Paul

Realclimate.org continues with its same line of attack. Wishfulclimate.org writers try again and again to concoct what appears to be deep critiques against skeptic arguments, but end up doing a very shallow job. All in the name of saving the world. How gallant of them.

A recap. According to realclimate.org, everything my “skeptic” friends and I say about the effect of cosmic rays and climate is wrong. In particular, all the evidence summarized in the box below is, well, a figment in the wild imagination of my colleagues and I. The truth is that the many arguments trying to discredit this evidence simply don’t hold water. The main motivation of these attacks is simply to oppose the theory which would remove the gist out of the arguments of the greenhouse gas global warming protagonists. Since there is no evidence which proves that 20th century warming is human in origin, the only logically possible way to convict humanity is to prove that there is no alternative explanation to the warming (e.g., see here). My motivation (as is the motivation of my serious colleagues) is simply to do the science as good as I can.

A brief summary of the evidence for a cosmic ray climate link:

Svensmark (1998) finds that there is a clear correlation between cosmic rays and cloud cover. Since the time he first discovered it, the correlation continued as it should (Svensmark, 2007). Here is all the other evidence which demonstrates that the observed solar/cloud cover correlation is based upon a real physical link.

1) Empirical Solar / CRF / Cloud Cover correlation: In principle, correlations between CRF variations and climate does not necessarily prove causality. However, the correlations include telltale signatures of the CRF-climate link, thus pointing to a causal link. In particular, the cloud cover variations exhibit the same 22-year asymmetry that the CRF has, but no other solar activity proxy (Fichtner et al., 2006 and refs. therein). Second, the cloud cover variations have the same latitudinal dependence as the CRF variations (Usoskin et al. 2004). Third, daily variations in the CRF, and which are mostly independent of the large scale activity in the sun appear to correlated with cloud variations as well (Harrison and Stephenson, 2006).

2) CRF variations unrelated to solar activity: In addition to solar induced modulations, the CRF also has solar-independent sources of variability. In particular, Shaviv (2002, 2003a) has shown that long term CRF variations arising from passages through the galactic spiral arms correlate with the almost periodic appearance of ice-age epochs on Earth. On longer time scales, the star formation rate in the Milky Way appears to correlate with glacial activity on Earth (Shaviv, 2003a), while on shorter time scale, there is some correlation between Earth magnetic field variations (which too modulate the CRF) and climate variability (Christl et al. 2004).

3) Experimental Results: Different experimental results (Harrison and Aplin, 2001, Eichkorn et al., 2003, Svensmark et al. 2007) demonstrate that the increase of atmospheric charge increases the formation of small condensation nuclei, thus indicating that atmospheric charge can play an important role (and bottleneck) in the formation of new cloud condensation nuclei.

4) Additional Evidence: Two additional results reveal consistency with the link. Yu (2002), carried out a theoretical analysis and demonstrated that the largest effect is expected on the low altitude clouds (as is observed). Shaviv (2005) empirically derived Earth’s climate sensitivity through comparison between the radiative forcing and the actual temperature variations. It was found that if the CRF/cloud cover forcing is included, the half dozen different time scales which otherwise give inconsistent climate sensitivities, suddenly all align with the same relatively low climate sensitivity, of 0.35±0.09°K/(W/m2).

A brief summary of why the attacks on the CRF/climate link are toothless:

1. The CRF / cloud cover link breaks down after 1994 (e.g., Farrar 2000). This supposed discrepancy arises because of a cross-satellite calibration problem in 1994. The problem is evident when considering for example the high altitude cloud data, which exhibits a jump larger than the variability before or after 1994. When the calibration problem is rectified, the significant CRF / cloud correlation continues unhindered (Marsh & Svensmark, 2003).

2. Large variations Earth’s magnetic field (for example, the Laschamp event and alike) should manifest themselves as climate variations. Their absence contradicts the CRF/cloud-cover link (e.g., Wagner et al. 2001). In principle, terrestrial magnetic field variations should indeed give rise to a temperature change, however, when the effect is quantified, the expected global temperature variations are found to be only of order 1°C (Shaviv 2005). This should be compared with the typically 5°C observed over the relevant time scales, of 104-105 yr. In other words, it is not trivial to find the CRF/climate signatures as is often presumed, but signatures do exist (e.g., Christl et al. 2004).

3. The Cloud cover data over the US (Udelhofen & Cess, 2001) or the cloud data following the Chernobyl accident (Sloan & Wolfendale 2007) does not exhibit variations expected from the CRF/cloud-cover link. These expectations rest on the assumption that the CRF climate link should operate relatively uniformly over the globe. However, the lower troposphere over land is filled with naturally occurring CCNs, such as dust particles. Thus, one would expect the link to operate primarily in the clean marine environments.

4. The secular solar activity is now decreasing, but the temperature is increasing. Hence, solar activity cannot be responsible for the recent temperature increase (Lockwood 2007). Indeed, the last solar cycle was weaker, and the associated CRF decrease was smaller. However, this argument assumes that there must be an instantaneous relation between solar activity and climate. In reality, the large heat capacity of the oceans acts as a “low pass filter” which releases previously absorbed heat. Moreover, heat absorbed over longer durations penetrates deeper into the oceans and thus requires longer durations to leave the system. This implies that some of the temperature increase is due to a previous “commitment”. In any case, some of the warming over the 20th century is certainly human. So having some human contribution does not invalidate a large solar forcing.

5. The work of Shaviv & Veizer (2003) was proven wrong. The work of Shaviv & Veizer attracted two published criticisms (Royer et al. 2004 and Rahmstorf et al. 2004). The first was a real scientific critic, where it was argued that the 18O/16O based temperature reconstructions (of Veizer et al. 2000) has an unaccounted systematic error, due to ocean pH, and hence the atmospheric pCO2 level. Shaviv (2005) considered this effect and showed that instead of an upper limit to the effect of CO2 doubling, of 1°C, Earth’s sensitivity increases to 1-1.5°C, but the basic conclusion that CRF appears to be the dominant climate driver remains valid (as later independently confirmed by Wallman 2004). Rahmstorf et al. 2004 published a comment stating that almost all Veizer and I did was wrong. We showed in our response why every comment is irrelevant or invalid. In their response to the rebuttal, Rahmstorf et al. did not address any of our rebuttal comments (I presume because they could not). Instead, they used faulty statistics to demonstrate that our results are statistically insignificant. (Basically, they used Bartlett’s formula for the effective number of degrees of freedom in a limit where the original derivation breaks down).

Anyway, the last slur says that my astronomical analysis is wrong. Well, I’ve got news. The argument raised by Jahnke and Benestad is irrelevant. It has two grave flaws to it.

First, the Milky way is not a typical two spiraled armed galaxy. It has four spiral arms. You can see them in a CO doppler map here. (Well, at least 3 arms separated by 90°. And unless the Milky Way is an amputee, a 4th should be behind the center of the galaxy). J & B also failed to tell their readers that all the 5 galaxies in the work they cited have a very dominant 2 armed structure. I wonder why they kept this detail to themselves. Thus, the conclusions of Krantz et al. 2003, as interesting as they are, are simply not applicable for the Milky Way.

Second point. Spirial arms can exist between the inner and outer Lindblad resonances (e.g., the galactic dynamics bible of Binney and Tremaine). If you force the 4 armed pattern to have a co-rotation radius near us (as J & S do), it will imply that the outer extent of the 4-armed pattern should be at roughly rout ~ 11 kpc. However, the patten is seen to extend out to about twice the solar-galactic radius (Shaviv, 2003 and references therein). Clearly, this would counter our theoretical understanding of spiral density waves.

Thus, B & J were wrong in their claims. Nevertheless, it turns out that surprisingly, they were not totally incorrect. Sounds strange? Well, it appear that the Milky Way has at least two independent sets of spiral arms, with two different pattern speeds. One is the above four spiral arms, which we traverse every 145 Myr on average. The second set is probably a two armed set which has a co-rotation radius near us (and hence we pass through it very rarely). This can be seen by carrying out a birth-place analysis of open clusters, as Naoz and Shaviv (2006) did. This result explains why over the years, different researchers tended to find two different pattern speeds, or evidence that we’re located near the co-rotation radius. We are, but not for the 4-armed spiral structure which we pass every 145 Myrs on average!

Incidentally, this is not the first time Jahnke tried to discredit my results. The previous time was when he unsuccessfully tried to debunk my meteoritic analysis. I wonder if this time was too prompted by a request from Stefan Rahmstorf.

To summarize, using the final paragraph of Jahnke and Benestad, we can say that:

Remarkably, the poor scientific basis of the attacks against the galactic cosmic ray hypothesis seems to be inversely related to the tenacity of the devout global warming protagonists all with a strong thrust of wanting to cast doubt on the possibility that natural climate drivers may have been important to 20th century temperature change.

From Nir Shaviv’s Sciencebits blog: ‘More slurs from realclimate.org’

References:

Christl M. et al., J. Atmos. Sol.-Terr. Phys., 66, 313, 2004

Eichkorn, S., et al., Geophys. Res. Lett., 29, 44, 2003

Farrar, P. D., Clim. Change, 47, 7, 2000

Fichtner, H., K. Scherer, & B. Heber, Atmos. Chem. Phys. Discuss., 6, 10811, 2006

Lockwood, M., & C. Fröhlich, Proc. R. Soc. A doi:10.1098/ rspa.2007.1880; 2007

Harrison, R. G., and K. L. Aplin, Atmospheric condensation nuclei formation and high energy radiation, J. Atmos. Terr. Phys., 63, 1811–1819, 2001.

Harrison, R. G. and Stepehnson, D. B., Proc. Roy. Soc. A., doi:10.1098/rspa.2005.1628, 2005

Marsh, N., and H. Svensmark, J. Geophys. Res., 108, 4195, 2003

Naoz, S. and N. J. Shaviv, New Astronomy 12, 410, 2007

Rahmstorf, S. et al., Eos, Trans. AGU, 85(4), 38, 41, 2004. And the rebuttals

Royer, D. L. et al., GSA Today, 14(3), 4, 2004. And the rebuttals

Shaviv, N. J., New Astron., 8, 39–77, 2003a.

Shaviv, N. J., J. Geophys. Res.-Space, 108 (A12), 1437, 2003b

Shaviv, N. J., J. Geophys. Res., 110, A08105, 2005

Shaviv, N. J., and J. Veizer, GSA Today, 13(7), 4, 2003

Sloan, T., and A. W. Wolfendale, in Proceedings of the ICRC 2007 (also arXiv:0706.4294 [astro-ph])

Udelhofen, P. M., and R. D. Cess, Geophys. Res. Lett., 28, 2617, 2001

Usoskin, I. G., N. Marsh, G. A. Kovaltsov, K. Mursula and O. G. Gladysheva, Geophys. Res. Lett., 31, L16109, 2004

Shaviv, N. J., and J. Veizer, GSA Today, 13(7), 4, 2003

Svensmark, H., Phys. Rev. Lett, 81, 5027, 1998

Svensmark, H., Astron. Geophys., 58, 1.19-1.24., 2007

Veizer, J., Y. Godderis, and L. M. Francois, Nature, 408, 698, 2000

Wagner et al., J. Geophys. Res., 106, 3381, 2001

Wallman, K., Geochem. Geophys. Geosys, 5, Q06004, 2004

Yu, F., J. Geophy. Res., 107(A7), 10.1029/2001JA000248, 2002.

Thus we have the reasoning as to why the science issues on Climate Science have been mostly ignored – the issue is not about climate science. The goal is to use the term “global warming” (with “climate change” used to make the concept cover all aspects of climate) not to ”motivate” change, but to force the public and policymakers to adopt specific policy and political actions that promotes particular agendas.

Clearly, this narrow approach is doomed to produce poor policy decisions. Unless the media starts to recognize this inappropriate use of climate science, we will continue down the road to many actions that will have unanticipated and undesirable consequences.

The above is an excerpt from Roger Pileke Sr’s Climate Science blog: ‘The Political Issue Of Global Warming’

The UK’s summer floods of 2007 were a freak event unrelated to global climate change, according to a report from the Centre for Ecology and Hydrology (CEH).

The key cause was that extended rains early in summer soaked soils that would normally have been dry at that time.

When heavy storms came later, water could not soak away into the ground.

The report said data does not support the notion that UK summer rainfall is increasing or rivers are showing faster flow rates than in previous years.

BBC website: 2007 floods ‘no link to climate’

There seems to be a conflict of opinion here between the CEH, Met Office, and the Environment Agency.

According to an analysis by Scafetta and West published in the March edition of Physics Today (subscription required), the Sun ‘could account for as much as 69% of the increase in Earth’s average temperature.’

Article title: “Is climate sensitive to solar variability?” By Nicola Scafetta of Duke University Physics Department and Bruce J. West of the US Army Research Office, Research Triangle Park, North Carolina

Excerpt: “Thus the average global temperature record presents secular patterns of 22- and 11-year cycles and a short time-scale fluctuation signature (with apparent inverse power-law statistics), both of which appear to be induced by solar dynamics. The same patterns are poorly reproduced by present-day GCMs and are dismissively interpreted as internal variability (noise) of climate. The nonequilibrium thermodynamic models we used suggest that the Sun is influencing climate significantly more than the IPCC report claims. If climate is as sensitive to solar changes as the above phenomenological findings suggest, the current anthropogenic contribution to global warming is significantly overestimated. We estimate that the Sun could account for as much as 69% of the increase in Earth’s average temperature, depending on the TSI reconstruction used. Furthermore, if the Sun does cool off, as some solar forecasts predict will happen over the next few decades, that cooling could stabilize Earth’s climate and avoid the catastrophic consequences predicted in the IPCC report.”

This article is based on Scafetta and West’s previously published peer reviewed papers.

Yes, I know Real Climate are exceedingly rude about this work and RC are entitled to their politically motivated views, just as Scafetta and West are entitled to their’s.

Update: Full article now available here.

A new paper published in Science magazine suggests that ocean the floors are getting deeper and sea levels have fallen by about 170 meters (560 ft) since the Cretaceous period 80 million years ago, due to tectonic shifts. Previous estimates were between 40 to 250 meters. On this basis of this work, a fall of 120 metres is expected over the next 80 million years, which equates to just 0.015 centimetres per century. Not much when we we consider IPCC projections of sea level rise. That said, the IPCC seems to have abandoned decadal projections in their latest report and gone for a 90-year projection, following the accuracy failures of the 1990, 1995 and 2001 reports. See the January 15th post over at Prometheus: Verification of IPCC Sea Level Rise Forecasts 1990, 1995, 2001.

The research article is entitled: ‘Long-Term Sea-Level Fluctuations Driven by Ocean Basin Dynamics’

The first paragraph reads:

Earth’s long-term sea-level history is characterized by widespread continental flooding in the Cretaceous period (145 to 65 million years ago), followed by gradual regression of inland seas. However, published estimates of the Late Cretaceous sea-level high differ by half an order of magnitude, from 40 to 250 meters above the present level. The low estimate is based on the stratigraphy of the New Jersey margin. By assimilating marine geophysical data into reconstructions of ancient ocean basins, we model a Late Cretaceous sea level that is 170 (85 to 270) meters higher than it is today. We use a mantle convection model to suggest that New Jersey subsided by 105 to 180 meters in the past 70 million years because of North America’s westward passage over the subducted Farallon plate. This mechanism reconciles New Jersey margin–based sea-level estimates with ocean basin reconstructions.

The paper is also reported by Reuters, with their usual perspective on climate change.