/ How much is known about global warming?

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SI - profile removed on 01 Jul 2010
Just finished reading Superfreakonmics which pretty much blew everything I thought I knew about global warming and carbon emissions out of the water. So how much is actually known about it? It seems like there's an awful lot of speculation.

Not that I'm arguing against reducing CO2 and less wasteful living, as it seems a good idea either way.
toad - on 01 Jul 2010
In reply to Shaun L: Care to summarise their perspective? Sounds like you want an awful lot of new discussion off the back of a 3 line post.
Mike Stretford - on 01 Jul 2010
In reply to Shaun L: Is this the book 'SuperFreakonomics Global Cooling, Patriotic Prostitutes, and Why Suicide Bombers Should Buy Life Insurance'

by Steven Levitt and Stephen Dubner (economist and journalist respectively)

?

It seems like an odd book to base what you thought you knew on.

Have a look at this

http://www.iop.org/news/archive/december/file_42373.pdf
tony on 01 Jul 2010
In reply to Shaun L:
> Just finished reading Superfreakonmics which pretty much blew everything I thought I knew about global warming and carbon emissions out of the water. So how much is actually known about it? It seems like there's an awful lot of speculation.
>
Superfreakonomics doesn't do a very good job of discussing global warming - there are lots of mistakes in it, and lots of false assumptions.

A lot is known about global warming. There's a lot more to be learnt about it, but there's an interesting discussion about what climate scientists think, and the degree of consensus, given here:
http://www.realclimate.org/index.php/archives/2010/06/what-do-climate-scientists-think/#more-4284

Pekkie - on 01 Jul 2010
In reply to Shaun L:

Just because a book is published doesn't mean that anything in it is true. Lots of trashy books are published which contain obviously wrong and outrageous claims just to make money. Superfreakonomics has been heavily criticised in quality newspapers and by the science community. One of the more interesting claims in the book is that we could solve global warming by geo-engineering the stratosphere. Do you think they could get insurance for that job when BP with its billions can't cap a single gushing oil well in the Gulf of Mexico?
SI - profile removed on 01 Jul 2010
In reply to tony: What mistakes? I know it's not a very highbrow book but it did make some convincing arguements (to me anyway), is it all bullshit?
Tiberius - on 01 Jul 2010
In reply to Shaun L:
> Just finished reading Superfreakonmics which pretty much blew everything I thought I knew about global warming and carbon emissions out of the water.

So, you've read one authors argument, and everything you've read before from any other source is now thrown out the window? That's not really a good way to progress your knowledge.

The idea that everything from one source is correct and replaces everything from another source is generally more akin to the religious thought process than the scientific one.
@ndyM@rsh@ll - on 01 Jul 2010
In reply to Shaun L: List the arguments, then get told what's wrong with them, if there is anything, i've not read it.
SI - profile removed on 01 Jul 2010
In reply to Pekkie: Fair enough. Just thought it might have been worth talking about.

<Looks down ... slowly and quietly wonders away>
tony on 01 Jul 2010
In reply to Shaun L:
> (In reply to tony) What mistakes? I know it's not a very highbrow book but it did make some convincing arguements (to me anyway), is it all bullshit?

It's not all bullshit, but it's pretty poor.

Have a read of http://scienceblogs.com/deltoid/2009/10/why_everything_in_superfreakon.php
http://climateprogress.org/2009/10/14/superfreakonomics-errors-nathan-myhrvold-intellectual-ventures...
http://scienceblogs.com/stoat/2009/10/superfreakonomics_global_cooli.php

Just because it's all published in a book doesn't mean it's right.
Tiberius - on 01 Jul 2010
In reply to Shaun L:
> (In reply to Pekkie) Fair enough. Just thought it might have been worth talking about.

It's all worth talking about, but your start point was that everything you knew about global warming had been blown out the water...as pointed out, that's a bit of a silly start point.
SI - profile removed on 01 Jul 2010
In reply to Tiberius: Bugger... I wish that there was some sort of re-write OP option on this site.

I guess I was just wondering if there was any truth to the (now seemingly) claims made in the book, which I guess I'm going to have to now summarise.

Ten minutes...
SI - profile removed on 01 Jul 2010
In reply to Shaun L: missed outrageous out there...
Mr Lopez - on 01 Jul 2010
In reply to Shaun L:
I've read their previous book and can assure you that the guys don't have a clue what they are talking about, and their books are half uninformed sensationalist bullshit, and the other are half-lies trying to be proven true by simplisticly omitting every fact that doesn't suit them.

As for climate change... No way to know for sure, as what is believed is based on various unreliable data, which can be ignored or omitted based on whether it suits the result you want to achieve, or not.
niggle - on 01 Jul 2010
In reply to Tiberius:

> So, you've read one authors argument, and everything you've read before from any other source is now thrown out the window? That's not really a good way to progress your knowledge.

How about rushing to attack and belittle anyone who starts threads to ask simple questions about important topics? Does that progress anyone's knowledge?
SI - profile removed on 01 Jul 2010
Ok, I can't really summarise the book. But it did quite convincingly put forward an argument I've heard snippets of hear and there, which quite surprised me too as I wasn't expecting it from that book.




P.s. Cheers Niggle.
Mike Stretford - on 01 Jul 2010
In reply to niggle:
> (In reply to Tiberius)
>
> [...]
>
> How about rushing to attack and belittle anyone who starts threads to ask simple questions about important topics?

I've just re-read the responses and I can't find an examle of that. I spent 5 minutes finding a simple answer to his question from the IOP for no response.
niggle - on 01 Jul 2010
In reply to Papillon:

> I've just re-read the responses and I can't find an examle of that.

Well of course you can't.
Mike Stretford - on 01 Jul 2010
In reply to niggle: It was quite a good natured thread till you turned up.
niggle - on 01 Jul 2010
In reply to Papillon:

Well instead of complaining, why not get it back on track? I'm interested too.

So what do you make of the moves by prominent scientists in the field to limit access to the data they based their findings on? There have been suggestions that there are serious flaws in their data and we know that even when information has been requested under the freedom of information act it hasn't always been forthcoming.

There seem to be good arguments against the content of Freakonomics, but it seems there are pretty serious problems with the orthodox view and its practitioners too.
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SI - profile removed on 01 Jul 2010
In reply to tony: Cheers Tony, read you're links and now feel suitably informed, and somewhat humbled... Wish I'd turned to goggle before UKC. I guess I am quite gullible and easily impressed, I'll blame it on youth rather than stupidity. :)
rcammack - on 01 Jul 2010
Tiberius - on 01 Jul 2010
In reply to niggle:

> How about rushing to attack and belittle anyone who starts threads to ask simple questions about important topics? Does that progress anyone's knowledge?

Not sure what you're getting at niggle, it's an internet forum, it works a little like a chat in a pub. Someone posts something and you answer, you don't wait a set period of time before you answer, forum posts are more like a conversation.

I'm not sure anyone has attacked or belittled anyone, although a few have pointed out that the stance taken has several weaknesses and the statements made about everything being thrown out the window are hard to justify.

Pointing out a better way of investigating supposedly scientific proposals certainly progresses people's knowledge. I would say that's why the people took the time and effort to highlight it.
SI - profile removed on 01 Jul 2010
In reply to Papillon: Sorry! I tried but I couldn't understand it, I'll have another go. There was quite a bit to respond to...
Coel Hellier - on 01 Jul 2010
In reply to Shaun L:

How much is known about global warming? Well, it's hard to answer that concisely. We are fairly confident that we know the basics of global warming and the effect of greenhouse gases, and we are fairly confident that climate change is occurring as a result of human CO2 emissions. However, the climate is a hugely complex system, so the amount of change, the timescale, and the effects of that change are all fairly uncertain. How human societies might respond to that change, and the best ways of ameliorating that, are even more uncertain.
ClimberEd - on 01 Jul 2010
In reply to Shaun L:

I'm not sure about their arguements for or against global warming (I haven't read the book) but I can sum up the (deal breakingly massive imho) problem with geo-engineering (their sulphar cloud idea) which is that we have no idea what other effects it will have beyond slowing atmospheric warming - these could well be catastrophic to the planets weather systems. (and therefore food etc)
niggle - on 01 Jul 2010
In reply to Tiberius:

> Not sure what you're getting at niggle

Again, of course you're not.
Coel Hellier - on 01 Jul 2010
In reply to niggle:

> So what do you make of the moves by prominent scientists in the field to limit access to
> the data they based their findings on?

I don't make much of it: they felt they were being harrassed by frequent demands for data that were not serious attempts to analyse the data, but merely attempts to derail the reseachers. Most research groups are not funded to respond to frequent data-requests.

> There have been suggestions that there are serious flaws in their data ...

Very weaselly wording "there have been suggestions". OK, climate-change deniers have indeed "suggested" that. But the results have been checked and corroborated by other groups, and the basics are not in doubt.

> but it seems there are pretty serious problems with the orthodox view and its practitioners too.

Such as? Is there any substance to these "serious problems"?
Mike Stretford - on 01 Jul 2010
In reply to Shaun L: No worries, if you get another chance to look at it and there's something your stuck with feel free to ask.
Mike Stretford - on 01 Jul 2010
In reply to niggle:
> (In reply to Papillon)
>

Coel has answered your question to me, so there's no point in me duplicating posts.

> There seem to be good arguments against the content of Freakonomics, but it seems there are pretty serious problems with the orthodox view and its practitioners too.

If there are serious problems, why don't we use the IOP release I posted as a starter, and you can point out where they've gone wrong?

niggle - on 01 Jul 2010
In reply to Coel Hellier:

> Such as? Is there any substance to these "serious problems"?

I'd say that refusing to allow skeptics to use the same data as you do, even when they request it under freedom of information, is a pretty serious problem.

I doubt you'd give much credence to a study whose authors refused to allow it to be reviewed by anyone who didn't agree with their findings. So why accept it from climate change theorists who do exactly that?
ClimberEd - on 01 Jul 2010
In reply to Shaun L:

The Proceedings of the National Academy of Sciences analysed who did and didn't support climate change.

It found that people who strongly questioned it were typically working in an unrelated field.

For everything else in life we rely on expert judgement, if not a single expert then the consensus.

Make of that what you will....

Paper here: http://www.pnas.org/content/early/2010/06/04/1003187107.abstract

BBC summary here:
http://news.bbc.co.uk/1/hi/science_and_environment/10370955.stm
niggle - on 01 Jul 2010
In reply to Papillon:

> why don't we use the IOP release I posted as a starter, and you can point out where they've gone wrong?

Sorry, did I question what you posted? Did I say it was wrong?
Mike Stretford - on 01 Jul 2010
In reply to niggle:
> (In reply to Papillon)
>
> [...]
>
> Sorry, did I question what you posted? Did I say it was wrong?

Yes you implied it with this statement

'but it seems there are pretty serious problems with the orthodox view'

niggle - on 01 Jul 2010
In reply to Papillon:

> Yes you implied it with this statement

Could you possibly stick to what I actually said instead of what you imagine I said? Thanks!
niggle - on 01 Jul 2010
In reply to ClimberEd:

> It found that people who strongly questioned it were typically working in an unrelated field.

If no one is allowed to question more experienced and published scientists than them, science will go nowhere.

Do you really judge ideas by who presents them and not their actual merit?
Coel Hellier - on 01 Jul 2010
In reply to niggle:

> I'd say that refusing to allow skeptics to use the same data as you do, even when they request
> it under freedom of information, is a pretty serious problem.

Some of these FoI requests are pure harrassment, such as the one by the Virginia Attorney General for just about all paperwork and emails from ten years of research.
http://blogs.physicstoday.org/politics/2010/05/an-unwelcome-climate-for-scien.html
http://www.washingtonpost.com/wp-dyn/content/article/2010/05/03/AR2010050304139.html

> I doubt you'd give much credence to a study whose authors refused to allow it to be reviewed
> by anyone who didn't agree with their findings.

It's not the case that they've refused to share data with other genuine scientists who are genuinely interested in doing a proper analysis of the data. Note that it takes time and money to collate and hand on data in a sensible fashion. It is hardly suprising that some groups have been reluctant to go to that effort with requests from denialists.

And global-warming trends do not depend on any single dataset -- they are corroborated by multiple datasets from independent groups.
SI - profile removed on 01 Jul 2010
In reply to Papillon: Ok, zoomed in and had a proper read. It's this bit I was hoping to predominately read a debate on.





There are some uncertainties in the precise strength of the effect these gases have on the climate, and further research is needed into areas such as what proportion of greenhouse gases emitted stays in the atmosphere and what is re-absorbed, and into feedback mechanisms – for example an increase in temperature might cause the release of methane from melting ice, but it may also spur plant growth and cause more carbon dioxide to be re-absorbed. Haigh says: “New satellite instruments are now being used to make global measurements of atmospheric and oceanic temperature and composition, as well as of the incoming solar radiation. These contribute to a database against which theories can be tested. Global climate models are becoming ever more complex, resulting in successful simulations of climate features such as El Niño and the ozone hole.”

Coel Hellier - on 01 Jul 2010
In reply to niggle:

>> It found that people who strongly questioned it were typically working in an unrelated field.

> If no one is allowed to question more experienced and published scientists than them, science will go nowhere.

The above comment said "working in an unrelated field", not "less experienced and un-published".
ClimberEd - on 01 Jul 2010
In reply to niggle:

The whole of science is about testing and questioning - at what point did I (or anyone else) imply that it wasn't.

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GrahamD - on 01 Jul 2010
In reply to ClimberEd:


> For everything else in life we rely on expert judgement, if not a single expert then the consensus.

...except possibly in the case of national football sides where everyone is an expert.
Mike Stretford - on 01 Jul 2010
In reply to niggle:
> (In reply to Papillon)
>
> [...]
>
> Could you possibly stick to what I actually said instead of what you imagine I said? Thanks!

It's a direct cut and paste from your post!
Coel Hellier - on 01 Jul 2010
In reply to Shaun L:

> "There are some uncertainties in the precise strength of the effect these gases have on the climate, ..."

Obviously true. "uncertainties in the *precise* strength". However, we do have a broad idea.

> "and further research is needed into areas such as what proportion of greenhouse gases emitted stays
> in the atmosphere and what is re-absorbed, and into feedback mechanisms"

Yes true, there are uncertainties in these things. Thus the degree of warming that carbon burning will cause is uncertain. As a result, things like the IPCC reports give quite a wide range in their warming projections.

SI - profile removed on 01 Jul 2010
In reply to Coel Hellier: So what conclusions do you draw from that?
Coel Hellier - on 01 Jul 2010
In reply to Shaun L:

> So what conclusions do you draw from that?

We are fairly sure that human CO2 emissions are causing climate change. We can estimate -- but with significant uncertainty -- how much the climate will change (see IPCC estimates). It is fairly clear that the greater our CO2 emissions are the greater the change of climate will be. We may (though it is uncertain) pass "tipping points" where the climate shifts to a much warmer phase -- afterall it has done so many times in the past, and that is the nature of chaotic systems such as climate.

The above is what the scientists can say. Whether society wants to "go along for the ride", or whether we want to radically change society to reduce the changes as much as possible, is more up to politicians and wider society than up to scientists. The effects of the coming changes on society, their timescale, and how best to deal with them, are all uncertain and hard to predict. As the Chinese curse goes: "may you live in interesting times".
Tiberius - on 01 Jul 2010
In reply to niggle:

> Again, of course you're not.

I know you're not English, but a high number of the scotish peoples still manage to communicate quite effectively in the English language. Perhaps I could suggest some books on effective communication?

no_more_scotch_eggs - on 01 Jul 2010
In reply to niggle:

ah, this is more like it! your insightful, patient and respectful posts over on the modern art thread just seemed so... un-niggle-like...
In reply to ClimberEd:

> The Proceedings of the National Academy of Sciences analysed who did and didn't support climate change.
>
> It found that people who strongly questioned it were typically working in an unrelated field.

Slate had a very interesting piece suggesting whilst the conclusion may well be right, the evidence provided didn't prove it. I think they called it bad social science trying to protect good natural science: http://www.slate.com/id/2258088/
ClimberEd - on 01 Jul 2010
In reply to TobyA:

Interesting, I'm happy to hold my hands up and say that I'm not in a position to evaluate social science methadology.
Dr.S at work - on 01 Jul 2010
In reply to ClimberEd:
"social science"? is that a bit like "home economics"?
Coel Hellier - on 01 Jul 2010
In reply to TobyA:

> Slate had a very interesting piece suggesting whilst the conclusion may well be right, the evidence
> provided didn't prove it. I think they called it bad social science trying to protect good natural science

Having just read the Slate piece and the original article I think the Slate criticisms are fairly minor and don't really detract from the main conclusion. The database used, Google scholar, is broad and not restricted to a small number of refereed journals, so the idea that the results could be explained by bias (ie journals being unwilling to publish denialist papers) is far fetched; it is almost impossible to prevent or surpress publication somehow, somewhere, in these days of the internet.

Thus the conclusion of this paper -- that there is not a substantial number of reputable scientists or publications in the field opposed to the idea of human-induced climate change -- is robust.
subalpine - on 01 Jul 2010
In reply to ClimberEd:
> (In reply to Shaun L)
>
> .. I can sum up the (deal breakingly massive imho) problem with geo-engineering (their sulphar cloud idea) which is that we have no idea what other effects it will have beyond slowing atmospheric warming - these could well be catastrophic to the planets weather systems. (and therefore food etc)

looks like geoengineering trials are about to begin..
http://www.telegraph.co.uk/earth/environment/globalwarming/7842592/Iron-to-be-dumped-at-sea-to-reduc...
god help us!

SI - profile removed on 01 Jul 2010
In reply to Coel Hellier: Cheers, I think you've pretty much answered the op.
Parrys_apprentice - on 01 Jul 2010
To answer the OP question, "How much is known about global warming?

The answer is paradoxically that we know too much (to ignore it) and nowhere near enough (to properly deal with it).


Coel Hellier - on 01 Jul 2010
In reply to Parrys_apprentice:

> The answer is paradoxically that we know too much (to ignore it) and nowhere near enough (to properly deal with it).

Well put.
SI - profile removed on 01 Jul 2010
In reply to rcammack: Cheers, I'll get it.
SI - profile removed on 01 Jul 2010
In reply to ClimberEd: Thanks for the links.
subalpine - on 01 Jul 2010
In reply to Coel Hellier: is geo-engineering one step too far for you then?
Coel Hellier - on 01 Jul 2010
In reply to subalpine:

> is geo-engineering one step too far for you then?

Well it's obviously risky, though what we're currently doing, pumping large amounts of CO2 into the atmosphere, is essentially geo-engineering already.
SI - profile removed on 01 Jul 2010
In reply to Coel Hellier: What about methane? Did humans start geo-engineering when we starting farming?
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Coel Hellier - on 01 Jul 2010
In reply to Shaun L:

> What about methane? Did humans start geo-engineering when we starting farming?

Yes we did, but human population was much lower through nearly all of our history ( http://www.gumption.org/1993/memo/landmarks/world_population.gif ), so until the explosion in population from 1800 on, plus the massive burning of fossil fuels since then, our greenhouse gas emissions would not have amounted to much.

But humans did radically change things before the modern era, for example England would have been one large forest in 2000 BC, and that changed to one large swathe of farmland by the middle ages.
SI - profile removed on 01 Jul 2010
In reply to Coel Hellier: It was just something from the now infamous book that stuck a chord with me, they claimed that the methane produced from farming does far more environmental damage than that of CO2 emissions, is that view supported by the scientific community?
SI - profile removed on 01 Jul 2010
In reply to Shaun L: That is assuming that the population of cows and sheep has risen in line with humans.
Coel Hellier - on 01 Jul 2010
In reply to Shaun L:

> they claimed that the methane produced from farming does far more environmental damage than that of CO2 emissions

Methane is a more potent greenhouse gas than CO2, however it also breaks down in the atmosphere relatively quickly, whereas CO2 lasts for hundreds of years. Overall methane is thus a smaller contributor to warming (about 20% of the effect of CO2 I think, though estimates will vary), but it is an important factor that is included in the models.
Coel Hellier - on 01 Jul 2010
In reply to Shaun L:

> That is assuming that the population of cows and sheep has risen in line with humans.

I expect their rise was later and faster than human population. Poorer human societies tended to be mostly vegetarian, with meat a rare treat. Meat consumptions has zoomed up in places like China and India over the last generation as their affluence has grown.
ClimberEd - on 01 Jul 2010
In reply to Shaun L:
> (In reply to Coel Hellier) It was just something from the now infamous book that stuck a chord with me, they claimed that the methane produced from farming does far more environmental damage than that of CO2 emissions, is that view supported by the scientific community?

Depends what you mean by environmental damage.

Methane represents around 15% of CO2E emissions under standard measurements. (or thereabouts)

If you take a 20year time frame, instead of 100years, which is arguably a better measurement, this jumps from 15 to 35%

Despite the 'general publics terminology' of CO2, CO2 is only part of the problem, you have methane, nitrous oxide, HFCs and various other gases contributing to the effects as well.
anonymouse - on 01 Jul 2010
In reply to niggle:
> So what do you make of the moves by prominent scientists in the field to limit access to the data they based their findings on? There have been suggestions that there are serious flaws in their data and we know that even when information has been requested under the freedom of information act it hasn't always been forthcoming.

Niggle. That's awfully vague. Which data and which scientists are you talking about?
subalpine - on 01 Jul 2010
In reply to anonymouse: scientists don't release bad data..
anonymouse - on 01 Jul 2010
In reply to subalpine:
eh?
subalpine - on 01 Jul 2010
In reply to anonymouse: no data, no argument..
SI - profile removed on 01 Jul 2010
In reply to Coel Hellier and ClimberEd: Cheers guys, I'm appreciating the free science lesson. I think that's all the questions I have for now. :)
subalpine - on 01 Jul 2010
In reply to Shaun L: well done - 2/10
SI - profile removed on 01 Jul 2010
In reply to subalpine: Eh?
subalpine - on 01 Jul 2010
In reply to Shaun L: the T(roll) index..
niggle - on 01 Jul 2010
In reply to subalpine:

> scientists don't release bad data..

Course they don't. They'd never make a link between, say, MMR and autism.

;)
SI - profile removed on 01 Jul 2010
In reply to subalpine: Can I have some of whatever you've taken please?
subalpine - on 01 Jul 2010
In reply to Shaun L: surely there should be at least some regulation with these wacky new geo-engineering projects/carbon offsets?
Coel Hellier - on 01 Jul 2010
In reply to subalpine:

> surely there should be at least some regulation with these wacky new geo-engineering projects/carbon offsets?

From your own link: "The trial needs to be approved by the UN London Convention, which regulates the dumping of substances at sea ..."

Note that so far these are only small-scale trials, way too small to have long-term effects. As yet there is no proposal to do large-scale geo-engineering; if and when there is it will need to be approved by appropriate authorities.
M. Edwards on 01 Jul 2010
In reply to Shaun L:

A few thoughts I have come across through talking to knowledgeable scientists I have met over the past few years...(whilst climbing with them)

Climate models can be very very varied in their results, and it is unfortunate that only the dramatic "end of the world" end of the scale have been released to the media.

Global Dimming: 9/11 saw all planes grounded in the States and the ground temp went up four degrees. Next day when all was flying again, the temp went back to normal. This is because the particles from the planes pollution reflex heat back into space. Particles are smaller than pollen, and if water vapor attaches itself it is not heavy enough to fall as rain, therefore a dry planet.

Temps are going up on Mars too... so whats happening there?

I am no expert...these are just some things I have listened to.

Coel Hellier - on 01 Jul 2010
In reply to M. Edwards:

> Climate models can be very very varied in their results, and it is unfortunate that only the
> dramatic "end of the world" end of the scale have been released to the media.

I don't see how that's true. The IPCC reports, for example, present a range of projections from modest warming to severe warming. I suspect it is more a case of the media choosing to highlight the more severe predictions because they tend to go for the sensationalist angle, whatever they're reporting.
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subalpine - on 01 Jul 2010
In reply to Coel Hellier: i don't see how geo-engineering is part of the answer-please advise...
M. Edwards on 01 Jul 2010
In reply to Coel Hellier:

You could be right. The media would sell more with worst case scenario.
Coel Hellier - on 01 Jul 2010
In reply to subalpine:

> i don't see how geo-engineering is part of the answer-please advise...

I haven't claimed that it is part of the answer. Though I'm not opposed to small-scale trails to see what happens.

(And, as I said, the real geo-engineers here are the societies who continue to burn fossil fuels when they've been warned of the possible consequences. Just imagine how you'd react if Big Pharma was doing something like that for short-term ends!)
i.munro - on 01 Jul 2010
In reply to Coel Hellier:


> I don't see how that's true. The IPCC reports, for example, present a range of projections from modest warming to severe warming.


That's projections ranging from modest to severe warming by 2100.

Whatever temp rise you consider to constitute 'doomsday' will be reached if the process continues.
If the most optimistic projections turn out to be correct it doesn't mean no doomsday it simply means that it will be a little later.

It's like jumping off a cliff & arguing about whether the height has been correctly estimated.
It doesn't really matter, you're going to hit the bottom sooner or later.


anonymouse - on 01 Jul 2010
In reply to Anonymous:

The post disappeared but never mind...

> Yes it is.
Same question to you as to niggle. Who has withheld data and what did they withhold?

> No it doesn't. The data is ftped to them and dumped into a folder - all they have to do to share the data is to make that folder public.
Depends on the data. It can take time (and hence money) to put data on the web in a sensible fashion. Sometimes you have to obtain permissions to do so, sometimes the permission isn't granted. Sometimes people can't read the data in the format you use. If you dump your data on an ftp site it might not be useful, then people email you and accuse you of being obstructive.

> This is true because the ‘denialists’ keep finding serious errors in the data. For example the recent discovery that they were missing the minus signs off of METAR data. So exceptionally cold temperatures recorded last winter have been logged as exceptionally warm ones.
The METAR problem was an error in the GISS data set that was spotted and corrected within a couple of days. The error had a very very small effect in the global temperature in one month.

> All the datasets have the same source.
There are large overlaps, sure, but each group uses some independent data. The data set creators use as many stations as they can because it gives a better analysis.

> The data is then adjusted by groups like Hadley and GISS for reasons that they won’t explain
The reasons are explained, in detail in the papers that describe the data sets. There's a brief description of the NCDC adjustments here:

http://www.ncdc.noaa.gov/oa/climate/research/ushcn

> and using algorithms that they won’t publish.
Descriptions of the algorithms are published. In the case of the GISS data set, the full working code has been published on the web.

http://data.giss.nasa.gov/gistemp/sources/

An independent team has recoded the whole lot, tested the code and they get... exactly the same answer as GISS do. See here:

http://clearclimatecode.org/gistemp/

> They effect of their adjustments is to create a warming trend that doesn’t exist in the raw data. If you look at the raw temperature data for the USA (for example) temperatures were higher in the 1930s than the present day.
This is where those explanations in the papers come in handy. The reasons for the warming adjustments in the US are described therein.

http://www.ncdc.noaa.gov/oa/climate/research/ushcn/#biasadj

There are versions of the global temperature curve with and without corrections to the US data. They don't make a lot of difference. The globe still warms.

Other indpendent teams grouped loosely around some skeptic blogs have created a suite of global temperature curves. Their estimates of global average land temperature show a higher rate of warming than GISS, NCDC or HadCRU. See the latest installment here:

http://rankexploits.com/musings/2010/replication/
Dominion - on 01 Jul 2010
In reply to Shaun L:

Haven't read all of this thread, but I've searched for "deforestation" and it doesn't seem to appear on this thread.

Humans produce a lot of carbon emissions. Whilst reducing carbon emissions is going to help, it is completely futile unless we stop cutting all the f*cking trees down...
SI - profile removed on 01 Jul 2010
In reply to Dominion: Especially the one f**king!



Dominion - on 01 Jul 2010
In reply to Dominion:

On another note, we pay a lot of farm subsidies to hill sheep farmers, just to support their industry.

How about we pay them a subsidy to stop breeding sheep, and plant trees all over the artificially denuded hillsides? And let them return to their natural state, where they can at least give us more time - more CO2 absorption - in order to cut down our emission excesses...

And stop the logging in the Amazon basin...

Probably the best way to combat that is to block politicians from having numbered foreign bank accounts that surreptitious payments can mysteriously arrive in...
anonymouse - on 01 Jul 2010
In reply to M. Edwards:
> Climate models can be very very varied in their results, and it is unfortunate that only the dramatic "end of the world" end of the scale have been released to the media.

This is from the IPCC report:
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch10s10-3.html

scroll down to Figure 10.4. The shaded areas provide an estimate of how varied the models are for different 'emissions scenarios'. We need different 'emission scenarios' - basically how much of greenhouse gases, sulphur and so on we might put into the atmosphere - because we don't yet know how much of each gas future-me and future-you will put into the atmosphere. There is variation between the models, but not so much that we can't say anything about possible future change.

The media can access these as easily as any of us. If they choose to emphasise the extremity of possibility that's up to them. It can make for a better story... depending on your definition of better.

> Global Dimming: 9/11 saw all planes grounded in the States and the ground temp went up four degrees. Next day when all was flying again, the temp went back to normal.
Yes. Maybe. Temperatures can vary by much more than 4 degrees from one day to the next. It makes it tricky to say exactly what caused that change. A lot of studies have considered contrails, some details here:
http://www.ipcc.ch/ipccreports/sres/aviation/040.htm

> Temps are going up on Mars too... so whats happening there?
http://www.skepticalscience.com/global-warming-on-mars.htm

M. Edwards on 01 Jul 2010
In reply to anonymouse:

Cheers! Always good to be enlightened.

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