The ‘consensus’ would include the radiative forcing aspect of CO2, which absent any other feedbacks would lead to an increase of about 1 degree C for every doubling of CO2. Note the doubling aspect - the relationship is not linear. If we’re at 400ppm today, and increased it to 800ppm, we’d see a 1 degree increase in temperature. But to get another 1 degree of increase we’d have to go to 1600ppm. And then 3200ppm to get to the third 1C increase.
So if we restrict ourselves to the ‘consensus’, we’d never get to 3 degrees of increase. And we’d have to increase CO2 to over 1000 ppm before we even got to the point where it was a net negative to the global economy.
Atmospheric CO2 has increased by about 90 ppm in the past 50 years. The rate has been increasing, and just before the financial crisis I believe it was about 3ppm per year. Since then the rate has actually declined a bit (the rate, not the actual amount). But let’s say we even double that rate. In 100 years then we would add about 600ppm of CO2 to the atmosphere, which the basic math tells us would result in a forcing of a little over 1 degree. Which is no big deal.
So the debate really isn’t about CO2 forcing - it’s about what that does to the system, and how various feedback loops might magnify the effect. And there the consensus stops. That’s why the IPCC’s forecasts cover such a wide range of outcomes.
No, I’m not talking about specific areas. I’m talking about the overall rise in temperature. To know that requires that we understand all the feedbacks. I’m confident that we don’t, because of the nature of the system.
For example, here are just a few:
Higher atmospheric temperature should result in more water vapor in the atmosphere - a potentially powerful positive feedback.
increased CO2 adds to plant growth - a negative feedback and a scrubber of CO2
Increased water vapor will affect cloud formation - probably a negative feedback, but we’re not sure.
Increased CO2 will result in ocean acidification once the natural buffers are overwhelmed. That’s probably bad, but we have a poor understanding of what feedbacks might be associated with that.
Higher temperatures may cause the release of frozen clathrates that would increase methane gases - a positive feedback.
Higher temperatures may cause ocean current changes, and ocean currents are one of the main ways energy is transported around the world. I don’t think we have a very good understanding of this yet.
Warmer temperatures could cause albedo changes with ice pack shifts - but it’s not clear if this is a positive or negative feedback. Increased moisture in the atmosphere could lead to more snow in the polar regions, increasing the size of the cap. But maybe not - perhaps it will melt faster than snow can replace it. Or perhaps changing weather patterns will make the poles dryer and drop more moisture elsewhere…
Eroding coastal regions due to rising oceans could result in the release of minerals into the water which stimulate algae blooms - and a single algae bloom can hold as much carbon as the U.S. emits in a year.
I could go on for pages. Some of these feedbacks are likely minor. Others are potentially major but poorly understood. One thing we do know is that in the past high CO2 concentrations are associated with warmer weather - but we also know that the temperature has fallen dramatically during periods where there were high CO2 levels. We just don’t know why.
I agree with you. Some mitigation is obvious and should be agreed upon by both sides. For example, we should stop subsidizing the construction of infrastructure in flood plains and coastal regions with federal flood insurance. That’s just ridiculous. We should start looking at current levee designs and make sure they can handle a modest sea level rise and shore them up if not.
But can we prevent global warming from happening by reducing CO2? I have yet to see a workable plan for doing that. Sorry, but a carbon tax in California or even across the U.S. is not going to do squat other than damage the economy.
My attitude is this: Knowing what we do about global politics, the fact is that every ounce of fossil fuel is going to be burned - until it becomes more expensive to do so than to use alternative energy. And costs of fossil fuel are increasing while the costs of alternatives are coming down. At some point in the not-too-distant future those curves will cross, and then you’ll see a dramatic decrease in fossil fuel use. That future isn’t all that far away, so I don’t think we have to worry about hundreds of years more of CO2 emissions.
I really question whether this process can be accelerated by fiat. Non-global carbon taxes will just shuffle the pattern of consumption around. Unless you’re prepared to go as far as military blockades to prevent the flow of fossil fuels, you can’t stop it from being burned.
More R&D on alternatives might be a good idea, but not if the government is going to pick winners and losers. Like the ants, we’re much more efficient if we rely on letting the system develop its own search algorithms rather than trying to centrally direct it. But there’s certainly things we can do to stimulate that. Prizes for breakthroughs, perhaps bulding public research facilities open to small researchers as Canada does with its NRC, removing regulatory roadblocks for nuclear development, offering scholarships for gifted students to incentivize them to go into energy research, that kind of thing.
This isn’t really true, as I point out above. And we’re nowhere near an unheard-of level of CO2 in the atmosphere - during the Cambrian period it was as high as 7,000 ppm. You’re right that it’s higher than it’s been during the current interglacial period, and likely for millions of years before. But I don’t believe that it’s increasing ‘with no end in sight’. Fossil fuels are a finite resource. Fossil fuels that are economically exploitable are even more finite, and probably won’t last more than 100 years. So there is a limit - but that limit may be higher than we’d like.
The median estimate is for an increase on the order of 2-4 degrees C over the next century. That’s certainly not insignificant, but it’s also not an end to civilization. So we’re back to doing a risk-reward calculation.
I’m an engineer, and when we talk about good things, we always ask “At what cost?” Something can be a good thing to do, but you still shouldn’t do it because it stops you from doing something else which would even be even better.
For example, if we make a change that causes GDP growth to drop from 3% per year to 2%, we would change the economy of 50 years in the future from being 4X our current GDP to being only 2X our current GDP. Do we want to cut our 50 year GDP in half to try to lower CO2? To know that, we’d have to know the net present value of the damages caused in 50 years if we do nothing, and how much Co2 reduction our 1% decline in GDP growth will cause and how damage that would avoid. After all, making the world of 50 years in the future half as wealthy is a pretty high price to pay. That means less money to pay for retirements and government programs, less development in Africa, poorer standards of living around the world. Is that worth it?
That’s not a simple question. There’s no consensus around it. I don’t think we have reasonable estimates yet for any part of that decision. We don’t know how much Co2 reduction will cost in terms of GDP, we don’t know how much CO2 we’ll emit, we don’t know what the costs will be on a future society because we don’t know how people will live or what breakthroughs in materials and energy might happen along the way.
Again, we’re back to risk management. We have to assign a cost to the risk, with suitable error bars. Then we have to make a decision regarding how much insurance we want to buy given our risk profile. But first we have to figure out how to feasibly reduce global CO2 in the first place, and whether or not that’s even possible given the political climate. If not, all we can do is worry about mitigation and in the meantime hope to discover and implement better sources of energy.
Once you have an argument that doesn’t negate all of medical science, please see me. Until then… I honestly don’t care. Yeah, climate is complex. But the evidence we have so far indicates catastrophic warming due to human influence, and all the “BUT WE COULD BE WRONG”-style denialism in the world isn’t going to convince me that you have a case. I’m really sorry that you spend the time to write something like 10 pages on it, because I honestly don’t care. Provide evidence or I just won’t give a shit.
Okay, maybe you can provide the single example of a scientist who was shat upon for challenging the status quo?
Sound like something the Heartland Institute would say.
As the latest IPCC report told us the costs are not going to be a huge burden, and you are then making a point that many others have done before, the problem is indeed at the congressional level because it is full of deniers.
The cases of how we did deal with acid rain and CFCs tell me that the issue is political indeed.
And we are back to what in reality are basic denial talking points.
Again, the costs that will get us should be enough for any conservative to stop supporting the ones that are telling us that it will not be a big deal.
As it is becoming very painfully clear, even though you are eons better than the deniers of the basic science out there, there are already several items that you are really only showing an ignorance that comes from the same groups that do deny the basic science, the only thing you are bringing is contradictory points or items that while you thought were outside the old denier talking points, you are missing a lot of the information that is out there or has been updated. As I have seen, several of the points you are making are also at the same level as the ones you report were already debunked.
Case in point, if there were no real examples I would think that indeed there are no good feasible ways to reduce emissions and continue to have progress, places in Europe are showing what can be done.
My entire life activists have been saying we need to act now before it’s too late. Since our most clever solutions so far include burning nat gas and economic depressions I’m waiting for the “it’s too late” newsletter.
What is ignored here is that it is too late to stop some of the effects of the CO2 already released, so you got it; but you are then now ignoring that even worse conditions can be expected if we do not control the emissions. It is like smoking in the sense that quitting does not mean that you will avoid the damage done after smoking for 2 decades, but one can avoid more severe problems later on.
Just do not let the scientists working for the tobacco companies to tell you otherwise, it is curious to know that after failing to prevent regulations to tobacco a few jumped to also work to prevent the regulation of fossil fuel emissions.
Yeah? Go talk to some immunologists and ask them how easy it is to figure out that complex system. Talk to the people who are still trying to figure out the role that gut bacteria plays in regulating our bodies. Go ask a neurologist how much we really understand about concept formation and higher intelligence in the brain.
Have a look at the state of psychological research, and see how much progress has really been made in the last 50 years in understanding what makes us behave the way we do. Have a look at how many blind alleys we’ve followed for years or decades, sure that we had it figured out.
The evidence we have does NOT indicate ‘catastrophic warming’. The evidence we have pretty conclusively shows that human-emitted CO2 is causing additional radiative forcing in the atmosphere. That’s what the evidence shows. The scenarios for catastrophic warming are still in the realm of theory and computer modeling. That’s why the IPCC assigns probability estimates to its conclusions, and why so many of the conclusions outside of the median are basically described as “better than 50-50 chance” or “We really don’t know”
I already gave a couple: Bjorn Lomborg and Roger Pielke. You could add Judith Curry to that list - a respected climate scientist who is not a ‘denier’ but is skeptical of the more extreme claims for catastrophic warming, and who has written extensively of the hassles her positions have put her through.
Whether or not the word “catastrophic” – or any other particular word – is used in any particular report is really rather irrelevant. What the evidence says is pretty clear. I’ve already posted links, for example, to the IPCC impacts assessment (WG2) and over here to the recently released US National Climate Assessment, and (also in that post) – just as a random example – to a new Nature article on reduced nutrients in major crops due to warming, just one of thousands of such impacts. I’m going to guess that you haven’t read either of those major assessment reports, let alone any of the underlying research.
Anyone reasonably familiar with the field of climate science would, quite frankly, be embarrassed to post any of those names. Bjorn Lomborg is a borderline denialist and anti-science activist notable for having been investigated for scientific fraud, and found culpable by the Danish Committees on Scientific Dishonesty, but partially excused for the interesting reason that he clearly didn’t understand the subject matter that he was lying about! Judith Curry I’ve already talked about several times; she no longer does much publishing and spends most of her time running a discreditable blog that caters to denialist extremists. She’s been widely and justifiably criticized for her scientifically unsound attacks on the science – in many cases knee-jerk reactions to papers that she clearly hasn’t even read – and her fringe viewpoints. And my comment on “Roger Pielke” would depend on which one you mean; Pielke Sr. is a legitimate scientist but with some very skeptical leanings and should be taken as such; Pielke Jr. is just a flat-out denialist lunatic.
This once again are off the mark concerning climate science, there is a lot that you have missed already and you are relying on ignorance to make your points.
Wrong again, the models also describe situations that are inconvenient (it depends on the levels of CO2 and the warming one can get on the different scenarios) and could be very bad depending on how we prepare (or do not prepare) for. Like the small ocean rise and more drier conditions in the south west at low levels of warming.
Of course once one realizes that there are different levels of harm that the models and calculations (that are not depending on models) this is misleading.
Whoa, ignorance hits, Bjorn Lomborg background is in economics with some environmentalism on the side, but no climate research; and Roger Pielke (Jr.) has a Ph.D. in political science but his later experience in climate science does give him creed, and Curry does have respect but unfortunately they have a history of squandering that creed thanks to ideology or/and cherry picks:
As for Pielke, this was posted before, when he repeats the mantra that the IPCC should not be trusted I have to remark that you are on the record of relying on the IPCC so this should be enough for you to stop using him:
As for Curry, IMHO she got to chummy with many in the sceptical circuit and was part of the Berkeley team that had Professor Muller as the lead, Curry expected that the Berkeley team she was helping was going to also confirm the issues that she had.
She got bupkiss and dissed Muller and the conclusions of the entire team that had been funded by sceptics.
So, an underwhelming team, that has been used more than once by the full deniers of the basic science, as you are not like that I really suggest again that you need to cleanse your sources of information on this subject.
Of course once one realizes that there are different levels of harm that the models and calculations the experts use (that are not depending on models) what you said about “not knowing” is misleading, IIRC it was noticed that the IPCC concentrated on the most likely scenarios and optimistic scenarios because the worst ones are too depressing to contemplate.
Regarding the models, once again the scientists do not rely just on them, models are a tool to see if more basic calculations are valid and they show better skill than the ones before, and this is because models are also confirmed against reality and old fashion calculations.
BTW, regarding the Berkeley team that applies to the subject of the thread in that it was a perfect example at an attempt at falsification of what NOAA and others had found regarding the data and reconstructions of paleoclimate.
GigoBuster, you really need to stop throwing around ‘ignorance’ and ‘denier talking points’ and making reference to the Heartland institute. First of all, it’s ad-hominem. Second, it’s kind of rich calling me ignorant when it seems to me fairly clear that you don’t know what I’m talking about. Third, it’s rather transparent that you can’t accuse me of being a ‘denier’, so instead you’re trying to discredit what I’m saying by trying to associate me with ‘denier talking points’, even though I’m not saying the same thing they are at all.
At for the Heartland Institute, I don’t like them, don’t agree with them, and don’t know what they’re currently saying about climate change at all, because the last time I read anything by them it was nonsense. I don’t think I’ve spent more than 5 minutes on their web site in a long time - probably less time than you have. So I’m getting a little tired of being smeared by being associated with them or with ‘right wing blogs’. My ideas are my own, arrived at by plenty of study of the literature on both sides. I tend to go for prime sources like the IPCC, and could give a rat’s ass what some religious institute has to say.
And, I’m as angry at the right over their obstinate denial of obvious science as you are. It drives me nuts. So cool it with the ‘denier talking points’ crap, will you? My arguments can stand on their own without your guilt-by-association tactics.
As for Pielke, I don’t really care what his reputation is - That’s also an ad-hominem attack. But I read the article on Nate’s site, and thought the reaction to it was way over the top. By the way - did YOU read it? Why don’t you limit your criticism to what it actually says, rather than quoting what some third party thinks about the man who wrote it?
It is not when conservative think tanks and denial sites are the most common source of those items. If they are not, then why not post the source of what you are claiming then?
Nope. wolfpup also noticed the problems, they are very clear to anyone with experience in the matter.
The results are the same, and this is even more painfully clear when you are using very questionable “climate scientists”
And here you only show that you did not check what the guys at Grist found about Roger Pielke, once again, if you are sincere here and you do accept the IPCC it is time to drop Roger Pielke and the other questionable sources/scientists that you are depending of, because in the end you are getting your ideas from poisoned wells (particularly Pielke and Lomborg)
Not really as I cited contrary evidence of your claim that scientists do not know what happened in the past or that models are the only thing that is telling them the most likely outcomes for the future.
Here you are not reading carefully: the quotes I made do refer to how Pielke, Lomborg and Curry deal with the evidence, if they do not like it they dismiss it.
So, based on this, the conclusion would be that it is irresponsible to use any of the evidence we’ve gathered so far, because later evidence might overturn it.
No, seriously, go back and re-read what you said, that pretty much sums it up. I personally find that irresponsible and unscientific. We don’t abstain from using the evidence we have because new evidence might come up. At most, we say “the evidence we have now isn’t good enough to draw conclusions on” when we don’t have enough evidence. This is not the case in climate science.
Um… No. Although reading this, I’m kind of getting the impression that no amount of evidence would convince you that we are going to be facing warming due to increased CO2 emissions, because there could be some mechanism that cancels it out. So basically, you won’t accept any prediction of future climate. If I’m wrong, please tell me - what would change your mind?
Interesting. Care to point out where their careers were ended, or they were harassed, or the like? Because just naming names doesn’t help me much.
In looking back, I see a few more things in drastic need of correction.
This comes from a long post in which you compile a long list of what are, superficially, reasonably plausible limiting or mitigating factors that could act to reduce or stop climate change. There’s just one problem: these things don’t happen – that is, there is no evidence that they occur or have ever occurred to limit climate change when GHGs are increasing, and lots of evidence for the reverse – that GHG increases actually cause accelerating long-term feedbacks and abrupt climate shifts called tipping points associated with runaway climate change.
What you are really raising is the old myth of the magical mystical self-limiting factor. No such magical mystical factor has even been seen in the paleoclimate record, nor is there any theoretical basis for it; on the contrary, there is ample evidence from paleoclimatology that when GHGs increase, the warming of the planet continues unabated – here is one example of such rapid warming, analogous to that of the present day. It ultimately transformed all life on earth.
But we don’t even have to go back that far. We see drastic climate changes in semi-regular intervals during the past 1.2 million years of glacial cycles, where CO2 fluctuates between about 180 ppm at glacial maximum to about 280 to 300 ppm at the peak of inter-glacials – a difference of only about 100 ppm accounting for the difference between mile-thick glacial ice sheets and the temperate climates of the present day. There is now a greater difference between the normal inter-glacial peak at which we had stabilized for thousands of years before industrialization – about 285 ppm – and the present off-the-chart 400 ppm. What that portends for the future climate is equivalently extreme.
That whole chain of reasoning is completely wrong on many levels, beginning with the basic premise of one degree of warming.
First of all what is the point of talking about CO2 forcing absent any feedbacks? Feedbacks are absolutely crucial in determining climate sensitivity, and they are overwhelmingly net positive. The median value of sensitivity estimates from many different sources is somewhere around 3.3, not 1, with a likely range of 1.5 to 4.5. So the whole basis of your calculation is wrong. And statements like if we increase CO2 “to 800ppm, we’d see a 1 degree increase in temperature” are utterly absurd; 800 ppm is by any rational estimation well past the point of catastrophes like desertification of one third of the planet and drought over half, extinction of up to 70% of all species, loss of major coastal areas from sea level rise, and major changes in ocean chemistry.
So as far as your “doubling” calculation is concerned, 800 ppm is not any kind of option; it represents the most disastrous of the RCP scenarios, and indeed it’s been widely accepted that the stabilization target should have been around 350 ppm, and anything above that implies an increasingly serious risk. The idea of predicting temperature increase at equilibrium for a doubling of CO2 is a theoretical construct for expressing climate sensitivity, not something that we’re actually going to be doing if we hope to survive.
The other thing that’s wrong with your calculations is that you assume ECS is a constant. It isn’t. At elevated levels of CO2 and temperature, many feedbacks are intensified – in particular, those feedbacks associated with albedo changes from reduced polar ice cover, whereas some mitigating factors like absorption of CO2 by the oceans significantly slow down and eventually reverse and become positive feedbacks. Eventually we can just watch the process of runaway climate change unfolding without adding any more CO2 at all.
Far from “never even getting to 3 degrees of increase”, we are almost certainly already committed to that. And going on as you are about “net benefits” to warming, I have to assume again that you haven’t read the IPCC WG2 report on impacts, or the US National Climate Assessment, or looked at charts like this. Whatever small benefits may accrue to warming will be more than offset by weather instability and weather extremes, unexpected regional climate changes including major precipitation changes, floods, and droughts, and poleward migration of invasive species. Furthermore, the IPCC notes that improved crop yields due to warming and CO2 fertilization will be short-lived, and occur only in the mid-latitudes if they occur at all, whereas the impacts will be (and already are) immediately negative in tropical regions that are the least resilient to begin with.
There’s that key prediction/assumption from the enhanced greenhouse effect theory once more. It is assumed that increasing CO2 will lead to increased warming at the poles, which will lead to less ice and snow, which will lead to increased warming, which will lead to less ice and snow, leading to more warming.
This is supposed to show up the most in winter, and is a sign of greenhouse gas increase causing warming. It’s a key assumption of the theory. It’s why NH winter warming is so important for the theory, and this feedback is a key mechanism of why the enhanced greenhouse effect is supposed to lead to drastic warming. Because along with the increased warming, there is an assumption that the increase in water vapor, from the winter/arctic warming will also lead to more warming. In fact, water vapor is the key mechanism that will cause the most warming.
It is assumed that more water vapor will cause more warming, which will cause more water vapor, which will cause more warming. Which is exactly where the wheels fall off and the entire theory falls apart.
Yep, I see that Dyson that was tossed under the bus for predicting that is still under the bus. No easy pickings indeed, you did point at him before as a go to guy until it came up that he did agree about the prediction of the warming of the poles.
And you have nothing nor good support to show that the feedback is not there.
It’s not “assumed”, it’s predicted, and it’s observed. In fact Arctic ice loss and temperature rise is one of the most obvious and dramatic manifestations of climate change.
This bullshit has already been thrashed to death in several threads, now closed, including the memorable one where you incorrectly claimed it’s been cooling since some arbitrary date you picked like 2003. I am most definitely NOT going to get into this again, I’ve wasted enough time on it. It’s not as if anyone with an understanding of science doubts that CO2 is a GHG and a primary climate driver.
You obviously don’t understand how water vapor feedback works. Not surprising, since you previously claimed here and here that water vapor wasn’t a feedback at all!
Now that you’ve learned that it is, let me further explain that water vapor feedback stabilizes because of cooling by increased IR loss from outgoing blackbody radiation as the temperature rises. The radiative flux to space from IR cooling per unit temperature rise is about twice that of water vapor feedback warming, so it’s a self-stabilizing feedback loop.
I was reminded in looking for those links on your water vapor comments how much time I’ve wasted arguing with you about things like water vapor feedback, and whether or not it’s been “cooling” for the past decade, and your nonsensical statements about solar variations driving the climate. From now on I’m keeping it brief or not replying at all. May I respectfully suggest that you consider taking a climate science course and then coming back after you understand some of the rudiments of the science.
