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Cooper13 at 02:24 AM on 27 November 2015The Road to Two Degrees, Part Two: Are the experts being candid about our chances?
We cannot ignore the opportunities for 'new' nuclear technologies, specifically thorium (molten salt) reactors, which China and India are working to ramp up (I believe Westinghouse may be part of the technology development on this).
There is far more thorium available than 'normal' uranium nuclear fuels, for several hundred years, and minimal nuclear waste as compared with present reactors.
Unfortunately, the word 'nuclear' has nuclear political implications to any candidate or party which backs it - this needs to be changed and change can only occur with an educated public on the opportunities we have for these reactors. Safer, cleaner nuclear could provide most, if not all, of the energy needed that solar and wind cannot deliver, and could produce energy to power our cars, etc.
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ianw01 at 01:42 AM on 27 November 2015The Road to Two Degrees, Part Two: Are the experts being candid about our chances?
Excellent article. I'd love to know what Anderson thinks of articles like the one in this SkS post that claim that the US can get to 100% renewables for all energy (without using nuclear or fossil fuels) by 2050.
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Joel_Huberman at 01:19 AM on 27 November 2015Two-faced Exxon: the misinformation campaign against its own scientists
Shi-Ling Hsu's well-written, brief (and occasionally humorous) book, "The Case for a Carbon Tax: Getting Past Our Hang-Ups to Effective Climate Policy" (published 2011, Island Press) provides good reasons why returning the revenue from a carbon tax as a dividend to citizens is a superior policy.
The international non-partisan volunteer group, Citizens' Climate Lobby, provides much useful information about carbon taxes and their (positive!) effects on emissions, the economy, and public health at its web site.
One wouldn't be aware of this based on their public statements, but Republican legislators, like Democratic legislators, are becoming increasingly aware of the dangers of climate change and increasingly willing to do something about it. The quiet, informed, behind-the-scenes lobbying done by Citizens' Climate Lobby volunteers in the United States has had a strong influence. I encourage everyone who is able to do so to join Citizens' Climate Lobby and participate in their team efforts. In the United States, this would involve writing letters to editors and Congress people, and visiting Congressional offices.
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Tom Curtis at 21:33 PM on 26 November 2015Two-faced Exxon: the misinformation campaign against its own scientists
Ogemaniac @1, this article suggests Exxon began supporting a carbon tax in 2009 rather than 2007. More importantly it shows that Exxon does not, in fact, support a carbon tax. Specifically it states that:
"Exxon’s political action committee gave nearly $1.2 million to political candidates in the past two years, 93 percent of it to Republicans, according to the Center for Responsive Politics."
The Republican's do not support a carbon tax in any form. In fact, they near universally oppose any action on climate change other than the slandering of, and inquisitions with regard to climate scientists. Had Exxon supported a carbon tax, their political spend would have gone to Democrats who would have legislated for that carbon tax. Instead they nominally supported a carbon tax for PR purposes while doing their best, with their political spend, to ensure that no such carbon tax was implimented.
As to the form a carbon tax takes, the more revenue neutral it is, the higher the tax can be without adverse effects of the economy. That means ideally that the revenue from a carbon tax should be returned to citizens in the form of a dividend. It can be returned as a reduction in taxes, but the purpose of a carbon tax is, in th end, to eliminate all carbon pollution. If we use the tax to replace other revenues, the effect is in the long term we reduce government income and have a political fight to reintroduce the current taxes again as the revenue from the carbon tax delines. Carbon taxes could be earmarked for specific expenditures, but that will only add to their cost and reduce their effectiveness unless those expenditures are ones we would be making in any event. In that case, however, you face the same problem of a diminishing revenue stream as the tax becomes more effective. Earmarking will also potentially create pressures to decrease the tax if revenue exceeds the cost of the earmarked projects.
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Ogemaniac at 16:44 PM on 26 November 2015Two-faced Exxon: the misinformation campaign against its own scientists
"Finally, I’ll note that we have long – and publicly – supported a revenue-neutral carbon tax"
As far as I know, their support for this began in 2007, about the same time they slowed down their denier-funding activity. However, saying "We will support a carbon fee if and only if all the money is returned to us in the form of tax cuts" is hardly a huge step forward. It is unclear as to why any of the money raised from these fees should be used for tax cuts, let alone all of it. The most obvious uses for the money is remediation of the damage caused by polluters and adaption in the case where the damage cannot be prevented.
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Tom Curtis at 08:24 AM on 26 November 2015Venus doesn't have a runaway greenhouse effect
MA Rodger @118 even considering Roscoe @7, his primary argument consists of the claim that there is an energy imbalance between incoming solar energy at the surface of Venus and outgoing thermal radiation at the surface of Venus with the later being 122 greater than the former, a gap that "no physical process" could explain in his view. He maintains this view by, first, not understanding the greenhouse effect, and second, not considering all energy flows at the surface.
The later point is best illustrated with the Earth's energy flows which are better known:
The equivalent numbers for the Earth are 161 W/m^2 for solar energy at the surface, and 397 W/m^2 outgoing thermal radiation - a significant energy imbalance that creates exactly the same theoretical problems as the imbalance at Venus. However it is obvious from the full chart once all energy flows are considered, the surface energy balance is close to 0. From the numbers given it is out by 1 W/m^2 downward, an obvious rounding error from the 0.6 W/m^2, ie, the imbalance at the TOA due to the temperature response to current forcing not yet reaching equilibrium values.
Given the full equivalent values for Venus, the surface energy balance would sum to zero with the downward thermal radiation consisting of a very large component. That the energy balance would sum to zero is confirmed by the comparison of the temperature profile of Venus with altitude versus two one dimensional radiative convective models (Tomasko et al 1977):
The solid lines are what is expected from the operation of the greenhouse effect together with convection given two slightly different assumptions about the composition of Venus' atmosphere, and closely match the observed profile. One dimensional models such as those shown work by maintain energy balance throughout the vertical profile. It should be noted that the slight difference in the observed lapse rate will be due to a slight difference in from the expected heat capacity of the atmosphere, ie, an error in understanding the variation in the precise chemical composition of the atmosphere with altitude, not with the radiative model.
Another way of noting the incoherence of Roscoe's argument (ie, the argument from the lack of energy balance when he ignores all components) is to note that by ignoring back radiation, he assumes that there is no greenhouse effect, as you note @119. That would again make his theory absurd "on the level of geocentrism". Perhaps more important to this discussion is that none of the above has any bearing on the runaway greenhouse effect, which is a theory about how Venus developed from a (putative) Earth like state to its current greenhouse dominated state with no surface water.
Roscoe may have a secondary "argument" that does specify the runaway greenhouse effect. Specifically, he writes:
"Where does this come from when a University Professor tells me the sutface of Venus receives only 132 W/sq m ?
I think this is a fair question. If it is from the greenhouse effect how did this develop initially ? 132 W/sq m couldn't possibly do it."
IMO the most sensible way to interpret this comment is that Roscoe did not distinguish between the runaway greenhouse effect (a process that would have taken tens or even hundreds of thousands of years) and the current Venusian greenhouse effect (an almost static state in quasi equilibrium and with no significant variation on decadal scales). However, assuming he was correctly referring to the runaway greenhouse effect it should be noted that, first, his argument consists of an argument from personal incredulity; and second, that he falsely assumes the albedo of Venus in the initial, earthlike, state of the runaway greenhouse effect must equal its current albedo. Without the later assumption he cannot assume that the surface insolation on Venus equaled the current value.
As a final note, 132 W/m^2 is not the insolation at the surface, contrary to Roscoe's repeated assertions. Rather it is the insolation at the TOA after adjustment for albedo and averaging over globe. A flat surface perpendicular to incoming sunlight and at the orbit of Venus would recieve 2625 W/m^2. Given the bond albedo of 0.9, that means total TOA insolation averages as 66 W/m^2, with only less than 6.6 W/m^2 reaching the surface.
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ribwoods at 04:49 AM on 26 November 2015So what's really happening in Antarctica?
bozzza @7:
"If we knew the snowfall history perfectly then there wouldn’t be any controversy!" is the final sentence of the article's fifth paragraph.
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martin3818 at 04:31 AM on 26 November 2015So what's really happening in Antarctica?
@Hank + @Sid
Realclimate is available at this back-up site http://realclimate-backup.org/
Apparently, 10 years ago, somebody registered the domain for them. The registration has now expired and they don't know how exactly to get it renewed.
Cheers
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MA Rodger at 01:04 AM on 26 November 2015Venus doesn't have a runaway greenhouse effect
Tom Curtis @118.
Sorry. When I said "initial", and RomanEmpire @115 said "beginning", this was not the very beginning @3 which is pretty incoherent stuff, but the Rosco comment @7. This fits with the description @115 "What Rosco was saying in the beginning is that Venus surface is far too hot for the current state of the affairs." I must admit that re-reading #7 I did manage to mis-interprete the comment, somehow reading into it the idea that the sun only heats the outer atmosphere (thus the 250 K limit), an idea which is actually absent. But in my defence, the actual argument/question presented @7 is entirely self-defeating - there is no greenhouse effect (thus temperature is as a black body) so how can there be a greenhouse effect?
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Tom Curtis at 23:59 PM on 25 November 2015Venus doesn't have a runaway greenhouse effect
MA Rodger @117, this is Rosco's original post upthread (@3):
"Venus is nothing like the earth - it is (-snip-) to claim it is. I have seen claims that the "greenhouse" effect on Venus is responsible for heating the planet by ~500 k. This is clearly impossible given the albedo of Venus reflects most incoming solar radiation.
If such an effect were possible it could easily solve Earth's energy problems - simply collect all the hot exhaust gases from a coal fired power station and force it into a chamber under 92 bar pressure, add sunlight and the runaway greenhouse would raise the temperature to over 700 K - and we could use this heat to drive turbines and eventually shut down the coal fired power station.
Yeah right - the whole idea is "beyond absurd"."
In successive paragraphs he shows repeatedly that he does not think there is any such thing as a greenhouse effect, that he does not know how it works, and (at the end of the second paragraph) that he does not understand the laws of thermodynamics.
The greenhouse effect is sufficiently well understood, and sufficiently well evidenced that the probability of it not existing is not meaningfully distinguishable from the probability that geocentrism is true. Ergo, his initial contribution is very much on a level with geocentrism.
There are things that are reasonably disputable, and even controversial in climate science. That the origin of the 20th century increase in CO2 is anthropogenic, and that an greenhouse effect and an enhanced greenhouse effect exist are not among them. Any denial of those facts merely shows an abysmal scientific ignorance. The lack of a civilized discussion that RomanEmpire points to is a direct consequence of that fact. It is not possible to have civilized discussion defending the thesis that black is white (or geocentrism; or rejecting the existence of a greenhouse effect) because one participant must lack an essential of civilized discussion in any such case - the desire or ability to be rational. Those who sheet home the failure of civilized discussion to the rational side of the discourse need to be reminded of this fact in no uncertain terms.
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MA Rodger at 23:19 PM on 25 November 2015Venus doesn't have a runaway greenhouse effect
Tom Curtis @116.
I think it is wrong to characterise the initial position of Rosco up-thread as being "on a level of geocentrism". RomanEmpire @115 is pursuaded that there was something in Rosco's initial position and thus it would be wrong to dismiss it entirely off-handedly.
The basic idea that seemed to confound Rosco was that he held that the sun (less albedo) should warm the insulating outer atmosphere of Venus to some 250 K and then he was perplexed that the surface temperature of Venus is some 750 K. How could this be? Addressing this point was not helped up-thread as Rosco arrived with a heavy load of misconceptions but let us ignore them. What Rosco simply failed to grasp was that when a planet gains a powerful greenhouse atmosphere, it takes very little energy to raise the temperature at its surface. So the vulcanism within Venus, if it had a similar heat output as Earth (which is likely) would require only a few million years (a mere blink of an eye in the evolution of a planet's climate) to warm its thick lower atmosphere from 250 K to today's 750 K.
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MA Rodger at 23:03 PM on 25 November 2015So what's really happening in Antarctica?
I thought to consider whether the Zwally contention could require snowfall to be maintained over a shorter period than the whole Holocene. Could it be a more recent increase and thus reduce the impact on sea level? The Vostok ice core gives ice depth and age from 5,679yBP suggesting that it takes half of the length of the Holocene for high Antarctic snow to compact completely into ice. And much of the compaction would occur in a far shorter time.
But I came away from the Vostok data with more of an appreciation of Zwally's contention. Note in the Vostok data that the annual ice thickness (which Zwally contends is the full cause of surface elevation rise) is 21mm/year thick through the early Holocene but 12mm/year through much of the last ice age (over a 60ky period, 13mm/y over 100ky period so presumably achieving a steady-state condition) providing the sort of additional ice (1cm/year) Zwally is arguing for. So does it not come down to the question of how the multi-kilometre thick ice sheet will react to a multi-millennial increased rate of snowfall. Would the extra snowfall (which the Vostok data suggests has resulted in an extra 120m of ice-equivalent added to the top of the sheet since the LGM) significantly increase the rate of ice flow? Are there other effects at play? Or does Zwally's contention need addressing? Okay it comes with problems for the Holocene SLR record, and the measured elevation change may not be all ice, but with an extra 120m of ice-equivalent on the ice sheet over 18,000y can it be argued that there should be a significant ice component within the measured surface elevation rise?
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chriskoz at 19:31 PM on 25 November 2015Study drives a sixth nail into the global warming ‘pause’ myth
Anders showed an excellent graph complementing this article
https://andthentheresphysics.wordpress.com/2015/11/24/one-graph-to-rule-them-all
(pointed by a commenter in TheGuardian)
Therein, you can see all temp trends starting at all years and see as clearly as ever why 17y is the "magic number" of years required for the significance of any trend.
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wili at 16:04 PM on 25 November 2015Study drives a sixth nail into the global warming ‘pause’ myth
RealClimate seems to be back up and running again, thankfully.
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Tom Curtis at 10:52 AM on 25 November 2015Venus doesn't have a runaway greenhouse effect
RomanEmpire @115,
1) Apart from the obvious point that 1% <10% so that there is no contradiction between Colose's claim and yours, we have the fact that Svedhem et al (2007) says:
" Less than 10% of the incoming solar radiation penetrates through the atmosphere and heats the surface."
Apparently a similar claim is made in Titov et al (2006). Finally we have Tomasko et al (1980) that concludes from the comparison of measurements with models that:
"Averaged over the planet, about 17 W/m² are absorbed at the ground (some 2.5% of the total solar energy incident on the planet)."
This is definitely inconsistent with the claim that there "... is no evidence that even 1% of solar radiation reaches Venus surface", which is revealed as hyperbole at best.
2) Chris Colose writes above:
"note Venus may never actually encountered a true runaway, there is still debate over this"
It follows that when you write "Chris essentially said ... that Venus surface is far too hot for the current state of the affairs ..., so there MUST HAVE BEEN a runaway greenhouse effect..." you are clearly misrepresenting his argument. His argument is that while the TOA insolation on Venus is sufficient to drive a runaway greenhouse effect, it is not sufficient on Earth. Venus may have reached its current conditions by either never having cooled down sufficiently from its initial heat of formation (due to a strong greenhouse effect) or to having experienced a runaway greenhouse after cooling down as the Earth did.
3) Roscoe espoused absurd theories (on the level of geocentrism). He refused to either be convinced by clear argument or evidence provided. Scientists, no matter how respectful, cannot be expected to persuade those who come into the discussion with a closed mind as Roscoe clearly did. Nor, if you abuse their patience by continuing to espouse nonsense rather than learn something new, can you expect the patience of scientists to persist.
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RomanEmpire at 08:29 AM on 25 November 2015Venus doesn't have a runaway greenhouse effect
Sorry for joining this discussion so late.
My understanding is that Chris Colose's piece (the origin of this debate) said is not totally inconsistent with what Rosco was saying (Rosco was, unfortunately, mobbed out of this thread; shame on us, scientists, for being unable to conduct a civilized discussion with a well-meaning outsider without patronizing, antagonizing, provoking, name calling, etc.).
So, Chris essentially said (again, this is my understanding) that Venus surface is far too hot for the current state of the affairs (insolation, albedo, atmosphere composition, etc.), so there MUST HAVE BEEN a runaway greenhouse effect in some (uspecified) past that heated it up, and the current state of the affairs does not let it cool too quickly.
What Rosco was saying in the beginning is that Venus surface is far too hot for the current state of the affairs. I don't understand why he had to be chased out of this thread for this, even though here Rosco and Chris seem to agree.
Where I disagree with Chris is when he says that "Less than 10% of the incident solar radiation reaches the surface." There is no evidence that even 1% of solar radiation reaches Venus surface, so dense is the Venusian atmosphere (if we live under an equivalent of 10 m of water - our atmosphere compressed, the on Venus the equivalent depth is >900 m, and this is without taking into account the dense clouds). The light observed by the Russian station was likely due to the lightening that is constantly illuminates the Venusian atmosphere.
Moderator Response:[PS] Rosco came to debate with a history of trying the moderator's patience and a strong dislike for either reading or comprehending information that contradicted his/her preconceptions. Please note that moderation complaints are always offtopic.
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Rob Painting at 07:57 AM on 25 November 2015So what's really happening in Antarctica?
Jimlj - that's a very good point. Ocean volume has been static for the last 4-5000 years - with relative sea level fall occurring in the farfield due to the effect of ocean siphoning. Zwally et al not only contradict the bulk of other Antarctic research, but Holocene sea level research too.
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Lionel A at 22:22 PM on 24 November 2015So what's really happening in Antarctica?
As noted at HotWhopper and now DeltoidThe RealClimate difficulty has a, I hope, temporary solution as RC has resorted to a backup server. It may be usefull to update the link in the heading to point to:
http://www.realclimate-backup.org/
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Tom Curtis at 21:19 PM on 24 November 2015So what's really happening in Antarctica?
billthefrog @13, as you can see in the video below, the melt of the Laurentide Ice Sheet was essentially over 8 thousand years ago
It appears the fennoscandian ice sheet also essentially disappeared by 5000 kya. Further, since about 8 kya, global temperatures have been slightly falling, or constant so that there is no additional sea level rise due to thermal expansion, and possibly some slight fall. It is not obvious, therefore, that there is a basis to assume compensation for an increase in Antartic ice mass over that period.
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billthefrog at 20:47 PM on 24 November 2015So what's really happening in Antarctica?
jimlj @ 12
My background is not in Paleo (although the wife keeps calling me an old git), but the long drawn out retreat of both the Laurentide and Fennoscandian ice sheets would certainly have emptied more than a few gallons into the oceans.
One would also have to factor in the delayed effects of thermal expansion. Even the surface layers of the oceans clearly show this, with oceanic temps reaching their annual maximum several months after the relevant hemispheric summer sostice. Think how long it is going to take for the deep ocean to equilibrate following the Last Glacial Maximum of about 20 - 21 kya.
My limited understanding is that thermosteric effects (i.e. thermal expansion) and eustatic effects (i.e. caused by the addition of extra waters) are currently of comparable magnitude. Taken together, these would account for the sea level rise of around 120+ metres since the LGM. The limked NASA article discusses this effect.
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jimlj at 17:34 PM on 24 November 2015So what's really happening in Antarctica?
According to Zwally's paper, not only is Antarctica gaining ice now, but as I understand it, has been for the last 10 millenia. If everything else were equal, that would have meant at least a couple of meters of sea level drop. But we haven't seen that, so what is the source of the water that has kept sea level relatively constant?
If I've misunderstood something, or gotten some facts wrong, I'd appreciate learning where I went wrong.
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Tom Curtis at 13:18 PM on 24 November 2015Tracking the 2C Limit - October 2015
Tor B @1, the indices you reference are simple temperature indices. That is, they plot the temperature in a small area of the tropical Pacific and use that as an index of ENSO states. However, because they simply take the temperature of a small region, any increases in temperature due to global warming generates a bias towards stronger and more frequent El Nino states (and weaker and less frequent La Nina states). Given that, we do not know to what extent the record values are a consequence of a strong El Nino, and to what extent they are directly due to global warming.
One way of avoiding this problem is to use ENSO indices that either are not direct temperature measurements (the SOI) or which use a variety of different indices so that any purely global warming signal does not bias the result (the Multivariate ENSO Index or MEI). Here are the recent values of the later compared to other historically strong El Ninos:
As you can see, it is only the third strongest El Nino by the MEI since 1950. The SOI shows the current ENSO value (-20.2) as weaker than five months of the 97-98 El Nino (peak at -28.5), and six months of the 82-83 El Nino (peak at -33.3).
There is no guarantee as to how El Ninos will develop. The current El Nino may collapse and fall away towards neutral conditions, but current predictions are that it will remain strong for several more months.
If it were to do so, it will not challenge either 97/98 or 83/83 as the strongest El Nino since 1950. It is however possible that it will strengthen again. If it does so, it may follow a similar pattern to the 82-83 El Nino and end up as the strongest since 1950. Or not. If it did, that would be grim news indeed.
As it stands, the big news about this El Nino is that it so hot globally relative to 97-98 when the El Nino event is not as strong as 97-98.
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Tor B at 11:18 AM on 24 November 2015Tracking the 2C Limit - October 2015
The most recent weekly Nino data (released today?) hit a new all-time record of 3.1. The base line for Nino datasets was reset early in 2015, a baseline raised from the previous baseline (I think by about 0.1); this makes me think this and last weeks record values all the more significant.
From the Arctic Sea Ice Forum's Consequences/El Nino? thread: "... NOAA data show[s] that the Nino 3.4 is now +3.1, that both the Nino 1+2 and the Nino 4 increased, and the Nino 3 remained constant at +3.0." Included is a table of recent week values of the several Nino regions.
Moderator Response:[PS] Added link
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0^0 at 05:22 AM on 24 November 2015The Skeptical Science temperature trend calculator
I see that some of my questions have actually been raised and answered already above.. Sorry about that..
Considering that my own calculation essentially has been verified through the replication of Foster & Rahmstorf original numbers, and that I get quite close (about rounding error level) to SkS calculator with "well defined" time series, I think I have no urgent questions anymore.
However, it still would be quite nice to have clear definition of exact data sources used, and the timestamp when SkS calculator has retrieved refreshed datasets. But I well understand the issue with time in a voluteer setup.
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MA Rodger at 04:17 AM on 24 November 2015So what's really happening in Antarctica?
Don Burrows @10.
It is not a "redistribution" Zwally is arguing for. Rather it is a millennia-long accumulation he is proposing. The argument is that the snowfall today is not much changed from the snowfall over recent millennia. Prior to this, in the distant past, there was both less snow and less ice. The snow compacts to ice that then, with time, flows off the summits of Antarctica towards the oceans. But the arriving snowfall, while constant over the millennia, is greater than the ice flow. So ice continues to build up as it has over all those millennia.
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Don Burrows at 03:14 AM on 24 November 2015So what's really happening in Antarctica?
I'm having a hard time comprehending the argument that an increase in precipitation 18,000 to 12,000 years ago could be seen as an increase in mass in recent years. Once a net gain has occurred then we're only talking about redistribution of the mass by ice movement.
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knaugle at 02:08 AM on 24 November 20152015 shatters the temperature record as global warming speeds back up
Yet no mention of the satellite data which is not aggreeing with the tone of this article. This particularly since Spencer & Christy rolled out UAH 6.0. Now both RSS and UAH seem to show there is no warming to speak of in the lower troposphere. Right? So long as that is the case deniers see that as confirmation this is a big hoax. I did find the comparison of RSS to RATPAC data in this link interesting:
https://tamino.wordpress.com/2015/09/24/exogenous-redux/
I don't know to what degree it is reliable, however. It does explain a lot to me about what is going one the past 15 years. Satellite vs. Surface temps.
Moderator Response:[PS] Fixed link. Please use link button in the editor to do this yourself.
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ianw01 at 02:01 AM on 24 November 2015The Road to Two Degrees, Part One: Feasible Emissions Pathways, Burying our Carbon, and Bioenergy
The chart Andy posted at #13 conspicuously rules out nuclear a priori. We are going to need all the tools available to meet this challenge, including new generations of nuclear technology. Again, its political ...
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oldmanthames at 22:26 PM on 23 November 2015Water vapor is the most powerful greenhouse gas
Water vapour and CO2 at high altitude.
The concentration of water vapour, a powerful greenhouse gas, at the earth's surface is usually tens of thousands of parts per million, which completely dwarfs the CO2's 400, let alone the changes in the concentration of the order of 100 parts per million. So say the skeptics.
But this isn't the case at high altitudes. At 40,000 feet, at the top of the troposphere, the temperature is around -50C, and so the water vapour is frozen out, with a vapour pressure of about 4Pa, (1Pa at -60C). Atmospheric pressure at sea-level is about 100,000 Pa, and about 20,000Pa at 40000 feet. If I assume that the concentration of CO2 remains about the same, with a bit of turbulence stopping the heavy CO2 molecules settling out to lower altitudes, then the pressure of CO2 would be about 8Pa=20,000x(400/1,000,000)Pa, which is twice the pressure of the water vapour. So maybe an increase in the CO2 concentration does matter. We shall all get warmer, regardless of the height at which the heat flow into space is restricted.
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Glenn Tamblyn at 12:55 PM on 23 November 2015Of Averages and Anomalies - Part 1A. A Primer on how to measure surface temperature change
PaulG
Read part 1B for more on the distances over which one can interpolate. And as scaddenp said, Hansen & Lebedeff 1987 is important to read.
Let me address why anomalies give better accuracy mathematically. This article at wikipedia on Accuracy & Precision is worth reading, particularly for the difference beteen the two terms.For any reading from an instrument, a thermomemeter for example, we know that the reading will consist of the true value of what we are interested in and some error in the measurement. In turn this eror is made up of the accuracy of the reading and the prcision of the reading. What is the difference between the two ideas.
Accuracy is the intrinsic, built in error of the instrument. For example a thermometer might be mis-calibrated and read 1 degree warmer than the real value. In many situations the accuracy of a device is constant - built into the device
Precision is how precisely we cane take the reading. So by eye we might only be able to read a mercury thermometer to 1/4 of a degree. A digital thermometer might report temperature to 1/100th of a degree.
So if we take many readings with our instrument each reading will be:
Reading = True Value + Accuracy + Precision.
This image might illustrate that:
So if we take the sum of many readings we will get:
ΣReadings = ΣTrue Values + ΣAccuracy + ΣPrecision.
And the Average of the Readings is the Average of the True values + the Average of the Accuracy + the Average of the precisions.
But the more readings we take, the more the average of the precisions will tend towards zero. The average of a random set of values centered around zero is zero. So the more readings we take, the better the precision of the average. Mathematically, the precision of an average is the precision of a single reading divided by the square root of the number of readings.
So if an instrument has a precision of +/- 0.1, an average of 100 readings has a precision of
0.1 / sqrt(100) = 0.01
10 times more precise.And the average of the accuracy (for an instrument with a fixed accuracy) is just equal to the accuracy.
So the more readings we have, the more the average tends towards being:
Average of Readings = Average of True Values + Accuracy.Now if we take an anomaly. When we take the difference between 1 reading and the average we get:
Single Anomaly = (Single True Value + Accuracy + Precision) - (Average True Value + Accuracy)
which gives us:
Single Anomaly = (Single True Value - Average True Value) + Precision.
So by taking an anomaly against its average we have cancelled out the fixed part of the error - the accuracy. We have effectively been able to removed the influence of built in errors in our instrument from our measurement.
But we still have the precision from our single reading left.
So if we now take the average of many anomalies we will get
Average of Read Anomalies = Average of True Anomalies.
Accuracy has already been removed and now the average of the precisions will tend towards zero the more anomaliess we have.
So an average of the anomalies gives us a much better measure. And the remaining error in the result is a function of the precision of the instruments, not their accuracy. Manufacturers of instruments can usually give us standardised values for their instrument's precision. So we can then calculate the precision of the final result.
But we have to abandon using absolute temperatures. They would be much less accurate. Since the topic is climate Change, not climate, anomalies let us measure the change more accurately than measuring the static value.
There is one remaining issue which is the topic of parts 2A and 2B. What if our accuracy isn't constant? What if it changes? One thermometer might read 1 degree warm. But if that themometer is later replaced by another one that reads 1 degree colder, then our calculation is thrown out, the accuracies don't cancel out.
Detecting these changes in bias (accuracy) is what the temperature adjustment process is all about. Without detecting them our temperature anomaly record contains undetected errors.
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bozzza at 11:51 AM on 23 November 2015Of Averages and Anomalies - Part 1A. A Primer on how to measure surface temperature change
Is Paul G asking for thermometers to cover the face of the earth? What about the depths of the ocean??
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scaddenp at 10:18 AM on 23 November 2015Of Averages and Anomalies - Part 1A. A Primer on how to measure surface temperature change
PaulG - the way you do it, it take lots of thermometers at varying distances from each other and see how exactly the correlation of anomalies vary with distance. That would be the Hansen and Lebedeff 1987 paper referenced in the main articles.
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PaulG at 09:58 AM on 23 November 2015Of Averages and Anomalies - Part 1A. A Primer on how to measure surface temperature change
Okay, I read the explanation that averaged anomalies at nearby locations will typically show less change than will average measured temperatures. That sort of makes sense. I am not sure how less change means more correct.
And I understand the idea of teleconnection. What I don't understand is how you can generalize, or interpolate, in areas where you don't have any measurements.
It seems to me that you won't be able to determine the correlation coefficients resulting from teleconnection unless you have all of the temperature measurements in the first place.
How can you determine the error in your averaging if you don't have all of the measurements to determine that error? The average of anomalies approach may intuitively feel better, but how is it mathematically justified?
Sorry, this does not make sense to me.
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knaugle at 08:05 AM on 23 November 2015Satellites show no warming in the troposphere
To add, bear in mind the denier mantra
"Satellites are true and NOAA lies."
is something I increasingly have trouble arguing against even considering the 10 positive indicators of a warming world show the idea we have not really warmed in 20 years makes no sense. But, satellites don't lie, right?Moderator Response:[Rob P] - It's informative to look at the satellite trend (for RSS) for the lower troposphere:
So the satellite data does in fact show a long-term warming trend. If one selects the super El Nino of 1997/1998 as a starting point it's possible to fool the uninformed, but that deceptive practice may soon come to an end with the current super El Nino likely to anomalously warm the lower troposphere in the next 4-5 months.
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knaugle at 07:59 AM on 23 November 2015Satellites show no warming in the troposphere
GregCharles is correct about UAH 6.0. It also points out the need for several popular web sites to "get with the times". Whatever the reason UAH 6.0 was adjusted, the effect was to make it nearly identical to RSS. This improves "consistency", but begs the question why UAH thought RSS right and everyone else wrong. Regardless, all the popular sites I visit still rely on older UAH 5.6 or thereabouts, and we are now left with the satellite data showing nearly no warming for the past 20 years, and the surface data sets with more significant warming. The clear discrepancy between RSS & UAH 6.0 and the surface data (GISS, HadCrut4, Berkeley, etc) is something this site should address and I'm not seeing it.
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0^0 at 07:10 AM on 23 November 2015The Skeptical Science temperature trend calculator
yes, but how do I find that series today and how is it different from NOAA? To my understanding both should be the same since last summer or so? So what is the difference here?
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scaddenp at 06:33 AM on 23 November 2015The Skeptical Science temperature trend calculator
The Karl et al 2015 paper that denier are objecting to is linked to on Tom's post. Another link here.
Full citation:Karl, Thomas R., Anthony Arguez, Boyin Huang, Jay H. Lawrimore, James R. McMahon, Matthew J. Menne, Thomas C. Peterson, Russell S. Vose, and Huai-Min Zhang. "Possible artifacts of data biases in the recent global surface warming hiatus." Science 348, no. 6242 (2015): 1469-1472.
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0^0 at 21:45 PM on 22 November 2015The Skeptical Science temperature trend calculator
I found the code that Tamino used for their 2011 paper and the way they calculated standard error. Looks like I am now able to replicate quite well the slopes and confidence intervals produced by SkS calculator - at least for those series that are clearly identifiable like Berkeley Land, UAH (5.6), RSS (TLT 3.3), GISSTEMP and HadCRUT4..
Unfortunately I still have some challenges with references like NOAA and Karl 2015 which I was not able to identify unambiguously. What I think they may mean (NCDC V3?) is not as close as I would have hoped for. Furthermore Berkeley global is a challenge for me as there my numbers deviate too much from SkS. It would be extremely helpful if the exact data sources (and last update time) were someplace visibe on the calculator page.
(To avoid issues related to possible missing data point in 2015 I have made my calculations for period January 1979 - December 2014.) -
Digby Scorgie at 19:43 PM on 22 November 2015The Road to Two Degrees, Part One: Feasible Emissions Pathways, Burying our Carbon, and Bioenergy
Michael: Yes, that is one of the articles that made me think it is possible to replace fossil fuels completely. Then I read other articles saying in response that it's not so easy! One thing glossed over is fuel for aircraft and ships. I've heard of emission-free synfuels (synthetic fuels) for aircraft — whether or not they work for ships I don't know.
The real blockage is of course political.
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TonyW at 18:38 PM on 22 November 2015So what's really happening in Antarctica?
Just a note about the Zwally paper. Whilst it has been recently published, the research is much older and I first saw it as a conference paper listed on a NASA page, in 2012. It was also referenced in a Nature article that year. The conference paper had the same title and the same authors (apart from one).
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hank at 15:42 PM on 22 November 2015So what's really happening in Antarctica?
Tried realclimate and got an immediate redirect to a screen saying
"Offer rdsa____.com" (I'm not posting the full URL, which is spoofed anyhow, nor the actual link that was hidden behind that text, which was long, complicated and suspicious
which changed immediately to
"Win NHL Jersey ____" (also not posting that URL which was also fake covering another long suspicious string of code)
Beware -— looks like it's hidden layers of something rather nasty, hidden under what appears to be mere adware, I think. -
michael sweet at 13:28 PM on 22 November 2015The Road to Two Degrees, Part One: Feasible Emissions Pathways, Burying our Carbon, and Bioenergy
Digby,
This article shows that it is possible to build a completely renewable energy supply by 2050. If a high carbon fee was instituted so that carbon paid for all the damage it causes, investors would build out the renewable energy we need. It would save everyone money and result in better health. The primary block is political due to the influence of fossil fuel companies who stand to lose trillions of dollars.
Fossil fuels are only cheap because they make everyone else pay for the damage they cause. Obama's clean power plan is completely justified by the health savings, the climate benefits are not considered.
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Digby Scorgie at 11:28 AM on 22 November 2015The Road to Two Degrees, Part One: Feasible Emissions Pathways, Burying our Carbon, and Bioenergy
There are actually two aspects to my "subversive thought". Firstly, is it physically possible to find ways to cope with declining supplies of fossil fuel over a thirty-year period? I don't know. From what I read, sometimes I think it is, sometimes I think it isn't. I just don't know. That's why I asked.
Secondly, how should declining supplies of fossil fuel be allocated between countries? This is the aspect you've latched onto, but this is a different problem altogether. It is a problem the world would've had to face if we'd really passed peak-oil and supplies really were declining. My subversive thought was to suppose the decline was imposed, not natural.
Another way to look at the second aspect is this: We're aiming to induce a decline in fossil-fuel use in the face of a plentiful supply. Well, good luck with that! Whatever methods are used, I'll believe them only when I see fossil-fuel production declining in reaction to declining demand. I fear that, as you imply, the threat needs to be immediate and life-threatening before this will happen.
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MA Rodger at 06:41 AM on 22 November 20152015 shatters the temperature record as global warming speeds back up
sauerj @10.
If you examine NOAA OHC data, you'll see a strong El Nino signal in the 0-100m Pacific record with OHC rising during El Nino. The signal reverses for 0-700m data but becomes far less obvious. So when global 0-2000m OHC data is examined there is nothing really left to see.
BC @9.
The 0-2000m OHC data does indeed record OHC reduced from 2015Q2 to 2015Q3. But the same thing happened in both 2014 and 2013 when it showed even greater reductions but without an El Nino. Indeed, in the post the "400 million atomic bomb detonations (27 zettajoules, or 27 billion trillion Joules)" figure for ΔOHC in 2015 appears to be the annual figure for 2015Q3 - 2014Q3 which is 27.6 Zj. Over the last 8 quarters the annual ΔOHC averages 22 Zj.
One comparison not made in the post but which I consider more interesting that numbers of bomb-equivalents is the global energy imbalance required to add, say, 22 Zj/year to the oceans. That would be 1.37W/m2 or according to IPCC AR5 Table AII.1.2 equal in size to the increase in all the positive human climate forcings 1978-2011 which, with these OHC figures, would thus still be up there warming away despite the level of AGW we have witnessed since that date. That's a rather scary equivalent.
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Andy Skuce at 05:52 AM on 22 November 2015The Road to Two Degrees, Part One: Feasible Emissions Pathways, Burying our Carbon, and Bioenergy
Digby: Suppose fossil-fuel producers were "forced" to cut production at the above rate. Would the free market coupled with human ingenuity find ways to cope?!
One question that springs to mind: how would the cuts be allocated, between countries and among fuel types? Also, this would drive prices up, so who would benefit, the producers or would governments have to institute some kind of windfall profits tax? It would also be regressive, so some form of compensation to the poor would be needed.
Perhaps a less regressive policy would be to ration fossil fuel use at the consumer level. But until there is a widespread consensus that we are facing a an urgent existential crisis, I can't see that being politically feasible.
Far better would be a cap and trade policy. After all, the goal should be to lower emissions, not necessarilly to reduce fossil fuel use. Even better than that, in my opinion, anyway, would be a steadily rising carbon-tax-and-dividend policy.
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sauerj at 03:54 AM on 22 November 20152015 shatters the temperature record as global warming speeds back up
It appears the rise in ocean heat content rate is trending up. Since 1990 (25 years), it appears to have increased ~21x10^22 J (15,668 atom bombs/hr), based on an atom bomb = 17x10^9 watt-hrs. In contrast, since 2008 (7 years), heat content appears to have increased ~8.5x10^22 J (22,650 atom bombs/hr).
Article notes the 2015's El-Nino driven spike in heat content amounting to 50,400 atom bombs/hr (14/sec).
I'm a bit preplexed: I had thought that in El-Nino years that the stored-up ocean heat content was expelled (more than avg rates) to the surface, causing spikes in land & ocean surface temps, and also causing a slight decrease in the rate-of-ocean heat content (compared to avg) due to this more aggressive expulsion of heat from the ocean. ... Opposite effect in La-Nina years, that the rate-of-rise of ocean heat content would be more than average. So, I'm surprised to see OHC rate-of-rise increase in 2015's El-Nino year. I obviously have something wrong here.Moderator Response:[Rob P] This years super El Nino has yet to really leave its mark on ocean heat content. The data for ocean heat content end in September and we're only reaching the peak of El Nino now. The next two quarters of OHC may tell a different story.
Time-series of globally-averaged (60°South to 60°North) ocean temperature anomaly from the monthly mean, versus depth in metres (pressure in dbar).(b) Time?series of globally-averaged sea surface temperature anomaly (black, °C), ocean temperature at 160 metre depth (blue), and the Nino3.4 regression estimate for SST (red). From Roemmich & Gilson (2011) -
2015 shatters the temperature record as global warming speeds back up
I would have thought that higher surface temperatures would have resulted in more infra red radiation out to the atmoshpere and space and less accumulation of heat in the oceans. That is, wouldn't there be more accumulation in cooler surface temp /La Nina years and less in El Nino years? Maybe that's why there's a downward turn at the end of the graph, which only goes to June 2015. That downward turn may continue while the El Nino unfolds.
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bozzza at 18:05 PM on 21 November 2015So what's really happening in Antarctica?
@ 5, where did you get this quote from: "If we knew the snowfall history perfectly then there wouldn’t be any controversy!" ?
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bozzza at 17:53 PM on 21 November 20152015 shatters the temperature record as global warming speeds back up
A little birdy told me government departments expect ice free Arctic summers by 2050. Talk about conservative..
I think we will see a lot of divestment into clean energy for good reason before 2020: the same people admit multi-year sea ice in the Arctic is looking very very ill!!
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Digby Scorgie at 13:20 PM on 21 November 2015The Road to Two Degrees, Part One: Feasible Emissions Pathways, Burying our Carbon, and Bioenergy
The scenario linked to is interesting, thanks. It seems to match the back-of-envelope estimate I've made in the meantime: If fossil-fuel use remains at 30 Gt per year until 2020 and thereafter declines at 1 Gt per year for almost 30 years one uses 585 Gt of the budget. That leaves a residue of 15 Gt to play with. Being so precise is a bit silly really, considering all the uncertainties involved. However, the overall effect does seem to match the "WWW and Ecofys" scenario, even to the small tail of fossil-fuel use from 2050 onwards.
As you point out, feasibility is a different story altogether. In this regard, let me offer a subversive thought: Suppose fossil-fuel producers were "forced" to cut production at the above rate. Would the free market coupled with human ingenuity find ways to cope?!
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