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michael sweet at 03:12 AM on 3 May 2017Industrial-era ocean heat uptake has doubled since 1997
Concerned Citizen,
Sunlight heats the ocean. There for the ocean is hotter than the overlying atmosphere. According to the laws of Physics, heat is transferred from the warm ocean to the colder atmpshere.
When the atmosphere is warmed from AGW, heat flows more slowly out of the ocean. Since the inflow of heat from the sun is the same and heat is leaving the ocean slower, the ocean heats up. Slow circulation patterns transfer the heat through the entire ocean. It takes hundreds of years to reach equilibrium.
Scientists have measured an increase in temperature through the entire ocean. It is harder to measure in the deep ocean because of the small change so far and the difficulty of accurately measuring the temperature in the deep ocean.
If you do not understand the basics it will be impossible for you to convince anyone here that your argument is correct. There are references to all these facts at SkS. Use the search function.
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Rob Honeycutt at 01:00 AM on 3 May 2017Industrial-era ocean heat uptake has doubled since 1997
ConcernedCitizen... Here's some good entry level college course materials on ocean-atmosphere coupling showing you're incorrect.
http://eesc.columbia.edu/courses/ees/climate/lectures/o_atm.html
And to claim that TCS and ECS are the same is, well, it's pretty much the height of hubris.
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HK at 00:44 AM on 3 May 2017SkS Analogy 2 - Ferrari Without Gas
gnmw #14, in your last paragraph you say:
"…and most heat loss from the surface is by sensible heat and latent heat transport."According to NASAs energy budget chart, 79% of the heat loss from the surface is actually by radiation, but most of that is absorbed by the atmosphere. Convection/advection and latent heat is then responsible for most of the heat transport within the atmosphere. Maybe you were referring to net heat loss defined as surface radiation minus back radiation? In that case, sensible heat and latent heat account for about 1.8 more surface heat loss than radiation does.
Regarding the blanket analogy, I would say the outside of the blanket corresponds to the average altitude of heat loss to space (about 5 km), while your skin is the Earths surface. The average temperature (-18°C) at that altitude is sufficient for the heat loss there to balance the 240 w/m² of incoming radiation from the sun. The lapse rate then sets the temperature difference between that altitude and the surface.
If the amount of greenhouse gases increased enough to raise the heat loss altitude from 5 to 6 km, the surface temperature would increase by about 6.5°C if the lapse rate and the Earth’s albedo remained unchanged. In reality, both would decrease somewhat and produce a negative and positive feedback to the initial warming, respectively.
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ConcernedCitizen at 23:39 PM on 2 May 2017Industrial-era ocean heat uptake has doubled since 1997
Regardless of heat ocean heat retention triggered by IR, the heat retained comes from SW. IR can only decrease the skin gradient and cause the ocean to retain SW energy. IR energy does not penetrate, and can not conduct along a positive gradient to depths.
Thus the oceans can not absorb IR energy and can not delay the effect IR has on the atmosphere, thus the supposed ‘ocean heat uptake’ as an excuse for poor CO2 response is not valid. TCR and ECS are one and the same and they are low.
Moderator Response:[JH] Please do not post the same comment on multiple threads. Your duplicate posts have been deleted.
[PS] And please take the time to review (again) the comments policy on this site. In particular the need to provide reference/data for assertions. Just because you havent understood something does not make it wrong. Furthermore, in bringing up (again) your misunderstandings again ocean heating, it would seem you have not bothered to look at material offered for your guidance here. People here can help if you wish to understand. Wilful ignorance is apparently incurable.
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joe - at 22:31 PM on 2 May 2017NY Times hired a hippie puncher to give climate obstructionists cover
Charles
joe: current rate of warming is 1.7 C/century, but that rate is accelerating because the rate of release of CO2 is accelerating (and will continue to do so in the RCP8.5 scenario.
Charles - 1.7C ? Nasa Shows the current warming rate 1.7f which is .9444c per century. Accelerating ? Yes if you include the el nino 2016 spike. The ncep cfsr global cfv2, HadSSt3 , UAH satellite for global lower atmosphere, the met office, all show 2017 temp trends reverting to pre el nino levels. So where is the acceleration?
Back to my original question - That projected rate of warming is 4x-5x the current rate of warming [in rcp8.5]. Is that even reasonable?
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gnmw at 20:23 PM on 2 May 2017SkS Analogy 2 - Ferrari Without Gas
vatmark @3
All Evan's analogy is saying is that it takes a combination of two things to get a result.
It takes both water and dirt to make mud. It takes both bread and a filling to make a sandwich. It takes water and light (along with other things) for a houseplant to grow. It takes both gasoline and an engine (along with other things, e.g. wheels) for car motion to happen. It takes longwave energy leaving the surface of a planet, along with gases in the atmosphere that absorb and re-emit much of that energy, for the greenhouse effect to happen.
Some of the things you point out (greenhouse gases in a car' exhaust, car's engine radiating heat, gasoline being the source of that heat) are certainly true, but aren't relevant to his analogy.
As to the actual greenhouse effect, you say one thing I think isn't true: "decreasing emission from the atmosphere". At equilibrium, the total radiation energy leaving the Earth and its atmosphere is equal to the total radiation energy entering.
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Charles S at 18:54 PM on 2 May 2017NY Times hired a hippie puncher to give climate obstructionists cover
ño
Michael Sweet: you can contact the New York Times public editor at: public@nytimes.com
joe: current rate of warming is 1.7 C/century, but that rate is accelerating because the rate of release of CO2 is accelerating (and will continue to do so in the RCP8.5 scenario.
Glenn: That really is impressive that macquigg's ridiculously inaccurate penultimate paragraph then led accidentally into their reasonably accurate last paragraph. The ball is going to go down the river, however the turbulence may bounce it up and down along the way. -
Glenn Tamblyn at 17:54 PM on 2 May 2017NY Times hired a hippie puncher to give climate obstructionists cover
macquigg
In addition to the moderation comment from JH, consider your last paragraph because it is instructive:
"The problem of predicting climate change based on known global warming and imperfect modeling of the earth's surface, atmosphere, and oceans is much like trying to calculate the course of one floating ball as it runs through the turbulence down the river."
Climate prediction. The floating ball will go down the river and end up miles away.Weather prediction. We aren't sure where the ball will go in the next 30 seconds due to turbulence.
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Glenn Tamblyn at 17:42 PM on 2 May 2017Water vapor is the most powerful greenhouse gas
LinkeLau.
Broadly yes. In a cooler world, due to less CO2, water vapor levels will drop, adding to the cooling. Where it stops depends broadly on two things. If nothing else has changed then on returning CO2 levels to where they were in the past, pre-industrial levels for example, we would expect climate to return to that pre-industrial state.
If... the reflectivity of the Earth hasn't changed. The Earth only absorbs around 70% of the sunlight that strikes it, the rest is reflected. Sunlight is relected by clouds, snow & ice mainly and to a much lesser extent by the land and ocean surface.
If the reversal of CO2 levels happens quickly enough, before the coverage of ice particularly can change, then we would go back to a past climate. However if the reversal is slow and the ice cover has contracted, then the earth would still be somewhat warmer because it is absorbing more sunlight and a full return would require enough time for the ice to expand again. -
LinkeLau at 15:49 PM on 2 May 2017Water vapor is the most powerful greenhouse gas
If water vapor is just an "amplifier" and co2 (within the current climate system) is the most important driver of current global warming does this also implicate that temperatures will go down in the future if we succeed in lowering atmospheric co2-levels? And will water vapor then also act as an 'amplifier' in lowering the temperature and if so, were will the cooling in that case stop?
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Doug_C at 14:23 PM on 2 May 2017NY Times hired a hippie puncher to give climate obstructionists cover
This fellow is so disigenuous, there's only one reason for climate change denial and that's to protect the interests of the people who gain the greatest benefit from the continued burning of billions of tons a year of fossil fuels.
And the "uncertainty" we're facing with climate change is how fast we bring on a catastrophe that if allowed to go far enough has the potential to wipe out most life on Earth as was detailed in the study that found we are entering the same scale of global climate forcing as events like the Permian extinction.
People like this are effectively advocting for a game of global Russian Roulette with a gun with all six chambers loaded. Nothing they say or do will change the horror of massive releases of methane ices in coming decades which as an too real possibility. And that's just one aspect of the unfolding disaster, how to even quantify the loss of the Great Barrier Reef system alone?
The only reason that commentators like this have a platform at all is the huge amount of resources that have been dedicated for decades to create the illusion of real doubt on the presense and almost certain catastrophic consequences of human forced climate change.
We live in a world where the Canadian city most closely connected with the tar sands bitumen projects mostly burned up due to an April heat wave in a region that can see -20 C at the time of year. I've lived near there, if people don't get that North Central Alberta baking in the early spring is a sign of looming disaster then I'm not sure what will make them wake up.
Having someone posing as an authority on this subject when he is in fact the end point of a very long and expensive campaign to defraud the genuine science is itself fraud. We should be able to take legal action against people who wilfully place us all in jeopardy this way. If not to protect people then what is the point of the law?
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gnmw at 12:14 PM on 2 May 2017SkS Analogy 2 - Ferrari Without Gas
vatmark@12
An analogy is just a comparison in which some aspects of situation A correspond in some ways to some aspects of situation B.
You're constructing a different analogy between a Ferrari and the greenhouse effect than the one Evan had in mind, i.e. using a different set of correspondences.
I kind of like his analogy, but I think it's actually pretty crude, i.e. it doesn't hold up well under close examination:
concentration of greenhouse gases size of car engine
infrared radiation emitted by Earth's surface gasoline
warming due to greenhouse effect What? Speed of car? Distance a car can travel?
The speed of a car doesn't depend on the amount of gas; as long as you've got one gallon (one quart? one cup?) the Ferrari can go top speed, albeit briefly.
The distance a car can go depends on how much fuel is in the tank, but it's approximately *inversely* related to the size of the engine. (Someone correct me if I'm wrong?)
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gnmw at 11:39 AM on 2 May 2017SkS Analogy 2 - Ferrari Without Gas
vatmark@13
The blanket is the greenhouse gases in the atmosphere & the body is the earth's surface*.
Suppose my skin temperature is 80 F, the air and walls of my bedroom are at 60 F, the lower surface of the blanket is at 75 F and the upper surface of the blanket is at 65 F. The blanket *has* absorbed some heat— if it weren't for my body, the blanket would be at 60 F.
Likewise the atmosphere and clouds absorb some heat. See https://en.wikipedia.org/wiki/Earth%27s_energy_budget#cite_note-energy_budget-7
and especially the NASA chart they give at https://en.wikipedia.org/wiki/Earth%27s_energy_budget#/media/File:The-NASA-Earth%27s-Energy-Budget-Poster-Radiant-Energy-System-satellite-infrared-radiation-fluxes.jpg
*(I'm no expert. Maybe, more technically, the body is 'a "surface" in the mid-troposphere'. See https://en.wikipedia.org/wiki/Greenhouse_effect
"The atmosphere near the surface is largely opaque to thermal radiation (with important exceptions for "window" bands), and most heat loss from the surface is by sensible heat and latent heat transport. Radiative energy losses become increasingly important higher in the atmosphere, largely because of the decreasing concentration of water vapor, an important greenhouse gas. It is more realistic to think of the greenhouse effect as applying to a "surface" in the mid-troposphere, which is effectively coupled to the surface by a lapse rate."
Moderator Response:[PS] Fixed links. Please learn how to do this yourself with link button in the comment editor.
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John Hartz at 11:05 AM on 2 May 2017SkS Team - Marching for Science around the globe
Baerbel: Wowser! You rock!
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Tom Curtis at 07:10 AM on 2 May 2017Humidity is falling
vatmark @40:
"When SST increase evaporation, the SST will decrease from evaporation. If the cause of increase in SST is increasing temperature of air, evaporation is driven by increasing kinetic energy of water molecules where the energy is coming from air molecules. Which means that the kinetic and thermal energy in air molecules will drop as a result of water having a much larger heat capacity than air. Water increase less in temperature than air from the same amount of energy absorbed."
Your scenario assumes a situation in which the air immediately above the water, along with the water, form an isolated system. Where the air is continuously warmed, your assumptions do not apply, and both air and sea will continue to warm with a continuously increasing evaporation. In other words, your assumptions are falsified in the case of warming due to a change in radiative forcing.
Even in the isolated system, the net cooling of air and water will be very small. For the ocean, it will be so small as to not be measurable except at the skin layer. That is simply because the heat capacity of the ocean is enormous, hence the evaporative cooling of the ocean will be miniscule. And (in the closed system), the air cannot cool to a lower temperature than that of the ocean.
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Tom Curtis at 06:51 AM on 2 May 2017Humidity is falling
vatmark @41:
The actual IPCC definition of "radiative forcing" was:
"Radiative forcing Radiative forcing is the change in the net, down-ward minus upward, radiative flux (expressed in W m–2) at the tropopause or top of atmosphere due to a change in an external driver of climate change, such as, for example, a change in the concentration of carbon diox-ide or the output of the Sun. Sometimes internal drivers are still treated as forcings even though they result from the alteration in climate, for example aerosol or greenhouse gas changes in paleoclimates. The traditional radia-tive forcing is computed with all tropospheric properties held fixed at their unperturbed values, and after allowing for stratospheric temperatures, if perturbed, to readjust to radiative-dynamical equilibrium. Radiative forcing is called instantaneous if no change in stratospheric temperature is accounted for. The radiative forcing once rapid adjustments are accounted for is termed the effective radiative forcing. For the purposes of this report, radiative forcing is further defined as the change relative to the year 1750 and, unless otherwise noted, refers to a global and annual average value. Radiative forcing is not to be confused with cloud radiative forcing, which describes an unrelated measure of the impact of clouds on the radiative flux at the top of the atmosphere."
(Emphasis added)
It is very clear that the definition given is the same as mine, which is no surprise given that I based mine on the IPCCs. The phrase you take out of context clearly applies to the report only, and is not part of the specific definition. Rather, it is a convention adopted for convenience in the report. Given that convention, if you use a different base date you should state as much, or make it very clear in context. Alternatively, you can discuss the radiative forcing for a given change in atmospheric concentration of CO2, etc. Again, if you do so, you should state as much, or make it clear from context. But a convention adopted for a report does not thereby become an essential part of the definition.
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Daniel Bailey at 02:13 AM on 2 May 2017Global warming theory isn't falsifiable
In addition to the mod's response to you, the unlamented PanicBusiness was one of many fake-accounts run by the same individual in an attempt to spam this venue. Those who have genuine interest in expanding their understanding of the science in question would have no need to resort to such subterfuge.
But then, you already knew that.
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macquigg at 01:01 AM on 2 May 2017NY Times hired a hippie puncher to give climate obstructionists cover
We need a better way to explain to the public the dangers of a small increase in global temperature. Here is an analogy everyone can understand:
Climate Change Analogy: Why is global warming so bad? Can't we just migrate to cooler areas over the next few decades? If some areas get too warm for comfort, won't there be some cold areas that get a little more comfortable?
The problem with this argument is, of course, that a small change in average temperature can have large, sudden, and seemingly random effects on local climates. Yes, it all averages to just a few degrees warming, but that is little consolation to the millions of people living in California, Arizona, and much of the Southwest, if the result is a near-permanent drought, or the millions who may face flood levels not seen in hundreds of years. Even if we could move big cities over a period of twenty years, climate changes could reverse just as we are completing the planned move.
Here is an analogy to help understand the problem of climate change. Model the Earth's climate as a one-mile section of river with lots of rocks and white-water rapids. At the top of this river run we are going to dump 100 ping-pong balls, each with number, and each number relating to one problem, like "temperature rises 10 degrees C", or "rainfall drops to 1000-year low". At the bottom of this river section, we will pick a point and let it represent an area of the planet we are worried about, maybe Southern California. We will place a fishing net there and capture the first ball into the net. If you repeat this experiment hundreds of times, the problems will average out to just a small amount of warming, but in the real world, the experiment will run only once.
The problem of predicting climate change based on known global warming and imperfect modeling of the earth's surface, atmosphere, and oceans is much like trying to calculate the course of one floating ball as it runs through the turbulence down the river.
Moderator Response:[JH] Please provide documentation to support the sweeping assertion you included in your concluding paragraph.
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joe - at 23:03 PM on 1 May 2017NY Times hired a hippie puncher to give climate obstructionists cover
In the red ‘burn lots of fossil fuels’ (RCP8.5) scenario, we’ll see a further 3.0–5.5°C warming between now and 2100.
That projected rate of warming is 4x-5x the current rate of warming. Is that even reasonable.
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scaddenp at 13:07 PM on 1 May 2017Increasing CO2 has little to no effect
""Isn´t that an example of doing radiation physics backways?"
I suspect you may be getting confused by the technical definitions here.
The simple definition is:
"The rate of energy change per unit area of the globe as measured at the top of the atmosphere"
It is used as way to put the various sources of radiative change (GHG, aerosols, albedo, change in solar insolation) onto an equal footing (more or less). Dont confuse the way in how the change in a particular forcing is actually measured with how it is recalculated to express it as a change in TOA radiative forcing.
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Tom Curtis at 12:26 PM on 1 May 2017Increasing CO2 has little to no effect
vatmark @311:
1)
"This seems very odd to me. You use a formula for radiation, not based on fundamental physics?"
The radiation models used to calculate radiative forcing are based on fundamental physics (ie, basic physical laws). The actual radiative forcing, however, depends on things like extent and type of cloud cover, type of ground cover, surface temperature, etc. These conditions cannot be directly calculated from fuandamental physics, but must be observed. It follows that the radiative forcing also cannot be directly calculated from fundamental physics.
2)
"And the changes in Outgoing Long Wave Radiation is corrected for radiation in the stratosphere, after you adjust the stratosphere in what way?"
Given a change in atmospheric concentration of a greenhouse gas, or of incoming insolation, the stratosphere will establish effective thermal equilibrium very quickly. As a result it is convenient to define radiative forcing with the stratospheric adjustment. You can do it differently. The Instantaneious Radiative Forcing is calculated without a stratospheric adjustment, for example. However, the values cited in the IPCC are for the adjusted Radiative Forcing.
The stratospheric adjustment would be made by adjusting the stratospheric temperature by successive approximation until energy into the stratosphere equals energy out of the stratosphere, and the various levels of the stratosphere are in local thermodynamic equilibrium. As noted above, I have seen an explicit technique for doing this, but do not currently remember it.
3)
"Isn´t that an example of doing radiation physics backways? To me it seems like you use the effect as a cause if you start at the last point where radiation leaves the climate system."
You appear to be confused. A change in radiative forcing can as easilly be due to a change in insolation (your forwards effect) as from a change in green hous gas concentration. The radiative forcing is used because the tropopause is an easilly defined and measured energy boundary. As such, it must satisfy the definition of conservation of energy - ie, that if more energy goes in than out, energy must be stored in some form within the boundary. Given that the energy levels involved are not sufficient for large scale energy to matter conversion, the energy will be stored as heat, and consequently will result in an increase in temperature. It is that fact that makes it possible to calculate the effects of changes in GHG concentration by using the concept of "radiative forcing".
I will note that GCMs and radiative transfer models do not use "radiative forcing" to calculate the consequences of changed GHG concentrations, or solar irradiance. They follow all the energy transfers in a step by step process as described in the preceding post. It is only when we do not have access to GCMs (or in specific contexts radiative transfer models), or we want to calculate approximate results without waiting for the several days or weeks of a GCM run that we make use of radiative forcing.
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Tom Curtis at 09:13 AM on 1 May 2017Increasing CO2 has little to no effect
vatmark @312, sorry for my delayed response. I am suffering from poor health at the moment, and am finding it difficult to respond to involved posts in a timely manner. Unfortunately this may mean a further delay in responding to two other posts directed to me by you on another thread, for which I also apologize.
1)
"This does not convince me that climate models are doing it right by using backwards calculations where emitted radiation is causing the temperature of layers below."
I should hope not, as that is not what General Circulation Models (GCM) do. Rather, they divide the ocean and atmosphere into a number of cells, and for each time step solve for all energy entering, absorbed and emitted from that cell, including energy transfers by radiation, latent heat, diffusion and convection. In doing so, they maintain conservation of energy and momentum (or at least as close an approximation as they can maintain given the cellular rather than continuous structure of the world). When they do this, properties of the simplified models of the greenhouse effect used primarilly for didactic purposes are found to emerge naturally, thereby showing those simplified models to capture essential features of the phenomenon.
2)
"He says that observed heat from the earth is not in balance, the heat flux from the sun that heats earth is larger than the amount of heat that earth emit to space. I find that logical, the earth is not equally warm throughout, and then it has to emit less energy. Only when the system is equally warm in every point inside, it emits as much heat to space as it receives."
You have taken a reqirement for a body, heated externally, and equally from all directions and assumed it is a universal condition. It is not.
To take a simple example, if a spherical body having the same thermal conductivity throughout, bathed in a fluid of uniform temperature, but having a significant heat source at the center. According to you it must have the same temperature throughout before energy in can equal energy out. But, based on Fourier's law of conduction, if there is no temperature gradient, there is no movement of energy by conduction. If follows that based on your theory, the heat from the heat source at the center can never leave, which must result in an infinite energy build up at the center.
Your assumed requirement does not even describe such very simple models. It has been falsified, in fact, since Fourier's experiments that led to his seminal work. It certainly does not apply to the complicated situation of an atmosphere, or a large, massive rotating sphereoid heated intensely from one side, and situated in a heat bath of near zero degrees absolute, ie, to the Earth.
Your claim is also refuted by the Earth itself, which has existed for long enough, with a very stable energy source, that it is in near thermodynamic equilibrium. If your supposed condition held, then there would be no significant difference in temperature with altitude. Despite that, ice has existed at altitude in the tropics for hundreds of thousands of years.
3)
"Hansen wrote about satellite measurements showing an imbalance of 6.5W/m^2 averaged over 5 years. Then he says it was thought to be implausible and they made instrumentation calibrations to align the devices with what the models say, 0.85W/m^2."
Satellite measurements currently suffer a disadvantage, in that while they are very accurate in showing relative changes in Total Solar Irradiance (TSI) and Outgoing Long Wave Radiation (OLR), they are fairly inaccurate in showing absolute values. This was known from design specifications, and also by comparison of the data from instruments of the same, or different design over the same period, as here:
That means, while we can know the annual change in the energy imbalance quite accurately, we cannot know it's absolute value from satellites alone. Two different methods are used to compensate for this. In the past, the values from climate models were used of necessity. Since the advent of Argos, the rise in OHC is sufficienty well known that it can be used to calibrate the absolute energy imbalance. Hanson discusses both methods (which approximately agree, and certainly agree far better than does either with the value from the satellites). Further, the specific use of computers you mention was not Hanson's, but that of Loeb (2006).
4)
"How can forcings be known accurately if they are not a result of measurements? Not any of the studies show how any numbers of forcing has been achieved."
Hanson does not say the forcings are known accurately. Rather, he shows the Probability Density Functions of the forcings:
As can be seen, the 95% confidence limits of the greenhouse gas forcing amount to a range of about 1 W/m^2, or approximately a third of the best estimate forcing. In constrast, the aerosol forcing has a 95% confidence limit range of about 3 W/m^2, or just over twice the best estimate.
5)
"And I can´t find any descriptions of the heat flow the way I think it should be done, or rather, the way I like it."
Given the level of understanding of thermodynamics shown by you in your claims about equal temperature, it is neither a surprise nor a problem that you cannot find descriptions of heat flow the way you like. GCMs do use, however, the standard laws of thermodynamics, and of heat flow in its various forms.
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John Hartz at 08:20 AM on 1 May 2017NY Times hired a hippie puncher to give climate obstructionists cover
Another critique of Bret Stevens' Op-ed by a fellow journalist...
NYT: Climate change impact is happening now. NYT: Eh, maybe not that big a deal., Opinion by Erik Wemple, Washington Post, Apr 28, 2017
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nigelj at 06:19 AM on 1 May 2017NY Times hired a hippie puncher to give climate obstructionists cover
NY Times, you are brainless. You have just alienated many of your establised readers and will loose plenty, and your obvious scheme to attract Donald Trump's supporters just wont work. You deserve a medal in stupidity.
I think Bret Stevens has strikingly similar views to Dr Vincent Gray. These people are in complete denial not just about climate change, but a whole range of historical environmental issues and other progressive style issues. They also appear to have very strong libertarian leanings, and come across as having an almost visceral hatred of environmentalism, almost a paranoia. That's not to say scepticsm is always bad, but their version is unusual and might be some form of personality disorder.
You cannot have them in the media and then claim you are balanced, responsible media.
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william5331 at 05:41 AM on 1 May 2017NY Times hired a hippie puncher to give climate obstructionists cover
If you want an overview of the New York Times, get Stone's book, The untold History of the United States. Look in the back under New York Times and then go to the text and read the articles referred to. Quite an eye opener.
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Rob Honeycutt at 02:17 AM on 1 May 2017Increasing CO2 has little to no effect
vatmark... It's rather interesting that you don't grasp this very simple concept but seem to believe that reflects poorly on the science and Hansen rather than you. It's not uncommon, though. We see a fair number of people who come here in a similar state and post extensive comments on how the entire global scientific community doesn't understands this stuff. People here patiently attempt to explain the science to the best of their abilities, and usually the person questioning the science either storms off, never to be heard from again, or gets so absurdly beligerent that we have to block them from posting.
At some point, in their early education, surely all these folks had to take some science classes. Or, perhaps, many of these people have children who have to take science. If they go through a section and tell the teacher they're wrong, and mark the wrong answers on the tests... They fail the class. Everyone, I believe, generally would find this to be unacceptable. The child needs to learn the materials and understand the current science. And even the child, I would assume, would also understand when they didn't study hard enough or put in enough effort to pass the class.
But somewhere these people grow into adults who, it seems fairly deliberately, choose to not accept the scientific materials, like vatmark here. He's seemingly concluding that the experts in this scientific matter are stating things wrong, even though he doesn't comprehend fundamentally simple science.
So, at some point in their lives, there has to be a transition. A point or a period of time over which they move from understanding they don't understand the science to rejection of the science in order to avoid understanding or cover for the incapacity to understand it.
I just find this whole process perpetually fascinating.
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Celestial Teapot at 02:05 AM on 1 May 2017Global warming theory isn't falsifiable
I have read the comments of this section and I would have to agree with SyntheticOrganic. Moderators should uphold policies to whom it may apply, whether or not they have doubt on AGW being scientific or not. TomDayton has committed an ad hominem attack on PanicBusiness and I have yet to see the moderators so something about it. Be it as it may that it has been years since those comments are made, it is disappointing to see that you don't see this as something that needs action.
I am here on the count that I am currently writing a paper specifically on falsifiability and would like to read about discussions in the comments to have a broader take on the picture. And yet it seems that you actively stifle those, although given that Panic Business may have been mistaken in saying that falsification is the ultimate definition of science, who are of a different position than what you and the majority's position. For a site called skepticalscience.com you don't seem to have a very friendly attitude towards those would be skeptics, even if they may possibly be mistaken.
I expect this comment to be either deleted after it has been read or given that green box with the comment in saying that my comment is of topic. This is again I think is also problematic. How else are we, the commenters, suppose to give our opinions on how you handle comments if you classify those such comments as off topic?
Again do what you will with this comment, I only hope that I have at least made a point.
Moderator Response:[PS] Moderation complaints are always offtopic. If you dont like our policy, please go somewhere else. What the moderators here do have is a very low tolerance of sloganeering of the type PanicBusiness was indulging in. Discussions around science and evidence are always welcome as are questions from people interested in learning more or improving understanding. It is does not pretend to be a site for general discussion - other places do that better - and certainly does not intend to provide an echo chamber for unsubstantiated sloganeering from pseudo-skeptics who have not the slightest interest in learning anything. This is a site for true skeptics (like scientists), not pseudo-skeptics who are "skeptical" about anything that challenges their a priori beliefs and unskeptical about utter nonsense that think supports it.
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John Hartz at 23:00 PM on 30 April 2017NY Times hired a hippie puncher to give climate obstructionists cover
Recommended supplemtal reading:
Some thoughts on Bret Stephens’ misleading climate take by Brian L Kahn, Medium, Apr 29, 2017
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michael sweet at 20:28 PM on 30 April 2017NY Times hired a hippie puncher to give climate obstructionists cover
Is there a way to write to the NYT if you are not a subscriber?
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william5331 at 15:38 PM on 30 April 2017We're heading into an ice age
Interglacials begin to end, generally, as soon as they reach their peaks. The slide into a glacial is much more gradual that the exit from a glacial As the snow can only accumulate as fast as precipitation exceeds melting of the snow deposited. Of interest is that the amount of warming we have observed is not the amount we have caused. To estimate how much we have caused we have to look at what the temperature would likely be at present without the influence of man. Apparently the interglacial with the Milankovitch cycle most similar to the present one is the interglacial which occured some 400,000 years ago. On this basis we are up to and probably over 2 degrees C. Using this point of view, the sensitivity for doubling Carbon dioxide increases a little since the anthropogenic heating per increas of Carbon dioxide is a little more than if we use the actual increase.
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David Lewis at 12:41 PM on 30 April 2017NY Times hired a hippie puncher to give climate obstructionists cover
After Trump was elected I wanted to support some of the great American insitutions of journalism. I bought a subscription to the NY Times.
I cancelled it when they decided to feature this Stephens clown.
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nigelj at 06:37 AM on 30 April 2017March against madness - denial has pushed scientists out to the streets
OPOF @12, I'm in full agreement about the need for sustainable development goals. I just thought the link was a bit confused, or incomplete on the the forces driving the historical issues and leadership issues they discussed. It was on the right track, but confused.
I think as per my comments above, if you look at history, western society has jumped from one extreme economic or environmental ideology to another over long term time frames, and sometimes "thrown the baby out with the bathwater" in other words we are looking for simplistic answers when none exist. We abandoned capitalism too much, in the 1930's, rather than just modifying some elements, and then went on to abandon the "mixed"economy of the 1960s, not realising some elements of it were very good. "Neoliberalism" has some problems that must be fixed, but we are at risk of throwing out the good elements like free trade.
This is why I admire Scandinavia to some extent, they combine a range of ideas, rather than getting bogged down with labels like capitalism or communism. Theodore Roosevelt seems to have a similar mindset to some extent. I guess this is pragmatism, and even Trump is a pragmatist, but he is making some very poor choices especially regarding the environment (arctic drilling)
Getting back to sustainable development goals, this can embrace a whole range of environmental and economic concerns. Its a no brainer for me, just so obviously needed at a point in human history when its obvious we are having some pretty huge impacts. This is why I despise economic or political ideologies ending with "ism" because we always have to keep open minds and deal effectively with new problems, and fixed ideologies can make that very hard. That's not to say we can work without guiding principles, and government is not the answer to everything either, but it is the answer to certain things and this is where we need better agreement across countries on what this is, and what things should be regulated by governments, and what shouldn't. I'm pretty clear in my mind, and Theodore Roosevelt was.
Regarding marketing and winners. It's interesting because competition has obviously had a positive side, but tends to go wrong if there are no boundaries. It's a case of improving awareness that boundaries are healthy, and not communism or some other "ism".
In fact competition goes most wrong where there is no competition, and you have corporate entities that are monopolies, that effectively become bullies. Again if we have any sense we should put some controls in place, Make no mistake they will keep on producing the goods but their behaviour will be better. History shows this.
It is the big corporations and especially the monopolistic, corporations driving the anti environmental policies. Theres plenty of evidence of this starting with the Koch Brothers. They have huge power.
Where companies are smaller and many are in competition, this is quite effective at forcing them to also behave well enough. Its larger monopolies that can become a real problem.
The less ethical players simply take all this to another level. By legitimising "greed is good" in the 1980s, along with massive financial deregulation, we opened the floodgates to excusing unethical behaviour, that is detrimental to the public good. We saw a perfect example of all this in the 2008 financial crash.
Marketing is a tough issue because it has a good and bad side. It's the price we pay for freedom of speech and a free society. We accept people are entitled to sell their ideas and products, and this is healthy, however the price we pay is all kinds of lies and rorts, and brainwashing. Immediately anyone says we need "controls" over advertising, or some quality standards for free speech, the corporate lobby cry socialism or big government.
Yet while I deplore ideologies like communism, there is nothing wrong with rules of conduct if we want a stable, prosperous society that balances production of goods with honesty of marketing, and a sustainable environment etc. Even our rights to free speech, which I strongly support, come with some unspoken responsibilities, such as a need to avoid verbal abuse and bullying or inciting violence.
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vatmark at 06:19 AM on 30 April 2017Increasing CO2 has little to no effect
It was supposed to say
-It seems like he is saying that if the thermal radiation emitted from the atmosphere decrease, it causes the temperature to increase?
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vatmark at 06:18 AM on 30 April 2017Increasing CO2 has little to no effect
I had a look at the link to general circulation models. After reading that my conclusion is that it seems like we are not much wiser
"For all the millions of hours the modelers had devoted to their computations, in the end they could not say exactly how serious future global warming would be. They could only say that it was almost certain to be bad, and unless strong steps were taken soon, it might well be an appalling catastrophe."
This does not convince me that climate models are doing it right by using backwards calculations where emitted radiation is causing the temperature of layers below.
After reading this I don´t get much wiser either:
https://pubs.giss.nasa.gov/docs/2011/2011_Hansen_ha06510a.pdf
It seems like he is saying that if the thermal radiation emitted from the atmosphere, it causes the temperature to increase?
He says that observed heat from the earth is not in balance, the heat flux from the sun that heats earth is larger than the amount of heat that earth emit to space. I find that logical, the earth is not equally warm throughout, and then it has to emit less energy. Only when the system is equally warm in every point inside, it emits as much heat to space as it receives. If we compare to a steam engine and the troposphere is the waterfilled cylinder, then it has to have an even temperature from the surface all the way up to the tropopause before the heat flux is equal to what the sun deliver to the surface.
I really don´t understand this radiative forcing and radiative imbalance, how does it work? How can less heat emitted from the atmosphere cause more heat elsewhere? The more I read about it, the more confused I get.
Hansen wrote about satellite measurements showing an imbalance of 6.5W/m^2 averaged over 5 years. Then he says it was thought to be implausible and they made instrumentation calibrations to align the devices with what the models say, 0.85W/m^2.
He says that the forcings is known accurately, but when measured it is corrected to follow the models. They don´t correct the models according to measurements?
How can forcings be known accurately if they are not a result of measurements? Not any of the studies show how any numbers of forcing has been achieved. And I can´t find any descriptions of the heat flow the way I think it should be done, or rather, the way I like it. Just using measured temperature to find out how much heat there is in the different parts, and from there you can describe the heat flow. That is how we always have done it, and it works. Steam engine, it works perfectly for earth, why use anything else? My teacher must have been very smart, or dumb enough to keep it simple. I was directed here after talking to people in the march and they couldn´t answer my questions. I thought it was strange, so many people marching for science, but no one knew anything about heat, but they all carried signs about temperature increasing and climate problems. I always thought that the issue was about the atmosphere getting so hot that it came near to surface temperature, from top to bottom, because that is what it takes to heat something up usually. But this is just strange and now I think that it must be a good thing Trump won the election. I thought he said some stupid things, but he seems to act like he knows what he´s doing.
I guess I won´t be coming back here anymore. Good Luck with your campaign, you are going to need it.
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vatmark at 04:11 AM on 30 April 2017Increasing CO2 has little to no effect
Tom Curtis at 11:04 AM on 20 April, 2017
" the formula for radiative forcing was not directly derived from fundamental physics. Rather, the change in Outgoing Long Wave Radiation at the tropopause, as corrected for radiation from the stratosphere after a stratospheric adjustment (which is technically what the formula determines), was calculated across a wide range of representative conditions for the Earth using a variety of radiation models, for different CO2 concentrations."This seems very odd to me. You use a formula for radiation, not based on fundamental physics?
And the changes in Outgoing Long Wave Radiation is corrected for radiation in the stratosphere, after you adjust the stratosphere in what way?
This is then used to calculate surface temperature, or some influence on it?
Isn´t that an example of doing radiation physics backways? To me it seems like you use the effect as a cause if you start at the last point where radiation leaves the climate system.
Do I understand it right that you adjust stratospheric radiation to co2 concentration, then correct Outgoing Long Wave radiation to that, then use that information as a cause, or part of the cause, of surface temperature?
Is the infrared radiation of the stratosphere the cause of infrared radiation in the tropopause, and the infrared radiation of the tropopause is the cause of infrared radiation from the surface? I see you write radiative forcing, but as I understand it, radiative forcing is still a change of infrared radiation.
Can you connect that to solar radiation? I guess this chain reaction stops at the surface since it is not possible for the surface to have an effect on heat from the sun. I thought a model had to be done in the other way around, you start with the heat source and find the amount of absorbed heat in the surface. Then continue to estimate the heat absorbed by the atmospheres different layers and then it leaves the system. That´s how I learned in school, but that is a long time ago, I guess something has changed.
But I think it is counterproductive to not use fundamental physics to explain temperature, or Outgoing Longwave Radiation. When we learned about solar radiation and the temperature of the atmosphere, our teacher used a basic model for heat. He used the surface temperature and the inverse square law. He said that the solar heat is absorbed and emitted according to the inverse square law and the difference in temperature, or heat flux, is the way to describe earth as a steam engine. That is fundamental physics and it gives the right amount of infrared radiation observed by satellites. Just use the difference and divide whats left by four.
When you say that you use a model doing it backways, in my view, and that it doesn´t use fundamental physics that describe heat, why is your way of doing it better?
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One Planet Only Forever at 03:53 AM on 30 April 2017March against madness - denial has pushed scientists out to the streets
nigelj,
To be clear, I consider the presentation in the SDGs of the changes of direction of development to be like the thoughts in the time of Roosevelt, but a far more comprehensive developed understanding.
Any aspect/system "Label" of what humans can achieve the SDGs through would be good, regardless of any legacy of bad impressions created by unethical people Winning by getting away with things in the aspect/system "Label".
Less ethical people who can get away with behaving less acceptably than others would be willing to get a competitive advantage in any game/system.
The potential good results (net-positive game results) of something like globalization achieving the SDGs needs to be presented as the counterpoint to the horrible things that people have been able to get away with. Bad things happen when too many people have a lack of awareness or better understanding, whether it is due to successful secrecy, deliberate misleading marketing, or a willful ignorance due to temptations like greed or xenophobia (racism, tribalism, nationalism). Less ethical players can and do ruin anything and everything as they pursue winning by playing in ways that can be understood to be net-negative sum game play (and they do not care because all they care about is personally perceiving themselves to be "The Winner").
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vatmark at 00:43 AM on 30 April 2017SkS Analogy 2 - Ferrari Without Gas
nigelj
"The blanket / body analogy is excellent, and will bring a wry smile to people, but I do think most people probably accept the greenhouse effect."
How do you explain the greenhouse effect with the blanket/body analogy then? Is the blanket the crust and the body is the hot interior? A blanket reduce the amount of heat absorbed by the surroundings from the hotter body, by being a poor conductor and a poor absorber. If you put something on your body increasing the amount of body heat that is absorbed, what you do is changing the surroundings of your body to suck more heat out of your body.
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vatmark at 22:51 PM on 29 April 2017SkS Analogy 2 - Ferrari Without Gas
"The concentration of greenhouse gases is like the size of a car engine: higher greenhouse gas concentration is like a bigger engine."
But greenhouse gases is the waste from the engine of a car. Or rather, the combustion product left after thermal energy is released. Making it low in internal energy and a potent absorber. First it is included in high energy hydrocarbon molecules, prone to release it´s internal energy. When energy is released it is in the opposite state, prone to absorb energy.
"Infrared radiation is like the gasoline in the tank of a car."No, it is like the heat leaving the radiating body, cooling it. Exactly that. Infrared radiation is energy leaving the engine, the sun is like the gasoline in the tank of the car.
"Just as gasoline is the fuel that drives an engine, infrared radiation is the fuel that drives the greenhouse effect."
No, heat from the sun is the fuel that drives the engine. What you refer to as infrared radiation I suppose is the thermal emission from the surface or atmosphere. That is exactly equal to the infrared radiation leaving the cooler of the engine when water circulate in contact with a high flow of air molecules across the surface. Like wind across the earth surface.
"Global warming occurs because infrared radiation emitted from the surface of the Earth is captured by greenhouse gases in the atmosphere, increasing the temperature of the atmosphere."
But I thought greenhouse gases increased absorption, isn´t that confirmed by decreasing emission from the atmosphere? How can the atmosphere increase absorption and temperature at the same time as it decrease it´s emission?
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vatmark at 22:30 PM on 29 April 2017Humidity is falling
"Technically that means if you are calculating the radiative forcing between 280 ppmv and 400 ppmv the model would need to be set for the relative humidity at an equilibrium temperature for 280 ppmv, and retain a constant water vapour pressure when calculating the the radiative forcing outgoing IR radiation at 400 ppmv. That in turn would require knowing the offset in temperature from 1976 to the temperature equilibrium."
I don´t get it. The definition given for radiative forcing is:
"For the purposes of this report, radiative forcing is further defined as the change relative to the year 1750 and, unless otherwise noted, refers to a global and annual average value."
How is the change relative to 1750 connected to the temperature offset from 1976 to what equillibrium? What is the difference in forcing between 400ppm and what value from 1750? 280ppm? Determined how?
"I should note that there exists a technique for adjusting for stratospheric equilibrium in calculating the strict radiative forcing, which I have seen explained by David Archer."
This then has to be connected to the equillibrium of the stratosphere in 1750, am I right? We have no information about that. How is this possible as a theoretic framework for making claims about evaporation and RH in the past, today or in the future? I see no possible way to use this to claim predictive ability in climate models.
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vatmark at 22:12 PM on 29 April 2017Humidity is falling
Tom Curtis
"That is intuitive. To a first approximation, all water in the atmosphere over land comes from the ocean. Therefore the specific humidity over land will increase in line with SST, not land temperatures."
When SST increase evaporation, the SST will decrease from evaporation. If the cause of increase in SST is increasing temperature of air, evaporation is driven by increasing kinetic energy of water molecules where the energy is coming from air molecules. Which means that the kinetic and thermal energy in air molecules will drop as a result of water having a much larger heat capacity than air. Water increase less in temperature than air from the same amount of energy absorbed.
Direct evaporative cooling in open circuit is lowering the temperature and increase the humidity of air by using latent heat of evaporation, changing liquid water to water vapor. In this process, the energy in the air does not change. Warm dry air is changed to cool moist air.
This is the principle of evaporation from warmer air. It is hard to combine that with how you describe it. If water vapor increases, it would have to be connected to decreasing air temperatures in those areas where evaporation increase. And the water surface that is warming at first when evaporation increase, would also be cooling at the same time. I can only see how water vapor cools water surface temperatures and at the same time cool the air.
"While global temperatures are increasing under global warming, the models predict a slight increase in relative humidity over the ocean, with a massive reduction over land."
So when temperatures increase globally, evaporation will lower temperature of the air over the ocean. And over land, plants and water surfaces will evaporate less? And the water vapor over oceans will stay there? And not follow the usual cycle where it precipitate over land areas?
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nigelj at 15:48 PM on 29 April 2017March against madness - denial has pushed scientists out to the streets
Red Baron @10
Yes, I mean exactly as Teddy Roosevelt was saying. I agree its silly to call that socialist, and such labels are just unhelpful anway. Of course there's more to it, but you have mentioned some important things.
In fact I knew very little about TR. I live in NZ, so your comments were an eye opener for me.
I think Jospeh Stiglitz has similar views. He is not anti corporations, but just a realist that power can become excessive, and some boundaries are perfectly healthy.
I don't know how you make it stick. That's a hard question. I would say the two main political parties in my country are slowly moving towards those values by public pressure, but dragged kicking, and screaming, and not fully there yet by a long way. But there does seem to be a consensus now on at least some elements, that has stuck pretty well. Its a case of improving and broadening that consensus. It's complex.
A lot of it has to be about improving public understanding somehow. I don't have any time right now to think much about it, but will sleep on it.
A lot of the problem is lobby groups and campaign financing dependent on corporate groups, and I dont know how you change that one.
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RedBaron at 12:05 PM on 29 April 2017March against madness - denial has pushed scientists out to the streets
@9 nigelj,
AHA. You mean like this? Teddy Roosevelt
Free markets for Main Street USA, Small family run business, and even mid level business, but strict regulation against mega-corporation, trusts, and Plutocrats. As well as strong environmental and public safety regulation. Instead of a wall, we build a canal which is profitable and benefits all the Nations in the hemisphere.
That's a whole different kind of populism, and not even slightly socialist/communist either.
Yes I would say we know what to do, and even how to do it, seeing as how it was done once already.
The question is how do we make it stick? Doesn't take long for gains like that to reverse themselves.
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nigelj at 11:36 AM on 29 April 2017March against madness - denial has pushed scientists out to the streets
OPOF @8, I found the article in your link interesting and worthwhile, and it's conclusion about a possible descent into nihilism rings true, but the material in the middle is a bit confused.
I think this issue is more about cycles. America, and various other countries went through a period of "laissez faire" (extreme capitalism) in the 1800s and up until the 1930s when it all collapsed due to inherent problems with the economic model. Thats definitely not to say capitalism is bad, simply that some issues became exposed.
Then America and most western countries went through a "mixed economy" phase combining capitalism and some socialist ideas from the 1930s up until the 1980s. This period had some merit, but in turn collapsed, or stagnated for certain reasons. It was also the end of a long wave economic and investment cycle, (a type of Kondratief wave) cycle, but thats another matter that would complicate the discussion.
Then in the 1980's we had the counter reaction, and entered the era of neoliberalism and "greed is good" which was an attempt to revert to laissez faire capitalism. This ideology promotes extreme individualism, free markets, open immigration, globalisation, privatisation, deregulation, etc. This ideology has some merit in parts, but become too extreme and is the source of numerous recent problems, and it sacrifices the environment. It has generated poverty issues for some groups of people. But elements of neoliberalism like free trade and globalisation have had positive effects for many people, so its not a simple issue
The counter reaction to some elements of this globalist, neoliberal ideology has been exemplified with Donald Trump, except that he has kept some elements of the ideology such as deregulation, and ther worst forms of deregulation, for example regarding the weakining of environmental standards. But essentially Trump is trying to revert to a nationalist, more isolationist agenda, and almost a version of crony capitalism. I'm not enthused.
We need to get back to a simpler, more commonsense philosophy as Scandinavia has, of a robust capitalism and moderately free markets, but with a human touch, including appropriate restraints and controls where appropriate, (especially over environmental impacts) in other words a refined, improved version of the mixed economy ideas of the 1950s. This will enable humanity to tap the benefits of free markets and private ownership, without killing the environment or causing instability or poverty. (Imho).
Putting it another way, entrepreneurship and private enterprise is good, but "greed is not good", and a completely uncontrolled business sector is destructive to the public good.
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curiousd at 07:13 AM on 29 April 2017Humidity is falling
Thank You Tom Curtis
This shows that its good to consult with someone who has a long view knowledge of a topic before jumping to confusions over short term data.
Glad I asked.
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william5331 at 06:41 AM on 29 April 2017New study: global warming keeps on keeping on
As has been pointed out by some scientists, the amount of warming is not what we observe. It is how much the present temperature is above what we would expect based on previous interglacials in which, as soon as we reached peak warming as we came out of a glacial, we immediately started the slow slide back into a glacial. Apparently the interglacial with a most similar Milankovitch profile to our own is the one which occured some 400,000 years ago. Using this expected cooling curve as the base line, the amount of warming is more than the 1 degree we observe.
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One Planet Only Forever at 06:39 AM on 29 April 2017March against madness - denial has pushed scientists out to the streets
A related comprehensive perspective was just published:
NYtime OpEd "America, From Exceptionalism to Nihilism" by Pankaj Mishra
It mentions the damage done by the irresponsible actions of some among the elite (but the item just refers to the elite as if the whole group deserves to be smeared, proof of how damaging the actions of a few can be, how willing some people are to make any excuse to resist having to accept input or understanding that they dislike).
The OpEd also mention of a loss or disapperance of ethics. This is key. The internationally developed Sustainable Development Goals (SDGs) present a well developed basis for 'justified ethics'. The ethical basis for their development has been the basis for many previous similar presentations of developed better understanding.
In spite of that clear example of what needs to be done, what is ethically required, the SDGs lack broad popular support. The lack of popularity of such a good ethical purpose, to genuinely help to raise awareness and better understanding with the objective of improving the future for all of humanity, is the root of the problem.
Climate scientists have continued to do their part, as have the many diverse NGO and Charity groups striving to help achieve the SDGs, each facing the uphill battle of the damage done by those who care less (are care and consideration free pursuers of what they think would make them happier). The ones among the Elite who are failing humanity are typically the less ethical wealthy undeserving Winners.
Distinguishing the most-worthy, trust-worthy, among the Elite from less ethical Undeserving Winners will be difficult. Many people are unfortunately very easily impressed. The thinking of the Marque de Sade “It is infinitely better to take the side of the wicked who prosper than of the righteous who fail”, will never produce a Good Result.
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Tom Curtis at 22:52 PM on 28 April 2017Humidity is falling
Curiousd @37:
1) Quoting a single year is not very informative. Rather you should quote the trend, as in this figure from the Hadisdh dataset:
The headline result is a -0.08 (-0.18- 0.04) %/decade trend in relative humidity from 1973-2013. The negative trend is steeper in the raw data.
Two things are noteworthy about the trend. First, the trend in RH is near zero in the first part of dataset, and noticably steeper from about 1998. Over the period of the steeper trend, there was a noticable trend away from El Nino conditions towards La Nina conditions. Given that El Nino's are associated with greater global relative humidity, the trend over that period is likely significantly influenced by ENSO. The overall trend, however, is likely to be primarilly the result of global warming.
Second, as the map shows, this is a land only record, and further is restricted by latitude so as to exlcude the poles. You will notice that the graph of relative humidity provided by the NOAA 2013 state of the climate report is for land only. Further, they show a greater increase in specific humidity over ocean than over land, while the SST has increased less than the land surface temperature. That suggests the change in relative humidity over the ocean is less negative than that over land, and may even be positive. So, lacking evidence to the contrary, I would assume the that where NOAA say, "...while relative humidity—how close the air is to being completely saturated with water vapor—was far below average", they are referring to the land only data. That interpretation is supported by the immediately following sentence in the quote.
2) While global temperatures are increasing under global warming, the models predict a slight increase in relative humidity over the ocean, with a massive reduction over land. They also predict significant increases in relative humidity at the poles, particularly in the Arctic:
(Source)
That is intuitive. To a first approximation, all water in the atmosphere over land comes from the ocean. Therefore the specific humidity over land will increase in line with SST, not land temperatures. Because land temperatures are increasing faster, that will result in a reduced relative humidity over land. (Here is a recent paper exploring the mechanisms in greater detail.)
If you hold CO2 concentrations constant at an increase level, the increase in land and sea temperatures will tend to equalize at the Earth approaches the equilbrium increase in GMST. If the mechanism discussed above explains most of the change in RH, that means RH over land will restore towards its original value. That is because the ocean will get warmer relative to land as equilibrium is approached, thereby leading to an even higher specific humidity over land.
I will finish by noting that the map in the first figure above shows a very similar pattern to the changes in relative humidity shown in the second figure, over those areas which actually have data.
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curiousd at 18:42 PM on 28 April 2017Humidity is falling
Here is a quote from NASA on their 2013 "State of the Climate"
"Specific humidity—the amount of water vapor–was well above average over land and ocean in 2013, while relative humidity—how close the air is to being completely saturated with water vapor—was far below average.
Overall, water vapor in the surface atmosphere has increased over land and ocean relative to the 1970s, while the atmosphere over land is becoming less saturated".The URL is https://www.climate.gov/news-features/understanding-climate/2013-state-climate-humidity
Rather than toss out any opinions of my own on this, because I am curious..
What are the opinions of others as to why relative humidity is decreasing, or should I not "jump to that confusion" from the NASA quote above ???
Curiousd
Moderator Response:[JH] Link activated.
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Tom Curtis at 12:07 PM on 28 April 20172017 SkS Weekly Climate Change & Global Warming News Roundup #16
joe @8, it has been a little difficult getting the data on the Mendenhall Glacier tree stumps. The only public record is limited, AFAIK, to an article in the Juneau Empire, and one in Live Science. No scientific paper reporting the results has been published as yet. Cathy Connor (the lead researcher involved) did give a 2014 conference report on the glacier, buit was not on the topic of the tree stumps.
From the Juneau Empire, we learn that:
"The most recent stumps she’s dated emerging from the Mendenhall are between 1,400 and 1,200 years old. The oldest she’s tested are around 2,350 years old. She’s also dated some at around 1,870 to 2,000 years old."
Please note that they are not continuous ages. Had the area uncovered been continuously forested from 2,350 to 1,200 years ago, the older trees would have fallen and rotted due to old age, and only trees from about 1,700 to 1,200 year old would have been found. Rather, what has happened is that the area was uncovered 2,350, 1870-2,000, and 1,200 to 1,400 years ago. It was likely covered inbetween times, although there may have been intervening periods in which the glacier left the area uncovered but in which the trees remained embedded in the gravel which protected them.
The most interesting finds are tree stumps in ice caves, ie, tree stumps still technically covered by the ice, such as the example below from Live Science (chosen to provide scale):
And here is an external view from the Juneau Empire, also to show scale:
And a modern 30 year old Spruce:
Comparison of trunk width shows there is no reason to think the trees were exceptionally old at the time of their destruction. Again, this shows your idea that the area was uncovered for "... a 1,000 to 1,200 year period going back from circa 1,000 AD..." is incorrect.
Finally, here is a photo from the Juneau Empire, whose caption read:
"Vertical tree stumps remain in some of the ice caves beneath the glacier. Two ice cave stumps have been dated at two different date ranges - between 670 and 780 AD, and between 620-670 AD."
That date range is consistent with the "1,400 and 1,200 years old" date range, ie, circa 600-800 AD, mentioned in Live Science. The MWP proper did not start till circa 900 AD, so the regional warm period shown by the Mendenhall Glacier preceded the MWP by (at minimum) 100 years, and appears to have been replaced by regional cooling during the MWP.
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joe - at 08:09 AM on 28 April 20172017 SkS Weekly Climate Change & Global Warming News Roundup #16
But I have the same reaction to the tree stump issue. Basically so what? It's well known that during the mpw some specific locations warmed more than others. The more important point is the mwp was rather weak overall,
But anyway Tom Curtis has cast very genuine doubt about whether you can conclude the region of the Mendenhall glacier was particularly warm.
Referencing back to the tree stumps from the MWP at the mendenhall glacier, both the age of the trees and the size should cast reasonable doubt as to both the short length and breadth of the mwp in the region. Its a 1,000 to 1,200 year period going back from circa 1,000ad without the glacier. Given that time frame, Tom's geniune doubt explanation is closer to a plausible explanation.
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