Are you saying that global temperatures aren't rising? Is the arctic icecap not rapidly getting smaller? I believe even the rising sea level is already measurable (though still small at this point).
The predictions are coming true in a quite alarming fashion.
Yes, see http://www.latimes.com/science/la-sci-climate-change-uncerta...
> Is the arctic icecap not rapidly getting smaller?
Well, it's not. http://www.dailymail.co.uk/news/article-2415191/Global-cooli...
> I believe even the rising sea level is already measurable
Sure. Global Sea Level Rise Dampened by Australia Floods - http://www.sciencedaily.com/releases/2013/08/130819141610.ht...
Science news almost universally overstates the effects of particular findings. These sources are more or less fine for announcing a new finding, but when you start to get into debating particular facts, they are utterly inappropriate sources.
In a forum such as Hacker News, you can expect most participants to be capable of reading the relevant portion of a peer reviewed study, and so that is the sort of citation that should be offered. News/op-ed articles bring nothing to the discussion.
And just to be clear, the ancestors our posts made unsubstantiated assertions based on their interpretation of the evidence, so in a sense, they are citing themselves, which in this sort of discussion, I think is fine. It's the appeal to low quality scientific authorities that is the issue.
[1]No offense intended by this at all, just giving a different perspective. ACQQ's comment was a catalyst for my own comment.
#3: Whenever possible, go outside the expertise of the enemy.
#5: Ridicule is man's most potent weapon.
#13: Pick the target, freeze it, personalize it, and polarize it.
All in one sentence at that. Excellent.
Really? The Daily Mail? And you think a one-year fluctuation contradicts a long term trend?
Had you actually looked into this subject, instead of clinging to some random image that seems to say what you wish to be true, you might have known that 2013 is still the sixth lowest year for arctic icecap size. And the other 5 are in the past 6 years.
You think a random image proves anything, but the only thing it proves is your own ignorance on the subject. The arctic icecap is rapidly getting smaller.
They haven't for the last 15 years, so that may be exactly what he is saying.
>Is the arctic icecap not rapidly getting smaller?
It is, but is the antarctic icecap not rapidly getting larger?
I hear people claim that, but I can't find anything that backs it up. From what I can tell, average global temperature in the mid-90s was lower than today. Since about 2000, the rapid rise from before seems to slowing or halting, but it seems a bit early to say that this is a persistent change in the long term trend. The steep climb from before is undeniable.
In other words, the last 15 years have still been a lot warmer than anything before.
http://www.skepticalscience.com/graphics/Escalator_2012_500....
To the best of our knowledge the East Antarctic Ice Sheet is gaining mass[1] due to increased precipitation and the West Antarctic Ice Sheet is losing mass[2] due to acceleration of glaciers. I believe there is also an increase in Antarctic sea ice extent [3]. As far as I know these increases are not enough to offset the reduction in mass in the Arctic but I don't have a comparison to hand. Wait a few days and the IPCC report will probably have a decent summary.
[1] https://en.wikipedia.org/wiki/East_Antarctic_Ice_Sheet#Ice_m... [2] http://www.realclimate.org/index.php/archives/2012/12/the-he... [3] http://tamino.wordpress.com/2013/03/16/antarctic-sea-ice-gai...
At best, you are exaggerating. Tell me which of the following claims in the article are false:
1) BBC reported in 2007 global warming would leave Arctic ice-free in summer by 2013
2) Almost a million more square miles of ocean covered with ice than in 2012
You said it's complete bollocks so let me know how the two items above are false or kindly admit you were exaggerating which does nobody advocating for AGW any favors.
There are obviously serious problems with the article - for example - I thought this part was ridiculous:
The Northwest Passage from the Atlantic to the Pacific has remained blocked by pack-ice all year. More than 20 yachts that had planned to sail it have been left ice-bound and a cruise ship attempting the route was forced to turn back.
Their apparent surprise of "The Northwest Passage" being blocked as being a major thing is just silly. It was blocked for most of the year until 2009. But I think it's better to point out things like that than to dismiss it as "complete bollocks" which is fairly easily falsifiable which reduces your credibility.
>1) BBC reported in 2007 global warming would leave Arctic ice-free in summer by 2013
Well that isn't strictly true. The BBC reported that some US scientists had made a prediction that the arctic 'could' be ice free by 2013. Of course the BBC reporting of that was pretty irresponsible, at least in the headline. Maslowski's actual prediction was for a range of years, with 2013 being at the low end and he is quoted in the article[1] saying "It might not be as early as 2013 but it will be soon, much earlier than 2040". For what it's worth I still think his productions will prove closer to reality than the not ice free till after 2040 ones.
>2) Almost a million more square miles of ocean covered with ice than in 2012
I will assume that this statistic is correct, but it is still very misleading. That is not a 'recovery' when you look at the longer trend: it doesn't make up for the losses to extent over recent years never mind decades. That is why I linked the above graph to put it into context. An increase from the all time low is hardly surprising at all. So this is an example of a lie of omission: they neglect to put the figure into the wider context. We could also quibble about mentioning only extent and not volume.
So here's the lesson. Say what you mean without exaggeration.
Because when you said it's "complete bollocks" what you actually meant was that it was misleading. When you exaggerate like that, it makes it seem like you're pushing an agenda.
http://www.washingtonpost.com/blogs/capital-weather-gang/wp/...
"Sometime earlier this week a cargo ship passed through the Northwest Passage into Baffin Bay, along Greenland’s southwestern coast, making it the first bulk carrier ever to make the voyage. This journey was completed by the Nordic Orion, a 225-meter, ice-strengthened vessel loaded with coal in Vancouver, British Columbia and headed for Finland."
http://thinkprogress.org/climate/2013/09/26/2683481/northwes...
Which predictions in particular?
The Met Office in Britain is one of the clearest. Are they predicting a wet summer for Britain? Brits should buy suntan lotion. Are they predicting a hot, dry summer? Brits should plant something that likes wet, dark conditions. They are the source of one of the models in the IPCC report, and they're predictions for a year or two out are wrong, consistently.
And I find the idea that a climate model can't predict a year in advance, consistently, but can be used for 10 or 100 years in advance to be absolutely ludicrous. Utter mathematical illiteracy is required to think that is true of a chaotic system. It remains unclear to me whether climate researchers actually understand that "a chaotic system" is actually a mathematically meaningful statement and not "an excuse for why we were wrong, again". (No sarcasm, it truly remains unclear to me. Chaos theory is a real thing, and I'd really like to think that climate researchers would know a lot about it, but I've only seen faint traces of it, where I expect the terminology to dominate the discourse.)
Given the utter failure of these predictions on a year and a decade scale (as I've said before, had the climate scientists said "hey, there's going to be a 15-year plateau because of this and this which will mask the problem but then this is going to happen", I'd be fine with that), I see no reason to believe they'll work on a century scale.
At the moment, the most reasonable explanation is that the models used by the IPCC up to this point have been grossly wrong about their positive heating feedback claims, which if you dig, were never really that well substantiated by actual evidence, they have always been modeling choices. In the real science world, those claims are being walked back quite rapidly with a variety of peer reviewed studies providing both evidence of this and potential models for explanations; this has not penetrated to the political portion of the AGW crowd yet. This is probably because the science, to my eyes, is rapidly converging on "global warming is unlikely to be a problem in this century, and may even be a net benefit to humanity". I wouldn't be surprised this is the dominant science consensus in ten years.
That doesn't mean that you cannot predict the kinds of behaviour the system will exhibit. You can still predict, for example, that in the long term summers will be hotter and drier. In fact everyone relies on this to some extent - even though it's impossible to predict the weather more than a few days in advance for the same reason, you're still more likely to pack shorts in summer than winter.
The same is true of simple, rigourously analysed chaotic systems like the Lorentz attractor - someone's actually proved that the long-term behaviour of that system is completely stable and will remain that way even in the face of outside noise, but also that even the slightest noise makes it impossible to predict the exact state of the system more than a small amount of time into the future.
What is your evidence for the current course not being catastrophic? How are you defining catastrophic? To the human species? Or to the daily lives of a couple of billion people? Those are quite different, and the first at least isn't seriously being suggested by scientists that I'm aware of.
And to be honest, as far as I'm concerned one must seek out predictions that have come true, quite selectively. If you randomly sample the ones that have completion dates in the past, they are almost uniformly false. You speak as if you feel yourself in a position of moral authority, but I do not accept the moral authority of people who choose words over the plain science.
And there's always the big one... those big curves drawn where temperatures go up, up, up over this entire century, where instead they've stayed flat, flat, flat, and we've fallen out of most of the confidence intervals (and very nearly out of the rest). The spinning on how this really is what we predicted all along is getting quite mind boggling. No, the temperature trend of the last 15 years is never what was predicted. It is merely what actually happened.
Goodness help us all if those who think the solar activity level actually sets our temperature on a several-year delay are correct, and the global temperature starts going down. How will that be spun, I wonder? (Though that is merely one possibly theory. At this point I consider the late-1990s catastrophic model that still dominates the discourse plainly false, but it remains rather unclear what is true. I'd still put quite a bit of probability on "the chaotic system is fundamentally unpredictable past a few years" myself. It's been the smart money for the past 20 years and I don't see a lot of reason to move it.)
Since 1975, global average surface air temperature has increased at a rate of 0.17 deg.C/decade (estimated by linear regression using either the NASA GISS or HadCRUT4 data sets). But the rate of increase hasn’t been perfectly constant over that entire time span.
As a matter of fact, there’s a 15-year time span during which the rate is notably different. Fifteen whole years!!! By at least one calculation, the difference is “statistically significant.”
That 15-year time span covers the years 1992 through 2006, during which the rate of warming was 0.28 deg.C/decade. That’s a lot faster than the warming rate from 1975 to now.
What was your position in 2006, given that 15 year trend? Is your argument that when the 15 year trend is above the longer term trend it's due to natural variability and doesn't indicate a long term change but when it's below then it's due to a real shift and that global temperatures are about to start going down?
What measure of evidence do your require?
Ditto the case for anthropocentric (human caused) contribution to climate change.
As a person interested in science, I consider this a fatal objection to any theory. AGW is not excepted. Anyone who has the mental gymnastic strength to talk themselves past this problem is merely demonstrating that they are not actually interested in science at this point, as the disparity between theory and fact is pretty clear at this point.
If "the public" are having problems with AGW for the wrong reasons, well, it's hardly the first time the correct conclusion has been reached for the wrong reasons.