Yes - you do. The evidence for a Medieval Warming Period and a Little Ice Age is only made possible by examing temperature proxies. If you reject proxy temperature data, then you cannot make any claims about what the temperature was like before 1850.
I’d like to clarify your position.
Do you agree that humans are the major reason for increases in greenhouse gases? (IPCC 3AR WG1: Chapter 3.4, esp. Figure 3-3; NAS CCR: Chapter 3;
IPCC 4AR WG1: Chapter 2.3, esp. Figure 2.3, and take special note of Figure 2.3(b))
Do you agree that greenhouse gases cause global warming? (first-principles derivation in post #1 and repeated in post #38; also IPCC 3AR WG1: Chapter 6.13, esp. Figure 6-6; NAS CCR: Chapter 5; IPCC 4AR WG1: Chapter 2.1, esp. Figure FAQ 2.1)
I like it when the argument gets over my head. But what that has to mean is that the issue is arguable, reasonable, and that contrary arguments exist. Arguments which involve math, and lots of it!
OK. so lets say that the situation is not nearly so desperate as us eco-fanatics insist. Lets just take that as a given.
But it might be. It’s like the Heidelburg Uncertainty Thing. Maybe yes, maybe no.
But if we put the energy into it, the research, the brain power, we might just do it. Green clean energy may be possible. Or it may not.
But would you bet a dollar, flip a coin, if the payoff was a million if it’s heads?
This thread is specifically about what the probability of heads and tails are and whether there is a positive payoff at all; I strongly object to any discussion about how much we’d bet and how big that payoff is because those are not strictly climatological questions.
It very well may be that global warming is real, anthropogenic, and harmful, but too expensive to solve - but this thread is only about the first three, because (1) scientists can only agree on the first three, and (2) the fourth question involves economics as well as politics.
Thanks for your answer. I’m sure there will be massive displacements. That’s why I mentioned a century or two afterward. By that time, I figure things will have settled down and people can get on with things. Personally, I see zero chance of stopping climate change. It’s just not going to happen. People and governments will still be discussing what to do right up to when the last ice particle melts.
I think what you are probably talking about, at least in part, is the idea the the parts of the earth covered by ice sheets and glaciers is much more reflective than the part by water or land. Hence, when these melt, the earth’s average albedo (reflectance) decreases somewhat, which means more solar energy is absorbed making things warmer still. This is what is called a “positive feedback effect” because a warming effect causes a feedback that causes further warming.
It also means that there is what is called “hysteresis” in the system, which means that we can’t necessarily, say, cool the earth down to where it was before pre-industrial times simply by reducing greenhouse gases back to pre-industrial levels once, say, the Greenland ice sheet has melted. In particular, if we did that, the Greenland ice sheet would not necessarily just come back (or, if it did, it would take an awfully long time).
On the part about whether survival would be possible if we melted all of the ice sheets, well, I don’t think we would go extinct but it would certainly create huge stresses on our society and on the environment that would be quite devastating (and that I imagine could lead to a sort of breakdown of society and increase the risks of nuclear wars or other horrific conflicts). And, I believe if all the ice melted, sea levels would rise a couple hundred feet, which in many places translates to the ocean advancing tens to hundred of miles inland. The good news though is that noone really thinks we will be able to melt the East Antarctic ice sheet. We may be able to melt the West Antarctic Ice sheet and Greenland, each of which could raise the sea levels by about 20 or so feet. How rapidly that could occur is the subject of debate now…Scientists used to believe it would take millenia but there is some who now argue it could occur considerably faster.
Well, I am somewhat more optimistic on this than you. I think it is a huge challenge but one that we can meet…and that will, once we seriously give the market the incentives to develop the necessary technologies, may turn out to be less difficult than we imagined.
I hate to hijack the thread, but how does melting ice increase sea level? Ice takes up more volume than liquid water, so wouldn’t the sea levels drop when all the displacement-causing ice melts?
Melting sea ice won’t raise the water level, but the ice sheets on Greenland and Antarctica aren’t currently displacing any water. The Greenland Ice Sheet is about 1100 km wide and 2400 km long, and is more than 3 km thick at it’s peak - it contains more than 2.3 cubic km of ice. If it completely melts, it’s expected to raise sea level by 7 meters.
The Antarctic Ice Sheet is even bigger - about 30 million cubic km. The mass of ice in the Antarctic Ice Sheet is equivalent to about 70 meters of sea level.
Also, as the ice that is floating melts, the temperature of the ocean will rise some. Higher temperatures for three thousand meters of water will result in some expansion of the entire mass of water proportional with the temperature increase. The exact amount of expansion that is to be expected is a nontrivial problem, even ignoring climatologic expectations of highly divergent predictions. The problem is subject to some very controversial differences of opinion among oceanologists about how the various currents exchange thermal energy. No one predicts zero expansion. But the lower values reported are sometimes only scientifically non zero.
I think there’s more to the ice sheets than just the albedo feedback, though. Melting ice affects both the temperature and salinity of the ocean surface at the poles, and these two factors are what lead to deep water formation in the North Atlantic. Deep water is formed when cold, highly saline water (both these factors increase the density of water) sinks below the thermocline. Melting ice is fresh water, so the salinity of the surface water is decreased… and in climates warm enough to melt polar ice, the sea surface temperatures will be elevated at the same time. The combination of these two factors has the potential to significantly change the formation of north Atlantic deep water.
Deep water formation is a critical component of ocean circulation patterns, and also acts as a carbon sink. The organisms entrained in the sinking deep water eventually die and settle to the ocean floor, and are thereby removed from the carbon cycle. The deep ocean is the single largest carbon sink on earth, and polar ice melting has the potential to disrupt the process.
Those are examples of some of the feedback loops that have been brought up a few times in this thread. The circulations and cycles involved in the Earth’s climate are incredibly complex, and each component has the potential to affect many other components, even those that at first glance might seem unrelated.
Interesting and worrisome…and this gets back to a larger point that sometimes gets lost, namely, that the remaining uncertainties, if anything, argue for erring on the side of caution and not for continuing on an uncontrolled experiment on the climate system of our home. What we know now is that the perturbation due to greenhouse gases is significant and we know that the earth’s climate system has in the past shown a tendency to shift quite dramatically. Or, as has been said more eloquently, “The earth’s climate system is an angry beast and we are poking at it with a large stick.”
I have reported this statement to the moderators. My response will depend on their response.
The calculation I was referring to was in Post 10. What you quoted is more of a conclusory statement than a calculation.
But anyway, I will do the calculation (using linear assumptions) and then show you why it’s questionnable.
Assume that total pre-industrial greenhouse warming is 35 C. If 5% is due to CO2, that’s 1.75 degrees due to CO2. 38% of 1.75 is indeed about 0.7.
Ok, now take a look at this chart that compares global temperature and CO2 levels:
Not really. It looks as though you have misunderstood my point.
Not at all. The models predict different amounts of CO2 increases AND different responses of the climate to those changes.
A specific example.
Nope. But you claim that two values can NEVER be compared if their magnitudes aren’t known. That’s simply false.
Can you give me some cites and quotes? Thanks!
Lol. Do whatever you want.
Then why did you say this earlier:
?
Sure.
Dude, you’re the one who brought up economic growth – it wasn’t me. But I’m happy to cease discussion of the issue in this thread and leave the discussion for my economic growth thread.
Personally, I believe that that the best interpretation of current science is that global warming is occurring, and man is partly responsible for it. However, I hate to see the politicization of science, and the global warming debate is far too politicized. Skeptics have a hard time getting government funding. Rent-seekers are using the global warming argument to attempt to push forward their own personal agendas. Too many of the people involved in the debate have financial interests in it coming out in their favor - either for or against. So it’s important to make sure the skeptical voices are not quashed in the stampede. With that in mind, here are some recent articles and papers on the other side of the debate: Skeptical Scientists descend on Global Warming Conference
This link is interesting, because one of the effects in current climate models of global warming is that cloud cover would be increased, trapping more heat. According to the study above, actual measurements show the reverse - heating thins the high cirrus clouds that trap heat. If the study is correct, estimates of the effects of Co2 emissions could be as much as 75% too high.
I would by no means call the debate closed. For that matter, no scientific debate should ever be called ‘closed’ but should always be open to new evidence and new theories. The global warming debate is showing signs of moving from reasoned scientific debate to political theater.
I can see that, however I see more evidence that the efforts to politicize this are more in favor of minimizing the effects of global warming.
(I do think this debate really has 3 sides, one worrying a lot, one that says it is worrying about it but doing little (so far this seems to be the consensus) and the one that tries to say nothing is happening)
Ignoring that there is indeed a political force driving the side that is denying the best evidence is more damming to me than a side that comes with the best evidence and has political backing. To prop up political differences is useless unless we check what is the data that is supporting one side.
And ignoring that the side that wants to deny this all together is the side that is being keep alive when there are bad scientific reasons for it is the biggest mistake.
Incidentally many of your links are pointing to evidence from Monckton:
Here is an examination of the evidence from Douglas that Monckton referred to:
By the way: are they right when they are saying that the Monckton paper was not peer reviewed? If that is so what I see here is indeed a paper by a policy institute, as political as you can get.
I don’t know about the Monckton paper being peer reviewed. The study before that, however, IS peer reviewed, and is very recent science (being published this month). If their conclusions are correct that warming tends to decrease the coverage of heat-trapping cirrus clouds, then that will require a significant downward reduction in the global warming estimate from current models.
And if it’s correct that the downwards correction could be as much as 75%, then that would put even the high-level estimates of warming in the range where the economic effects are not necessarily negative.
BTW, for people like me who lean towards global warming but hate the left-wing tilt of most warming advocates, circuses like the Bali conference do more harm than good. For example, this week they lambasted Canada. In the past, Canada has been held up as one of the ‘good guys’. This despite the fact that the previous government in Canada has a worse environmental record than the current one, and presided over a huge increase in CO2 output. So why the sudden hatred of Canada? Gee, you don’t suspect it might be that we elected a conservative government, do you?
Likewise, watching Gore shake his fist at his own country and claim that the U.S. is the biggest problem is really annoying, especially coming a week after China announced that they’d crank out as much CO2 as they damned well please, and the rest of the world could go stuff it.
The Bali conference is like all these other conferences - rich people with power show up to pat each other on the back, tell each other how wonderful they are while jetting around the world and hanging out on yachts after the conference, and issuing a series of press releases which call for global government, more regulations, and point fingers at every conservative or free market supporter they can find.
Global warming would gain much more acceptance from the right and from the business community if they didn’t suspect that much of the hysteria is designed to promote a political agenda they disagree with.
You’ve got me thoroughly confused. I’m not arguing the temperatures. Or the ice cores.
I agree that we’ve been emitting plenty of CO2.
Wrong question. I’ll repeat: has the CO2 we’ve emitted caused the warming we’ve seen? It is entirely possible - there’s a good corellation - but TTBOMK, it has yet to be proven. But there might be another cause entirely: we’re currently at the warming level of the MWP and AGW didn’t cause that. Or did it?
