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What Do We Think About Climate Change

Discussion in 'All Things Boats & Boating' started by Pericles, Feb 19, 2008.

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hoytedow Fly on the Wall - Miss ddt yet?

Boston said: ↑

Guillermo said: ↑

From Boris Komitov's The "Sun–climate" relationship III. Solar eruptions, north-south sunspot area asymmetry and earth climate
(Research report. Accepted on 12.12.2009)

please not with Komitov again
we debunked this way back on page 312
can we try at least to move forward rather than revisit the same old tired and failed arguments again and again

thanks

B
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Don't let schooling interfere with your education.
Mark Twain
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"The American Revolution represented the informed and mature convictions of a great mass of independent, liberty-loving, God-fearing people who knew their rights, and possessed the courage to dare to maintain them." President Calvin Coolidge

hoytedow, Jun 1, 2010

#7486

Boston Previous Member

ok how about if I repost a few simple things so that everyone can see the GCR trend VS the temp trend

There is little evidence for a connection between solar activity (as inferred from trends in galactic cosmic rays) and recent global warming. Since the paper by Friis-Christensen and Lassen (1991), there has been an enhanced controversy about the role of solar activity for earth’s climate. Svensmark (1998) later proposed that changes in the inter-planetary magnetic fields (IMF) resulting from variations on the sun can affect the climate through galactic cosmic rays (GCR) by modulating earth’s cloud cover. Svensmark and others have also argued that recent global warming has been a result of solar activity and reduced cloud cover. Damon and Laut have criticized their hypothesis and argue that the work by both Friis-Christensen and Lassen and Svensmark contain serious flaws. For one thing, it is clear that the GCR does not contain any clear and significant long-term trend (e.g. Fig. 1, but also in papers by Svensmark).

Svensmark’s failure to comment on the lack of a clear and significant long-term downward GCR trend, and how changes in GCR can explain a global warming without containing such a trend, is one major weakness of his argument that GCR is responsible for recent global warming. This issue is discussed in detail in Benestad (2002). Moreover, the lack of trend in GCR is also consistent with little long-term change in other solar proxies, such as sunspot number and the solar cycle length, since the 1960s, when the most recent warming started.

The fact that there is little recent trend in the GCR and solar activity does not mean that solar activity is unimportant for earth’s climate. There are a large number of recent peer-reviewed scientific publications demonstrating how solar activity can affect our climate (Benestad, 2002), such as how changes in the UV radiation following the solar activity affect the stratospheric ozone concentrations (1999) and how earth’s temperatures respond to changes in the total solar irradiance (Meehl, 2003). Furthermore, the lack of trend in GCR does not falsify the mechanism proposed by Svensmark, i.e. that GCR act as a trigger for cloud condensation nuclei and are related to the amount of low clouds. As for this latter issue, the jury is still out.

FIGURE 1. GCR counts from Climax (red) and the aa-index (blue). The straight lines show the best linear-fit against time estimated through linear regression. The GCR measurements are shown in solid black line, from which a trend of -180 +/- 253 counts/decade is estimated, and this is associated with a p-value (the probability of this being different to the null-hypothesis: zero trend) of 0.477 (not statistically significant at the 5% level). The aa-index is represented by the blue line, and the corresponding trend of 1.5 +/- 0.4/decade is associated with a p-value of 0.0002 (highly statistically significant). A regression analysis points to a clear link between GCR and the aa-index, and the analysis of variance yields R2 = 0.1466 and the p-value= 0. The yellow line shows the global mean temperature from CRU for comparison. [Data source: http://ulysses.uchicago.edu/NeutronMonitor/neutron_mon.html'' , "http://www.cru.uea.ac.uk/cru/data/temperature/" and ``ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA'].

References:

Benestad, R.E. (2002) Solar Activity and Earth’s Climate, Praxis-Springer, Berlin and Heidelberg, 287pp, ISBN: 3-540-43302-3

Damon, P.E. and P. Laut (2004), Pattern of Strange Errors Plagues Solar Activity and Terrestrial Climate Data, Eos, vol 85, num 39, p. 370

Friis-Christensen, E. and K. Lassen (1991), Length of the solar cycle: an indicator of solar activity closely associated with climate, Science 254: 698-700

Meehl, G.A., W.M. Washington, T.M.L. wigley, J.M. Arblaster, A. Dai (2003): Solar and Greenhouse Gas Forcing and Climate Response in the Twentieth Century, J. Climate, 6: 426-444

Shindell, D., D. Rind, N. Balachandran, J. Lean and P. Lonergan (1999): Solar Cycle Variability, Ozone and Climate, Science, 284: 305-308

Svensmark, H. (1998), Influence of Cosmic Rays on Earth’s Climate, Physical Review Letters, vol 81, num 22, 5027-5030
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Boston, Jun 1, 2010

#7487

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Marco1 Senior Member

I know how we can deal with climate change.

a) Kill all white particularly from western countries. Blue eyed are specialy nasty.
b) Kill everyone else who disagrees with climate change being the biggest moral challenge of our time.
c) Decimate as a disincentive all those who do not recycle, do not compost, do not fertilise with their own excrement and refuse to use a straw hat.

By now we will have reached the Wilderness society goal of one billion people tops for planet earth. Prince Philip can now rest assured that he does not need to reicarnate in a virus to decimate humanity and so fulfill his dream in life. Greens can do it for him.

Simple stuff really I don't know what are you all debating about.

There's only one corner of the universe you can be certain of improving, and that's your own self.
Aldous Huxley

Marco1, Jun 2, 2010

#7488

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Marco1 Senior Member

Guillermo said: ↑

(There are several hundreds additional studies showing a warmer than present MWP around the globe. Shall I post all of them here?)
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Warmer than now you mean? Do you mean to say that the hockey stick is actually wrong?
Bummer!

Guillermo, do you have any serious/credible studies into the theory of the methane produced by the large dinosaur?

Boston, your graph are too big, they do not fit in my screen, do you think it is because of rapid climate change?

There's only one corner of the universe you can be certain of improving, and that's your own self.
Aldous Huxley

Marco1, Jun 2, 2010

#7489

mark775 Guest

Graphs grow larger with increased gas, not increased heat. don't get your cause and effect confused.

mark775, Jun 2, 2010

#7490

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Marco1 Senior Member

Gas...yes...cold gas hits hot spot and wham, expansion.

Wov that is how the compressed air engine works. Fascinating. I want one of those, but a V8 not those piffy 6 cylinders they make.

And my compressor will be plugged in the grid powered by cosy warm clean COAL....aaaah the good feeling of being green!

I love coal man

There's only one corner of the universe you can be certain of improving, and that's your own self.
Aldous Huxley

Marco1, Jun 2, 2010

#7491

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fasteddy106 Junior Member

Boston said: ↑

Guillermo said: ↑

From Boris Komitov's The "Sun–climate" relationship III. Solar eruptions, north-south sunspot area asymmetry and earth climate
(Research report. Accepted on 12.12.2009)

please not with Komitov again
we debunked this way back on page 312
can we try at least to move forward rather than revisit the same old tired and failed arguments again and again

thanks

B
Click to expand...

What's this "we debunked" crap, just because you post an opinion by someone else and then back it up with a graph from a crossword puzzle or whereever you get the non-related junk you post, doesn't mean it is debunked. I just re-read page 312, you posted out of date material and Guill kicked your *** at the end of the page. No debunking there, except your junk. Just more of your irrelevent and pointless posturing and pretension of intelligence.
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WHO IS JOHN GALT?

31,486 scientists have signed the Petition Projecthttp://www.petitionproject.org/gw_article/Review_Article_HTML.php

fasteddy106, Jun 2, 2010

#7492

Boston Previous Member

even just the one graph presented shows clearly that there is no cosmic cycle that mirrors this centuries warming

the information from various researchers has been presented numerous times ( at least three by my count ) and in a number of different ways by several visitors to the thread and still

the simple reality is there is no corroborating rise in solar activity or GRC to account for the rise in temp, co2 or methane

the debunking of the solar connection is not only thorough but widespread within the established literature

rasmus @ 31 March 2006

In a recent paper in Geophysical Research Letters, Scafetta & West (S&W) estimate that as much as 25-35% of the global warming in the 1980-2000 period can be attributed changes in the solar output. They used some crude estimates of ‘climate sensitivity’ and estimates of Total Solar Irradiance (TSI) to calculate temperature signal (in form of anomalies). They also argue that their estimate, which is based on statistical models only, has a major advantage over physically based considerations (theoretical models), because the latter would require a perfect knowledge about the underlying physical and chemical mechanisms.

In their paper, they combine Lean et al (1995) proxy data for the TSI with recent satellite TSI composites from either Willson & Mordvinov (2003) [which contains a trend] and of Fröhlich & Lean (1998) [data from the same source, but the analysis doesn't contain a trend, henceforth referred to as 'FL98']. From 1980 and afterwards, they see a warming associated with solar forcing, even when basing their calculations on the FL98 data. The fact that the FL98 data doesn’t contain any trend makes this finding seem a bit odd. Several independent indices on solar activity – which are direct modern measurement rather than estimations – indicate that there has been no trend in the level of solar activity since 1950s.

But, S&W have assumed a lagged response (which they state is tS4~4.3 years), so that the increase prior to 1980 seems to have a delayed effect on the temperature. The delayed action is a property of the climate system, which also affects greenhouse gases, and is caused by the oceans which act as a flywheel due to their great heat capacity and thermal inertia. The oceans thus cause a planetary imbalance. When the forcing levels off, the additional response is expected to taper off as a decaying function of time. In contrast, the global mean temperature, however, has increased at a fairly steady rate (Fig. 1). The big problem is to explain a lag of more than 30 years when direct measurements of quantities (galactic cosmic rays, 10.7 cm solar radio, magnetic index, level of sunspot numbers, solar cycle lengths) do not indicate any trend in the solar activity since the 1950s.

Global mean temperature from NASA GISSFig. 1. Global mean temperature from GISS.

In order to shed light on these inconsistencies, we need to look more closely at the methods and results in the GRL paper. The S&W temperature signal, when closely scrutinised (their Fig. 3), starts at the 0K anomaly-level in 1900, well above the level of the observed 1900 temperature anomalies, which lie in the range -3K < T < -1K in Fig. 1. In 1940, their temperature [anomaly] reconstruction intercepts the temperature axis near 0.12K, which is slightly higher than the GISS-curve in Fig. 1 suggests. The S&W temperature peaks at 0.3K in 1960, and diverge significantly from the observations. By not plotting the curves on the same graph, the reader may easily get the wrong impression that the construction follows the observations fairly closely. The differences between the curves have not been discussed in the paper, nor the time difference for when the curves indicate maxima (global mean temperature peaks in 1945, while the estimated solar temperature signal peaks in 1960). Hence, the decrease in global temperature in the period 1945 – 1960 is inconsistent with the continued rise in the calculated solar temperature signal.

Another more serious weakness is a flawed approach to obtain their ‘climate sensitivity’, and especially so for ‘Zeq‘ in their Equation 4. They assume a linear relationship between the response and the forcing Zeq=288K/1365Wm-2. For one thing, the energy balance between radiative forcing and temperature response gives a non-linear relation between the forcing, F, and temperature to the fourth power, T4 (the Stefan-Boltzmann law). This is standard textbook climate physics as well as well-known physics. However, there is an additional shortcoming due to the fact that the equilibrium temperature is also affected by the ratio of the Earth’s geometrical cross-section to its surface area as well as how much is reflected, the planetary albedo (A). The textbook formulae for a simple radiative balance model is:

F (1-A)/4 = s T4, where ’s’ here is the Boltzmann constant (~5.67 x 10-8 J/s m2K4).

(‘=’ moved after Scafetta pointed out this error. )

S&W’s sun-climate sensitivity (Zeq =0.21K/Wm-2), on which the given solar influence estimates predominantly depend, is thus based solely on a very crude calculation that contradicts the knowledge of climate physics. The “equilibrium” sensitivity of the global surface temperature to solar irradiance variations, which is calculated simply by dividing the absolute temperature on the earth’s surface (288K) by the solar constant (1365Wm-2), is based on the assumption that the climate response is linear in the whole temperature band starting at the zero point. This assumption is far from being true. S&W argue further that this sensitivity does not only represent the direct solar forcing, but includes all the feedback mechanisms. It is well known, that these feedbacks are highly non-linear. Let’s just mention the ice-albedo feedback, which is very different at (hypothetically) e.g. 100K surface temperature with probably ’snowball earth’ and at 300K with no ice at all. In their formula for the calculation of the sun-related temperature change, the long-term changes are determined by Zeq, while their ‘climate transfer sensitivity to slow secular solar variations’ (ZS4) is only used to correct for a time-lag. The reason for this remains unclear.

In order to calculate the terrestrial response to more ephemeral solar variations, S&W introduce another type of ‘climate sensitivity’ which they calculate separately for each of two components representing frequency ranges 7.3-14.7 and 14.7-29.3 year ranges respectively. They take the ratios of the amplitude of band-passed filtered global temperatures to similarly band-passed filtered solar signal as the estimate for the ‘climate sensitivity’. This is a very unusual way of doing it, but S&W argue that similar approach has been used in another study. However, it’s not as simple as that calculating the climate senstivity (see here, here, here, and here). Hence, there are serious weaknesses regarding how the ‘climate sensitivities’ for the 11-year and the 22-year signals were estimated. For linear systems, different frequency bands may be associated with different forcings having different time scales, but chaotic systems and systems with convoluted response are usually characterised with broad power spectra. Furthermore, it’s easy to show that band-pass filtering of two unrelated series of random values can produce a range of different values for the ratio of their amplitudes just by chance (Fig. 2). As an aside, it is also easy to get an apparent coherence between two band-pass filtered stochastic series of finite extent which are unrelated by definition – a common weakness in many studies on solar-terrestrial climate connection. There is little doubt that the analysis involved noisy data.

Histogram of amplitude ratios for two band-pass filtered stochastic seriesFig. 2 showing band-passed random data. A range of 0.5 – 2.0 suggests that there is a risk that one of the amplitudes in two noisy series is twice the value of the other.

The fact that there is poor correspondence between the individual amplitudes of the band-passed filtered signals (Fig. 4 in Scafetta & West, 2005) is another sign indicating that the fluctuations associated with a frequency band in temperature is not necessarily related to solar variability. In fact, the 7.3-14.7 and 14.7-29.3 frequency bands may contain contributions from El Niño Southern Oscillation (ENSO), although the time scale of ENSO is from 3-8 years. The fact that the amplitude of the events vary from time to time implies slower variations, just like modulations of the sunspot number has led to the proposition of the Gleissberg cycles (80-90 years). There is also volcanic activity, and the last major eruption in 1982 and 1991 are almost 10 years apart, and may contribute to the variance in the 7.3-14.7 year frequency range. S&W argue that their method eliminates influences of ENSO and volcanoes because their calculated sensitivity in the higher frequency band is similar to the one derived by Douglass and Clader (2002) by regression analysis (0.11 K/Wm-2). This conclusion is not valid. Having signals of different frequencies in the 7-15 years band, the amplitude of the signal in the higher band may correspond roughly to the 11-year signal by accident, but that doesn’t mean that there are no other influences.

S&W combined two different types of data, and it is well-known that such combinations in themselves may introduces spurious trends. The paper does not address this question.

From regression analysis cited by the authors (Douglass and Clader 2002, White et al. 1997), it seems possible that the sensitivity of global surface temperature to variations of total solar irradiance might be about 0.1K/Wm-2. S&W do not present any convincing result that would point to noticeably higher sensitivities to long-term variations. Their higher values are based on unrealistic assumptions. If they would use a more realistic climate transfer sensitivity of 0.11K/Wm-2, or even somewhat higher (0.12 or 0.13) for the long-term, and use trends instead of smooth curve points, they would end up with solar contributions of 10% or less for 1950-2000 and near 0% and about 10% in 1980-2000 using the PMOD and ACRIM data, respectively.

We have alread discussed the connection between solar activity (here , here, here, and here), and this new analysis does not alter our previous conclusions: that there is not much evidence pointing to the sun being responsible for the warming since the 1950s.
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Last edited: Jun 5, 2010

Boston, Jun 2, 2010

#7493

Boston Previous Member

and again this from about a year or two more recently

rasmus @ 19 May 2005

In a paper in Geoscience Canada, Veizer (2005) states that ‘the multitude of empirical observations favours celestial phenomena as the most important driver of terrestrial climate on most time scales‘. This paper was cited by a contributor to a debate on the website openDemocracy . In short, the argument is that the cosmic ray flux (CRF, also denoted as ‘GCR’ – galactic cosmic rays – in some papers) is the most important factor affecting our climate. Since this issue is likely to crop up from time to time, it is worth taking a closer look at the Veizer (2005) paper ( Here is a link to short summary, but the actual paper requires subscription). [Update: The actual paper is now available as supplemental material on the Geoscience Canada website.] I will try to show that CRF explanation for the recent global warming is easy to rule out.

One of the main planks of the argument that CRF is responsible for the most recent warming is based on figure 14b in Veizer (2005), where there appears to be a trend in CRF from eg Climax neutron monitor (also, see plots at this URL). This CRF-curve was a surprise to me, and furthermore, it’s at odds with CRF-evolution presented in figure 17 in the very same paper (showing no systematic change) – how can these accounts be so different? The inconsistency becomes even more apparent when it is argued that the ‘balloon and satellite data ([Veizer, 2005] Fig. 17) do not show any clear temperature trend… Instead, their interannual temperature oscillations correlate clearly with … CRF’ (p. 22, 2nd column). Again, no long-term trend in the CRF-data. It has been argued earlier on RealClimate that there is no long-term trend in the modern CRF measurements. The lack of systematic trends in CRF and other solar activity proxies is well-known and published in the scientific literature (eg. Richardson et al, 2002). In fact, the CRF curves presented by some of the key cosmic-ray hypothesis proponents, Marsh & Svensmark, do not exhibit any trend, yet it has been claimed that CRF is responsible for the most recent warming (Marsh & Svensmark say that the wiggles correlate, but don’t discuss the [or lack of] observed trends).

There are other aspects which appear as problematic for the CRF-interpretation for the recent global warming. First of all, according to IPCC (2001) the night-time temperatures have in general increased more than the day-time temperature (the diurnal temperature range, DTR, has decreased in most areas, except over middle Canada, and parts of southern Africa, south-west Asia, Europe, and the western tropical Pacific Islands). Since individual clouds have a life time of hours, and the CRF-interpretation involves changes in the reflected light as well as ionisation, a climatic response from change in CRF is hypothetically almost instantaneous, and it is a challenge to explain why the night side (where there is no sunlight and hence reflection cannot play a role) warms more strongly than the dayside, if the CRF were to drive the recent warming trend. Another equally important challenge is the fact that there are pronounced ~11-year variations in the CRF, but the presence of ~11-year variations in the global mean temperature are much less pronounced than the trend over the 3–4 most recent decades. If the CRF were so important (and the cloud response near-instantaneous) why do we not see more pronounced ~11-year variations in the global mean temperature?

The paper also gives the impression that there is no trend in satellite-based temperatures (MSU), which is wrong. There are various analyses of the satellite trends, all of which indicating a warming trend in the troposphere.

When Veizer summarises in bold type face ‘(above) empirical observations on all time scales point to celestial phenomena as the principal driver of climate’, he neglects to discuss the fact that the stratosphere has been cooling, which at higher levels is consistent with an enhanced greenhouse effect (most of the cooling in the lower stratosphere is related to changes in ozone) but inconsistent with enhanced solar activity and his CRF-hypothesis. Another argument Veizer uses to support his hypothesis is that the correlation between the proxy indicators for CRF is better correlated with ‘climate’ than between CO2 and climate. Yet he does not provide any references or justify his argument. I find this statement rather puzzling, as it seems to me that there is a good correlation between the CO2 and temperature proxies such as can be seen in Veizer’s own figure 7. The same seems to be the case in Fig. 1 below:

Fig.1: A comparison between CO2 and CRF indices with temperature proxy. Superimposed is the Beryllium-10 (blue). All curves are standardised. (paleaoproxy.R).

If we’re looking at the last century, then there is a sulphate aerosol “blip” that worsens the CO2-T correlation. But there are also times when there are distinctive features in the CRF proxies in Veizer (2005) figure 8, when there is no corresponding response in the temperature (figure 7 of Veizer, 2005). Actually, I do not see much resemblance between the CRF-proxies presented in the paper and the temperature proxy, and there is no quantitative statistical analysis of their correspondence. Thus, the above statement appears to be a value judgement, rather than an objective observation. Along the same vein, the paper claims there is a good degree of correspondence between the timing sunspot minima and minima in precipitation curves in Veizer (2005) figure 16. I do not find his (hand waving?) arguments convincing. Note, the paper does not offer any quantitative statistical analysis on the correspondence of these curves. Nor does it discuss how the CRF-proxies may have been affected by past variations geomagnetic field, which clearly would degrade any correlation between CRF and climatic indices. It should be noted that proper attribution studies don’t just do correlations, they are rather more sophisticated. There is the possibility of the presence of a common cause that may have affected the various isotope records (representing both CRF and ‘climate’), and Veizer does not even mention the possibility that the deposition efficiency of these may be affected by climate itself (e.g. circular reasoning).

At other times, the discussion misrepresents the current knowledge when comparing only the clouds’ albedo effect with the CO2 forcing, and not the net effect including the absorption of long-wave radiation (p. 14, 2nd cloumn). The Veizer (2005) paper also tends to make strong statements based on controversial papers (eg. Soon and Baliunas, 2003; p .20, 3rd column – several editors left the journal after it was published because they felt it was flawed). I find Veizer’s reference to other work very selective. The role of CRF as a driver for climate is indeed controversial, and this fact is not acknowledged in the paper.

On a more technical note, an R-script gcr.R is available from this site which helps you retrieve the CRF-data over the Internet and plot the data. Please use it, play around, and see for yourself. Another script, paleaoproxy.R is also available here, and is makes Fig. 1 above.

References:
Richardson et al. (2002), “Long-term trends in interplanetary magnetic field strength and solar wind structure during the twentieth Century”, J. Geophys. Res., Vol 107, A10

Veizer, J. (2005) “Celestial Climate Driver: A Perspective From Four Billion Years Of The Carbon Cycle”, Geoscience Canada, vol 32, no. 1, 13-30.
30 June 2005
Addendum: “Celestial Driver” Part 2

In the above post, time permitted us only to discuss a few of Veizer’s arguments, focussing mainly on the cosmic ray flux. Here we take a look at some of the other arguments presented in his paper.

Solar cycle length
Veizer suggests the recent global warming might be driven by changes in solar activity (his Fig. 14a – dashed line is temperature, solid line with diamonds is solar cycle length). But the figure only shows the temperature record from 1935-1990, even though of course more recent data are available. Veizer must be aware that in view of these more recent data, the scientist who originally proposed this correlation in 1991, Knud Lassen, has concluded in 2000 that solar cycle variations cannot explain the ongoing warming trend [1].
In the figure below, we have superimposed the standard CRU data set (blue curve) of global mean temperature on Veizers graph.

We see that the graph selectively shows a part of the time series dominated by the well-known temporary “dip” in the global warming trend, reaching a minimum around 1970. The correlation of temperature and solar cycle length applies mainly to this “dip” in the curves. Thus, solar cycle variations may or may not explain this “dip” (one similar-looking dip in two curves is not a significant correlation and could easily be coincidence; there is a better-founded explanation for this “dip” resulting from cooling by aerosol emissions – see the figure from Hansen et al. coming up below).

But there is no indication that solar cycle variations could explain the ongoing warming trend. There is simply no significant trend in this (or any other) solar indicator since 1940. Veizer fails to discuss the key issue (namely, whether the data support the idea that the warming trend, rather than just the temporary dip, could be explained by solar cycle variations). The (often faulty or misleading) use of these solar cycle data by “climate sceptics” has quite a pre-history, see e.g. Damon and Laut (2004). Note that the relative vertical scale of the curves is arbitrary. The article by Damon and Laut (2004) also shows that when solar cycle length is scaled up as much as it is in the above figure in order to match the 1940-1990 temperature record, that this implies a great mismatch for the earlier periods in time. Veizer should be aware of this problem of his proposed match, but he fails to mention it.

As an aside, one of the data points in the above graph is incorrect; the National Geophysical Data Center gives a solar cycle length of 11.8 years for 1963, where Veizer plots 11.0 years.

[1] P. Thejll and K. Lassen, 2000: Solar forcing of the Northern hemisphere land airtemperature: New data. Journal of Atmospheric and Solar-terrestrial Physics, Vol. 62 (13),1207-1213.

Greenland temperature variations
Veizer’s paper argues that the local preindustrial climate fluctuations over the past millennium in Greenland were not driven by CO2. As a proof, Veizer shows a temperature reconstruction for Greenland together with the CO2 concentration in his Fig. 12. Now, the preindustrial CO2 concentration over this period was constant, and therefore nobody has ever proposed that CO2 could have caused any climate variations during this time. It obviously can’t. Showing this in a plot is thus a completely moot point that is clearly not aimed at any fellow scientist; it is something meant to impress uninformed lay-people. Indeed, the graph is not from a scientific publication, but was reproduced from a popular climate-sceptics book that has been distributed in Germany by the coal-industry lobby.

Using a time period when CO2 did not change at all, to support a general conclusion that “CO2 is not the driver of climate change” and hence is not responsible for the current warming, is hardly logical. It merely highlights the fallacy of looking for one single “driver” that explains climate variations on all time scales. It is well-established in climatology that different causes and mechanisms have caused climate changes in the past (orbital variations, plate tectonics, solar variability, volcanic eruptions, etc.), so that a cause-effect relationship has to be determined for each individual case, rather than looking for one overall “driver”.

(As an inconsequential but telling aside, Veizer wrongly attributes the CO2 curve in Fig. 12 to the Greenland ice core GISP2. It is well-known amongst paleoclimatologists that there are no successful CO2 measurements from Greenland, the record shown is obviously from Antarctica. It is strange how this slipped by the journal’s review.)

A strange temperature graph
Veizer, Fig. 14d
Veizer publishes the above graph to suggest that temperature and CO2 concentration do not look alike, hence CO2 has not caused the warming.

First, Veizer’s temperature curve looks unlike anything published in the scientific literature. Temperature in the year 2000 no warmer than 1960? Clearly something is wrong with this – seemingly hand-drawn – graph. It is once again not a scientific diagram but lifted from the german climate sceptics book “Klimafakten” mentioned above. It is remarkable (and perhaps a novelty in the history of science) that the paper takes several graphs straight from climate sceptics PR material produced for lay-people, rather than basing its case on peer-reviewed scientific sources. It is surprising that the faulty temperature graph – which sticks out like a sore thumb to any climatologist – could slip through the review procedure at Geoscience Canada.

Second, this is a very naive argument. CO2 has increased in a smooth trend, hence it can obviously only explain the overall trend in the temperature data, but not any shorter-term variability around this trend. Nobody has ever suggested it should, thus this graph is another moot point clearly not aimed at scientists.

The observed temperature evolution can of course only be the result of all forcing factors combined (including solar variability, volcanic eruptions, and man-made aerosols) – not CO2 alone. If all these forcing factors are taken into account in a recent model simulation, the temperature evolution looks like this:
Hansen (2005)

The black line is the average of five model runs. This is not only in excellent agreement with the observed temperature changes at the surface (blue stars), it also correctly reproduces the observed heat storage in the oceans – a strong indicator that the model’s heat budget is correct. The agreement of this model with observations is particularly good and perhaps partly fortuitous, given that there is still uncertainty both in the climate sensitivity and in the amplitudes of the aerosol and solar forcings. But our main point does not depend on that and is robust: with any model and any reasonable data-derived forcing, the observed 20th Century warming trend can only be explained by anthropogenic greenhouse gases, while other factors can explain the shorter-term variations around this trend. The serious scientific discussion is about the exact contribution of each factor, not about identifying one single “driver”.

Is the CO2 increase anthropogenic?
In this paper (as in the past) Veizer is strangely vague on the question whether the recent CO2 increase in the atmosphere – which is at the very core of global warming concerns – is caused by humans. He claims that the “carbon cycle is piggy-backing on the water cycle”, and he states that “while CO2 may act as an amplifying greenhouse gas, the actual atmospheric CO2 concentrations are controlled in the first instance by the climate, that is by the sun-driven water cycle, and not the other way around.”

Veizer’s alternative hypothesis for 20th century global warming does appear to be: the warming was caused by a “celestial driver” (i.e., a change in solar activity – despite the lack of observed trend), and it is this warming which has increased the CO2 concentration, not the other way round.

If this is Veizer’s hypothesis (and we welcome his clarification if we have misinterpreted it), then this is indeed radical. That humans have caused the increase in CO2 is proven beyond reasonable doubt, and is generally accepted even by “climate sceptics”. We have summarised the evidence here. Not only do we know how much CO2 we emitted (more than is now left in the atmosphere – which means that the natural reservoirs have taken up part of our CO2 emissions, rather than having released CO2 in response to a climate change). That the increasing amounts of CO2 in the atmosphere come from fossil fuels was already demonstrated by isotope analysis in the 1950s. CO2 increases not only in the atmosphere but also in the global oceans – this is documented by 10,000 measurements – and very likely in the biosphere. And it would be difficult to argue that through a natural climate change, CO2 has suddenly increased to values about 30% higher than at any previous time for the past 650,000 years, and that this occurred by chance just at the same time as humans released more than enough CO2 to explain the rise.

In the light of this evidence, it is difficult to believe that Veizer means to suggest the CO2 rise is a response to a natural warming. So perhaps Veizer does agree that the CO2 rise is caused by humans? Then it logically follows that Veizer also agrees there must be anthropogenic warming, since Veizer does agree to that basic fact of physics: that CO2 is a greenhouse gas – see his quote above.

Some final remarks
It is a normal, essential and very valuable part of science to develop and present alternative hypotheses, even if they appear unlikely at first, go against the mainstream, or turn out to be wrong later. Without this process, there would be no progress in science. Hence, any attempt to find an alternative explanation for the ongoing global warming is to be welcomed.

However, to facilitate this process, science has developed a culture with certain rules and standards for scientific discourse. These rules include, for example, that all relevant data are shown: if I want to make a credible case for any hypothesis, I must not hide parts of a data set which do not fit my hypothesis. Rather, I need to discuss them. In a scientific paper, a selective or misleading graph may be of little consequence (except for the author’s reputation), as scientific readers are familiar with the further data and the previous scientific discussions, so they can easily judge the merits of an argument. However, it is in our view more serious and ethically questionable when such selective and misleading use of data is made in a press release: an example from a media release by Veizer / Ruhr University is discussed here.
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there are numerous commentaries concerning each of the papers regarding solar cycles being responsible for recent warming and in a nut shell all of the papers are shown to be flawed

doesn't mean there isn't a solar cycle or that once before man started spewing co2 and methane into the atmosphere on a global industrial scale there was no possible corelation between the solar cycles and our climate, it just means that burning fossil fuels has changed our atmospheric chemistry to the point were its screwing up the climate and the sun had nothing to do with it

cheers
B

Boston, Jun 2, 2010

#7494

Boston Previous Member

even the claims about the sun being at some record high has been debunked years ago with the simple admission that recreating the solar history has been problematic

therefor making wild assumptions based on one single data set is hardly representative of ethical science

maybe once the various proxies can be calibrated and a good solid historical record is established

but within the time of direct measurements there is simple no data to support an increase in solar or cosmic activity corresponding to the increase in atmospheric co2 or methane nor does any correspond to the increases in temp associated with the two previous

Did the Sun hit record highs over the last few decades?

3 August 2005

Guest commentary by Raimund Muscheler

The solar influence on climate is a controversial topic in climate research (see previous posts here and here). The irradiance changes are assumed to be relatively small and the importance of potential amplifying mechanisms is still a matter of current debate. One reason for these uncertainties is that there are only approximately 25 years of satellite-based observations of the solar irradiance. Sunspot observations for the last 400 years clearly indicate that current levels of solar activity are very different from the state of the sun during the Maunder minimum (from approx. 1645 to 1715 AD) where almost no sunspots could be observed.

Cosmogenic radionuclides (such as 10Be and 14C) records are the most reliable proxies to extent solar activity reconstructions beyond the period of direct observations of the sun. They are produced in the atmosphere by the interaction of galactic cosmic rays with the atoms of the atmosphere. High solar shielding of the galactic cosmic rays during periods of high solar activity decreases the radionuclide production rates and vice versa for low solar activities. Cosmogenic radionuclide production rates are also influence by the geomagnetic field. Similarly to the solar magnetic modulation, high geomagnetic field intensity decreases the flux of galactic cosmic rays and radionuclide production rates and the opposite for low geomagnetic field intensity.

The processes responsible for the radionuclide production are well known and can be modeled quantitatively. The biggest uncertainties lies in the interpretation of the radionuclide records that can be measured in natural archives such as ice cores in the case of 10Be or tree rings in the case of 14C. This is due to the fact that changes in atmospheric transport and deposition in the case of 10Be or changes in the carbon cycle in the case of 14C can influence the measured concentrations. Unidentified climatic influences lead to errors in the reconstruction of solar activity changes based on these records. This problem is illustrated by two alternative reconstructions of past changes in solar activity based on ice core 10Be records. Based on a 10Be record from Antarctica Bard et al. (2000) conclude that currents levels of solar activity were also reached or exceeded around 1200 AD. By contrast, Solanki et al. (2004) conclude that solar activity during recent decades is exceptionally high compared to the past 8000 years. Their method seems to be confirmed by a 10Be record from Southern Greenland (Dye 3, Beer et al, 1990). However, the two 10Be records from Antarctica and Greenland exhibit big disagreements for the last 55 years which is the main reason for these very different conclusions (Raisbeck and Yiou, 2004).

Obviously, at least one of these records must also be influenced by changes in climate. Since 14C is influenced by completely different geochemical behavior than 10Be, the investigation of 14C records can help to solve the contradictions. Since carbon cycle models allow us to understand past changes in atmospheric CO2 and 13C concentrations it is also possible to use these models to infer the 14C production rate based on measured 14C concentrations in tree rings. Until 1950 AD, when significant amounts of anthropogenic 14C were released into the atmosphere by the nuclear weapons tests, we can calculate the variations in the 14C production rates and infer the solar magnetic modulation from these records. There are uncertainties in connecting the 14C production rate to recent instrumental measurements of solar magnetic modulation (see figure). However, regardless of these uncertainties the conclusions by Usoskin et al. (2003) and Solanki et al. (2004) cannot be confirmed by the analysis of the 14C records (Muscheler et al., 2005). The 14C tree ring records indicate that today’s solar activity is high but not exceptional during the last 1000 years.

Figure 1: Reconstructions of the (11-year smoothed) solar magnetic modulation based on 14C data from tree rings combined with instrumental measurements (Muscheler et al.,2005). The purple curve shows the results according to a normalization using balloon-borne measurements. The black and green curves show results using an alternative normalization and the northern hemisphere (black) and globally averaged (green) 14C data. The red curve is the group sunspot number.

Are there additional proxies that could shed light on the solar history? First of all the sunspot record represents a good proxy for solar variations during the last 400 years. While the group sunspot record indicates high solar activity during the last 60 years compared to the preceding 350 years, the Wolf sunspot record reached today’s values for a short period around 1780 AD (with the exception of the very strong sunspot maximum around 1957 AD). Aurora observations also provide information about the history of the sun. However, there are no systematic observations and therefore the conclusions are uncertain. 44Ti measurements in meteorites have the potential to provide high quality estimates of past changes in solar magnetic modulation but, until now, the data are sparse and exhibit large errors (Castagnoli et al., 2003). 36Cl is another useful cosmogenic isotope, but that too has data quality and bomb contamination problems in the modern period. Therefore, it is not yet possible to draw firm conclusions about solar activity changes during the last 400 years based on these data. To conclude, depending on the applied 10Be record different histories of the sun have been inferred. The 14C tree ring record does not confirm the 10Be record from Southern Greenland and the assertion that recent solar activity levels are exceptional. Alternative estimates of the history of the Sun are not yet good enough to be used as independent checks.

Therefore, in the view of the uncertainties and the conflicting data it doesn’t seem to be appropriate to make uncritical and sensational claims about the history of the sun. As long as the differences between the 10Be records are not understood, conclusions based on only one of these records should be treated with caution. Atmospheric 14C concentrations, on the other hand, are much less sensitive to a climate influence during the last 1000 years and, therefore, can provide good estimates of the history of the sun. However, the disagreement between 14C-based solar activity and group sunspot number (Muscheler et al., 2005) should remind us that the variations of the solar activity are not yet completely understood.

Regardless of any discussion about solar irradiance in past centuries, the sunspot record and neutron monitor data (which can be compared with radionuclide records) show that solar activity has not increased since the 1950s and is therefore unlikely to be able to explain the recent warming.

References:

Bard, E., Raisbeck, G.M., Yiou, F., Jouzel, J., 2000. Solar irradiance during the last 1200 years based on cosmogenic nuclides. Tellus 52B, 985-992.

Beer, J., Blinov, A., Bonani, G., Finkel, R.C., Hofmann, H.J., Lehmann, B., Oeschger, H., Sigg, A., Schwander, J., Staffelbach, T., Stauffer, B., Suter, M., Wölfli, W., 1990. Use of 10Be in polar ice to trace the 11-year cycle of solar activity. Nature 347, 164-166.

Cini Castagnoli, G.C., Cane, D., Taricco, C., Bhandari, N., 2003. GCR Flux Decline during the last Three Centuries: Extraterrestrial and Terrestrial Evidences. In: T. Kajita, Y. Asaoka, A. Kawachi, Y. Matsubara, M. Sasaki. (Eds.), GCR Flux Decline during the last Three Centuries: Extraterrestrial and Terrestrial Evidences, Universal Academy Press, Inc., pp. 4045-4048.

Muscheler, R., Joos, F., Mueller, S.A., Snowball, I., 2005. How unusual is today’s solar activity? Nature 436, E3-E4.
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Boston, Jun 2, 2010

#7495

1 person likes this.

Joined: Apr 2010
Posts: 91
Likes: 6, Points: 0, Legacy Rep: 33
Location: North America

DrCraze Junior Member

First casualties of climate change. Would you care more if your entire nation was 1 meter above sea level?

DrCraze, Jun 2, 2010

#7496

Joined: Jun 2009
Posts: 130
Likes: 16, Points: 18, Legacy Rep: 116
Location: USA

alanrockwood Senior Member

Marco1 said: ↑

I know how we can deal with climate change.

a) Kill all white particularly from western countries. Blue eyed are specialy nasty.
b) Kill everyone else who disagrees with climate change being the biggest moral challenge of our time.
c) Decimate as a disincentive all those who do not recycle, do not compost, do not fertilise with their own excrement and refuse to use a straw hat.

By now we will have reached the Wilderness society goal of one billion people tops for planet earth. Prince Philip can now rest assured that he does not need to reicarnate in a virus to decimate humanity and so fulfill his dream in life. Greens can do it for him.

Simple stuff really I don't know what are you all debating about.
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Marco1, if you want people to quit calling your posts stupid you need to quit making stupid posts.

Oh, wait a minute, maybe it's just a joke. OK, a joke... still stupid though.

alanrockwood, Jun 2, 2010

#7497

mark775 Guest

Crazy, I'm sorry that the island is in subsidence. It's been happening awhile (since it was made) http://www.pnas.org/content/12/2/99.full.pdf . I am even more sorry for the plight for which there is a cure and Western society has denied these people - malaria. It was mentioned in your touching appeal for money, and if we were to attack this disease with the fervor we once did, those people could concentrate their efforts on what they have always done - hop to another island atoll as the one they are on erodes and subsides. If we are compassionate, we will try to help them find another island and insure that they have enuf food to eat. Large puppy eyes aside, what an idyllic life these people could lead! They look pretty well fed, so far, but we shud definately stop in every so often to make sure. Thx!

mark775, Jun 2, 2010

#7498

mark775 Guest

Wood, it's pretty close to what your team would have happen with the power - not so much of a joke.

mark775, Jun 2, 2010

#7499
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Joined: Jun 2009
Posts: 130
Likes: 16, Points: 18, Legacy Rep: 116
Location: USA

alanrockwood Senior Member

mark775 said: ↑

Wood, it's pretty close to what your team would have happen with the power - not so much of a joke.
Click to expand...

775, another stupid comment. First, you have no idea whether I belong to the "team" as you call it. Second, you have not identified what the so called "team" is, at least not in this post, if any. Third, you have not documented that the "team" as you call it, actually called for a reduction of the human population to residual levels. Fourth, you have no knowledge of what my view is on whether the number of people on the earth should be reduced.

alanrockwood, Jun 2, 2010

#7500

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