Israeli Astrophysicist Nir Shaviv: “Solar Activity Responsible For About Half Of 20th Century Global Warming”

Israeli scientist Nir Shaviv recently posted at his site an article on the effects of cosmic radiation on climate. At the end he summarizes:

The results have two particularly interesting implications. First, they bring yet another link between the galactic environment and the terrestrial climate. Although there is no direct evidence that cosmic rays are the actual link on the 32-million-year time scale, as far as we know, they are the only link that can explain these observations. This in turn strengthens the idea that cosmic ray variations through solar activity affect the climate. In this picture, solar activity increase is responsible for about half of the twentieth-century global warming through a reduction of the cosmic ray flux, leaving less to be explained by anthropogenic activity. Also, in this picture, climate sensitivity is on the low side (perhaps 1 to 1.5°C increase per CO2 doubling, compared with the 1.5 to 4.5°C range advocated by the IPCC), implying that the future is not as dire as often prophesied.

The second interesting implication is the actual value of the 32-million-year oscillation. The relatively short period indicates that there is more mass in the galactic plane than accounted for in stars and interstellar gas, leaving the remainder as dark matter. However, this amount of dark matter is more than would be expected if it were distributed sparsely in a puffed-up halo as is generally expected. In other words, this excess mass requires at least some of the dark matter to condense into the disk. If correct, it will close a circle that started in the 1960s when Edward Hill and Jan Oort suggested, based on kinematic evidence, that there is more matter at the plane than observed. This inconsistency and indirect evidence for dark matter was also advocated by John Bahcall, who for many years was a Faculty member here at the IAS.”

Read the entire post here.


12 responses to “Israeli Astrophysicist Nir Shaviv: “Solar Activity Responsible For About Half Of 20th Century Global Warming””

  1. DD More

    It should be noted that the idea that cosmic rays affect the climate is by no means generally accepted. The link is contentious and it has attracted significant opponents over the years because of its ramifications to our understanding of recent and future climate change.

    A nice way to put “who and how are we going to tax & control that?”

  2. Denis Ables

    I think you and Svensmark on onto something. Howsomever, the cosmological hypothesis looks about as dubious to me as does the alarmists’ AGW hypothesis.

    Dark matter, dark energy, dark flow, ancient well formed galaxies located 12 billion light years away. The plasma physicists are onto something that makes more sense — an electric universe. Gravity is likely not the ruler out there in space, it’s more likely EM, much stronger, and with both attractive and repulsive powers.

    And, the red shift may simply be an intrinsic value associated with plasma at various distances.

    OOps. There goes the 11 or 13 dimensional stuff, along with string theory.

  3. Realist

    Wait, you mean to tell me a ball of nuclear fusion with a mass of 1.988 x10^30 kg that is 2.7×10^17 km away from earth has something to do with climate changes on earth? Say it aint so!

  4. Bruce of Newcastle

    Dr Shaviv is in line with others such as Prof. U.R. Rao. I’ll add however that the ~60 year cycle was responsible for another third of the temperature rise in the 20thC because of the choice of endpoints (ie the start and end of the century). You can immediately see this in the detrended HadCRUT data (this is from Dr Scafetta’s 2010 paper).

    If you choose a starting point such as 1880 to cover two complete cycles you immediately can see the temperature rise in 120 years was only about 0.5 C, compared to 0.7 C for the 20thC.

    That means if half was due to the Sun, another third due to the ~60 year cycle then about a sixth was due to CO2.

    Which means ECS is below even Dr Shaviv’s range. My calcs using a similar proxy for overall solar influence, and the ocean cycles, gets a value for ECS of about 0.7 C/doubling. Therefore CO2 is harmless.

    1. Dean Chancey

      “That means if half was due to the Sun, another third due to the ~60 year cycle then about a sixth was due to CO2.”

      Well stated but one might question the CO2 designation. How about 1/6th due to anthropogenic factors.

      Does bring into question the utter futility of carbon-taxing.

  5. AndyG55

    “That means if half was due to the Sun, another third due to the ~60 year cycle then about a sixth was due to CO2.”

    You have forgotten to allow for the “adjustments”

    Half due to the sun,
    Third due to the 60 yr cycle… and …
    60%, at least, due to the “adjustments”

  6. Paul Vaughan

    The 32 & 145 Ma cycles are *observed*. That will drive climate modelers nuts. Maybe it won’t be long before people who (dare) believe in observations are rounded up and…
    chilling — for real — because it indeed looks like that’s the way it’s going

    1. DirkH

      There are bigger fish to fry, in the central banking / general Keynesian catastrophy circles, warmism is just one little agitprop instrument, so I would worry more about currency reforms, capital controls, (US banks are required to snitch on anyone withdrawing 5000 USD)…

  7. Orville

    So if 1/2 excess heat is solar then the rest must be from CO2. Mankind is not the only source of CO2. Some is released by nature. I read somewhere that the CAGW models are off by about two thirds.

    1. Dick Cobus

      Al Gore will slap you!

      1. Ralph

        Slap him back!

  8. derfel cadarn

    Seeing as fully 90+% of all the Earth’s energy comes from the sun it is not difficult to realize that even small variations can have significant impact on this planet. Whether warmer or cooler the answer is to be found in the Sun.