Martin A.,

I'll ask you, also: What is the solution of the equation dT(t)/dt = constant?

There is considerable evidence for solar influence on the Earth’s pre-industrial climate and the Sun may well have been a factor in post-industrial climate change in the first half of the last century. Here we show that over the past 20 years, all the trends in the Sun that could have had an influence on the Earth’s climate have been in the opposite direction to that required to explain the observed rise in global mean temperatures

Recent oppositely directed trends in solar climate forcings and the global mean surface air temperature
Lockwood & Frohlich 2007. (How time flies)

See Figure 1c for GCR flux.

http://rspa.royalsocietypublishing.org/content/royprsa/463/2086/2447.full.pdf

Martin A

Alas, I can do algebra, but not calculus. You will need to explain your equation.

Phil Clarke

Your link failed.

I found this at NASA

It reports a recent surge in cosmic ray intensity on top of an ongoing increase since 2001

Increasing GCR intensity coupled with increasing temperatures is definitely NOT what was predicted by Svenmark and Shaviv.

Yes, GCR flux is negatively correlated with the solar cycle and Cycle 24 started off with a whimper so a surge in GCR would be exactly as expected.

Try this link for the Lockwood paper or just Google the title, its public domain.

As is this study from 2013, which did a comprehensive search for a correlation between GCR and both cloudiness and albedo, albeit over only half a cycle and came up with nada.

Phil Clarke

Erlykin et al(2013) also failed to find any link between GCR and climate.

Alas, I can do algebra, but not calculus. You will need to explain your equation.
Apr 6, 2016 at 11:10 AM | Unregistered CommenterEntropic man

OK, fair enough EM. I had not intended the question as a maths examination. Actually, it's clear from previous discussions that you have a firm grasp of the idea of rates of change, which is all that calculus is really.

Two or three commenters had, like you, stated something more or less equivalent to "cosmic ray flux has been constant, therefore an increase in 'global temperature' can not have been the result of cosmic rays".

The point I was hoping to get across is that that does not follow logically.

I have no idea what is the relation, if any, between 'global temperature' and cosmic ray flux but it hardly seems likely that they'd be related simply by a scale factor. Much more plausible is that there would be some kind of dynamic relationship, where the rate of change of global temperature depended in some way on the cosmic ray flux.

So, to get to my equation. If T(t) denotes the global temperature at time t, then dT(t)/dt represents the rate of change of global temperature at time t.

So (just guessing at the simplest possible dynamic relationship) if the rate of change of global temperature is proportional to the cosmic ray flux, and the cosmic ray flux is constant, then we'd have the following equation for the rate of change of global temperature.

dT(t)/dt = constant .. .. .. .. (1).

Of course, to keep things simple, this leaves out a load of other things to account for all the other things, known and unknown, that global temperature also depends on.

If the rate of change of a thing is constant, then the thing itself has to be increasing as a straight line (ie proportional to the independent variable). So the solution of the equation (1) is

T(t) = constant . t + k (where k is another constant).

To sum up:

If Y is changing and X is constant, that fact does not tell you that Y does not depend on X. So to say "temperature has changed, cosmic rays have not, so cosmic rays don't affect temperature" is fallacious.

Vindicated. Again.

"Recent Warming But No Trend in Galactic Cosmic Rays"

Like I said.

Svensmark's hypothesis is all about a correlation between solar activity and temperature, via the physical mechanism of a modulation of cloud cover.

EM

"The 1998 El Nino peaked in February at anomaly 0.88C. In February 2016 the peak was 1.35C. That is a like-for-like increase of 0.47C in eighteen years. GCR has stayed constant over that time, but CO2 has increased. CO2 is more likely to be the cause."

Are you implying a that an increase in El Nino peak temperature of 0.47ºC - a 53 percent increase over 18 years - is consequential on an increase in atmospheric CO2 concentration of 37ppm - a 9% increase over 18 years. If not - what is the point you wish to make?

Martin,
Thanks, that's what I thought. Now can you explain why - if the integrated response to a constant cosmic ray flux is relevant - we haven't undergone runaway warming yet?

Spectator

Let's try a back of the envelope calculation to compare theory with observation.

The radiative forcing equation for CO2 is 5.35ln(C/CO).

The change in forcing since 1998 using your figures is 5.35ln(400363) = 0.519W/M^2

With a climate sensitivity of 3.0 that becomes 0.519*3=1.56W/M^2

The IPCC estimate that a 3.7W increase in forcing raises surface temperatures by 1C. The forcing becomes 1.56/3.7=0.422C

That's clear enough. 89.8% of the increase in surface temperature since 1998 can be explained by the increase in CO2 over the same time.

Spectator

You realise, I hope that your 53% increase refers to the increase in anomaly relative to a 14.0C baseline.

For purposes of physics the true increase in temperature should be measured in Kelvin.

The increase in temperature should be described as from 287.88K to 288.35K.

This is an increase of 0.47/288.7 *100 = 0.16%

The increase in CO2 is 37/363 *100 = 10.2%

It is amazing how different things look when one uses the correct units.

Is there a term for an addiction to Micky Mouse, pseudo-scientific calculations?

diogenes 9:33

yes, it is called 'climate science'

Diogenes 9.33

Yes, it is called "climate science denial".

EM, you are the only person on this thread making calculations of a pseudo-sciency kind. Does this mean you are what you so graciously term a denier.?

Martin, as I understand what we might call the "Galactic Cosmic Ray Gambit", the aim is not to describe recent warming, as it is obvious to anyone that changes in the amount of GCRs are not the cause of recent warming (you can have fun with the idea that constant (give or take a solar cycle wiggle) levels of GCRs drive up temperatures, but that is not a runner, as ATTP pointed out). Instead the aim of the Gambit seems to be to undermine estimates of climate sensitivity that are based upon paleo evidence. If past temperature rises were plausibly caused by changes in GCRs and not (only) CO2, then climate is obviously not as sensitive to CO2 as might otherwise be thought. It is a clever argument, lacking only evidence, though that likely wont dampen people's ardor.

Raff, I have no idea what effect if any cosmic rays have on climate. Except that anyone who has seen a Wilson cloud chamber in operation can hardly help finding it plausible that high energy charged particles result in the creation of clouds.

People who believe the CAGW hypothesis seem very fond of coming up with Mickey Mouse calculations and Mickey Mouse arguments which they seem to find convincing, despite the fact that the climate system is evidently complex beyond the capacity of current science and resources to analyse. My reaction to such calculations/arguments is along the lines that someone who believes them will believe anything (that suits them).

All I was trying to do was to point out that "temperature has changed, cosmic rays have not, so cosmic rays don't affect temperature" is an argument in that category, unconvincing to all but the faithful who, as shown by it having been repeated several time in this thread, seem to have accepted it uncritically.

Raff has it right, Henrik Svensmark was the main protagonist of the GCR-Climate link, publishing several papers, a popsci book, The Chilling Stars and putting out several press releases that tended to claim rather more than was justified by the evidence. The theory was also featured prominently in the mockumentary 'The Great Global Warming Swindle'.

Here's a typical extract

When the Sun is active, its magnetic field is better at shielding us against the cosmic rays coming from outer space, before they reach our planet. By regulating the Earth’s cloud cover, the Sun can turn the temperature up and down. High solar activity means fewer clouds and and a warmer world. Low solar activity and poorer shielding against cosmic rays result in increased cloud cover and hence a cooling. As the Sun’s magnetism doubled in strength during the 20th century, this natural mechanism may be responsible for a large part of global warming seen then
.
That also explains why most climate scientists try to ignore this possibility. It does not favour their idea that the 20th century temperature rise was mainly due to human emissions of CO2. If the Sun provoked a significant part of warming in the 20th Century, then the contribution by CO2 must necessarily be smaller.

(BTW That was from 2009, in the same piece he warned 'In fact global warming has stopped and a cooling is beginning', which puts him right up there with Piers Corbyn in the forecasting skill stakes)

Svensmark's main plank of evidence was a correlation between GCR flux and cloud cover. And the correlation was remarkable, if you looked at the right type of clouds, over the right period. More recently the correlation has gone AWOL and temperatures continue to rise inexporably, while the long term trend in GCR remains insignificant.

All I was trying to do was to point out that "temperature has changed, cosmic rays have not, so cosmic rays don't affect temperature" is an argument in that category, unconvincing to all but the faithful who, as shown by it having been repeated several time in this thread, seem to have accepted it uncritically.

The proponents of the theory proposed correlation as the confirming evidence. Thus when the correlation breaks down, the theory (at least as formulated by Svensmark et al) is falsified.

Martin A

Thank you for the help.. I can understand the principles of calculus, but somehow I cannot use it as a working tool. A bit like knowing how a car works but not being able to drive.

Continued exponential growth, a "runaway greenhouse effect", looks unlikely for several reasons.

a) There is not enough releasable CO2 available. Even if you emptid the biosphere, permafrost, methane clathrate and ocean sinks and threw in a shield volcano it would be very difficult to push CO2 past 2000ppm.

b) There is a big water vapour/ cloud negative feedback at higher temperatures. Increasing cloud cover albedo would limit further warming.

c) We have been there before. There is paleo evidence for CO2 over 1000ppm and temperatures 9C warmer than today. No runaway warming occurred.

We are in the exponential growth phase of a sigmoid curve. Resistance will kick in eventually to slow the growth rate and stabilise temperatures at a higher level.