Guest post by Bart Verheggen, Department of Air Quality and Climate Change , Energy research Institute of the Netherlands (ECN)
In Part I, I discussed how aerosols nucleate and grow. In this post I’ll discuss how changes in nucleation and ionization might impact the net effects.
Cosmic rays
Galactic cosmic rays (GCR) are energetic particles originating from space entering Earth’s atmosphere. They are an important source of ionization in the atmosphere, besides terrestrial radioactivity from e.g. radon (naturally emitted by the Earth’s surface). Over the oceans and above 5 km altitude, GCR are the dominant source. Their intensity varies over the 11 year solar cycle, with a maximum near solar minimum. Carslaw et al. give a nice overview of potential relations between cosmic rays, clouds and climate. Over the first half of the 20th century solar irradiance has slightly increased, and cosmic rays have subsequently decreased. RC has had many previous posts on the purported links between GCR and climate, e.g. here, here and here.
The role of ions
The role played by ions relative to neutral (uncharged) molecules in the nucleation process is still very much under discussion. For instance, based on the same dataset, Yu and Turco found a much higher contribution of ion induced nucleation (to the total amount of particles produced) than Laakso et al did. Evidence for a certain nucleation mechanism is often of an indirect nature, and depends on uncertain parameters. Most literature points to a potential importance of ion induced nucleation in the upper troposphere, but the general feeling is that neutral pathways for nucleation (i.e. not involving ions) are likely to be dominant overall. Most field studies, however, have been performed over land, whereas over the open ocean nucleation rates are generally lower due to lower vapor concentrations. In theory at least, this gives more opportunity for ion induced nucleation to make a difference over the ocean (even though the ion production rate is smaller).
The ion production rate (increasing with altitude from ~10 to ~50 ion pairs per cubic centimeter per second over land) sets a limit to what the particle formation rate due to ion induced nucleation can be. Based on his model for ion induced nucleation, Yu found that at low altitude, the number of particles produced is most sensitive to changes in cosmic ray intensity. At first sight, this may be a surprising result in light of the increasing cosmic ray intensity with increasing altitude. The reason is that high aloft, the limiting factor for particle formation is the availability of sulfuric acid rather than ions. Above a certain GCR intensity, increasing ionization further could even lead to a decrease in ion induced nucleation, because the lifetime of ion clusters is reduced (due to increased recombination of positive and negative ions). In contrast, at low altitude particle formation may be limited by the ionization rate (under certain circumstances), and an increase in ionization leads to an increase in nucleation.
How important is nucleation for climate?
Different modeling exercises have been performed to investigate this question. The strong dependency on input data and assumptions used, e.g. relating to primary particle emissions and nucleation parameterizations, and the different sensitivities tested, hampers an overall assessment. However, it is clear that globally, nucleation is significant for the number of cloud condensation nuclei (CCN) e.g. in the absence of boundary layer nucleation, the number of CCN would be 5% lower (Wang and Penner) or 3-20% lower (Spracklen et al.), and in a recent follow up study, they concluded that the number of cloud droplets would be 13-16% lower (in 2000 and 1850, respectively). Pierce and Adams took a different approach and looked at the variation of predicted number of CCN as a result of using different nucleation schemes. The tropospheric number of CCN varied by 17% (and the boundary layer CCN by 12%) amongst model runs using different nucleation rate parameterizations. Note that the globally averaged nucleation rates differed by a factor of a million (!).
It should be noted that the sensitivity of the number of CCN to nucleation depends greatly on the amount of primary emissions and secondary organic aerosol (SOA) formed. These are very uncertain themselves, which further limit our ability to understand the connection between nucleation and CCN. If there are more primary emissions, there will be more competition amongst aerosols to act as CCN. If more organic compounds partition to the aerosol phase (to form SOA), the growth to CCN sizes will be quicker.
Locally, particle formation has been observed to contribute significantly to the number of CCN; the second figure in Part I gives an example of freshly nucleated aerosols which grew large enough to influence cloud formation. Kerminen et al observed a similar event, followed by activation of part of the nucleated aerosols into cloud droplets, thus providing a direct link between aerosol formation and cloud droplet activation.
How important are cosmic rays for climate?
At the recent AGU meeting (Dec 2008), Jeff Pierce presented results on the potential effects of GCR on the number of CCN (their paper at GRL (sub. required)). Two different parameterizations for ion induced nucleation were used (Modgil et al and an ‘ion-limit’ assumption that all ions go on to form a new particle). They ran their model with both high and low cosmic ray flux, simulating conditions during solar maximum and minimum, respectively. This happens to be comparable to the change in cosmic ray flux over the 20th century (mostly confined to the first half), and amounts to a 20% change in tropospheric ion production. With both mechanisms of ion-induced nucleation, this leads to a 20% change in globally averaged particle nucleation, but only to a 0.05% change in globally averaged CCN. The authors concluded that this was “far too small to make noticeable changes in cloud properties based on either the decadal (solar cycle) or climatic time-scale changes in cosmic rays.” To account for some reported changes in cloud cover, a change in CCN on the order of 10% would be needed. More studies of this kind will undoubtedly come up with different numbers, but it’s perhaps less likely that the qualitative conclusion, as quoted above, will change dramatically. Time will tell, of course.
The bottom line
Freshly nucleated particles have to grow by about a factor of 100,000 in mass before they can effectively scatter solar radiation or be activated into a cloud droplet (and thus affect climate). They have about 1-2 weeks to do this (the average residence time in the atmosphere), but a large fraction will be scavenged by bigger particles beforehand. What fraction of nucleated particles survives to then interact with the radiative budget depends on many factors, notably the amount of condensable vapor (leading to growth of the new particles) and the amount of pre-existing particles (acting as a sink for the vapor as well as for the small particles). Model-based estimates of the effect of boundary layer nucleation on the concentration of cloud condensation nuclei (CCN) range between 3 and 20%. However, our knowledge of nucleation rates is still severely limited, which hampers an accurate assessment of its potential climate effects. Likewise, the potential effects of galactic cosmic rays (GCR) can only be very crudely estimated. A recent study found that a change in GCR intensity, as is typically observed over an 11 year solar cycle, could, at maximum, cause a change of 0.1% in the number of CCN. This is likely to be far too small to make noticeable changes in cloud properties.
David Benson (24),
The limiting factor for nucleation to occur over the open ocean is the concentration of suitable precursor gases (such as SO2 and DMS, to form H2SO4). That is probably why nucleation rates are lower there (even though there is also less aerosol surface area for the H2SO4 to condense on).
Hank Roberts (29) and Timothy Chase (37),
Ice Nuclei are generally insoluble particles, such as certain types of mineral dusts, soot or black carbon, metallic particles, as well as some biological materials (bacteria, pollen). I’m not aware of any trends in biological aerosol though.
If BC can indeed serve as an ice nuclei (there’s evidence for that, see eg http://www.agu.org/pubs/crossref/2008/2007JD009266.shtml, though other material such as dust is though to be much more effective) than its increase since preindustrial times could have caused a glaciation indirect effect (http://www.agu.org/pubs/crossref/2002/2001GL014357.shtml), whereby more IN caused an increase in precipitation (ie opposite to the “warm” second indirect effect).
David Cooke (32),
“I am curious if you have any insights regarding a relationship between the GCR presence in the upper troposphere and barometric high pressure (anti-cyclonic) systems?” No, I don’t. But the explanation you give in your second paragraph sounds very implausible to me. A few more aerosols don’t make the air sink down. (If anything, the aerosols fall out if they are big enough, leaving most of the air where it is.)
Pekka Kostamo (34)
The final, revised paper is here: http://www.atmos-chem-phys.net/8/7373/2008/acp-8-7373-2008.html. I’ve heard a presentation of the lead author at the EGU last year; he’s been ‘auditing’ (pun intended) the cosmic ray hypothesis for a while now. They look whether introducing several time delays would make the correlation better, but it didn’t. The time that matters here is the time needed from nucleation to cloud droplet activation; this can be shorter than the average aerosol lifetime.
Hi James (40, 42),
Was fun out west indeed.
I don’t have a pet theory regarding marine boundary layer nucleation, but I’ve understood that a likely scenario is that particles were formed in the free troposphere and than mixed downward. That could explain the non sea salt particles observed. I think the extent to which eg oxidation products from DMS, emitted from phytoplankton, contributes to nucleation is still largely unknown. That would be an example of a process that we haven’t properly characterized yet. But to get a more accurate picture, more in-situ observations are needed as well. (hope I didn’t avoid the question too much here…)
Jonas (48), you wrote:
“Hypothetically, if high GCR does play a more significant role in global temperature this does not necessarily detract from the positive effect of CO2 in causing warming.”
Exactly. It could only add to the picture; it could not replace it (unless all we know about radiative forcing of GHG is disproved at the same time, but that is extremely unlikely)
If you put it the way you did, I indeed don’t see a reason to be defensive at all. The problem is when people claim that a hypothetical effect from GCR would mean we can throw out of the window everything else we know. The comparison I like to draw for that line of argument is that observing a bird in the sky doesn’t disprove gravity.
Off topic 48: Oulu is in Finland, not in Greenland
Re: 25, 41
Dirty smoke and acid rain would have made a bigger contribution to climate than CO2 since we’d hardly started using oil (the UK navy only started usin oil instead of coal around 1910, IIRC) and coal had always at that time been quite hard to remove (try working a steam engine on the coal face…).
So how were the models completely wrong for that period?
One reason (of many) is that major aerosol producers were located in the mid-latitude regions of the NH, but the region which experienced the greatest cooling (by far) was the Arctic. According to the GISS zonal record the Arctic (64N-90N) cooled by just under 1 deg C between 1940 and 1970 which was about 4 times as much as any other latitude band.
Another reason concerns the uncertainty (or certainty) of the effect of aerosols in the Arctic. The effect is reckoned to be one of warming rather than cooling. This is from the wiki page (http://en.wikipedia.org/wiki/Arctic_haze)
Which is interesting because it also cooled faster between 1940 and 1970.
A third reason is that there is no evidence of any increase in aerosol production in the late 1930s or early 1940s. And remember we are looking for something which not only caused cooling, but also reversed a strong warming trend. According to GISS, the Arctic warmed almost 2 deg between 1910 and 1940. What was it that suddenly caused arctic temperatures to nose-dive? Not aerosols, that’s for sure.
None of this contradicts the possibility of enhanced CO2 warming, but it does mean that the IPCC statement about “Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations.” is totally groundless
[Response: Your logical faculties seem to fail you in the last line. That is discussing global mean temperatures, not the Arctic.- gavin]
re: carbon capture technology
I’m all for the guy who wants to genetically engineer trees to poop diamonds. Imagine having to go outside periodically to shovel diamonds off your lawn. Gigatons of diamonds. DeBeers would have a fit, but that’s a small price to pay.
John, #53. As gavin said, you seem to be taking the IPCC statement and thinking they’re talking about something they aren’t (artic temps!=global temps) and then saying that because this thing they aren’t saying isn’t true (artic temps not following global temps), then the IPCC got it wrong.
> no evidence of any increase in aerosol production
> in the late 1930s or early 1940s
John Finn loves the attention he gets posting easily refuted stuff.
http://www.nzetc.org/etexts/WH2Cret/WH2CretP015a(h280).jpg
http://www.life.com/image/3271767 Duh. Google him for much more.
very interesting articles Bart
But I’m interested, also, by the recent evolution of different aerosols concentrations and as a result, the evolution of the estimation of different radiative forcings (direct and indirect)
I already asked Gavin why there was not an update of the related NASA files.
For example, Gavin, in this file( http://data.giss.nasa.gov/modelforce/RadF.txt) there is no update since 2003 and, for example, the BC effect is the same since 1990.
Is it real?
I suppose that we can get an updated file but where?
Or is it impossible to get the recent evolution and in this case how can we follow the influence on climate?
[Response: The files will be updated as we finalise the AR5 models and forcings. They will include aerosol changes to 2005, but the emissions inventories that are needed for that are only now being finalised. This does imply that the models aren’t yet in a position to say what the post 1990s impact of aerosols on climate has been. – gavin]
John Finn, Uh, where do you think that much of the energy that warms the high latitudes comes from? Here’s a hint: it’s not just sunlight. Warm ocean currents play a major role in warming the polar regions. What is more, during their relatively short airborne lifetimes, aerosols put on a lot of miles. That is how tropical volcanoes in the Indian Ocean affect climate in Northern Europe, say.
As to the change in aerosol emissions. Hmmm. What historical event started in the late 30s and increased industrial output? What could it be? Oh yeah! WWII!! You remember. And then there was the rebuilding of Europe…
Why are you so resistant to learning the actual science (or history, for that matter)? Are you afraid it would inhibit your creativity?
Gavin said: […This does imply that the models aren’t yet in a position to say what the post 1990s impact of aerosols on climate has been. – gavin]
Interesting, and thank you. That is the sort of information that is hard to come by for those not in the field.
Look, I am not trying to be a troll here. This is a serious issue.
The link between sunspot count and climate is shown in graphs like this one http://upload.wikimedia.org/wikipedia/commons/thumb/2/28/Sunspot_Numbers.png/800px-Sunspot_Numbers.png
[Response: No it doesn’t. It just shows the sunspot number and it’s smoothed variations. – gavin]
One theorized causal link between sunspots and climate has been aerosols stimulated by GCRs. The topic here is a direct study of aerosols and their formation. The statements in the main post are to the effect that cosmic rays do not stimulate enough aerosol formation to cause a climate shift. There seems to be a lot of uncertainty in the results. Such a link is a key idea brought out by AGW skeptics.
One alternative is to be a ‘Maunder minimum denier’ and say there is no such correlation and there was no Medieval Warm Period, no Maunder Minimum, and no Dalton Minimum. Is that what the editors of this site believe, and if so where is the counter evidence?
If it is true that GCRs can not cause sufficient aerosols in the upper atmosphere to cause a global cooling, then we need to look for a different causal link.
It seems to me that science should proceed from obvious correlations to theories, and then they details of the theory gets verified or disproved. The correlation between climate and sunspot count seems so direct that it should be an intense area of study.
The underlying danger in all of this is that public policy is being railroaded through based on undecided science.
R. Keene
[Response: No, the danger here is deciding that well-understood physics should be trumped by politically expedient hand-waving based on very poor and usually highly-manipulated correlations. – gavin]
Hi John Mashey,
This is my last comment on this off-topic issue. The problems with Stanford’s GCEP program can be seen in the project approval process that GCEP uses, as well as in language on intellectual property rights contained in the agreement, which gives the sponsors exclusive access to any GCEP inventions.
1) The major program funding came from Exxon, Schlumberger, General Electric, and Toyota. Note that these companies are all in the fossil fuel sector in a big way. They are all given executive positions on the GCEP “sponsor management committee”, which holds final approval over funding decisions.
From the agreement: “The Sponsors and the University will maintain a “Management Committee” whose members will be one designated representative of the University and each Sponsor.”
Translation: the four sponsors get one vote each, as does the university. Academic peer review of grants doesn’t normally work this way – it’s a far more democratic process. There was an article at Stanford’s local paper on this, but it was pulled from the web site – that’s okay, Google cached it.
2) GCEP has never carried out any real climate research, despite the name. Almost all resources are devoted to “clean coal technology” – and this has gone on with the quiet acceptance of Stanford’s “environmental activist community”, as seen in this interview:
That’s a touchingly naive perspective, but the fact of the matter is that exclusive technology licensing agreements between universities and large corporations are seriously damaging the academic system in the U.S. Furthermore, just being a faculty member at Stanford means you are involved with it – attempting to deny all personal responsibility for your institution’s actions earns you the “fellow traveler” tag.
What is needed is a new law that forbids exclusive technology licensing by taxpayer-funded academic institutions in the United States – meaning that patents will be available to all interested parties. This will not halt “technology transfer” – human growth hormone would be in use if it had not been exclusively licensed to Genentech, no fear. However, an honest scientific examination of the use of UC Davis-Monsanto rGBH in cows might lead to a ban on that practice – but that would eliminate the U California system’s $100 million patent royalties from rGBH. Do you think UC researchers realize that investigating rGBH in detail might be a career-terminating decision? Of course they do. The same goes for physicists who insist on working on silicon photovoltaics rather than fiber optic cables, and so on. Academic freedom? Hardly.
Now, let’s get back to aerosols. Keep in mind that galactic cosmic rays (energy level: 100 MeV to 10GeV) are a steady background feature. Cosmic rays are electrically charged, and as the zip across the galaxy they interact with many EM fields, randomizing their direction and making it impossible to determine their origins. They are affected by the sun’s magnetic field and by the earth’s magnetic field. Thus, it seems that any local changes in GCR intensity must be due to changes in the EM fields of the sun and earth. The biggest factor is the solar wind, consisting of ions and electrons from the solar corona moving at about 400 km/sec (1/750th the speed of light), which keeps GCRs out of the inner solar system.
Also, the Sun itself can sporadically emit cosmic rays of energy 10-100 MeV due to coronal shock waves and solar flares. This tends to correlate with the 11-year solar cycle – which doesn’t show any trend over the past fifty years, according to the neutron flux data. Thus, there is no way cosmic rays could ever account for even a small percentage of our warming trend. It’s obvious, but SLAC doesn’t discuss it in any detail – they just link to Svensmark’s site. That’s the politically safe thing to do if you rely on DOE funding for your survival – recall what happened to the USGS and the National Biological Survey in the 1990s?
Mark,
I understand “uncertainties”, in general and as this thread represents.
My point was there are many similar uncertainties with many aspects of the AGW theory. And obviously with climate in general.
Few are acknowledged especially in terms of the weight of uncertainty the totality of the many uncertainties represent.
Well beyond uncertainties there are serious flaws in the AGW structure.
This should not be misinterpreted as my suggesting any uncertainty is a disqualifier. Or that uncertainties are not an acceptable reality in general.
My point was, and remains, how many “uncertainties” does it take to cause a rethinking and withdrawal by those so committed to AGW?
Side stepping into defining uncertainty is not helpful.
SecularAnimist Says:
My questions up thread were pretty simple. Casting them as ignorant and arrogant seems to me to be evasive.
So with all due respect, you really need to understand that you haven’t the slightest idea what I know or don’t know.
Ray Ladbury Says:
Your convenient assumptions wander away from reason. I have met, know and visit with scientists. Your presumption that I have not appears to be some sort of protest. Your presumptuous idea that I “think knowing uncertainties is a bad thing” is also off base.
I never came even close to suggesting such an asinine thing.
Your effort appears to be one that allows you to create a basis for your then ad hominem conclusion I am therefore “utterly ignorant”.
I am quite certain there are plenty of scientists who devote, oh, say 20-40 years of their lives to climate related study who disagree with your opinions about current climate theories.
Of course, in a big way, we don’t understand absolutely every aspect. However the degree which we can be confident that what we don’t understand does not outweigh what we do understand remains unsettled.
There is much concern that some very grave misunderstandings are being sugar coated and left without adequate consideration.
These grave misunderstanding are leading many experts and informed people to conclude the case for humans behind recent warming is inescapable fatal flaw. The cross section of people studying climate trends are developing clearer observations and measurements almost daily. Many of which fall into contradicting prior AGW assumptions.
What are you waiting for? “Good jokes”?
R Keene: “minimum denier” appears to come from on blogers responding angrily to this very new paper:
http://www.sciencemag.org/cgi/content/abstract/sci;324/5923/78
Science 3 April 2009, Vol. 324. no. 5923, pp. 78 – 80
DOI: 10.1126/science.1166349
Reports — Persistent Positive North Atlantic Oscillation Mode Dominated the Medieval Climate Anomaly
Hat tip to:
http://solveclimate.com/blog/20090406/scientists-debunk-favorite-denier-claim-about-climate-change
R Keene 60.
A quick comparison (not necessarily scientific), the graphs have been scaled for easier comparison.
http://www.woodfortrees.org/plot/gistemp/scale:200/plot/sidc-ssn
Hope this helps clarify things.
R. Keene, Given that GCR fluxes are not changing significantly and have not done so for over 50 years, that would suggest that if they ever were a major driver of climate, their contribution is not significant at present.
Again, don’t like the inescapable conclusion that we’re warming the planet? Then come up with a model that explains Earth’s climate better than the current model. It’s called science.
The oracle of ReCAPTCHA: zapping accepted
John H wrote: “I am quite certain there are plenty of scientists who devote, oh, say 20-40 years of their lives to climate related study who disagree with your opinions about current climate theories.”
Certain you may well be. But you are still wrong.
John H wrote: “These grave misunderstanding are leading many experts and informed people to conclude the case for humans behind recent warming is inescapable fatal flaw.”
Wrong again.
Would you care to list the “scientists who devote 20-40 years of their lives to climate related study”, and the “experts”, who believe that “the case for humans behind recent warming is inescapable fatal flaw”?
What are their qualifications? What is there experience in the field? What is the “fatal flaw” that they have found, which has somehow escaped the attention of hundreds upon hundreds of climate scientists who have diligently studied the issue for decades? And has also escaped every major scientific body in the world that has addressed the question, including the national scientific academies of every developed country on Earth?
Or are you just saying that such people exist because that’s what you’ve been told by denialists?
Actually, John H., you were doing just fine giving the impression of utter ignorance without any help.
Care to actually suggest what some of these “grave misunderstandings” might be, or are you more content to leave things vague. Just one. Pretty, please. Last count, the proportion of climate scientists who actively publish in the field who agree with the consensus account was more than 95%. Not one professional or honorific scientific organization that has looked at the issue has dissented from the consensus. So if there are all these “grave misunderstandings” just where are they being published?
Thanks, gavin, for your helpful statement that aerosol forcings are not yet settled science. As Bart pointed out, black carbon is definitely warming (additive to CO2), but other aerosols are thought to be cooling. The world and I will have to wait for more clarification, but finding out what needs to be worked on is a good step forward. Cautious equivocation may be good science etiquette, but strong fact-based advocacy by climate scientists also has its place in the current public discussion of global climate change.
I am. Your post is a bad joke. Surely you can do better?
I think you’ll feel more comfortable at this blog, whose author seems to share your beliefs.
Dr. Verheggen, the paper you gave us above (the “recent follow up study”) is open for comment; the one commenter points out that many more simulations could have been run picking different numbers from within the range of uncertainty, but says “I understand how expensive these simulations are, so I don’t recommend running any new simulations.”
Can you say something about the cost of doing these simulations?
That’s kind of amusing, Hank, and here is why, a quote from the web site:
“NAO was in a persistent, centuries-long positive mode. Nowadays, NAO is nowhere near that persistent. Over the last 100 years, NAO has been up and down. We didn’t know it was possible that NAO could be in the same state for such a long period of time.”
What kind of oscillation is that? They are only called oscillations because that is an underlying assumption of the time series analysis tools (which was originally developed for use in astronomical observations – and with planetary orbits being highly periodic, it was a safe assumption).
There are many phenomenon which appear periodic, but which are actually random – I’m sure you could come up with a “periodicity” of volcanic eruptions using time series analysis as well.
Now, about that web site you linked to – solveclimate.com
According to the Wayback Machine, it appeared around Oct 29 2007, with a list of standard industry PR topics – “replace dirty coal with clean coal”, etc. – and tellingly, no mention of solar or wind or biofuels. It also included a “we are running out of oil” theme – we are not running out of oil, and the Fossil Fuel age will not come to an end due to lack of fossil fuels – same as for the Stone Age. Finally, it attempts to portray the climate issue as a “left vs. right” issue, as in “Evagelicals “turn left” on climate.” Those are all industry PR themes.
Let’s restate those PR themes for clarity:
1) “Clean energy means clean coal”.
2) “Fossil fuels are precious resources we cannot live without.”
3) “Left-wing radicals push climate issues for political advantage.”
Don’t forget that the fossil fuel PR industry has a very specific defintion of “victory” when it comes to climate issues, as seen in the leaked AIP report, 1998:
http://www.euronet.nl/users/e_wesker/ew@shell/API-prop.html
Quote:
Now, take a look at solveclimate.com on Kyoto:
http://solveclimate.com/blog/20071031/kyoto-compliance-cost-japan-10-5-billion-only
[edit – be nice]
Of course, the last thing the fossil fuel industry wants is a lot of vocal scientists pointing out the facts to the general public.
The fossil fuel industry PR goal hasn’t changed – they’ve just replaced “Kyoto” with “Copenhagen.” The goal is still to prevent government regulation of fossil consumption, maintain government subsidies for fossil fuels, and prevent the rise of renewable competitors via political machinations.
Re: #60,
R. Keene,
Some things to note regarding various causes of global temperature change over the last millenium, and in recent times.
1. The swings in global temperature haven’t been that great, a few tenths of a degree on average between MWP and LIA (land + ocean), although with more regional variation.
https://www.realclimate.org/index.php/archives/2008/09/progress-in-millennial-reconstructions/
http://en.wikipedia.org/wiki/File:1000_Year_Temperature_Comparison.png
http://www.sciencemag.org/cgi/content/abstract/294/5549/2149?hits=10&RESULTFORMAT=&FIRSTINDEX=0&maxtoshow=&HITS=10&fulltext=%28solar+AND+forcing%29&searchid=1&resourcetype=HWCIT
So even if one attributed the gradual trend in global temperature changes over those centuries to solar activity, the amount of change is relatively small and gradual compared with present warming.
2. Solar activity seems likely to have played a role, as well as volcanic activity. The gradual cooling trend from MWP to LIA also saw an increase in volcanic activity. See section 6.6.3.
http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter6.pdf
Also see Hank’s citation (#63) of a recent study on NAO and the MWP.
Some other possible contributors on the LIA.
http://news.bbc.co.uk/1/hi/sci/tech/4755328.stm
http://news-service.stanford.edu/news/2009/january7/manvleaf-010709.html
I’d like to see an RC post on these at some point – how scientifically robust they are. I’m personally skeptical of a significant human impact on global climate change in mainly pre-industrial centuries.
3. There are likely some noticeable short-term affects from the 11-year solar cycle, but this is reasonably constrained as well.
http://data.giss.nasa.gov/gistemp/2008/
4. Your graph also notes a slight decline in sunspot activity in the 2nd half of the century (a bit more so with the recent lull), yet temperatures have risen rapidly.
http://en.wikipedia.org/wiki/File:Temp-sunspot-co2.svg
Consequently, although I’ve seen a few claims to the contrary, solar activity can’t explain any significant amount of recent warming.
http://www.pnas.org/content/104/10/3713.full.pdf
and has possibly been a cooling influence in recent decades:
http://publishing.royalsociety.org/media/proceedings_a/rspa20071880.pdf
“I understand “uncertainties”, in general and as this thread represents.
My point was there are many similar uncertainties with many aspects of the AGW theory. And obviously with climate in general.”
There is little evidence of you understanding uncertainties.
For you only posit that they can make a difference in reducing the problem of AGW. You’re oddly *certain* about that.
And what effect do the uncertainties have?
There are uncertainties about stellar physics. Does this mean that the sun is not warming the earth?
Again, you seem unusually *certain* that these uncertainties mean we cannot say anything significant about the climate.
Why are you so certain about these uncertainties? Especially when you say you understand what it means scientifically…
@ jaydee Says:
16 April 2009 at 12:39 PM
“R Keene 60.
A quick comparison (not necessarily scientific), the graphs have been scaled for easier comparison.
http://www.woodfortrees.org/plot/gistemp/scale:200/plot/sidc-ssn
Hope this helps clarify things.”
I think that http://www.woodfortrees.org/plot/sidc-ssn/scale:0.01/mean:200/from:1850/offset:-.8/plot/hadcrut3vnh/from/mean:40
makes it even clearer.
It’s obvious that the rise in temperature starting around 1920 reflects magnetospheric/GCR coupling from tachyon monopoles emitted concurrent with (Though the term ‘concurrent’ is a rather slippery concept in the context of the physics of tachyons) the rise in sunspots between ~1940 and 1960. My apologies for the timing; I posted this April 1st, based on my reading of GCR dependent cloud patterns, but it’s only showing up now because of some strange twist in causality…
On another subject – my own previous post re GCR-charged CCN-rainfall – some googling led me to Mauas et al,APS » Phys. Rev. Lett. » Volume 101 » Issue 16
Phys. Rev. Lett. 101, 168501 (2008) [4 pages]
Solar Forcing of the Stream Flow of a Continental Scale South American River
“Here, we analyze the stream flow of one of the largest rivers in the world, the Paraná in southeastern South America. For the last century, we find a strong correlation with the sunspot number, in multidecadal time scales, and with larger solar activity corresponding to larger stream flow. The correlation coefficient is r=0.78, significant to a 99% level. In shorter time scales we find a strong correlation with El Niño.”
I would think that more GCR = more clouds = more rain, even leaving out any charged aerosol attraction effects. Apparently not, at least in the Paraná watershed. Maybe it’s something to do with those damn slippery tachyons….
Ike,
Regarding solveclimate.com and Kyoto:
:”Within two months of taking power, Bush rejected US participation in the Kyoto Protocol. It was — and continues to be — one of the most stunning political betrayals in environmental history.”
http://solveclimate.com/solutions/sign-global-treaty
On “replace dirty coal with clean coal”:
“The phrase “clean coal” defies common sense, but hear it often enough, and it starts to sound real. It isn’t. When you hear “clean coal” think of a unicorn, and you’ll be closest to the truth. ”
[…]
“The best thing going is a thing called IGCC — Integrated Combined Cycle Gasification — which is a power plant that produces less emissions that a traditional plant that burns pulverized coal. It has yet to be proven reliable — there are only 2 of them in operation in the US as of 2007. They also cost much more to build, so the electricity they would generate would cost 30% more. So there’s not much point in building these things because the same investment in energy efficiency measures and renewable energy alternatives would produce the electricity needed at similar cost without a wisp of CO2.”
http://solveclimate.com/solutions/no-more-dirty-coal
On clean energy:
http://solveclimate.com/solutions/clean-energy
Ike, you need to spend more time reading solveclimate.com, you’ve really misrepresented it. Took me about two minutes wandering around to see that.
“…tachyon monopoles…”
?!!
o moderators, where art thou ?
[Response: I think it was supposed to be satire (tachyons being faster than light particles which therefore allow one to reverse causality) – gavin]
“I would think that more GCR = more clouds = more rain, even leaving out any charged aerosol attraction effects. ”
Yes, you could think that.
Now, if the clouds were low down, they would keep things warm. If high up, they keep things cool.
And there’s only rain when there’s ENOUGH moisture to make a volume of water condense into one element too large for updrafts to keep there.
Ever wonder why you don’t get drizzle from altostratus or cirrostratus clouds? They DO fall. But they fall through dryer air (if it were moist, there’d be lower clouds beneath them) and dry out before hitting the ground.
So you could, ironically enough, get LESS rain by promoting nucleation. The effect you WOULD get is a deepening of the moist layer. And remember what low cloud does to temperatures..?
I do NOT know enough to work out which is the bigger effect or how well it balances out.
But I *do* know enough to know that I don’t know. And enough to know when someone’s ideas are only half thought through.
Come on, this is O level Physical Geography. Or was in my day.
Note to anonymous commentators: it’s clear that solveclimate.com ignores solar, wind and biofuel energy, which really are the only plausible large-scale replacements for fossil fuels.
This is something of the new approach by the fossil fuel PR industry – lacking any valid scientific results that challenge the IPCC conclusions and those of more recent research, they have resorted to deceptive tactics which appear to be aimed at “solving climate” but in reality simply provide cover for business-as-usual – the technical term is “greenwashing”.
In other news, we have another Science paper out on the role of the Atlantic Ocean – seems to be a “banging of the AMO drum” paper, which has has already received coverage at numerous sites. The actual gist of the paper can be seen in this quote:
Going to a single site, taking a core, and deriving the entire climate history for the past three thousand years from it is a bit questionable… and another press release says this:
Not quite sure how that correlates with the “30 to 60 year oscillation” of the AMO. For a different interpretation, see Tropical Atlantic Cooling And African Deforestation Correlate To Drought, Report Scientists
This has something to do with aerosols (not the GCR variety) in that dry periods in Africa are expected to increase mineral dust loading over the Atlantic, which should cool the ocean, not warm it – which makes you wonder even more about the “AMO”. Notice also that the current drought is not a regional phenomenon brought on by natural variability, but a consequence of a warming atmosphere and expanding Hadley cells across all subtropical belts.
In any case, this particular topic certainly shows that climate science is not a settled issue – the part about CO2 and other greenhouse gases warming the climate is well understood, but there is a great deal of very active research into the regional effects.
Ike Solem
“Stanford and DOE – they are also big backers of carbon capture and sequestration. They say that 90% of carbon emissions from coal plants can be captured this way – not that they have any working prototypes to support such claims.”
From the information I’ve seen, CCS will not be cheap. Estimates for power from coal with CCS are about 16 cents/kWh. How will that compete with wind at 6-8 cents or so now, solar thermal at under 10cents /kWh in probably 4 years and 4-8 cents/kWh in ten years or less? Or PV solar for that matter? And they are far cleaner than coal even with CCS. The NREL estimates that California deserts have the potential for at least 640 GW of solar thermal w/ heat storage, just on land with 1% slope or less, and avoiding environmentally sensitive areas. Land up to 3% slope is considered good. California’s total generating capacity is now 58 GW, from all sources.
“Solar and wind provide clean electricity with no need for water for cooling, but are intermittent power sources and require storage technologies, batteries or fuel cells.”
Well, solar thermal has it’s own heat storage, which happens to be much cheaper than storing electricity in batteries.
By the way, concentrated PV solar does need cooling, one Israili company is turning this into an asset, by producing electricity and hot water from CPV. Solar thermal can be air or water cooled.
Also, I believe the intermittency issue is far overblown. Denmark has managed with 20% wind energy. They trade it to Germany for base load power. There is a good argument that base load is also overhyped; and that the dispatchable power from solar thermal has more value, particularly when trying to balance and intergrate the new energy sources into the grid.
“Why CSP should not try to be Coal”
http://www.altenergystocks.com/archives/2009/04/why_csp_should_not_try_to_be_coal.html
He argues that Joe Romm shouldn’t call it solar base load, but because he agrees with him, that it’s better than base load.
http://climateprogress.org/2008/07/28/solar-baseload-update/
Solar baseload update
The Base Load Fallacy
Author: Mark Diesendorf energyscience.org.au
http://www.energyscience.org.au/BP16%20BaseLoad.pdf
Here’s the mission statement from CivicActions, who owns “solveclimate.com”.
Ike Solem claims it’s an industry shill site.
Doesn’t sound like it to me:
Here are the deep-cover industry shills Ike Solem warns us against.
I’m sure they’ll be as surprised as you are to realize they’re just programmed robots working against their own values.
I’d say at this point it’s up to Ike Solem to prove that CivicActions is funded by the fossil fuel industry, which in order to provide deep cover is funding, among things like world peace and the like, endorsement of Union of Concerned Scientists recommendations that fossil fuel consumption be deeply cut.
Show us your source that proves that this is actually industry-funded, Solem. Otherwise, quit slandering.
Here is Ike Solem’s definition of “business as usual”, from solveclimate.com (which adopts the Union of Concerned Scientists recommendations).
Does this sound like a fossil fuel industry recommendation to you?
Of course, that’s all targetting coal-fired electrical plants, not automobiles, but don’t I keep hearing that coal’s the #1 problem?
And isn’t coal a fossil fuel?
Here, solveclimate.com endorses Big Oil’s position that CAFE standards should be abandoned:
Oh, wait, they *don’t* take the industry position.
31:
It is possible to build air cooled Nuclear plants. They would be more costly and less efficient than water cooled ones, but it can be done. Note water would still be used as a heat transfer mechanism, but it is in a closed loop.
Brian Dodge (74),
You wrote: “more GCR = more clouds = more rain”
The last part is incorrect. The causality would be more CCN = more but smaller droplets = less rain (since rain formation requires the droplets to grow large enough to fall down).
Mark (78),
You wrote: “if the clouds were low down, they would keep things warm. If high up, they keep things cool.”
It’s opposite in general. See e.g. here and here. The colder (=higher) the cloud, the less energy (re-radiated from absorbed IR) they radiate into space, so the more the atmosphere will warm.
(Captcha: Barth sculptures ?!)
CivicActions only built and host the solveclimate.com site. They built it for a New York PR Consulting company called ScienceFirst Inc – http://civicactions.com/projects/solveclimate . ScienceFirst does not seem to have its own website and there is no indication within solveclimate.com on who funded ScienceFirst to build the site in the first place.
Captcha – game rookies
“It’s opposite in general.”
I thought otherwise. Hey, it’s been about 24 years since I did physical geography at school.
But then you have the same issues, just they start the other way round and progress oppositely.
And you still don’t get drizzle from high cloud.
Thanks for correcting me on the way round, though.
“Here’s the mission statement from CivicActions, who owns “solveclimate.com”.
Ike Solem claims it’s an industry shill site.”
Maybe rather than attacking Ike, ask where he got the impression they were a shill site?
For every action, there is an opposite and equal action that act on different bodies.
Yell him down, he’ll yell you down.
John Finn writes:
World War II ring a bell? Massive ramp-up of industry? The US coming out of the Depression like an express train and turning out thousands of liberty ships and flying fortresses?
Bart Verheggen, thanks very much for the interesting post and the discussion that followed.
Having watched RC for some time, it is realy performing a great service. Thanks to Gavin and all the others who give their time.
Plimer is loading us up again with a new book.
http://www.smh.com.au/opinion/beware-the-climate-of-conformity-20090412-a3ya.html?page=-1
Can you guys do a ripost to this rundown of the content?
Re: 53
[Response: Your logical faculties seem to fail you in the last line. That is discussing global mean temperatures, not the Arctic.- gavin]
Gavin,
With respect to the mid-20th century cooling (and to a lesser extent the 2 warming periods), the arctic dominates the cooling. Cooling in the arctic was 4 times as much as any other region. Your response imples that cooling between 24N and 64N was due to aerosols, but above 64N it was due to something else entirely.
This has to be true because of the number of studies which find that the effect of aerosols in the arctic is warming. So the increased cooling effect of aerosols in the NH mid-latitudes (which I don’t accept) must have resulted in an increased warming effect in the arctic. Despite this GISS suggests the arctic cooled by ~1 deg C.
I focused on the arctic because it provides a much clearer indication of the shifts that have taken place. My bet is that the arctic just amplifies what’s happening in the lower NH latitudes (or the NH gets a reduced effect of the arctic – take your pick)
Re: 58
John Finn, Uh, where do you think that much of the energy that warms the high latitudes comes from? Here’s a hint: it’s not just sunlight. Warm ocean currents play a major role in warming the polar regions.
Yes, Ray, thanks. So why bother invoking aerosols to explain the long term climate shifts (as the IPCChas done). We’ve seen 3 strong shifts in arctic temperatures in the past century – all of which are almost certainly due to ocean current shifts.
As to the change in aerosol emissions. Hmmm. What historical event started in the late 30s and increased industrial output? What could it be? Oh yeah! WWII!! You remember. And then there was the rebuilding of Europe
Any Data by any chance? I think you need to gain some perspective on the “increased industrial output”. The early 1940s were nothing as compared to what happened in the post-1950 period and the huge invcrease in mass produced cars and domestic goods.
A decent proxy for industrial production would be …. CO2 emissions. See here http://en.wikipedia.org/wiki/File:Global_Carbon_Emission_by_Type_to_Y2004.png.
Note between ~1920 and 1950 there is very little change. Yet you’re claiming that an increase in industrial production in the early 1940s was sufficient to a) stop a strong global warming trend of ~0.13 deg per decade (since ~1915) and b) actually reverse it to produce a cooling trend.
Let’s just say I’m moderately sceptical on the issue.
Re: 91
World War II ring a bell? Massive ramp-up of industry? The US coming out of the Depression like an express train and turning out thousands of liberty ships and flying fortresses?
Yes it does but the “ramp up” in production was nothing compared to the 1950s (see my other post) and doesn’t even measure a blip in the output of CO2 emissions (see graph – used as a proxy for aerosols). I also note the US is used to represent “global” again.
Re #80, We are going to beam it down from space now.
http://www.guardian.co.uk/environment/2009/apr/16/solar-energy-farms-space
This is simply another idea just because of the constant supply argument.The USA has vast wind corridors and some very good CSP abilities but some people just long for sci fi solutions and it is getting tiresome.
“Beware the climate of conformity”
Well, there’s a problem to begin with.
Is gravity a false theory just because people conform to the idea that “things fall down”?
“The most important point to remember about Plimer is that he is Australia’s most eminent geologist.”
And when your surgeon is operating, do you want to know if he’s got a medical degree or is a certified chartered accountant?
“but he fundamentally disputes most of the assumptions and projections being made about the current causes, mostly led by atmospheric scientists, who have a different perspective on time.”
This does not mean that different perspective makes HIM right and the atmospheric scientists wrong.
“If we look at the last 6 million years, the Earth was warmer than it is now for 3 million years.”
And there have been fewer humans in the last 100,000 years than the last 100. Do we cull the human population. What does this have to do with current changes?
“Is the temperature range observed in the 20th century outside the range of normal variability? No.”
And? If I’m up on a murder charge, how much mileage do you think I will get explaining to the judge that I can’t be guilty because the observed mortality rate observed when I went on my putative killing spree was within the range of normal variability?
“To reduce modern climate change to one variable, CO2, or a small proportion of one variable ”
Strawman.
Read the IPCC report on attribution.
Is there more than one line there?
Yes. So that statement isn’t applicable.
“To try to predict the future based on just one variable (CO2) in extraordinarily complex natural systems is folly. ”
And GCM’s don’t use just one variable.
“Over time, the history of CO2 content in the atmosphere has been far higher than at present for most of time.”
And, Milord Judge, there have been many more people killed before I was born so I cannot have killed all those people.
“The hypothesis that human activity can create global warming is extraordinary because it is contrary to validated knowledge from solar physics, astronomy, history, archaeology and geology.”
Nope, it’s within all of them.
Solar physics: the sunspots are darker because the optical depth at which you “see” a surface is higher.
Astronomy: the absorbtion spectra are because the optical depth at which you “see” a surface is higher when there is an absorbtion line in the gasses.
Archaeology has litte to say on HUMAN caused CO2 production because we haven’t drilled oil for that long.
Geology doesn’t concern itself with anything other than ***finding*** oil, not burning it and it proves that CO2 has a large effect on temperature ranges over the planet’s history.
“Observations in nature differ markedly from the results generated by nearly two dozen computer-generated climate models.”
Not markedly different.
“Natural systems are far more complex than computer models.”
But so complex that no computer model can simulate the broad-picture? If this were true, modern aircraft would be falling out of the sky because they are designed by computer model.
“The setting up by the UN of the Intergovernmental Panel on Climate Change in 1988 gave an opportunity to make global warming the main theme of environmental groups.”
This is no proof that the science is wrong, just proof that the writer has a problem with environmental groups.
“He is a prize-winning scientist and professor.”
And what about the other (more numerous) prize winning scientists and professors who say AGW is real and correct? If your metric for believing someone is how they have won prizes, you would be for AGW.
The whole piece is hand-waving that would put Magnus Pike to shame.
This is off topic — sorry. A survey just announced shows that only 47% of the US thinks that AGW is real.
See the depressing story at
http://pewforum.org/docs/?DocID=238
Burgy
Hank Roberts (70):
Bart Verheggen asked me to reply to your comment.
“Dr. Verheggen, the paper you gave us above (the “recent follow up study”) is open for comment; the one commenter points out that many more simulations could have been run picking different numbers from within the range of uncertainty, but says “I understand how expensive these simulations are, so I don’t recommend running any new simulations.”
Can you say something about the cost of doing these simulations?”
I can really only speak from personal experience with the models that Peter Adams and I have used, but the GLOMAP/TOMCAT model that Ken Carslaw’s group uses (used in the paper you mention) has a similar aerosol microphysics scheme to ours, so the “costs” are likely also similar. By “costs” I am referring to computational time, not a monetary value (though there probably is some conversion).
For these models with online aerosol microphysics, simulating one year takes on the order of one month of real time if it is ran on a single processor. Therefore, if you have 8 processors to work with, you could simulate one year in a few days by parallelizing the code with 100% efficiency (though efficiencies are generally much lower, so the computation time would be longer), or you could run 8 simulations at the same time and have each simulation take about 1 month.
With most journals, you only have about a month to revise your paper (though they may honor extensions), so I tend to be conscientious of the time it takes to simulate new runs. Obviously, if I feel that there are major issues with a paper that require new runs, I’ll ask for these runs to be done. However, my opinion is that the referenced paper above is solid and contributes new information to the field, so it is better to address the uncertainties verbally and publish the paper quickly. There are currently about 5 groups publishing papers on how cloud condensation nuclei and cloud droplet number have changed between pre-industrial times and today and the uncertainties associated with this calculation, so it is highly likely that future papers will explicitly explore these uncertainties in more detail.
Burgie,
And about the same percentage believe in evolution (within errors as a matter of fact). It merely shows us that we’ve got our work cut out for us. As George Carlin says, “The average person is an idiot, and 50% are stupider than that.”
Polls like this provide pretty strong support for that assertion.
There are no shovel-ready solutions for CO2 from coal plants. Coal power is the largest source of CO2 emissions in the US and worldwide. China is going to build 800,000 MW of new coal-fired generation in the next decade, an amount 2.5 times the current installed base of US coal-fired power plants. Renewables (with the possible exception of concentrating solar) are not suitable replacements for coal as baseload power because renewables are intermittent and storage is an unsolved problem. The grid becomes unreliable if renewables are more than 20%.
There will be no money in the US for any new CO2 technology to be developed. Future research money at DOE has already been allocated ($80 billion to 16 contractors, awarded at the close of the Bush administration). http://www1.eere.energy.gov/ femp/ news/ news_detail.html?news_id=12150
Because of that allocation, the US is already committed to drill further into the dry hole of chemical carbon capture (amine and chilled ammonia scrubbing of flue gas) and underground storage (sequestration). Chemical capture is not scalable, particularly not for huge volumes of hot and dirty flue gas from existing pulverized coal plants, and sequestration is not practical. http://www.gao.gov/new.items/d081080.pdf