Arguments
Solar activity & climate: is the sun causing global warming?
The skeptic argument...
It's the sun
"Over the past few hundred years, there has been a steady increase in the numbers of sunspots, at the time when the Earth has been getting warmer. The data suggests solar activity is influencing the global climate causing the world to get warmer." (BBC)
What the science says...
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In the last 35 years of global warming, sun and climate have been going in opposite directions |
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Over the last 35 years the sun has shown a slight cooling trend. However global temperatures have been increasing. Since the sun and climate are going in opposite directions scientists conclude the sun cannot be the cause of recent global warming.
The only way to blame the sun for the current rise in temperatures is by cherry picking the data. This is done by showing only past periods when sun and climate move together and ignoring the last few decades when the two are moving in opposite direction.
Figure 1: Global temperature (red, NASA GISS) and Total solar irradiance (blue, 1880 to 1978 from Solanki, 1979 to 2009 from PMOD).
Last updated on 19 March 2013 by Stephen Leahy. View Archives
I said nothing about what climate IS. We are all pretty much aware of what it DOES. The best climatologist is a meteorologist with a PHD (presumed). They do quite well on both short term and long term predictions (it's mid-term where they run into trouble). But there is little understanding of what really drives climate and that is what I refer to. The GHG hypothesis came and went and came back again, the level of uncertainty is quite high.
They only recently discovered how vulcanism drives ENSO.
There are a lot of assumptions made by predictors and most are highly questionable which is why there is not a single climate model that works.
The GHG 'hypothesis' is hardly that. It is like saying that the sun heats the earth is also only a hypothesis.
It is true that the predictors can not be 100% sure of what the climate will be like in a 100 hundred years any more than they can tell what the weather will be like in 100 days.
But they are just as likely to be guilty of underestimating the climate changes as overestimating them.
Wrong question because the perspective is wrong.
History shows us that ice ages are the climatic dominant feature and that warm periods are the anomalies.
The question is "What causes the warm periods"?
You are talking about glacations within an ice age and yes the interglacials are longer than the glacations but there are only 4 known ice ages and they comprise only about 10% of the earths known history. I am not looking at just the 4th ice age but all of earth history when I say that hotter is normal.
sandy
I do not disagree with what you say except that the GHG hypothesis can not be viewed as theory due to lack of testing. It has not made accurate predictions because of the overestimated sensitivity. In other words the earth is not very sensitive to CO2 as a GHG. If it was we would have looked like Venus during the Mesozoic. So the simple answer is that the IPCC has seriously overestimated the sensitivity to CO2 while doing the opposite for TSI.
Glacial-Interglacial cycles
Point taken, however if you plot proxy temps from Cambrian to present you get a downward trend in GMT from around 21C GMT to present 13.8C.
Also latest thinking on Venus proposes the lack of a magnetic field has allowed water vapour to be dissociated by UV and the lighter H atoms stripped away by solar wind effects thus eventually depriving the planet of any water and therefore no oceanic component to modulate heat tranfer.....connect to the impending reversal/decline of our magnetic field???
Regarding climate sensitivity to CO2 modulation: This seems to me to be considerably overstated.
Again, paleoclimate proxies indicate far higher CO2 levels than now without any thermal runaway. During the Carboniferous period CO2 levels were around 800ppm yet the GMT was apparently only 14C. Later, in the Mesozoic, CO2 jumped to circa 1800ppm and the GMT rose to around 17.5C...hardly supporting the idea of thermal runaway or tipping.
The carboniferous period actually teaches us a valuable lesson about how biomass substantially impacts CO2 levels: without the CO2 locked up during that period in oil/gas/coal we wouldn't be having this debate..........
Interesting site. They mention CO2 as a GHG released from the ocean but did not mention CH4 that was released at the same time. Now why is that? They also fail to explain why the cycles do not have the same effect because they are ignoring other cycles that happen to overlap. Read "The Solar Jerk".
Mizimi
I agree that the earth has cooled and that the overall trend is one of cooling (each thermal maximum is shorter and less intense) but short term (for the earth) is slowly coming out of Ice Age 4 and temperature slope for the last 5 million years is positive (there will likely be another glacation or two but it is really unpredictable).
National Oceanic and Atmospheric Administration, the second GHG
http://www.esrl.noaa.gov/research/themes/forcing/Methane.pdf
Search NOAA
Interesting presentation on how it's important. It shows how strong it is as a GHG. For many years now paleoclimatologists have felt that it was the feedback that produces increased warming, not CO2, and I agree with them. The CO2 article is misleading because they say it follows temps closely but do not mention the lag which various papers put anywhere from 200 -/+ 800 to 1000 +/- 300. Afterall, they are biofeedbacks not cause, and CH4 is way stronger as a GHG than CO2. I think that the manner in which they present these GHGs is misleading.
See Mizimi comments for formula.
As a side note: I can’t say CO2 doesn’t contribute to warming, more likely so. Absorbs infrared energy. I agree to disagree in other words.
We had been discussing CH4 and tropospheric clouds in a recent article on how they form with Mizimi. Unfortunately I don't remember where I put the link to the article but I don't think it was flying cows. I believe it may have been about methane hydrates but now I can't remember. :)
I’ll watch this thread for the link, and thank you.
I found the original story (I still can't remember where I put the lik originally).
Strange Clouds Spotted at the Edge of Space By Jeremy Hsu, Staff Writer, posted: 01 September 2008 08:50 am ET, 30 Comments
A brief opening quote:
“The noctilucent or “night-shining” clouds are at an altitude of 47 to 53 miles (76 to 85 km), where meteors and bright aurora lights are not uncommon and the atmosphere gives way to the blackness of space.”
and from the body of the article:
“Another likely source of water vapor is methane oxidation”
It's an interesting read. :)
I actually do not disagree with AGW, it is a valid hypothesis. What or more specifically who I disagree with, are alarmists who twist the works of skeptics and totally neutral scientists either into a denial or falsely supporting AGW, and activists who seem to worship their word as gospel. Dr. Hansen is without any doubt an alarmist from his "or we are all toast" statement, rendering his judgement clouded in my view. And since he is the primary author at Real Climate, it in turn is alarmist, so I don't go there anymore.
My issue with CO2 is purely one of sensitivity.
I see other causes that are stronger than CO2 induced AGW simply because AGW is weaker than originally thought and the emphasis on CO2 in particular is distracting the science and preventing finding the actual problem. I don't know if it is a blind faith, cognitive disonnance, an agenda or something else. I was taught to question everything that did not seem logical and that had stood me well in an engineering environment (I am now retired) so I do not understand their irrational behavior.
If you are interested in what I think is happening see the volcanos thread, which I feel is related to this thread via Dr. Rhodes Fairbridge's (non-peer reviewed) solar hypothesis.
For some reason the link I posted for you is dead. I probably made another typo so here is the text, just copy and paste:
http://www.livescience.com/space/080901-mm-night-shining.html
The real climate fear from actual science is swift change, which the world past shows how volatile it truly is.
CO2 views as an industry and population agenda. Ultimately humans have a natural tendency to tackle problems viewed solvable, especially when the problem involves their back end. The "other climate” mentioned have been known for quite a while but CO2 was narrowed which is ludicrous. The world itself will never be narrow.
No we would not have looked like Venus during the Mesozoic because Venus and the earth are different in many ways.
For one thing Venus is nearer the sun. It has no magnetic field to protect the atmosphere and it has no plate tectonics or satellite.
But carbon dioxide has the same properties on Venus as it does on earth.
I would though like to see some evidence that the IPCC has overestimated sensitivity to CO2.
I suggest that you read Spencer's work on sensitivity.
It is linked here somewhere, possibly in the "sensitivity" thread. The fact is that CO2 and all other GHGs are feedbacks to solar energy. Change the solar input and the feedback changes with it. So when you see an increase in temp from GHG it is caused by changes in solar output. The case for venus is a bit more complicated but as that isn't the subject I kept it on a simplified level, using it the same way that the alarmists have (they claim we will look like venus if we don't take action, so I used their absurd notion).
I am glad that the absurdity was not lost on you.
http://www.er.doe.gov/OBER/CPDC/January_14_2008_DraftReport3_1.pdf
I cant open that site. Is there a typo maybe?
Any water vapour present would have been dissociated by UV and 'blown away' by the solar wind due to the lack of a magnetic field, thus stripping the planat of water.
Currently there is a project to carry out a detailed 2 year investigation of Venus' climate and compare its' evolution with our own.
http://www.lpi.usra.edu/vexag/may2008/presentations/5Titov.pdf
Thanks, that works.
Mizimi
They have determined that some volcanos also eject high amounts of SO2 on earth. It was mentioned in one of the articles that I linked on the volcanos thread here.
Now it’s overestimated or was. The scare tactic is dying.
That was an interesting read, even if it was a draft copy. I found the sections on ENSO and other ocean oscillations particularly of interest. Thank you.
http://www.biomind.de/nogreenhouse/daten/EE%2018-2_Beck.pdf
:) welcome
Actually I have not read it yet and I don't know if its the same as what Mizimi read but I will take a look at both links later.
One possible way to check 'accuracy' is to check out the annual coal tonnages around the 1850-1960 periods as oil did not supplant coal until after this period.
I rather suspect (!!)a surprise, especially since coal-burning appliances were notoriously inefficient in those times. Equally ...how much wood was burnt during this period? rather a lot I think, and in very inefficient ways.
In rural America, coal and wood still warm many homes, albeit the systems have become somewhat more sophisticated than they were when I was growing up. I would like to use a windmill here but they are quite expensive. I'm waiting for the prices to come down.
In both cases the AGW by CO2 hypothesis has some big trouble. Please don't try to make it a theory. We need it to be much better, but I don't know if it needs to be discarded.
I agree.
BTW
Have you had a chance to view any of the articles that I linked to on the volcanos thread? Every time I look for newer articles I run across another one on climate sensitivity to something or another. Spencer says it lower to CO2, Kay says it higher for TSI and the last article I posted a link to in volcanos says it's plate tectonics.
I just finished reading the short version Beck draft. What did you find objectionable?
Mizimi
What web site are they posting this argument on?
I don't say we are certain but it is starting to look like there is no way CO2 can be a large climate driver. Coupled with the paleo record clearly saying it isn't...
C3 plants cannot cope with low CO2, they require 180 -220ppm for successful growth. Experiments indicate a 58% reduction in photosynthesis if the level is dropped from 380ppm to 150ppm and up to 90% reduction below 150ppm.
C4 plants require a lower ppm value as they are 'more efficient': the first C4's were grasses. Before the appearance of grasses, most plants used phosphoglyceric acid (3 carbon atoms)to photosynthesise. Hence the name C3.
Grasses, on the other hand, use oxaloacetic acid ( 4 carbon atoms) for photosynthesis, and are called C4 plants.
As C4 plants were more efficient they began to dominate the planet creating vast eares of savannah and effectively locking up CO2.
Thure Cerling has demonstrated that C4 plants "fixed" large volumes of CO2 from the atmosphere during photosynthesis and subsequently into the soil upon death. It is considered that this lowered the level of CO2 and thus GMT, resulting in the extinction of many of the large mammals.
Keelings response to Becks paper:
www.biokurs.de/treibhaus/180CO2/Response-Beck-by-R-Keeling-2.doc+keeling+beck&hl=en&ct=clnk&cd=1&gl=uk
Beck reply:
www.biokurs.de/treibhaus/180CO2_supp.htm
Thanks
After reading both comments and the rebuttal I tend to agree somewhat with Beck, but also fail to see the relavence to sensitivity.
I am not familiar with C3 and C4 (except for the plastique kind) but from what you said I take it that pines are C3 and maples, elms and oarks are C4. What about the leafy evergreens like cedars, C3 or C4?
Plants are classed biochemically as C3, C4 and CAM.
C3 plants are the earliest evolved class and include all trees, bushes, shrubs with high wood/lignin & tannin
content. They are the source of coal.
C4 plants evolved relatively recently (8mya) and essentially are the grasses..oats, wheat, barley,bamboo
alfalfa and so on. They can be woody (bamboo) but use a 4-carbon molecule in photosynthesis, hence the name.
CAM's are specialists...they have means to cope with stress...high Temp, low water or CO2 etc...and include cacti, succulents and so on.
Because C4 plants are more efficient chemically than the others, they return LESS CO2 to the atmosphere during respiration (about 25% less than an equivalent C3)so eventually lock up CO2.
Ok, I thought you meant trees as I had read somewhere that some are better than others as carbon sinks. I also had read that grasses were better carbon sinks than trees but not why. Interesting, thank you.
C3's can tolerate much higher levels of CO2 than C4's
as in early epochs, but they cannot work with low levels of CO2 (under 220ppm for example).
C4's can work with very low levels of CO2 because they concentrate the gas in tissue before using it. BUT they don't like very high CO2 levels according to recent research...though this is contended by others.
Thank you, I was not aware of that.
John's thread on
Solar Cycles is also relavent to this thread. Naturally when I used this in the Arctic Sea Ice Melt thread I was attacked by alarmists who apparently did not read it.