Readers of Ben Sandilands’ yesterday may be confused by the suggestion that a climate change “debate” is taking place based on cyclic variations in solar radiation. But this ignores the fact that solar variations are one order of magnitute lower than the effects of rising greenhouse gas levels, in terms of temperature effects on the Earth. So whereas the 11 (+/-1 to 2) years-long sun spot cycle results in temperature variations of +/-0.1 to 0.2 degrees C, the greenhouse gas levels have affected a rise of +0.7 degrees C since mid-20th century.
For those of you who may be uncertain about the role of the sun in global warming, allow me to explain.
In the face of overwhelming evidence of severe climate disruption by the world’s leading research organisation (NASA, Hadley-Met, CSIRO, Potsdam, numerous universities), a denial syndrome continues to resort to long-discarded arguments, including variations in solar insolation.
However, according to Sami Solanki, an international authority in solar science, “solar variability is unlikely to have been the dominant cause of the strong warming during the past three decades”.
The luminescence effect of solar magnetic storms (sun spots) on the Earth surface is an order of magnitude less than the effects of rising CO2 gases since the midth 20th century. Sun spot variations account for changes of less than +/-0.4 Watt/m2 (+/-0.1 to 0.3 degrees C). For example, the change from near-zero sun spots during 1650 — 1700AD (“Maunder Minimum“) to near-150 sun spots at 1800AD correlates with temperature rise of +0.3 degrees C. The change from about 70 sun spots at 1900AD to near-180 sun spots at 1950AD correlates with +0.25 C.
According to the IPCC AR4 Report (Fig. TS5) the solar factor accounts for 0.06 – 0.30 Watt/m2 (less than 0.2C) rise since 1750AD. NASA’s Goddard Institute of Space Science indicates total solar irradiance variations of +/-0.3 Watt/m2 (~0.2C) since 1980. Solar vriations can not account for the sharp temperature rise since 1960, a period during which sun spot activity oscillated (correlated with +/-0.1 degrees C), hardly consistent with the +0.7 degrees C rise induced by CO2 rise from 315 to 387 ppm.
Another parameter of global warming is the intensification in the frequency and intensity of the ENSO cycle (El-Nino Southern Oscillation) (Power and Smith, Geophys. Res. Lett., 2007), expressed by cyclic surface warming up to 2 degrees C in the central Pacific, with a peak in 1998, affecting droughts in the southern continents.
But climate “skeptics” can expect some “good news”. Should further melt of Greenland ice and slow down of the Gulf Stream take place, resulting in freezing temperatures in Europe and northeast USA, no doubt the “skeptics” will resume their claims of “global cooling”.
Andrew,
You refer to warming in mainland Antarctica in your most recent comment.
I don’t think that should pass unquestioned. I responded to that report when it was logged on our Rooted blog, not because AGW isn’t of urgent and valid concern, but because it seemed odd.
This is the comment I posted.
(From Rooted):-
I have an uneasy feeling, having read both the linked coverage, and other stories written about this report, that it has been contrived to create the impression that an anomaly in the world wide warming trend has been eliminated for reasons of ideology rather than science.
Both the msnbc and BBC reports are full of caveats arguing against the conclusions the paper’s authors draw, and which are also contradicted by the long term on the ground records taken on the main Antarctic continent as distinct from the rather more temperate conditions of the Palmer Peninsula.
And one of the reports finally points out the blindingly obvious, that ice shelves do break off. They are extrusions of glacial ice. If they didn’t break off they’d eventually reach Tasmania.
Is it really necessary to contort every piece of data to fit the perceptions and agendas of climate change? Climate change, and the serious human inputs are real enough, without any help from those who set out to ‘find’ data to fill in the blanks and somehow invalidate the real historic ground level observations on the larger part of the ice continent.
This reminds me of the disgraceful attempt made several years ago to blame a rabbit plague and widespread erosion on Macquarie Island on global warming, when in fact, it was an act of idiocy in the Australian administration of the island in which the feral cats, which had been keeping the rabbits in equilibrium, were killed without dealing with the rabbits simultaneously. That act of barbarous and ignorant vandalism has destroyed much of the world heritage area. It had nothing to do with global warming.
(ends extract.)
Ben you tried to create the impression that somehow the long sunspot cycle posed significant questions about whether anthropogenic climate change is real. Why is the sunspot cycle so interesting now? You tried to imply that it was being ignored by the main stream media because it dosen’t suit “their” argument. Problem is that sunspot activity is a second or third order effect that is basically irrelevant. The sun is a mass of hot matter in various states that are pretty chaotic. Of course the sun spot activity isn’t constant at exactly 11 years it never has been. There is nothing particularly interesting about this except to scientists who take a particularly active insterest in the sun as a part of their vocation.
“according to Sami Solanki, an international authority in solar science, “solar variability is unlikely to have been the dominant cause of the strong warming during the past three decades”.
Interesting choice of words here -” unlikely” is not the same thing as is not.
Andrew,
The clear aim of your item was to smear me as a climate change denier, and discourage those who sing outside the choir stalls of climate change dogma from straying from the song list.
I was not questioning the research you quoted. I was drawing attention to something interesting. I don’t think the reporting of such matters has to be viewed through the filters of AGW orthodoxy, and certainly not through the prisms of denialism or inaction.
Ben
Anyone who doesn’t believe in global warming should come to Adelaide. A record heatwave in March last year and now it looks like there will be an attempt by the world to better that record this year. The earth is cooling – not down here it’s not.