So, this is happening, it’s getting worse, & apparently it didn’t happen like this for hundreds of years before the Industrial Revolution & the Population Explosion. Yes, in strict deductive logic, “post hoc ergo propter hoc” is considered a fallacy. In the empirical fashion by which we actually must perceive the world, correlation sometimes is the only available indication of very real causation.
I withheld judgment. I said, maybe it’s a blip. Now, I think the USA should sign the Kyoto accords & just bear it.
Sometimes yes. In this case no. There are various ways in which we can ‘observe’ past trends in the Earth’s climate, and that tells us that it isn’t and never has been a stable system.
To try to put this latest data into perspective, remember that
Around 1000 years ago the extent of glaciers in the Alps and Scandinavia was much less than what it is now.
Trees were still growing well into what is now tundra in Canada and Siberia 900 years ago.
Glaciers and tundra only began to advance 600 years ago as a result of the little Ice Age.
The sea ice only advanced to lock out Greenland 600 years ago.
The little ice age only ended 200 years ago.
As you can see the climate of the Earth is remarkably turbulent.
The little ice age is particularly pertinent to this discussion. That’s because it ended 200 years ago, well before any effect of anthropogenic global warming could have been felt. And it’s also lasted for hundreds of years “before the Industrial Revolution & the Population Explosion”.
Given that knowledge it shouldn’t come as a surprise that things are warmer now than they have been for the past 100 years. Things are warmer than they have been for the past 400 years, but everyone interested pretty much knew that 100 years ago, so that’s no surprise. We knew that temperature was on an upswing at the beginning of the 20th century.
So no, this is defintitely not just a blip. I think that everyone agrees on that point. With the normal uncertainty and deviations temperature fell steadily from around 1100 until around 1800, and since then it has been climbing steadily ( http://www.atmos.washington.edu/1998Q4/211/project2/group4.htm) ( http://www.ipcc.ch/present/graphics/2001syr/large/05.16.jpg ) . This isn’t a blip. The question is whether this is human induced. The best climate models we have been able to produce say that it simply can not be defined in that way. Because temperatures have been climbing steadily for the last 200 years it’s simply impossible to separate out the human impact from what would have happened naturally.
The point of all that is that in this instance we are not limited to “post hoc ergo propter hoc”. We can say fairly clearly that temperature was already climbing well before the industrial revolution could have resulted in global warming. We can say that sea ice, glacierds and ice sheets were smaller 1000 years ago than they are today , and that they grew as a result of cooling during the middle ages which ended 200 years ago.
This is the biggest complication of the whole global warming debate. Unfortunately the industrial revolution has apparently coincided with a warming event. At the very least it coincided with the lowest temperature for the last 500 years and the second lowest in the last 100 years. Things were already either heating up or due to heat up when people started interfering. Evidence seems to favour human influence exacerbating the warming effect, but it’s till too early to call.
You do realise that Kyoto won’t do anything to solve this problem if it is human induced? Even the most optimistic proponents admit that. Kyoto is at best a first step in a very long process and will have no meaningful impact on its own beyond the symbolism.
So, there is no correlation between global warming and billions of pounds of extra and unnatural CO2 that have been released by the industrial revolution? It is only speculation? You are saying that because we can’t do anything immediately, we should do nothing?
Are you an ostrich?
If I close the door of my plush, air conditioned SUV, its sound insulation means that I can only just hear you. If I rev its throaty 4 litre engine and stick my fingers in my ears and sing “la la la la la”, I can no longer hear you.
So I don’t know about it, its not happening, and it’ll go away. Can we get back to discussing the more important things, like fuel prices?
[quote=Blake]
You do realise that Kyoto won’t do anything to solve this problem if it is human induced? Even the most optimistic proponents admit that.
[quote]
Won’t do anything at all? No, I don’t admit that: it might well do nothing, but it might just make all the difference in the world.
The problem here is encapsulated by the phrase tipping point:
The CO[sub]2[/sub] concentration is currently 378 ppm and rising by a record 3ppm per year.
So, we could just carry on as normal for a couple of decades and then screech to a halt and never emit any more CO[sub]2[/sub] ever. Or, we could spend trillions right now to ensure we stabilise at 450ppm. The first is arguably impossible, the second economically unfeasible. Kyoto is one way to start the process, and our grandchildren may get to those tipping points and wonder why we didn;t try helping them out with making their halt less screeching.
So the question is do you feel lucky, punk? Shall we ignore the world’s climatologists with their warnings about tipping points, given that the only absolute way they could be proven correct is by their horrific predictions actually happening? Yes, the warming might have occurred without the enormous push off CO[sub]2[/sub] equilibrium, but when you’re scalding yourself in the shower, does it not make sense to just try not pushing the dial even further into the red? Here is what the US government itself think of that option.
Won’t do anything at all? No, I don’t admit that: it might well do nothing, but it might just be the straw which makes all the difference in the world.
The problem here is encapsulated by the phrase “tipping point”:
It’s your prerogative to believe the tiny number of qualified scientists who deny human causation of global warming; but to claim that the best climate models have been unable to define global warming as human-caused is a falsehood.
And, thus, with one sentence does Blake dismiss the entire field of “detection and attribution”. (And, this chapter will probably be considerably enlarged in the 4th assessment report, what with the new work on looking at the warming of the oceans and what not.)
You’ve got to be kidding me. Some bloggers note another planet is heating up, and figure that explains climate change on Earth? That one observation negates all other evidence gathered on this planet? And where in any of your cites is “solar warming” offered even to explain the Martian climate change?
This is completely missing the point that a lot of posters here have been patiently making. Namely, it’s widely agreed that we’re probably experiencing a warming trend as part of our ordinary climate cycle (this is still an interglacial period, after all). And it makes perfect sense that Mars might be going through a similar trend in roughly the same era.
But human-caused warming can ALSO be occurring at the same time, and having a much more drastic impact. And that’s what most climate scientists agree seems to be happening. The effects of the predictable, cyclical warming trend are being dwarfed by human-caused greenhouse-gas forcing.
Climate change deniers like kanicbird (and to a lesser extent Blake, though Blake seems to have more awareness of what the science actually says) remind me of someone who goes to a casino during a stock market downturn and blows half his savings at the blackjack table. “What difference does it make? I was losing money on my investments anyway!”
Uh, yeah, Einstein, but the trouble is you’ve now made your financial problem far more serious, and you’re delusionally blaming it all on the part of the problem that was actually comparatively minor.
It does make sense if the sun somehow coordinates it, like going through cycles of higer energy output
you are assuming facts not in evidence. If anything I would assume humans to have a negligable impact in global temp’s
Funny you remind me of the casino goer who is convinced that you can make a living palying slots because someone told you so. In such you have sacrificed your future.
Findings from this report from The National Snow and Ice Data Center (NSIDC) - a NASA organization - not mentioned in the OP’s cite:
the ice is now melting at roughly 0.8 percent per year
the cap could be free of ice during the summer months by 2060
today 5.35 million square km are covered by ice, down 20% from the 1978 - 2000 average.
This report confirm the findings in a report released last year by the Arctic Climate Impact Assessment (ACIA) (BBC story), also predicting an ice-free cap, this time by 2100 at the latest. Other reports have predicted a no ice scenario as early as 2040.
The problem with both assessments is that they are based on measuring the area covered by ice instead of measuring volume - though submarines have collected data indicating a 40% reduction in volume from 1960 to 1990. A new satellite (Cryosat) which will be able to measure current volume of ice accurately is due for launch in October.
While the argument that our planet’s climate is changing constantly is interesting, noone so far has given a plausible explaination on why things now are changing so rapidly in such a short time. I’m still waiting for that one.
Myself, I have no real doubts that we are going through a period of global climatic change. I don’t really have any many doubts that human activity, especially in the last century or so are contributing some non-trivial amount to this…though how much and what the actual effect might be are still in question IMO.
What I question is a statement like this: “Now, I think the USA should sign the Kyoto accords & just bear it.” Its like Kyoto has taken on a near magical aspect with people…a silver bullet guarenteed to slay the mighty global warming dragon and lead us to a green utopia. Or something. The science just isn’t there IMHO to either predict what the future impact of the current trend in climatic change will or could be to any reasonable degree of accuracy, nor to show definitively that the Kyoto Accords can or will have a significant impact (well, except economically) on changing global climate. I remain unconvinced at this point, despite being in many of these threads, that Kyoto is the proper solution to this ‘problem’…or even that it will have any effect at all except for a short/medium term hit to our economy, which I doubt we really need right now.
BTW, as an aside, does anyone have a list of all the countries who have definitely gone on board with the accords? How is it going with them…are they all doing well and meeting their quotas? It hasn’t been very long I realize…but has there been any noticable effect?
I already said that it does make sense that Earth and Mars could be experiencing simultaneous warming trends as part of their natural climate cycles. (In other words, I agreed with you on this one point.) This might indeed be related to cycles of solar irradiance, which I presume is what you’re getting at.
However, the natural warming trend that we’d expect from increased irradiance and other astronomical factors is apparently not enough to account for the observed level of warming. In other words, we’ve got a natural warming trend that is admittedly occuring but that is being swamped by anthropogenic warming, as I said. Refer again to the links provided by LHoD and jshore for the evidence of this (as if you bothered to read them the first time, but I suppose it’s polite to pretend that I think you did).
Sorry, but facts about anthropogenic global warming are in evidence. Your completely unsupported “assumption” that humans can’t cause non-negligible climate change is entirely irrelevant to what the actual evidence is.
You know, it’s one thing to point out that climate science is still developing and we still have a lot of uncertainty in our predictions. That’s a valid and useful point to make in the process of overcoming ignorance.
But it’s quite another thing, and a far stupider one, to decide that you’re simply going to ignore reasonably confident scientific findings just because you personally “would assume” that they couldn’t be true. That’s just crazy. That’s taking refuge in “manufactured uncertainty”: you’ve decided that since nobody knows all the answers for certain, your opinion is as good as anybody else’s.
As far as you’re concerned, reading scientific reports and evaluating evidence is equivalent to believing something blindly “because someone told you so”. That’s nuts. I’m stating a position that is backed by a strong scientific consensus based on factual evidence that is quite sound, even if it’s admittedly far from perfect. Show some equally sound evidence that convincingly refutes it, or admit that you simply don’t know what you’re talking about.
They note the only substance found on Mars that could explain the pitting is CO2, which must now exist in greater concentrations in the Martian atomosphere than it did in the past, when it was locked up in dry-ice “snow”.
It’s rather easy to see how a small perturbation in the CO2 cycle, perhaps occurring hundreds of years ago, might feed back on itself and lead to a warming trend. Why, because, as the author notes: “Carbon dioxide is a ‘greenhouse gas’ believed to warm climates when its atmospheric concentration increases.”
You get an unusually warm period, perhaps many centuries ago or more, it releases CO2, which warms the atomosphere, which causes more CO2 to be released, and so forth. Modern “solar warming” isn’t even necessary, nor anywhere posited, that I can see. More data is needed, obviously, to see if they can actually measure CO2 levels and current changes in Martian climate, to get a better idea of the suggested trends. But I think suggesting there is strong evidence for a correlation between present Martian climate change and Terran climate change is beyond simplistic. Even if there is a correlation due to “solar heating”, it would appear that CO2, the same gas implicated in global warming on Earth (and not increasng as a result of “solar heating”) as on Mars, but as a result of human activity, ought to play a role on both worlds.
