"There is nothing new under the Sun" an article about 20th century global warming - my point of view

After a long lull in activity, I decided it's about time I write an update about my thoughts on global warming. Here it is.

20th century global warming - "There is nothing new under the Sun" - Part I
20th century global warming - "There is nothing new under the Sun" - Part II
20th century global warming - "There is nothing new under the Sun" - Part III

Incidentally, this article is based on the adaptation (and translation) of another article I wrote to an Israeli science quarterly called "Odyssey". It is probably the first (and last) time I write something in Hebrew and then translate it. Somehow it doesn't feel right to write about science in Hebrew. The Hebrew source can be found here.

Although it is my ever lasting wish to write more interesting stuff in sciencebits, don't expect a significant increase (sorry). The reason now is that in a strange twist of fate, I am the head of the coordinating council of the heads of faculty unions of the 7 universities in Israel (capo dei capi...), well at least temporarily I hope. But I am always tempted to write! For example, just the other day I realized that the barometric readings I look at every day have a very conspicuous signal due to atmospheric tides! This signal can be used to learn the mass of our moon!

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Comments

But if this is what it takes to read something from you, I'll let it pass :-)

Wouldn't CRF also ionize molecules in other fluids, such as oceans and magma? And wouldn't magnetic field changes affect the movement in fluids? And magnetic field changes could affect geological stability.

Long Solar Cycles correlate with Volcanic Activity

About the long-term coordinated variations of the activity, radius, total irradiance of the Sun and the Earth's climate

"The 11-year cycle represents a simultaneous parallel change in both the activity level and the total irradiance of the Sun. So, in case of variations of the amplitude of the activity level - a power of a cycle - the amplitude of solar irradiance variations is expected to change correspondingly. The identical correlated course of the long-term variations of activity and luminosity of the Sun on the secular timescale has been observed earlier by Eddy (1976), and Borisenkov (1988). Moreover, according to the data of Borisenkov (1988), in each of 18 deep Maunder-type minima of solar activity, revealed over the span of the last 7500 years, the cooling of climate had been observed, while warming occurred during the periods of high maxima. Thus, the integral radiation has always been essentially higher at the maximum, and it had noticeably decreased at the minima. Therefore, quasi-periodic variations of the solar activity during both the 11-year cycle and 80- and 200-year cycles are accompanied by proportional variations of the integral flux of solar radiation, which result in geophysical effects. The main cause of climate change during the last millennia is the corresponding cyclic variation of the 80- and 200-year component of irradiance correlated with activity. That is why, the contemporary is not anomalous but is ordinary secular global warming (Aguilar 2003; Reid 2000), as well as previous similar cases of warming during the periods of secular activity growth is still mainly connected with an increase of the secular component of solar irradiance variation."

On long-term variations of the total irradiance and on probable changes of temperature in the Sun's core

"It is shown that the observable 11-year cyclic variation of the total irradiance of the Sun is caused by respective alterations of the radius and effective temperature of the photosphere, which are a consequence of fundamental global processes occurring deeply inside. The 11-year cyclic variation of "solar constant" almost entirely results from respective alterations of the area of the photosphere radiating surface as its effective temperature keeps practically constant. Hence, 11-year heliocycle represents the simultaneous coordinated fluctuation of the activity, radius and irradiance both for the phase and amplitude. The century component is first directly found in variations of "solar constant". We suppose that the observable long-term identical variations of activity, radius and irradiance are a result of the same processes occurring deeply inside and are coordinated by a global variation of the entire Sun which is caused by cyclic changes of temperature in the Sun's core. As this takes place, the long-term global variations of the whole Sun can serve the catalyst of the generation of solar cycles. We predict the approach of the following sufficiently deep minimum of activity, irradiance and radius of the 200-year cycle of the Sun near the year 2040+10. The minimum will be close to the level of the Maunder Minimum. "

aaron

Oh --but you ARE the enemy of the environmental movement because the hard right is using you as one of their poster children why nothing should be done for our environmental pollution.

And I looked at your paper. It is based on high level statistics at the stratosphere level where cause and effect can be easily distorted.

For example, re: your affection for Svensmark's theories:

Criticism of Svensmark work can be found on the RealClimate.org site: Recent Warming But No Trend in Galactic Cosmic Rays, Taking Cosmic Rays for a spin, 'Cosmoclimatology' - tired old arguments in new clothes.
Svensmark's book 'The Chilling Stars' received a very critical review in Physics World.

Here are some of the arguments against it,

1. Svensmark's condensation nuclei (these are the precursors of clouds) are orders of magnitude smaller than those needed to produce clouds.

2. It appears there are already plenty of cloud condensation nuclei present in the atmosphere without need for cosmic ray synthesis.

3. His hypothesis would predict that we should have been in cooling periods when the sun is in a low sunspot activity phase and we're getting warmer, just the opposite of what he predicts.

Parts of his theory have been proven wrong.

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Data centres are major power users with considerable carbon footprints. Such huge clusters of servers not only require power to run but also power to be cooled. It’s estimated that data centres, which house internet, business and telecommunications systems and store the bulk of our data, consume close to 4 percent of the worlds power supply. see http://www.datacentredesign.co/elec-requests.php
The current volume estimate of all electronic information is roughly 1.2 zettabytes, the amount of data that would be generated by everyone in the world posting messages on Twitter continuously for a century. More stunning: 75 percent of the information is duplicative. By 2020, experts estimate that the volume will be 40 times greater than it was in 2010.

I would like to add a point that I think the IPCC exaggerates. The lifetime of an elevated CO2 level in the atmosphere is thought to be up to 200 years in the IPCC calculations. Reality shows that CO2 levels rises almost linearly whilst emissions of CO2 has risen exponentially. The IPCC simply states that half of each years emissions is taken up by the biosphere, but, reasonably, plants don't care if the molecule was emitted this year or twenty years ago: it is the levels that matter. That implies an e-fold time of some 30-40 years, not several hundreds.

Hello,
It would be interesting to receive your informed opinion on israeli company BetterPlace initiative of building a grid of electrical cars stations. Is it definitely a answer to pick oil? Is it energetically effective? Etc.

Nir
I am an amateur caught up in the general interest in our atmosphere and the prospect of global warming.

A solar multiplier to me is any positive feedback to solar forcing eg. cosmic rays, cloud cover etc. The total positive solar feedback should be able to be measured by comparing the sensitivity during the ice ages with the sensitivity during the last milenium.

During the ice ages temperature changes were caused by changes in the earth's orbit and tilt etc. The temperature sensitivity during this period would, therefore, not be effected by the solar multipliers mentioned above as the solar radiation changes are not significant. It is generally agreed that 7w/m2 produced 5C of warming during this period, a sensitivity of aprox. 0.7.

During the last milenium on the other hand, the temperature changes were largely caused by changes in solar radiation and included the solar multipliers. The range of solar forcing during this period was, I believe, between 3 and 4 w/m2 which translates to between 0.5 and 0.7 w/m2 at the earth's surface. By all reputable temperature series (Hockey stick excluded) the temperature range was between 0.8C and 1.0C. This gives a temperature sensitivity to changes in solar radiation plus multipliers of aprox. 1.5.

In conclusion, the temperature sensitivity without the add on effect of cosmic rays, clouds or whatever is 0.7 while this sensitivity increases to aprox.1.5 when the add on sffects are included. In other words cosmic rays or whatever have the effect of doubling the sensitivity of the earth's temperature to changes in solar radiation.

There are large margins of error of course. Is this something that needs to be explained by the alarmists ?

I am trying to balance two points in your excellent article.
1. Over the 500 Myr timescale, CO2 has been much higher and does not seem to correlate to temperature.
2. Over the 400 Kyr timescale, the Vostok cores show a seemingly clear CO2 correlation to temperature.

Assuming the 400 Kyr correlation is CO2 lagging temperature from ocean outgassing due to temperature, shouldn't this have imprinted on the other record?

I am wondering if at some saturation point(s) CO2 has both reduced impact to temperature as an input and is less responsive (as ocean outgassing) to temperature. Or is that the on the longer timescale, the fluctuations are not discernable (just noise)?

Robert L Hamilton, Engineer
Richardson, Texas, USA

In all my prying around 'climate science' yours is the first mention of the Moon's tidal forces -- or of the Sun's -- on Wx.

Hello Nir,

I enjoyed your recent summary, which I note was written in August 2010.

I wonder if you could comment on current state of play re TSI, CRF etc given the recent announcement that 2010 is 2nd hottest year at a time when Solar activity is now apparently very low. Presumably CRF has or will come into play? Does it correlatre well with last 6 months? Does it have a role in recent severe snow storms in NH and severe flooding (and cool weather) in Australia?

Shaviv,

I was researching climate sensitivity for a post on my blog when I came accross your site.

http://madmikedavies.wordpress.com/2011/04/20/insolation-albedo-and-atmosphere/

I have scanned most of your climate pieces and in principle I am in agreement with all of your conclusions. My new piece not yet published will make the following claims. The IPCC sensitivity given in Wikipedia is erroneous. ('The computed climate sensitivity is therefore 5/7.1 = 0.7 K(W/m2)−1. We can use this empirically derived climate sensitivity to predict the temperature rise from a forcing of 4 W/m2, arising from a doubling of the atmospheric CO2 from pre-industrial levels.')

During glacial epochs the climate sensitivity alters and is at its highest during transitions between glacials/interglacials when it approaches 1 and > 0.5 during 90 kyr glacial phase. Prior to 1Myr climate sensitivity was >0.5 and prior to 3 Myr climate sensitivity was >0.2.
This can be gleaned by critically examining the 5 Myr temperature graph on Wikipedia. Examination also shows that temperature sensitivity increases after the Vostok equivalent temp falls below 0 degC and I believe is related to ice sheet dynamics.
It is also probable that above 0 deg C VEq C02 controls the sensitivity, such that rising C02 levels will reduce climate sensitivity to >0.1 and will oppose forcing from other sources.
Also since the younger dryas total climate sensitivity seems to have stabilised at >0.2 which would gives a temp rise of >1 deg C for C02 doubling.
These calculations are based on an unrepeatable experiment recorded in ice cores and rocks. The earth itself is the most accurate GCM

Mike Davies