I actually don't believe it is 100% natural. CO2 is a greenhouse gas, and more CO2 will tend to warm the climate. The problem is that climate scientists didn't stop there. They built climate models that multiply that heat an additional 3 - 4 times, turning the relatively benign warming from CO2 into dangerous warming. These "positive feedbacks" assumed in the models are unproven. There is no clear evidence that the earth is hypersensitive to CO2 heating and will react by amplifying that heat threefold. The latest climate sensitivity estimates are much lower.
If you are genuinely interested in hearing out the other side, Judith Curry's blog is a good place to start.
Global warming has indeed "paused". This "cherry picking" argument is nonsense but apparently nobody has bothered to check. They hear a plausible sounding refutation, and that's good enough for them. Contrary to what you've heard, the starting point most skeptics choose is 1997, before the "particularly warm year" of 1998. Here is the temperature trend for the last decade. You can see for yourself that temperatures have not been increasing for the last decade. In fact, there is a slight cooling trend, although not statistically significant.
Regarding the "relentless" warming, before 1950 there was not enough anthropogenic CO2 to cause significant warming, and the consensus position is that humans are responsible for more that half of the warming since 1950. For the 30 years prior to 1976 there was a slight cooling trend. The warming you (and everybody else) is talking about occurred from 1976 to 1998. While it is supposed to be a period of "highly unusual warming", it closely resembles a warming period earlier in the century from 1910 - 1945. In fact, there was as much or more warming in the first half of the 1900's as there was in the second half. Most of the warming in the 1900's was natural, a recovery from the Little Ice Age.
I'm sure I could regurgitate some typical right-wing slurs against dreaded "liberals", but to what purpose? Besides, I'm a lefty. Nice to see the "nuanced" thinkers from both sides really do deserve each other.
Antarctic Ice is at record highs and arctic ice has quickly recovered since the 'great arctic cyclone' 'wreaked havoc' on sea ice in 2012. Not sure how the fraction of a degree the IPCC says we have contributed to warming (so far) can melt glaciers. ? You do realize the world was already warming?
Surface temperatures have been flat for about a decade and a half, depending on what data set you use. The RSS data shows the least amount of warming. You can see a slight, insignificant cooling trend (starting before the warming peak in 1998). The HadCRUT4 dataset shows a slight warming trend in the same timeframe that is also statistically insignificant.
Perhaps it is you that needs to learn to read a thermometer?
I said: "we can't measure the deep oceans with any accuracy". I didn't say that there was no data collected. When I say "deep" I include depths below 2000 meters.
I'm not American. That's a pretty funny caricature. I admit that there are many who would be skeptics regardless of what the science says. Sadly the same is plainly true for most global warming activists. It is sad to see otherwise thoughtful people resort to silly stereotypes. You hold up the Sarah Palins of the world as though they are the leading thinkers in the skeptical camp. What a joke. Why not seek out the best skeptical minds out there and hear what they have to say? Judith Curry's blog would be a good place to start.
I don't need to cherry pick 1998. We could start at 1997 if you prefer. You would see a slight heating trend but nothing statistically significant. See my response above.
The warming has plainly "paused" in recent years. Even the IPCC now admits this. That is why Nature publishes articles explaining why "sixteen years into the mysterious ‘global-warming hiatus’, scientists are piecing together an explanation." If the warming between 1976 and 1998 was so significant (the warming the IPCC attributes to humans - responsible for more than half of it they say) then why is the lack of warming from 1997 - present (depending on which dataset you use) not significant?
How much longer does the current "no warming" trend have to continue before the climate models are falsified? (Some climate scientists have said that 15-20 years of no warming would call their models into question.)
CO2 by itself does not cause net harmful warming. The harmful part comes from how the atmosphere is predicted to *react* to the additional warming. The models predict the atmosphere will react by amplifying the CO2 warming by an additional 2-3 degrees. This "climate sensitivity" is at the heart of the debate.
As I pointed out, the global warming "hiatus" is real. You can see it for yourself by looking at the data. So how could it have been debunked hundreds of times here on Slashdot? Who exactly is peddling bullshit? (And I'm not American btw.)
My understanding is that most of the warming since the 1850's was natural, a recovery from the little ice age. There was roughly the same amount of warming in the first half of the 20th century, almost all of it natural, as there was in the second half, where humans are said to be responsible for "more than half" of the warming.
To answer your question though, the largest "denier" site in the world supports innovative nuclear power. If people were genuinely concerned about global warming I would think they would jump at this opportunity. But all I hear is crickets.
Climate scientist to layperson: "And here's where things get interesting. CO2 by itself only warms the planet modestly, at about one degree per doubling. We introduced feedbacks into our models which amplify that warming by 300%, turning a fairly benign warming into a dangerous one. This has garnered us a lot of international attention. Unfortunately, nature has not been cooperating and surface temperatures have not increased for the last decade and a half, despite an enormous increase in CO2. Rather than revise controversial feedbacks, we figured out a way to preserve the theory by claiming the deep oceans have absorbed all the extra heat. Since we can't measure the deep oceans with any accuracy it's not falsifiable, and since we don't know if or when the heat will "reappear", we can continue to educate the public for another 50 years even if surface temperatures start to cool."
When you say "that is simply how scientists write", are you saying we shouldn't take the IPCC statements at face value?
I don't think we need other models to recognize and point out the deficiencies in the current model. Science is supposed to embrace scrutiny. If the climate models don't work, if their forecasts continue to diverge further and further from empirical observation, you could still say that any criticism is meaningless until somebody proposes a better theory.
But there are other models out there. According to Judith Curry: "...the problem is that the IPCC and climate models only provide one method for making predictions. Guessing, climatology, stadium wave, extrapolation of trend, are all methods that might produce better predictions, and these are ignored/dismissed by the IPCC and policy makers in favor alarming predictions from climate models."
The survey did not ask "has human activity become the predominant factor in global warming?"
That's precisely the point I've been trying to make. The survey did not ask that question. Therefore the graph you posted misrepresents the survey results.
I'm not sure what you mean. I am disputing the strength of the consensus that human activity is the dominant driver in global warming. That's why I said that there is a big difference between saying "humans are causing some warming" and saying the warming is "largely caused by humans". The graph misrepresents what the Farnsworth and Lichter study actually says. (That's the first study the graph references, and the only one I've checked so far.)
As I've said before, phrases like "broad scientific consensus" and "97%" are often used, but they are simply not accurate. And global warming activists don't seem to care about accuracy in cases like these. (Granted, this kind of behaviour is endemic to human nature. Both sides tend to turn a blind eye to the "inaccuracies" and errors promulgated by their own camp.)
The IPCC says that it is "very likely" that the extra CO2 we've introduced is responsible for at least 50% of the warming since 1950. That's not a very precise statement. Without high climate sensitivity, that estimate would be much lower, and that's a fact.
Your graph is misleading. Just to take the first statistic listed, it it is based on a study by Farnsworth and Lichter. Here's some information I found regarding its findings (from http://journalistsresource.org...):
--
97% of the 489 scientists surveyed agreed that that global temperatures have risen over the past century. Moreover, 84% agreed that “human-induced greenhouse warming” is now occurring.”
“There was greater debate over the likelihood of substantial warming in the near future, with 56% seeing at least a 50-50 chance that temperatures will rise” 2 degrees Celsius over the next 50 to 100 years.
“When [survey participants were] asked to rate the effects on a ten-point scale from trivial (1) to catastrophic (10), the mean response was 6.6, with 41% seeing great danger (ratings of 8-10), 44% moderate danger (4-7), and 13% little danger."
That doesn't convey an overwhelming consensus in catastrophic global warming at all. Most skeptics agree that "'human-induced greenhouse warming' is now occurring”, including myself. That is much different than saying "global warming is largely caused by humans". Be careful when relying on wikipedia.
You know how much heat CO2 should 'trap', if the earth behaved like a simple lab experiment. What you wrote above vastly overstates the level of certainty and understanding, and does not explain how climate sensitivity estimates can vary from 1 to 10.
I cite and you cite back. That's not obvious? Do whatever you like. I'm pretty sure you are looking at two different articles. I understand Stocker has misrepresented the actual report, but maybe because he was looking at the report for policy makers? It's a bit more "informal". Why don't you find out what the official report says and find out for yourself? (You don't know what the report says, do you?) Yeah, I know. It's up to me to provide a web page, and a page line, and a direct quote. IPCC reports are not easy for my grandparents to find either. Just goes to show you don't know WTF you are talking about. Apparently it's my job to educate you about what YOUR SIDE ACTUALLY SAYS, and then I have to defend against your RANDOM accusations, often against your own 'sides' position. I'm looking forward to witnessing more of your ridiculous grandstanding. It suits my purpose. Just in case we are unclear: I have no respect for your abilities what-so-ever. (At least, if this is all you have to offer.)
BTW, this SkS page describes WFT as excellent: http://www.skepticalscience.com/temperature_trend_calculator.html. And yes, I hate myself a little bit for having to reference a SkS page.
He may have qualified his statement a bit, but it was clearly misleading and meant to scare people. Other scientists have said there is no possibility for a runaway greenhouse effect on earth, which I think is the general view.
Slashdot Mirror
I actually don't believe it is 100% natural. CO2 is a greenhouse gas, and more CO2 will tend to warm the climate. The problem is that climate scientists didn't stop there. They built climate models that multiply that heat an additional 3 - 4 times, turning the relatively benign warming from CO2 into dangerous warming. These "positive feedbacks" assumed in the models are unproven. There is no clear evidence that the earth is hypersensitive to CO2 heating and will react by amplifying that heat threefold. The latest climate sensitivity estimates are much lower.
If you are genuinely interested in hearing out the other side, Judith Curry's blog is a good place to start.
Global warming has indeed "paused". This "cherry picking" argument is nonsense but apparently nobody has bothered to check. They hear a plausible sounding refutation, and that's good enough for them. Contrary to what you've heard, the starting point most skeptics choose is 1997, before the "particularly warm year" of 1998. Here is the temperature trend for the last decade. You can see for yourself that temperatures have not been increasing for the last decade. In fact, there is a slight cooling trend, although not statistically significant.
Regarding the "relentless" warming, before 1950 there was not enough anthropogenic CO2 to cause significant warming, and the consensus position is that humans are responsible for more that half of the warming since 1950. For the 30 years prior to 1976 there was a slight cooling trend. The warming you (and everybody else) is talking about occurred from 1976 to 1998. While it is supposed to be a period of "highly unusual warming", it closely resembles a warming period earlier in the century from 1910 - 1945. In fact, there was as much or more warming in the first half of the 1900's as there was in the second half. Most of the warming in the 1900's was natural, a recovery from the Little Ice Age.
I answered your conspirator.
My statement was based on the latest IPCC report and the temperature data sets. You?
I'm sure I could regurgitate some typical right-wing slurs against dreaded "liberals", but to what purpose? Besides, I'm a lefty. Nice to see the "nuanced" thinkers from both sides really do deserve each other.
You mean this guy: "It is ironic if some people treat me as a traitor, since I was never a skeptic"?
Obviously you know very little about skeptics or their arguments, and prefer to rely on infantile stereotypes. Suit yourself.
That's rubbish. It's embarrassing how many global warming activists rely on their childish caricatures of "deniers".
Antarctic Ice is at record highs and arctic ice has quickly recovered since the 'great arctic cyclone' 'wreaked havoc' on sea ice in 2012. Not sure how the fraction of a degree the IPCC says we have contributed to warming (so far) can melt glaciers. ? You do realize the world was already warming?
Surface temperatures have been flat for about a decade and a half, depending on what data set you use. The RSS data shows the least amount of warming. You can see a slight, insignificant cooling trend (starting before the warming peak in 1998). The HadCRUT4 dataset shows a slight warming trend in the same timeframe that is also statistically insignificant.
Perhaps it is you that needs to learn to read a thermometer?
If you are truly interested in moving beyond childish stereotypes of "deniers", you could start at Judith Curry's blog.
How do you explain failed climate model predictions?
I said: "we can't measure the deep oceans with any accuracy". I didn't say that there was no data collected. When I say "deep" I include depths below 2000 meters.
I'm not American. That's a pretty funny caricature. I admit that there are many who would be skeptics regardless of what the science says. Sadly the same is plainly true for most global warming activists. It is sad to see otherwise thoughtful people resort to silly stereotypes. You hold up the Sarah Palins of the world as though they are the leading thinkers in the skeptical camp. What a joke. Why not seek out the best skeptical minds out there and hear what they have to say? Judith Curry's blog would be a good place to start.
I don't need to cherry pick 1998. We could start at 1997 if you prefer. You would see a slight heating trend but nothing statistically significant. See my response above.
The warming has plainly "paused" in recent years. Even the IPCC now admits this. That is why Nature publishes articles explaining why "sixteen years into the mysterious ‘global-warming hiatus’, scientists are piecing together an explanation." If the warming between 1976 and 1998 was so significant (the warming the IPCC attributes to humans - responsible for more than half of it they say) then why is the lack of warming from 1997 - present (depending on which dataset you use) not significant?
How much longer does the current "no warming" trend have to continue before the climate models are falsified? (Some climate scientists have said that 15-20 years of no warming would call their models into question.)
CO2 by itself does not cause net harmful warming. The harmful part comes from how the atmosphere is predicted to *react* to the additional warming. The models predict the atmosphere will react by amplifying the CO2 warming by an additional 2-3 degrees. This "climate sensitivity" is at the heart of the debate.
As I pointed out, the global warming "hiatus" is real. You can see it for yourself by looking at the data. So how could it have been debunked hundreds of times here on Slashdot? Who exactly is peddling bullshit? (And I'm not American btw.)
My understanding is that most of the warming since the 1850's was natural, a recovery from the little ice age. There was roughly the same amount of warming in the first half of the 20th century, almost all of it natural, as there was in the second half, where humans are said to be responsible for "more than half" of the warming.
To answer your question though, the largest "denier" site in the world supports innovative nuclear power. If people were genuinely concerned about global warming I would think they would jump at this opportunity. But all I hear is crickets.
http://wattsupwiththat.com/2014/08/27/a-universally-acceptable-and-economical-energy-source/
Climate scientist to layperson: "And here's where things get interesting. CO2 by itself only warms the planet modestly, at about one degree per doubling. We introduced feedbacks into our models which amplify that warming by 300%, turning a fairly benign warming into a dangerous one. This has garnered us a lot of international attention. Unfortunately, nature has not been cooperating and surface temperatures have not increased for the last decade and a half, despite an enormous increase in CO2. Rather than revise controversial feedbacks, we figured out a way to preserve the theory by claiming the deep oceans have absorbed all the extra heat. Since we can't measure the deep oceans with any accuracy it's not falsifiable, and since we don't know if or when the heat will "reappear", we can continue to educate the public for another 50 years even if surface temperatures start to cool."
What nonsense. You apparently have no idea what real critics of global warming are discussing. You are at least as ignorant as those you caricature.
When you say "that is simply how scientists write", are you saying we shouldn't take the IPCC statements at face value?
I don't think we need other models to recognize and point out the deficiencies in the current model. Science is supposed to embrace scrutiny. If the climate models don't work, if their forecasts continue to diverge further and further from empirical observation, you could still say that any criticism is meaningless until somebody proposes a better theory.
But there are other models out there. According to Judith Curry: "...the problem is that the IPCC and climate models only provide one method for making predictions. Guessing, climatology, stadium wave, extrapolation of trend, are all methods that might produce better predictions, and these are ignored/dismissed by the IPCC and policy makers in favor alarming predictions from climate models."
The survey did not ask "has human activity become the predominant factor in global warming?"
That's precisely the point I've been trying to make. The survey did not ask that question. Therefore the graph you posted misrepresents the survey results.
I'm not sure what you mean. I am disputing the strength of the consensus that human activity is the dominant driver in global warming. That's why I said that there is a big difference between saying "humans are causing some warming" and saying the warming is "largely caused by humans". The graph misrepresents what the Farnsworth and Lichter study actually says. (That's the first study the graph references, and the only one I've checked so far.)
As I've said before, phrases like "broad scientific consensus" and "97%" are often used, but they are simply not accurate. And global warming activists don't seem to care about accuracy in cases like these. (Granted, this kind of behaviour is endemic to human nature. Both sides tend to turn a blind eye to the "inaccuracies" and errors promulgated by their own camp.)
The IPCC says that it is "very likely" that the extra CO2 we've introduced is responsible for at least 50% of the warming since 1950. That's not a very precise statement. Without high climate sensitivity, that estimate would be much lower, and that's a fact.
--
That doesn't convey an overwhelming consensus in catastrophic global warming at all. Most skeptics agree that "'human-induced greenhouse warming' is now occurring”, including myself. That is much different than saying "global warming is largely caused by humans". Be careful when relying on wikipedia.
You know how much heat CO2 should 'trap', if the earth behaved like a simple lab experiment. What you wrote above vastly overstates the level of certainty and understanding, and does not explain how climate sensitivity estimates can vary from 1 to 10.
I cite and you cite back. That's not obvious? Do whatever you like. I'm pretty sure you are looking at two different articles. I understand Stocker has misrepresented the actual report, but maybe because he was looking at the report for policy makers? It's a bit more "informal". Why don't you find out what the official report says and find out for yourself? (You don't know what the report says, do you?) Yeah, I know. It's up to me to provide a web page, and a page line, and a direct quote. IPCC reports are not easy for my grandparents to find either. Just goes to show you don't know WTF you are talking about. Apparently it's my job to educate you about what YOUR SIDE ACTUALLY SAYS, and then I have to defend against your RANDOM accusations, often against your own 'sides' position. I'm looking forward to witnessing more of your ridiculous grandstanding. It suits my purpose. Just in case we are unclear: I have no respect for your abilities what-so-ever. (At least, if this is all you have to offer.) BTW, this SkS page describes WFT as excellent: http://www.skepticalscience.com/temperature_trend_calculator.html. And yes, I hate myself a little bit for having to reference a SkS page.
He may have qualified his statement a bit, but it was clearly misleading and meant to scare people. Other scientists have said there is no possibility for a runaway greenhouse effect on earth, which I think is the general view.