August 13, 2013 at 1:11 am Suppose that the solar influence on global mean surface temperature, setting aside natural internal variability, varies as the time-integral of solar activity over the previous 11-year cycle.
Suppose also that the very small peak-to-trough difference in incoming solar radiance (it’s about 0.15% of total activity) were amplified sevenfold by cosmic-ray displacement, as Svensmark and many others think.
In that event, there could be half a Celsius degree of global cooling by 2020, and possibly more beyond that date, even after allowing for the small warming influence of CO2. The scare will not survive even seven more years without warming. Perhaps the end is in sight.
First his "half a Celsius degree of global cooling by 2020". You reckon?!
 |
| Data Source: NASA plus Monckton |
Next his "supposing" about cosmic rays. Galactic cosmic rays (GCRs) originate from outside our solar system. (In addition there are charged particles that come from within the solar system and the sun.) GCRs are affected by the solar magnetic field. The amount reaching earth is inversely correlated with the approximately eleven year solar cycle. So when the sun is least active, that's when more cosmic rays will reach earth. For a good short introduction to cosmic rays, you could start with the Neutron Monitor Database website.
For a detailed discussion of cosmic rays and clouds (ie effect on the climate), there is a detailed article by Jeffrey Pierce on realclimate.org.
One of the main notions put forward is that cosmic rays form clouds which reflect incoming solar radiation back out again. So if there is more cosmic radiation then there is more global cooling. Thing is, there hasn't been much variation in cosmic radiation in the past 50 years and more as discussed at realclimate.org by Jeff Pierce (above) as well as in an article by Rasmus E. Benestad - with the data presented graphically as follows. The grey dots represent cosmic rays but multiplied by -1 to emphasise the correlation with the solar cycle (in other words, they are the inverse of what is shown below).
 |
| A comparison between time evolution in the global mean temperature (dark red) and different solar indices (bottom) as well as CO2 forcing (green). All the curves here have been standardised, and the solar curves are shown along the bottom. The GCR are shown in grey, and have been multiplied by -1 to emphasise the correlation with the other solar indices. |
So there is nothing to suggest that the earth's current climate will be affected to a measurable extent by cosmic rays even if they were shown to play a part in cloud formation.
How would you spot a drop in temperature from "a low-activity sun"?
This next comment is from Dermot O'Logical who has the absurd notion that a drop of one whole degree Celsius would be lost in "natural variability".August 13, 2013 at 1:26 am @Kev-in-UK I think any drop in temps from a low-activity sun is not going to show up as a distinct signal – there are so many other factors in play with regards to surface temps.
Let’s suppose there is an actual effect of -1C over 10 years. How would you spot a 0.1C / yr effect amidst the noise of natural variability and be able to assign certainty to the cause being a quiet sun?
Here is what Dermot thinks would not be spotted "amidst the noise of natural variability"!
 |
| Data Source: NASA plus Dermot |
That's probably as cold as it's been in the entire Holocene. It wouldn't take much to notice that.
I'm seriously stunned even by our newcomer Thomas. Seriously :D
ReplyDeleteThomas - are you seriously excusing Monckton by arguing "he didn't really mean it, he only said could"?
That CO2 is a greenhouse gas is physics. The cause is known the evidence supports it. Are you seriously saying you don't accept the greenhouse effect?
You put up evidence from the northern hemisphere. It isn't the entire world you know.
The Little Ice Age is generally regarded as the coldest time of the entire Holocene. Do you seriously think it's reasonable to argue whole earth will suddenly drop to being as cold as the coldest it got over the Northern Hemisphere during the LIA (that is, in the entire Holocene) - and all this in just ten years from now - dropping to the lowest low from probably the hottest it's ever been in the Holocene?
Are you seriously arguing that it's not supremely unrealistic to argue for a drop of one degree Celsius in ten years?
Seriously?
Oh, and no need to prove you'll grab at anything - this time "cosmic rays" - to deny AGW. Without showing any sign of understanding the science. Typical Thomas.
ReplyDeleteThomas asks: "what was the climate concern du jour of the late 1960s through mid-1970s? "
ReplyDeleteHere's the answer:
What 1970s science said about global cooling - very little
The Peterson et al paper showing that science said very little about global cooling and more about global warming
And since climate science deniers rely on newspapers for their memes, try these:
This one's pre-1960 - A newspaper article from 1957, about how weather experts in the Antarctic would take air samples to check a theory that the earth's climate was gradually warming because the amount of carbon dioxide was increasing.
This one's from 1967 - the late '60s: They note that there has been an increase in carbon dioxide in the atmosphere largely because mankind has burned so much coal and oil in recent decades. Scientists believe this excess carbon dioxide should make the planet warmer. Nevertheless there has actually been a slight decrease in temperature, first noticed during the 1940s and thought to be continuing today.
This one's from the early 70's, 1972: Even without experimentation there was a possibility that global temperature increases produced by man's injection of heat and carbon dioxide into the environment could greatly reduce or even eliminate the Arctic Sea ice.
GCRs amplify solar changes sevenfold?!?! That's just freaking moronic.
ReplyDeleteIt's desperate. They have nothing else.
DeleteLaschamp excursion. You need to know your paleoclimate, Tommy.
ReplyDelete