No. It is actually lighter than air.
You can work this out from the fact that a gas’s density is proportional to its formula mass.
If we take the atomic masses of Carbon (C) as 12, Hydrogen (H) as 1, Oxygen (O) as 16 and Nitrogen (N) as 14 then:
Air contains Nitrogen (N2) – 78% and oxygen (O2) 21%. The equivalent ‘formula mass’ of air is therefore just slightly more than 28 (2 x14)
Methane’s (CH4) formula mass is 12+ 4 or just 16 – so it is lighter than air as the formula mass (and hence density) is less than 28.

[I haven't referenced this as stefanthedenier doesn't believe in references]

“My main question is why adaptation should be attempted and funded only for AGW, and not to address risks associated with the current climate and natural climate variability? ”

Where I live (UK) there are vast amounts of money being spent to mitigate against current natural events such as coastal erosion, flooding in low lying areas, tidal surges, etc. I’m pretty sure that we’re not alone in this (isn’t the Netherlands pretty famous for its dykes?).

Web hub says (4.42): “Last time I checked, orbital changes don’t create a feedback loop, and neither does angle of incidence. Those are known perturbations, with an easily estimated forcing function.” The net annual and global radiative forcing from orbital changes and angle of incidence is indeed close to zero. This fact is used by some people to discount the role of such variations in global climate change. However that argument misses the point, which is that what seems to count is a regional (rather than global) and seasonal (rather than annual) control, namely (as Milankovich suggested) the slow cyclic variation in summer insolation on the earth’s land hemisphere. It is mainly on the NH land areas that the initial positive feedback is felt, with growth and shrinkage of the area covered by snow and ice and attendant albedo changes. So far so good. However the question of how this regional pattern can extend to become a global one is still a matter for further debate. Some people argue that atmospheric CO2 feedback plays an important role; others find that solution unfeasible because of the time lag. At least that’s how I see the situation. There seems to be plenty of scope for further study.

Louise -
Isn’t the point that those types of things continue to be sensible, whereas scrabbling around for something to adapt to on the basis of a model projection lacks the same common sense?
My understanding is that most people – particularly poor people – aren’t particularly vulnerable to climate change, they are vulnerable to climate. It seems very strange to be searching for special kinds of ‘AGW’ weather to worry about when natural variability provides problems we know about already?
You’re right that this goes on anyway – mostly in rich countries. I agree with Dr C that if this activity is made more widespread, it doesn’t need to be done on the basis that anything is ‘changing’. I think that is spurious. Especially because regional and local projections are (and will continue to be) so lousy. Dr C’s proposals for more efforts with 2-6 week forecasting projects are very different, and again not to do with climate changing but climate just being climate.
I’m guessing you agree with all that…. we didn’t put up the Thames Barrier because of James Hansen’s predictions did we?

The dust layer covering the moon’s surface (the regolith) is the result of meteorite impacts over the whole history of the satellite. The regolith material is a mix of (a) original moon rock fragmented (and occasionally melted) by larger impacts and (b) extraneous material including fragmented meteorites and dust particles. There is some evidence that (a) is the dominant component, as even with the naked eye from the earth one can see that the regolith is not uniform, but varies regionally in composition. This regolith variation must reflect variation in the composition of the underlying solid rocks, as if extraneous material was dominant the regolith would tend to be of uniform composition.
I have read that the main difficulty that lunanauts had with the lunar dust was that it is so sticky, clogging up equipment in a way that they were not accustomed to with earth dust

Use Google Scholar to search for Roe 2006 “in defense of Milankovitch”.
The correlations work better for rate of change of volume. It should gibe you a PDF.

“And there IS a decent coating of dust on the moon, though not waist deep. But the depth of that dust should be IMHO an indicator of how much dust has arrived on Earth, too. That said, I’d like to know why anyone’s claim or argument would vary very much from that. On average, what falls on the Earth would also fall on the Moon. Sometimes one or the other screens the other, but even that should average out as a wash, I think. Yes, the Earth has a bigger gravity well, and that might make a difference. But it might also lens the paths of some dust (which is traveling probably at what? 15-30 km/sec?) and bend it around the Earth, and if the Moon is on the back side, it might get more than its share.”

A difference between the Moon and Earth, is a car size rock is stopped by the earth’s atmosphere, on the Moon it directly impacted on the lunar surface. Pea size or even microscopic dust hits the lunar surface at [as you said] 15-30 km/sec. Though the most common impact speed is about 20 km/sec, but there is a wide range of possible impact velocities. The range is +70 km/sec to somewhere around the Moon’s escape velocity [2.4 km/sec]. It somewhat rare to have low velocities of around 2.4 km/sec, but those impacting at those speeds would be affected by the Moon gravity.
To impact the Moon or Earth at these lower velocities [around their escape velocities] requires that an object be in the same orbit around the sun as the Earth.
The reason is quite simple, earth is traveling around the Sun at 29.8 km/sec, and most objects are crossing earth’s orbit. So it’s like highway where cars are traveling 60 mph, if you on bicycle going with traffic and you cross the traffic, it’s the car’s speed which mostly determines the impact velocity.
And the higher velocities involve earth hitting cometary material- if they miss earth they going go out beyond Jupiter. A lot material which hits earth or Moon comes from Jupiter gravity affecting on asteroids in the Main asteroid belt- Jupiter the reason we have a constant supply- without Jupiter impacts would be much rarer then they are.

As for lunar dust, all the impactors are “gardening” the lunar surface- the turn over or gardening of lunar regolith occurs around every few million years:
“The lunar regolith, or the uppermost few meters of the Moon, consists of soil and highly fragmented rocks formed by repeated impacts of meteoroids with the Moon’s surface. These impacts eject material from the craters that are formed, and the ejecta are usually deposited nearby. The overall effect of many such impacts is a continual overturn of the regolith, which keeps it well mixed. This can be thought of as a sort of gardening, analogous to the mixing of soil performed by a farmer’s plow.
…
The degree of mixing in the regolith depends on the size of an impacting body, with larger impacts mixing material to greater depths. Small impacts are much more common than larger impacts, and so mixing to small depths occurs more often than mixing to large depths. Current estimates are that mixing to a depth of 1 centimeter occurs on average every million years, while mixing to a depth of 1 meter occurs only about once every billion years.”
http://www.lpi.usra.edu/lunar/missions/apollo/apollo_17/experiments/lnp/

Regolith Depth:
“We find that median regolith depths in
the mare regions are typically 2-4 m, whereas median
regolith depths on the farside and non-mare nearside
areas are typically 6-8 m.”
http://www.lpi.usra.edu/meetings/lpsc2011/pdf/2607.pdf

The impacting also compacts regolith [or dust], and smaller impactor/micrometeorites sputter the surface. Leaving a thin layer few inches [in which astronaut made all their footprint] which is on top of meters of compacted regolith.

bob droege

This exchange is beginning to become a bit repetitive.

Rather than refuting ANY of the “what we know” points I made at the start of this discussion, you now bring up hypotheses of what might happen some time in the future regarding the “mix of forcings”.

Then you add an analogy regarding capital growth in a diverse investment basket.

This is all very nice, bob, but does not change “what we know” one iota.

So let’s break this discussion off.

Max

My main question is why adaptation should be attempted and funded only for AGW, and not to address risks associated with the current climate and natural climate variability?

I would guess for reasons of predictibility and politics.

Presumably the purpose will be to establish some kind of risk metric, similar to flood-years currently used by local and state planners, and provide a risk-evolution timeline. Even under the considerable uncertainty of future scenario and climate sensitivity this is feasible in relation to anthropogenic changes but not so much for natural changes, which are currently unpredictable, or happening on timescales well beyond normal planning practice.

There’s also the element of political unwillingness to subsidise people who choose to live in locations which are inherently climatically vulnerable. If those areas carry economic advantages those can be used to pay for necessary defenses.

tempterrain

Pardon me for interjecting myself into an exchange you were hoping to start with our host, but this phrase you wrote caught my eye:

However, the change which is looming now, anthropogenically induced, will happen much quicker than anything previously experienced so it does make sense to treat that as a special case.

Extreme weather events can cause problems for humans, particularly those in poorer countries, who have less resources available to forecast and adapt (Dr. Curry’s point).

Fortunately the human toll to extreme weather events has decreased markedly over the 20th century (Goklany), partly as a result of better forecasting and adaptation possibilities.

But we should be aware that these events will continue to always be with us in the future, as they were in the past, and Dr. Curry’s suggestions on better forecasting to allow for local adaptation if and when required are very well made.

Now to the hypothesis that human-induced climate change from fossil fuel combustion might result in a perceptible increase in the incidence or severity of extreme weather events, there are no empirical data to support this premise. It is purely based on model simulations, which have shown to be extremely poor in forecasting our planet’s climate, let alone severe weather events that might result from a change in climate.

Preparing for extreme weather events makes sense.

Treating those purported events caused by AGW as a “special case” as you suggest does not.

Just my opinion, of course.

Max.

Photovoltaics are quantum mechanics in action. Extracting energy from entropic sources is applied statistical mechanics, aka stochastic mechanics.

That’s a start for mitigating a reliance on fossil fuels.

There is very little in this paper. The base idea is a very simple one: you cannot predict how societies will react to particular changes, even if you are able to predict the changes themselves.

Yes, this is true. There is a long record of such failures, particularly of failures to predict the social consequences of technological innovation. It is quite true that the social consequences of a warming or cooling of 2-3C are not very predictable. They will not necessarily include wars famine and mass migration.

This simple idea is wrapped in a large quantity of post-modern wet flannel, stuffed with some historical background, and covered with a lot of references to make it publishable.

One says to the author, glad you finally woke up. Now go back to bed again. The rest of us have been up for quite a while.

Robert,
I went to what I assume is your blog, and found the following article:

“Semiletov v Dmitrenko: The tale of the tape”

If this is indeed your work, I am very disappointed. Basically, the writer used the number of citations of each author to determine which is more believable. How is that in any way related to the content of the work itself? The short answer is, there is no correlation. All it demonstrates is the number of people who agree with the views of the author.

BTW, I see you going on at length about how may of the posters here do not have the scientific background to credibly argue their case. Okay, where is your body of published work? All I see on the blog is links to the work of others. How about providing a link to an example of your expertise? If you are worried about anonymity, feel free to send the link to my email address:

rjemery@cox.net

I will be more than happy to keep anything you send me private.

gbaikie -
I think you’re right – people are interested in the future, and will create simplistic one-dimensional visions. I don’t agree that we are ‘throwing up our hands’ when we cast doubt on these simplistic visions – it is merely a constant necessity.

I don’t believe we should stop trying to understand where paths will lead and what consequences follow from particular actions. However, as Hulme points out, it is easy to ignore the capacity for human agency when we take a single variable model of the future and characterise people as ‘dumb farmers’ waiting for climate or climate change to ‘happen’.

I think the response should be cautionary. Much as my response is to any prediction of doom. Part of the reason a completely normal state of affairs is a significant portion of humanity believing ‘we’re heading for disaster’ [all the time] is this extrapolation of one single variable and leaving everything else static and impotent – the hitting of future generations with the big idiot stick. It’s like imagining everybody of 2100 being 8 years old, vulnerable and incapable.

As far as I know the only antidote is studying history and realising that being certain that the future looks catastrophic is wholly consistent with the future being in its essence, just like the present. This includes yet more people convinced (and convinced of their evidence) that the future is yet again going to be terrible.

There are good psychological reasons for the human imagination to extrapolate problems. However, when shared among many, they take on the characteristic of hysteria. That doesn’t mean that we shouldn’t take current processes seriously, just that ‘experts predicting a catastrophe’ in the past meant ‘experts being wrong’. We need to remember that a scientific attitude is one that sees experts as ignorant, particularly when they start making projections about the future.

Sorry, but I have to side with WebHubTelescope on this one. Mitigation does NOT require governmental intervention. It could be something as simple as individuals acting to reduce their energy footprint.
Conversely, adaptation can be carried out by the State as well as individuals. Case in point – Pentagon spending on the electronics used to relay strategic information to tactical commanders (platoon leaders, for example) so that they can better coordinate when dealing with non-state hostiles.

It’s scary when I find myself agreeing with WHT, but facts is facts…

Robert
The language is a mouthful, no doubt, but the core arguments hold.

You have got to be joking when you suggest that there is “no factual case against climate science in general or climate modelling in particular”. At the 2009 WMO meeting Mojib Latif -the doyen of climate modellers- acknowledged what a lot of others also knew or were thinking but weren’t saying out loud: climate models are a failure across the board, and have the predictive value of astrology or fish gut reading [your pick]. And nothing has changed for the better since then.

Why are climate model fatally flawed? Because it is not possible to model one of the most complex, non linear, chaotic systems known to man, in which -crucially- there is not one single independent variable. The moment you treat even one variable as independent, you thereby introduce a fatal flaw into your model. How do we know? Because we have tried something very close to climate modelling in another system with very similar fundamental characteristics: proteomics. 10 years and a few billion dollars worth of R&D funds later, the entire effort was abandonned. For precisely the same reasons.

And no case against climate science in general? With all the respect due to our host, are you still – with a straight face- telling us that? After all we have learnt over the years about Hansen cooking the GISS numbers, the “follow the pea” selective statistical methods -including upside down splicing- that are the handywork of e.g. Mann, Steig, Trenberth or Dessler. Or after what we learnt from CG1 and CG2 or the inner workings of the IPCC?
That is not science as I was taught to understand it on my way to a PhD. That is “science” for a “cause” [dixit Mann. That is: not science at all.

To base -as we continue to do- far reaching economic and social policies on “science” that has been fatally hijacked by individual and institutional fraudsters and on models that have no scientific or predictive value whatsoever, is not only dangerously stupid but -because of the negative consequences- ethically and morally reprehensible.

(Moved this part of the thread to the bottom to un-nest it.)

@David Young in climate science the data is so noisy and the effects are so small, that statistics becomes much more important than in other fields.

For the several centuries prior to 1850 you may well be right. That period is beyond my ken, and I wouldn’t want to come down strongly on either side of this extraordinarily passionately fought debate. I’ve deliberately limited my own studies to the period since 1850 where the data is nowhere near as noisy as in say the 16th century. It would be stupid of me to work on the earlier hard-to-interpret data because I would be opening myself up to the sort of legal actions with which Mann has been threatened.

Had McShane and Wyner limited their remarks to before 1850 I would not have objected, the strong political slant of their paper notwithstanding. However they seemed to feel their statistical analysis is just as applicable to the past century or so as to half a millennium ago. I strongly disagree: the greatly increased reliability of instrumentation technology since 1850 allows us to pass from dubious statistical reconstructions of very imperfect data to much more reliable data. The role of statistics decreases in inverse proportion to the reliability of the data.

On the question of whether there are errors in Mann’s analysis, I am utterly unable to accept the legalistic approach to science in which the way to attack your opponent is to accuse him or her of illegalities. If you seriously believe that bringing legal action against Mann is the way to settle scientific differences then we have nothing further to discuss. You talk about my arguments being stupid: I say that threatening scientists you disagree with with legal action is the ultimate in stupidity. This is how the Tea Party works, which is anti-intellectualism at its worst!

The Tea Party of course will say that it is the scientists that are stupid. On that point the Tea Party and science will have to simply agree to disagree.

Not Chrichton again.
Predictions were made that coal-burning would foul urban atmospheres early on. Once the problem occurred in places like London, only then did the reactive mitigation steps take place. Raising smokestack height was one of these. Does Chrichton mention this? No, because he is a contrarian who wanted to sell books. So he sets up strawman arguments about horses. The equivalent for this was the risk mitigation strategy of our interstate freeway system, and perimeter freeways. Was that proactive in hindsight?
Some decisions can be made proactively.

One of my first computer science projects was to model the population of caribou and wolves, based on the observed behavior and probabilities of prey and predator. Sometimes when a wolf chases a caribou it catches the caribou, sometimes it doesn’t. Sometimes caribou find sufficient food to reproduce, sometimes they don’t. Sometimes they die young, other times they die old.

What was notable about the model is that it did not average out like a coin toss. Each time the model ran it gave a different answer. Sometimes the populations exploded, sometimes they didn’t. Sometimes they went extinct, sometimes the didn’t. Nowhere in the model did we change the climate, or any of the probabilities. Yet it gave different answers each time we ran the model, and there was no tendency for the model to converge on a single answer for the “future”.