I think the point is that the alarmist of 1975 appear to be cut from the same cloth as those in 2007 predicting exactly the opposite. If the experts were wrong in 1975, then it seems reasonable that experts could be wrong again. Who cares what the alarmists think? Compare what experts are saying now to the situation then, and the two situations are not so similar.
The article is out of date. Shutting down the North Atlantic thermohaline circulation would only drop northern Europe's temperatures a few degrees, and that cooling would be exceeded by the global warming necessary to shut down the THC, leading to a net warming of Europe (albeit less than other parts of the world). However, there would be a huge drop in winter temperatures over Greenland and the Nordic seas. See Rahmstorf's short Nature review.
The debate centers on whether it is a natural phenomenon or caused by mankind. That may be what the public debate centers on, but the scientific community has pretty much come to the conclusion that it's partly natural but mostly caused by mankind. The scientific debate centers on how much warming will occur this century and what its effects will be.
However, this time, by silencing the minority, we admit we might be ignoring data or at least questions that can lead to a better understanding of the problem. The minority is not being "silenced".
Its become hot and cold before, without our influence. What makes humans think they did it this time? Mostly, the fact that we know that X amount of greenhouse gas emissions produces Y amount of warming. But on top of that, there is the general correspondence between the timing, rate, and magnitude of the warming with the amount of human GHG emissions, and on top of that, there is a lack of alternative mechanisms available to produce the observed warming.
I don't know, but I seem to recall that the combined amount of CO2 emitted by both animal respiration and decay of dead organisms is about balanced by the intake of CO2 by plants. If you're interested, you want to search for the "carbon cycle" and "respiration".
"Scientific consensus"? Are you joking? There is no such thing in the real world. Even without political dickering it's never a reality. Yeah, like there's no scientific consensus over the validity of quantum mechanics.
There's plenty of debate about specific details in climate science, but "the Earth is warming" and "it's mostly because of us" are indeed the consensus; the debate has moved on, to what will happen in the future.
Could it have anything to do with opposing theories being squelched and the presenters labeled as cranks? If they had good arguments, they'd be published. Opposing theories are found everywhere in science, it's just that they're the good theories.
Let's face facts, that's exactly what they're trying to do in this case on a very formal level. Let's face facts, nobody has proposed anything of the kind. The original blogger merely said that certified broadcast meteorologists have a professional obligation to be informed about climate science. She didn't advocate removing their certification. And even if she did, that has squat to do with "squelching opposing theories". Certification just means you get to be a TV weatherperson, it has nothing to do with whether your can publish in scientific journals.
Is that why so many others in this "community" are allowed to run wild screaming "the sky is falling" while anthropogenic global warming is still just a theory? Is anthropogenic global warming "just a theory" like evolution and the Big Bang?
Everything in science is a "theory". Some theories have enough evidence in their favor that they are regarded as established. AGW is one of them.
See, we have a control, another planet that is very similar to ours in terms of planetary scale Actually, Mars's climate is much different from ours, due to its lack of oceans, lack of life, near-lack of atmosphere, different atmospheric composition, different orbital position, etc.
Go back farther to Huygen's observations in the 17th century and they are smaller again. Seems to be reacting to something OTHER than human interaction. Yeah, well, duh. The Earth had climate changes too before humans were ever around. That's got squat to do with the evidence regarding anthropogenic climate change on Earth.
Thus, you observation about Sun cycles makes a lot more sense as the root cause. Except for the fact that variations in solar output are demonstrably not responsible for the majority of the global climate change on Earth, or the recent regional climate change on Mars. (Mars' south pole has been recently warming while the Sun's output was decreasing slightly, and the solar output fluctuations aren't correct in either timing or magnitude to match the Earth's temperature changes, whereas the greenhouse effect is.)
We are allowed to have someone say man aused everything in global warming but not discuse Natures impact Both natural and anthropogenic forcings exist. Nobody is denying this, let alone preventing you from mentioning it. As it happens, the anthropogenic forcings are the more significant of the two concerning the recent climate, but the natural forcings are not negligible.
or even the fact that water vapor is the single most potent effect on the "green house effect". mand made green house gasses (Co2 specificly) anly account for around 2% of the total greenhouse effect. That argument was dumb the last time you posted it and it's still dumb now.
As I responded last time, it's true that most of the greenhouse gases in the atmosphere are natural. Without them, the Earth would be tens of degrees cooler. Our contributions are a relatively small addition on top of that effect, but they are still enough to raise temperatures by several degrees, which is what the whole global warming issue is about.
I don't hear anyone claiming we should stop using water though. Because that would be stupid, and unlike our CO2 emissions, our water vapor emissions are not causing substantial climate change.
Carbon emisions alone are not likley going to be enough to stop global warming. At this point, we're past "stopping" global warming — not this century, anyway. The point of reducing CO2 emissions is to reduce global warming, not to eradicate it. It's not an all-or-nothing thing.
Here is a graph of U.S. CO2 emissions; they're still going up, although they have slowed over the last 5-6 years. I'm still looking for a sourced graph, but I do know that they are still increasing. I don't know much about other countries' emissions, but the data is out there somewhere.
Read here and here for more on what scientists themselves were saying at the time. In short, they knew there was a natural cooling trend, but they also knew they didn't have a good handle on manmade greenhouse gas emissions, and they also knew that their climate models weren't up to solid prediction. They said that on the basis of extrapolating the past trend alone, cooling would result. However, they also said that they couldn't predict cooling based on modeling, and that they didn't know whether anthropogenic emissions would outweigh the cooling. Some decades of continued data collection, improvement in statistical techinques, and better climate models later, they now can say with credibility that warming will continue over the next century at least.
Back in the 70's, the climatologists thought the world was going into an ice age. If we had actively tried to prevent an ice age, we could have done something to contribute to global warming, not realizing it was right around the corner anyway. That's because they had estimates for natural climate trends, but not the human contribution, nor did they have good models for extrapolating into the future. Now they do.
Likewise now, if we try to prevent global warming, without really knowing the causes or what may be around the corner, we may get ourselves into more trouble than we'd have had otherwise. We do know the causes and we know that there is warming around the corner; we just don't know how much.
The AC did not ignore the trapping of heat by atmospheres. Venus's atmosphere and Mercury's lack thereof is the reason why Venus's temperature is higher than Mercury's maximum temperature.
What evidence is there that global warming is primarily caused by humans, and that the effects of any enviromental factors (such as sun-spot cycles, for instance), are minimal at best? RealClimate has a series of posts on how recent CO2 increases are primarily due to humans here, here, and here (in increasing detail; also read the comments). The link between CO2 and global warming is direct and based on simple physics. But on top of that, you have to take into account the other natural warming and cooling effects. Other environmental factors aren't "minimal"; they contribute to a substantial minority of the warming. That would require many more links to discuss. Solar variations in particular are fairly minimal, but not totally.
From what all I've heard, despite our best efforts to scale back the use of greenhouse gasses in the US and Europe, things are still getting worse. The US and Europe have not scaled back GHG emissions; they're still increasing. Maybe increasing at a slower rate though (I can't remember what the current estimates are).
By penalizing those who disagree with the analysis of humanity's impact on climate change, [...] The original blog post never advocated sanctioning broadcast meteorologists; she just said that those with certification have a responsibility to be educated. Which they do. Most TV weatherpeople have very little training in climatology, yet they pontificate about it on the daily news.
Actually, the temperature increase started around the same time as the anthropogenic CO2 increase. You seem to believe that humans weren't contributing to CO2 before 1940, but the Industrial Revolution began before 1940, and indeed before 1880. Try referring to a combination of the hockey stick and a CO2 reconstruction, like here. The temperature really started ramping up a little after 1900, during which CO2 emissions were already on their way up.
What's being discussed here is the AMS Certified Broadcast Meteorologist program. You don't need certification to be a scientist, but evidently you do in order to be a TV weatherperson. The original blog post merely said that if you're a certified TV weatherperson, you have a responsibility to be educated about climate change; evidently a lot of them spout off about it on the daily news when they have no training in the area.
Is the debate about global climate change or manmade global climate change? The scientific debate is about how much warming will occur in the future.
The climate of the planet has been much warmer for long periods in the past. True, but that's fairly irrelevant to the question of what the climate of the planet is going to do in the next century.
Attributing these changes to manmade causes(i.e. driving my car) is due largely to the reliance on the misleading per capita carbon emission figures. We have good estimates of our past emissions, and the recent climate changes are largely due to them. There is a lot of uncertainty about what future emissions will be like, and corresponding uncertainty on what the climate will do as a result.
A bit further down on the list of ways to get modded up is to point out this fact. Good on ya!
And a preemptive strike: you might also get modded "plus-one Funny" if you posted this comment... And if I post this reply... uh.. only a great fool would the wine in front of me! But you must have known that I am not a great fool... Aaah, I think I got a stack overflow from the recursion.
We also create a lot of other gasses. And affect the environment in 1000 other ways. Some of them destroy greenhouse gasses and other lead directly to global cooling. Of course that's true, but the net effect still is of warming.
That's not a huge spike, and the Industrial Revolution was meaninglessly recent on a geological timescale. It is a "huge" spike when you consider the rate of increase compared to the climate over the previous thousands of years.
Earth has seen average temps higher than now, and those were *good* times. What is a problem is not global warming, but the rate of warming. If it happens slowly enough, it's easy to adapt to. But right now, existing societies are rather adapted to a specific set of conditions, and rapid enough change is difficult to adapt to. If some areas become more hospitable (better agriculture, less underwater, etc.), others become less, and that sucks for the people who live there. That can lead to economic, political, and social disruption. That's why it's important to study the question of "how much, how fast", and not assume a naive view that we are headed for some Edenic paradise.
Further, CO2 - which is a greenhouse gas - is largely produced by Mother Nature herself through the process of life. It's something like 29:1 in favor of Mother Nature pumping it out. Water vapor is also a greenhouse gas, and there's a lot of that in the air. Human effects are arguably minimal. This argument comes up so frequently it's worth pointing out why it's wrong. Or rather, the facts are right, but the conclusion isn't. Yes, natural greenhouse gases (GHG) are responsible for most of the warming of the Earth. That's why the planet isn't a frozen iceball right now; the overall greenhouse effect warms the planet by something like 40 degrees C. The human GHG emissions, while small comparable to the total amount of GHGs in the atmosphere, are still sufficient to raise temperatures by an additional several degrees over the next century — that's what global warming is about.
In fact the last plot I saw with global warming super-imposed on the ice age cycle showed a small rise in temperature (due to global warming) followed by a large drop in temperature caused by the natural ice age cycle. Actually, the natural trend does appear to be towards cooling, but it is now being outweighed by warming.
10-15 years ago climatologists seemed to be more worried about the impending ice age which global warming would postpone for a bit but ultimately fail to overcome. People were not still worried about "impending ice ages" 10-15 years ago. Try 30.
At that time, they weren't able to estimate the global warming contribution very well; it is now known to be larger than was once thought. And, in the long run, the Earth will eventually experience more cooling. It's just not going to happen over the next century or two, which is what people are worried about.
Only 15 years ago they were worried about an ice age and now they are worried about it getting too hot so is might there be a similar shift back in a few years time when they improve their understanding again? 30 years ago they knew about X (natural cooling) but not much about Y (global warming). Now they know about X and Y. While there is still uncertainty in both X and Y, it has been steadily reduced, and now the uncertainty is about "a little warming" or "a lot of warming", at least over the next century. (They can't predict much past that.)
I have yet to see any evidence that our tiny levels of CO2 (we are still somewhere around 0.3% total, compared to the 90% back when life appeared) are going to make any measurable difference. Even if you ignore the actual measurable difference in temperature that has taken place, there is also the known physical fact that the "tiny" levels of CO2 in our atmosphere are enough to produce significant warming; we know quite well what CO2's spectral adsorption properties are, and can calculate fairly directly what that translates into in terms of heat retention.
They tried that one years ago. Noone took them seriously back then, and noone does now. You are grossly misinformed.
The problem with that argument is that it fails to account for Venus being closer to the sun. When you sit on the electric heater, CO2 is not the reason your ass gets hot. Being closer of the Sun makes Venus hotter than it would be if it were in Earth's orbit, but Venus is hotter than its mere location would account for — hotter even than Mercury, which is closer to the Sun! The greenhouse effect is the reason why.
There are three main factors which govern its overall temperature: the amount of energy it receives from the Sun (insolation), the amount of that energy which is reflected by its atmosphere (albedo), and the amount of energy retained by the atmosphere (greenhouse effect). If you take only the first two into account, you get the wrong temperature; if you take the third into account, you get the right one.
Agreed, we to create a lot (on a human scale, not on planetary scale) of CO2, and should cut down where we can. But still no evidence that we are changing anything. Yeah, other than the fact that it's getting dramatically hotter in exact coincidence with the timing, magnitude, and rate of our CO2 emissions.
Not only that, but average temperature has been going up since the last ice age. Actually, they went up dramatically at the end of the last ice age (hence "the end of the last ice age"), but for the most part remained constant or even gradually declined over the last 8000 years.
Maybe that's why the ice melted in the first place? Er, yes. So what?
We do produce lots of CO2, and it can theoretically increase the temperature. We just haven't seen any evidence at all, that the CO2 we create is enough to make a difference. Other than the fact that we do see a big difference, and that we can calculate the difference that the CO2 we create ought to make, and the two are compatible.
You're correct about what the media was saying at the time, but that was somewhat at variance with what scientists were saying at the time. In short, they knew there was a recent cooling trend, but they didn't know whether it would later be offset by anthropogenic warming. After another decade or so of data collection and model improvements, they found that warming would be dominant.
I remember being worried about [global cooling in the 1970s], which is why I am not worried about global warming now. Your logic is broken.
They're probably Slashdot or Digg users. Group-think is very strong in both of these online communities and you will get moderated down if you disagree with the accepted collective doctrine. Heh. Quickest way to get moderated up on Slashdot? Say "I know I'll get modded down for saying this, but..." Then all the righteous defenders of free speech and heterodoxy will ensure the opposite happens.
Slashdot Mirror
The article is out of date. Shutting down the North Atlantic thermohaline circulation would only drop northern Europe's temperatures a few degrees, and that cooling would be exceeded by the global warming necessary to shut down the THC, leading to a net warming of Europe (albeit less than other parts of the world). However, there would be a huge drop in winter temperatures over Greenland and the Nordic seas. See Rahmstorf's short Nature review.
I don't know, but I seem to recall that the combined amount of CO2 emitted by both animal respiration and decay of dead organisms is about balanced by the intake of CO2 by plants. If you're interested, you want to search for the "carbon cycle" and "respiration".
There's plenty of debate about specific details in climate science, but "the Earth is warming" and "it's mostly because of us" are indeed the consensus; the debate has moved on, to what will happen in the future. Could it have anything to do with opposing theories being squelched and the presenters labeled as cranks? If they had good arguments, they'd be published. Opposing theories are found everywhere in science, it's just that they're the good theories. Let's face facts, that's exactly what they're trying to do in this case on a very formal level. Let's face facts, nobody has proposed anything of the kind. The original blogger merely said that certified broadcast meteorologists have a professional obligation to be informed about climate science. She didn't advocate removing their certification. And even if she did, that has squat to do with "squelching opposing theories". Certification just means you get to be a TV weatherperson, it has nothing to do with whether your can publish in scientific journals. Is that why so many others in this "community" are allowed to run wild screaming "the sky is falling" while anthropogenic global warming is still just a theory? Is anthropogenic global warming "just a theory" like evolution and the Big Bang?
Everything in science is a "theory". Some theories have enough evidence in their favor that they are regarded as established. AGW is one of them.
As I responded last time, it's true that most of the greenhouse gases in the atmosphere are natural. Without them, the Earth would be tens of degrees cooler. Our contributions are a relatively small addition on top of that effect, but they are still enough to raise temperatures by several degrees, which is what the whole global warming issue is about. I don't hear anyone claiming we should stop using water though. Because that would be stupid, and unlike our CO2 emissions, our water vapor emissions are not causing substantial climate change. Carbon emisions alone are not likley going to be enough to stop global warming. At this point, we're past "stopping" global warming — not this century, anyway. The point of reducing CO2 emissions is to reduce global warming, not to eradicate it. It's not an all-or-nothing thing.
P.S. It's "El Niño", not "El Mino".
Here is a graph of U.S. CO2 emissions; they're still going up, although they have slowed over the last 5-6 years. I'm still looking for a sourced graph, but I do know that they are still increasing. I don't know much about other countries' emissions, but the data is out there somewhere.
Read here and here for more on what scientists themselves were saying at the time. In short, they knew there was a natural cooling trend, but they also knew they didn't have a good handle on manmade greenhouse gas emissions, and they also knew that their climate models weren't up to solid prediction. They said that on the basis of extrapolating the past trend alone, cooling would result. However, they also said that they couldn't predict cooling based on modeling, and that they didn't know whether anthropogenic emissions would outweigh the cooling. Some decades of continued data collection, improvement in statistical techinques, and better climate models later, they now can say with credibility that warming will continue over the next century at least.
The AC did not ignore the trapping of heat by atmospheres. Venus's atmosphere and Mercury's lack thereof is the reason why Venus's temperature is higher than Mercury's maximum temperature.
Actually, the temperature increase started around the same time as the anthropogenic CO2 increase. You seem to believe that humans weren't contributing to CO2 before 1940, but the Industrial Revolution began before 1940, and indeed before 1880. Try referring to a combination of the hockey stick and a CO2 reconstruction, like here. The temperature really started ramping up a little after 1900, during which CO2 emissions were already on their way up.
We have the technological capability to influence the climate. Whether doing so is economically or politically feasible is another matter.
What's being discussed here is the AMS Certified Broadcast Meteorologist program. You don't need certification to be a scientist, but evidently you do in order to be a TV weatherperson. The original blog post merely said that if you're a certified TV weatherperson, you have a responsibility to be educated about climate change; evidently a lot of them spout off about it on the daily news when they have no training in the area.
And a preemptive strike: you might also get modded "plus-one Funny" if you posted this comment... And if I post this reply... uh.. only a great fool would the wine in front of me! But you must have known that I am not a great fool... Aaah, I think I got a stack overflow from the recursion.
At that time, they weren't able to estimate the global warming contribution very well; it is now known to be larger than was once thought. And, in the long run, the Earth will eventually experience more cooling. It's just not going to happen over the next century or two, which is what people are worried about. Only 15 years ago they were worried about an ice age and now they are worried about it getting too hot so is might there be a similar shift back in a few years time when they improve their understanding again? 30 years ago they knew about X (natural cooling) but not much about Y (global warming). Now they know about X and Y. While there is still uncertainty in both X and Y, it has been steadily reduced, and now the uncertainty is about "a little warming" or "a lot of warming", at least over the next century. (They can't predict much past that.)
There are three main factors which govern its overall temperature: the amount of energy it receives from the Sun (insolation), the amount of that energy which is reflected by its atmosphere (albedo), and the amount of energy retained by the atmosphere (greenhouse effect). If you take only the first two into account, you get the wrong temperature; if you take the third into account, you get the right one. Agreed, we to create a lot (on a human scale, not on planetary scale) of CO2, and should cut down where we can. But still no evidence that we are changing anything. Yeah, other than the fact that it's getting dramatically hotter in exact coincidence with the timing, magnitude, and rate of our CO2 emissions. Not only that, but average temperature has been going up since the last ice age. Actually, they went up dramatically at the end of the last ice age (hence "the end of the last ice age"), but for the most part remained constant or even gradually declined over the last 8000 years. Maybe that's why the ice melted in the first place? Er, yes. So what? We do produce lots of CO2, and it can theoretically increase the temperature. We just haven't seen any evidence at all, that the CO2 we create is enough to make a difference. Other than the fact that we do see a big difference, and that we can calculate the difference that the CO2 we create ought to make, and the two are compatible.
P.S. Forgot my links to what scientists (as opposed to the media) were saying in the scientific literature at the time: here and here.