Is the Sun causing global warming? Who are the deniers now?
A prominent global warming denier recently claimed
"Some people simply deny that the sun is more active now and and been increasing in activity since the Little Ice Age (well except for the past few years as it now appears to be remaining quiet)."
Then linked this graph: http://www.junkscience.com/Greenhouse/irradiance.g...
And asked "who are the deniers now?".
I'm not aware of anyone who's denying the fact that solar activity is higher now than it was during the Little Ice Age. But if I'm reading that graph correctly, it shows that average total solar irradiance has remained right around 1366 W/m^2 since 1950.
So you've got one group who's claiming that a 60-year flatline in solar activity has caused the planet to warm 0.55°C over the past 30 years. You've got another group which says that makes no physical sense.
Who are the deniers now?
"Also, the temps have been flat since the late 1990s.
That's a fact."
No, it's not.
- MTRstudentLv 61 decade agoFavorite Answer
My department has found some very interesting results on solar activity: Friis-Christensen, Svensmark etc have argued for a correlation between cloud cover and galactic cosmic rays ('GCRs', modulated by the Sun's magnetic field, with sunspots as a proxy).
However, the papers by Wolfendale, Erlykin et al argue that if it were GCRs, you'd expect the cloud response at about 10km up in the atmosphere. There is no correlation for medium and high clouds, but there is a correlation for low clouds at ~3km. This suggests cosmic rays aren't that important.
The biggest surprise to me was that the majority of the changes in cloud formation occur BEFORE the change in GCR, but more in line with changes in the TSI. Since the majority of changes occur a few months before the change in GCR flux, they're probably not being caused by cosmic rays.
They think that changes in convective heat transfer in the tropical atmosphere caused by changes in TSI are a better explanation of changes in low cloud cover.
They conclude in one paper that solar changes in total may explain up to 14% of observed warming.
The papers are available here:
(the last one mentions 14%)
- amancalledchudaLv 41 decade ago
Yes Dana, a very good point.
Of course, exactly the same argument can be made against CO2, which started to rise quickly in the 1940s, just as temperatures started falling and is currently rising as fast as ever, while temperatures have currently stopped rising.
And where do you get this 0.55⁰C rise over the last 30 years from? I’ve just checked and I get values from as low as +0.37⁰C (UAH) to as high as +0.48⁰C (GISS, predictably). So you appear to be inflating the figure somewhere from 15% - 50%.
Finally, your last comment (at time of posting) regarding the temps being flat since the late 1990s is another example of your disingenuous nature. Clearly Didier is selecting hot 1998 to make his claim, so you can argue Didier has cherry-picked all you like. But you don’t, you go and do exactly the same thing by cherry-picking the dodgy GISS dataset to disprove him. As you are well aware, all other dataset *do* show cooling since 1998. So, this is a classic example of the pot calling the kettle black.
As ever with Global Warming - don’t believe the hype.
- andyLv 71 decade ago
Once again, both graphs show data with no information on where that data comes from, how it was gathered or created or anything else. Finally, once again, just because temperatures have surprisingly gone up from the end of the Little Ice Age does not proof or disproof any of the theories. I get a kick out of the the stupidity on both sides of the issue. I tend to lean towards the natural side with man's greenhouse gases adding another 5-15% of the temperature increase but not being the primary driver.
- Anonymous1 decade ago
Solar irradiance and Earth Albedo must be factored together before any rational statement can be made based on either.
Warming, to the extent that it is a function of either one, is a function of both.
Dana, you could read what I write for you. It might help. Instead of just being a machine gun of propaganda. Ask questions to get answers, not just as agitprop.
In Greek, when two things are inextricably linked in the effects they produce they are called hendyadic, which means arising together.
In this case, whatever warming is related to solar activity, is also related to Albedo variations. These constitute a hendyadic pair of factors.It's not just what the sun pumps out, it's also what the Earth absorbs and fails to reflect back into space. Warming causes albedo reduction. so 1366 W/m^2, changed a bit up or down, has albedo knock on effects that magnify the outcome produced.
Please try to get your half-scientific community college friends clued in to this reality.
You are about 60% on the right side, and about 40% of what's in your head is garbage -- call Waste Management, get rid of it.
Well, that's what education is I guess.
My advice to the young -- "grow up"Source(s): The Fountainhead of All True Knowledge told me.
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- Anonymous1 decade ago
I wouldn't go that far that it makes no physical sense. There are too many variables here. I mean, say if its only due to solar activity (lets put aside SUVs for the time being), would a temporary climate change be a subject of a few years turnover or raise in 1950 could have a long term impact? I mean its a bit difficult to analyze, and definitely not a reason to buy a hybrid.
- JimZLv 71 decade ago
There are a lot of factors. One of them is the ocean. What does the approximate 800 year lag in CO2 concentrations vs temperature tell us? It tells us the ocean is very voluminous and tends to moderate the temperature and smooth out the variations over time. We are still experiencing some of the effects of the warming that we had 20 years ago or more. Clearly the graph you linked to shows dramatic increase in solar irradiance over hundreds of years. Frankly, even if there was a decrease in solar irradiance, it shouldn't be surprising that there may be a "flattening" of the temperature. I wouldn't call it a flattening. I would simply call it indeterminate at this point. Even the NASA graph you linked to shows that.
- Anonymous1 decade ago
You might just study this for a while because they point out just how bad two of your golden hero's screwed up in predicting an intense cycle 24.
- Anonymous1 decade ago
I thought we have been having a rather extended period of low solar output. I've even read a couple of reports from NASA personnel that are starting to compare it to the Maunder Minimum.
I do think that the sun is the prime mover in our global climate...but I have no idea where this guy is getting the idea that the sun is more active now.
- 1 decade ago
Imago: Technically your SUV will kill us all, either from it's pollution that causes lung cancer or you having an "accident" and it rolling over. Have a nice day! :D
- Didier DrogbaLv 61 decade ago
How does this "60 year flatline in solar activity" jibe with the 11-year sunspot cycle?
Also, the temps have been flat since the late 1990s.
That's a fact. It's not "getting warmer." It's still warm. That's the grammatically correct way to describe the temperature. For it to still be warming, the temperature would have to be HIGHER.