Chronos said:
Climatology is a frustrating science. There are more variables than scientists. The geological record tells us it does as it pleases. Given the ebb and flow of climate change over the history of earth, I doubt human activity greatly disturbs whatever cycles are preferred by nature. Human contributions to the atmosphere are undoubtably significant, but only over a century or two. Climactic volatility supercedes the human factor by billions of years. Our hubris exceeds our understanding.
I'd rephrase the first part of this.
Science is frustrating. There are more variables than scientists and more questions than answers.
... except that I don't find it frustrating. I *like* living in a complex world with a depth of detail that leaves no apparent end to the questions and no easy path to answers. Science is fun, and difficult, and worthwhile, and makes progress with no apparent end point.
Why single out climate? What about cosmology, or anthropology, or medicine, or a host of other examples we could mention? I don't think there is anything particularly different about climate that makes it in a class of its own. Each field of science has its particular problems. If they didn't science would be much easier -- and more boring.
You make some assertions in the rest of the post that seem odd. You state them apparently with a degree of confidence, and then complain about hubris. That doesn't ring true to me. Why would the ebb and flow of climate over Earth's long history mean that human activity cannot greatly disturb things? The scientific evidence is pretty unambiguous that human activity has indeed disturbed things significantly. Can this be quantified? Well, yes, it can, though as is common in science the estimates come with uncertainties. This isn't unique to climate.
You acknowledge that effects on the atmosphere are significant, but the assertion that this is only over a century or two is unsupported and dubious on its face. The scale and duration of impacts are an open question; but they are investigated, and in line with physicsforums we should not be just soliciting opinions, but looking to see if the question is actually being addressed in the actual practice of science. It is.
Contrary to what some posters seem to suggest, you really don't need to have an expert on hand to look into the question. It would help, of course; but the literature is not that hard to survey and the Earth forum guidelines already has a sticky thread with pointers that would be enough to get good appreciation of what is being done.
Also, contrary to what some posters have suggested, we really do have people involved here
right now who can pick up such questions and address them with reference to the actual practice of science, and we've had them for some time. I'm one of them, and I am not the only one. Nor am I limiting myself only to individuals who share all my views on the various specifics of climate. There are a number of contributors, with a range of views, who are all well able to back up their posts with useful and directly relevant references from the work of science being done right now. (Me, Andre, mheslep, Xnn, joelupchurch, Skyhunter, chriscolose, Bill Illis, and my apologies to lots of folks I have omitted. Every now and again I notice some really first rate contribution coming in from a contributor who is not all that regular.
I do not mean contributions that merely state a point I agree with. Indeed, some of the folks I list don't agree with me. What makes a good post, in my opinion, is one that actually gets substantive on the questions of a thread, and backs up the information with references people can use to explore further what is actually being done on the subject within working science.
You don't need to have one person who can cover all the bases. Indeed, I think the whole desire to get a climate scientist on the staff is fundamentally missing the point. I support whole heartedly support the idea of finding someone like that, it would be great. It would help a lot. They wouldn't even need to be a mentor, frankly.
And yet... this won't get to heart of the problem -- which is that too many people, even some within staff, simply don't trust climate scientists.
On how best to deal with a question relating to climate
This is not a debate thread, so I am not proposing at all to debate the question raised. But Chronos makes a claim above, and it is worth looking at HOW it might be addressed without trying to actually make that debate here and now, which would be off topic.
The claim I mean is this:
Human contributions to the atmosphere are undoubtably significant, but only over a century or two.
Seeing the claim made I immediately recognize without even looking up the papers that this is a fairly hot topic in climate being actively investigated, and there are a couple of recent papers that explore the likely duration of significant consequences of the anthropogenic impact. I think I have at least one of those recent papers already in my own private collection of downloaded resources that I have been using as I've studied this whole area for myself.
If this claim had appeared in the relevant science forum, and if the forum had remained open to actually talking about such questions in the light of existing work on science, I would very likely have noticed, and presented a brief explanation of what durations are thought likely, and why, and with a reference to one or more papers that deal specifically with the topic.
I know already, from the responses I have received from different people, that this kind of contribution is useful and appreciated. It doesn't tell you what you must believe. It gives information about what is going on in existing science in relation to the question. And that, in my opinion, is what physicsforums is all about.
No personal criticism of you in intended, Chronos! Indeed, just the reverse. Having input like this, so that it can be addressed, is really useful. I would not expect anyone to be immediately satisfied with my response. The idea, IMO, is simply to give people the background and the pointers to explore further if they are interested. If anyone actually changes their mind, that's their own doing and their own thinking through resources from the discussion and from whatever else they look into. (I've touched on the nature of debate generally at my blog as well; links are in my signature.)
On why a substantive response still has problems
And yet, even given a substantive, properly referenced post, that gives some insight into the actual practice of science on the matter, there are going to be people who object.
(1) There's an unrealistic desire for a complete answer. There's no such animal. Scientists actually DON'T have the hubris, in general, to think their work resolves such things with a final answer or finished understanding.
(2) There's an unrealistic desire for equal time to some other allegedly equivalent alternative perspective. The expectation by many contributors that climate science is about equally credible alternatives is flatly mistaken. Contrasting ideas exist, of course, and the work of science is focused on resolving discrepancies and identifying those ideas that are wrong. Think "falsification". The work of science includes minority views, and they are perfectly on topic for the forum. But a presumption of equal legitimacy is not any part of science. For instance... the idea that changes will persist only over a century or two not really backed up by any scientific work of which I am aware. The best you can get is a lack certainty on potential longer durations for the effects of a human impact to dissipate; and that is already a part of the work I'd be citing on the matter.
Be that as it may, anyone else who wants to add depth to discussion by giving properly referenced alternative is making a useful contribution. Anyone who remains skeptical of the scraps provided by one contributor is perfectly within their rights. It's not a good idea to post with the objective of changing someone else's mind. The proper objective is simply to give some useful additional information.
(3) There's an unrealistic desire for authority. Science doesn't depend on authority. It's great to have an expert available, but for a basic question like this one, a student who has looked at bit at climate science will already have some useful contributions to make. Anyone who takes the time to try and learn about the subject will quickly come to a point of making useful substantive contributions. We don't need final authoritative answers to everything, or complete agreement even within staff, before the discussions become helpful.
(4) People confuse the lack of answers to some questions with the lack of answers to all questions. There are a heap of wide open problems in any area of active science. That's what keeps it active. At the same time, there are some useful discoveries and fundamental theories that make a solid foundation for pushing back the boundaries of what is known.
Of course there's a heck of a lot unknown in climate science. But frankly, the biggest problem is with people who think everything is unknown, or at least behave as if they think that. I listed back in [post=2523110]msg #26[/post] some foundational points that are often disputed in climate discussions but which could (I hope!) be usefully recognized by staff as a common basis that is not actually in any credible dispute. They are:
- Temperatures are increasing over recent decades, with a total gain of roughly 0.7 C since the start of the twentieth century. Even if people question the importance of this, the actual change itself is real and significant.
- The greenhouse effect is real. The atmosphere does interact with thermal radiation and this does result in a much warmer surface temperature than would exist otherwise. (About 33 degrees warmer, on average.)
- Atmospheric carbon dioxide has a significant effect on climate. (A forcing of about 5.35 W/m2 per lateral log of atmospheric concentration.)
- Humans have a significant effect on carbon dioxide levels. (The 30% increase in atmospheric levels since the start of the industrial revolution, and the measured increase in the present, is being driven by human activities.)
All of these are solidly established well quantified information. It is by no means a complete account of everything that matters, but it is a solid foundation not in any credible doubt. We can easily explain and reference these points for newcomers, and recognition still gives full reign to all manner of "skepticism" on various points of climate.
(5) People mix up confidence in scientific theories with the importance of scientific theories. That's a distraction from dispassionate consideration of what we can actually know and with what confidence. This is a very politically charged topic, and we should not even attempt to resolve all the political questions of appropriate policy responses. The unique contribution of physicsforums, and our greatest strength, is the capacity to help people learn more about the scientific questions. That will, no doubt, inform their views on policy as well, and I don't see why we can't allow for political discussion in the designated subforum. But our prime business is education in the science itself, regardless of how important you think it is. We'd still consider it as an interesting scientific topic even if there were no immediate pragmatic consequences; and policy considerations should be ruled as a divergence of topic for a thread that focuses on a scientific question.
I'm not saying that it is easy to manage this issue. I continue to support the new policy, albeit reluctantly, and to hope that it might indeed be temporary, without presuming so. But I do think it is a failure of physicsforums to achieve its stated aims, at least as far as this one topic is concerned, and that the major problem has been lack of unity within the staff. This isn't surprising; it is a reflection of deep lack of unity in the community. If it was only disagreement between different competing ideas in science the problem would be manageable; science takes competing ideas in its stride.
The problem is far deeper, with disagreement as to whether scientists are actually really doing honest science at all. And that makes it very hard indeed to keep to the physicsforums mandate:
"to help students learn the current status of physics as practiced by the scientific community". If people think the current status of science practice is riddled with fraud or incompetence or distortion, then the whole basis for this physicsforum mandate is undercut. And so -- most regrettably -- this active area of science is going to be ruled off limits here. Not because physicsforums has determined that the practice of science is compromised, but, in my opinion, because the staff cannot even agree on whether the practice of science in this area is something that should be the basis for education.
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Sorry this has been over long. I'm presuming this thread will probably close off as well, though I'd like to see it open for a little bit longer to let people comment on whether they would like to see physicsforums find a way to manage this, or give some more thoughts as to what that might take.
Cheers -- sylas