"No solar link to global warming"

When Lockwood was talking about this over five years ago there was already on a little wiggle-room for a solar effect. It rather looks as if solar-activity and global-warming have diverged even further in the last few years which removes the last chance of a purely-solar explanation for global warming.

I'm not sure "duh" is a very well-considered response. The Svensmark/Friis-Christensen hypothesis was a well-formulated (though admittedly pretty speculative) theory. It was capable of further development and both observational and experimental testing. The very fact that it has now been falsified shows that it was "good science". That it has been abused by global warming skeptics is a sad commentary on the way politics interacts with science, but what are scientists supposed to do - keep their mouths shut and avoid rocking he boat?

Interesting isn't it.

Lockwoods method is this.

For the last 20 years, there isn't a correlation between solar irradiation (not other solar effects) and global temperatures so that means no solar effect on current GW.

Interesting standard of proof.

1945-1975, CO2 went up, global temperatures went down.

By the same standard of proof, we have now falsified CO2 as the cause of GW.

The observations demonstrate that a single factor model based on either solar or greenhouse effects is wrong, and that a two factor model invoking both requires that the greenhouse effect is currently dominant.

Lockwood & Froehlich don't claim to show that CO2 is the cause of global warming, but they have successfully falsified the theory that solar forcing is the dominant or sole cause.

"Duh" is what you get at midnight after a long, hot, busy day.
The solar forcing conjecture has been weakening over the last few years as data cumulates both on Earth's climate and sun's activity - really only required one solar cycle to nail down the effect.

The Svensmark/Friis-Christensen hypothesis was a reasonable testable hypothesis, the physical mechanism was plausible, but the quantitative effect was always a bit of a reach - any messing about with albedo and cloud cover to explain climate change has two root problems - the percentage change required is large (because of that pesky fourth root in the dependence on Teff) and large changes in cloud cover are climate change in and of themselves. Of course it moved the "blame" from Us to The Sun.

But, the presence of external modulation by the sun doesn't change the radiative properties of CO2 - you'd still have radiative forcing from carbon emission, just superposed on larger than expected natural variability due to solar forcing.
One thing you can not plausibly do is provide a negative feedback between CO2 concentrations on the Earth and activity of the sun.

Actually a three factor model, with aerosol forcing (global darkening) which is largely responsible for the pre 1975 cooling. In fact it looks like the solar forcing is small enough to ignore for practical purposes, so a two factor model GHG(not just CO2), and aerosols should cover most variation.

The problem is that this fitting of 2, 3 factor models is done just for the industrial era.

As such the models are useless for determining what is going on.

You need to have a model that works before industrialisation.

You then see if that model works post industrialisation.

If it does, then there is no need to introduce anthropogenic effects.

However, if introducing man made CO2 emmisions gets a statistically significantly better fit, then you have evidence for an anthrogenic effect.

It also solves the question of attribution.

Now since the alarmists go bonkers and say you can't attribute, it also means they cannot have got this statistical type of model to work. [realclimate]

This also applies to the proxies. The proxies are supposed to show average global temperatures. However, the proxies were fitted to the real temperatures 1902-1980. Post 1980 they do not match real temperatures. There is a 0.6C difference which is larger than the 0.5C GW rise.

Again straight forward statistics.

Nick

I supose the 25 pound cost ($50) of the paper is one of those negative effects of GW.

Nick,

There is a paucity of data for the pre-industrial data, but if you run the existing models using pre-industrial, natural forcings, you do get pre-industrial climate.

However, while pre-industrial data helps, it is not necessary for attribution. If you use purely natural forcings during the industrial data, you don't get the industrial climate. Only if you add anthropogenic forcings do you get something like the correct climate. That alone tells you that natural forcings are not adequate to explain current trends. Showing that natural forcings, using the same models, get the pre-industrial climate right only adds to the story.

I have no idea what you mean when you claim that "alarmists" say that you cannot attribute climate change. That's the whole point.