warming phase, it means the temperature will continue to rise for a hundreds of years, causing drastic changes to the climate.

I don't buy this. Why should it be so? More importantly, in my opinion, has anyone published a scientific paper that makes this claim?

 

[Slimething]

This is not just opinion. It is scientific research, following the tried and proven scientific method.

Well, yes and no. The measurements indicating a warming planet are fairly well established. But that is not the controversy. For now, let's call the science part global warming in small letters and the front-page controversy Global Warming in caps. They really are only related in name.

The controversy is fueled by the interpretation of the measurements which, to my mind, bears little resemblance to the scientific method. Atmospheric models developed to track current effect and predict future results of the current warming rate have not yet been validated. In fact, one of the anti-global warming's best points against Global Warming is that the models are deviating significantly from measured temperatures in the short run. Yet, we have some Global Warming people proclaiming that we are already doomed. (Does that sound like sound science to you?)

In my view, politicians and headline-hogs are using Global Warming to scare the pants off people. This is far from what is needed. What is needed is for the science of global warming to get on track and finesse the models such that they are fairly predictive so we can see the scope of the problem. This would be a true application of the scientific method.

The models then can also be of much use in determining what the best remediation plan would be to get us out of a jam (if indeed we can). Short of this, we are rooting around in the dark.

I do agree that it's doubtful that there would be no consequence of humans spewing of all that garbage into the atmosphere but that does not mean we have to abandon reason and mischaracterize the possible problem of global warming. However, at this point in time, I can fairly attest that no one knows for sure if there is a problem, how serious it is or what exactly to do about it.

A final word. I'm a scientist. There is an age old maxim that holds pretty well in predicting that, given n scientists in a room, you have n+1 opinions. Don't hold your breath waiting for a consensus on anything from that community.

 

[a_unique_person]

Well, yes and no. The measurements indicating a warming planet are fairly well established. But that is not the controversy. For now, let's call the science part global warming in small letters and the front-page controversy Global Warming in caps. They really are only related in name.

Not really. The IPCC is predicting consequences that are severe. I have a scientist friend working for the CSIRO on this, including work on the models. He does believe AGW is real, but he thinks we can work to manage the consequences, but that governments are ignoring those consequences. He does not believe there will be a runaway effect, but he does believe the temperature will keep rising for many years to come.

The controversy is fueled by the interpretation of the measurements which, to my mind, bears little resemblance to the scientific method. Atmospheric models developed to track current effect and predict future results of the current warming rate have not yet been validated. In fact, one of the anti-global warming's best points against Global Warming is that the models are deviating significantly from measured temperatures in the short run. Yet, we have some Global Warming people proclaiming that we are already doomed. (Does that sound like sound science to you?)

What are the errors with those models? From what I have read, the only error is that they underestimate the effects of AGW, since the Arctic and glaciers are melting faster than was estimated.

 

[Schneibster]

Having done some source research on the Telegraph, I find that I'm pretty certain now that, unfortunately, it appears Julian Morris (may his soul rot in... well, a place very much like here will be pretty soon if his ilk don't catch a fatal case of ebola) means, specifically, "Global warming isn't real, and we shouldn't spend money on it." So I'd have to say that I'm pretty much not in agreement with that.