One of the tropes of the skeptic community is .... ITS THE SUN, STUPID! (Solar irradiance the basic idea is that climate change is pretty simple.... the sun done it! The variable output of the sun being measured by solar irradiance and sun spots (the number sun spots ,for some reason, seems to correlate with solar irradiance so I thought it it would be fun to present a graph of these factors so that we could discuss the evidence that recent climate change is driven by the sun The way I read this... If solar irradiance is driving climate change We should now be seeing a significant cooling trend am I missing something
Personally, from my investigation, I think that changes in cloud-cover can adequately explain recent global warming, but I also think that the role of the Sun has been downplayed by the IPCC et al. Below is a quote taken from my blog-post with a reconstruction graph showing a significant increase in TSI over the last 200 years..
One thing to remember is that TSI is NOT in units of solar forcing. TSI is the average incident radiation received at TOA (top-of-atmopshere) perpendicular to the surface over the course of 1 orbital period. You have to convert changes in TSI to solar forcing units by first normalizing TSI to the spherical shape of the planet and then apply a reduction factor to it so that it represents what happens at the surface instead of TOA. Here is the formula. ΔF = (ΔTSI / 4) * 0.7 So a +1 W/m^2 change in TSI would result in a +0.18 W/m^2 change in solar forcing. Note that +1 W/m^2 change in TSI is about what happened from the Maunder Minimum to the Modern Maximum. The IPCC figure of +0.05 W/m^2 of solar forcing (not TSI) from 1750 to present is spot on. And for point of reference CO2 forcing is now at +2.0 W/m^2 which is 10x larger than the effect of the solar grand cycles. Changes in TSI only account for about 0.1 to 0.2C (at most) of the 1.1C of warming that has occurred.
There is a delay in the effect of solar irradiance and solar activity (different than irradiance) of about 15 years, mostly due to the heat capacity of the oceans that are the main drivers of climate. The only thing that heats the oceans is the sun and do a very minor extent, internal heat from the Earth. Solar scientists ARE predicting coming cooling so basically if you dismiss that then you would be a science denier. During the short time we have actually measured irradiance it has changed by 1 to 2 watts per square meter so it is more variable than thought before. Solar activity on the other hand is much more variable and thought to affect cloud cover, one of those things they do not model.
You're post certainly takes that into consideration, but the vast majority of solar forcing discussions on here and elsewhere miss this crucial step.
Another thing not taken into account is how paths to radiance back to space may vary based on the pathway. Currently it is fairly basic but like in parallel circuits resistance in one circuit can increase the current in another.
One of the tropes of the anti-CO2 hysteria campaign is that the only way solar activity can affect climate on earth is through TSI. After examining all the possible indices of solar activity, it was determined that TSI has the lowest correlation with global temperature, so TSI was selected as the only permissible way for climate science to relate solar activity to changes in the earth's climate. It was a deliberate choice to remove solar activity from climate science: See? Another anti-CO2 hysteria trope is that there is no inertia in the climate system, which is always at equilibrium, so no factor can affect climate unless a change in that factor immediately reverses the recent trend in temperature. So for example, if sunspot activity is claimed to correlate with climate, then any change in sunspots would have to immediately show up in temperature records: if normal sunspot activity is 100, and sunspot activity has been at 150 while temperature rises, then if sunspot activity declines to 120 and temperature doesn't immediately fall, or even keeps rising, then sunspots can't be a proxy for anything that could affect climate. This "logic" says that if you put a pot of water on the stove on High, and it warms up, then if you turn the stove down to Medium, the water should start cooling down.
If I am missing something, please explain it to me are you saying the sun causes climate change... but it is unreasonable to look for correlation between changes in suns irradiance and warming?
Why? You just refuse to know facts that prove your beliefs are false. I am saying it is unreasonable to look for such correlations ONLY with the variable that is already known to be weakly correlated, and refuse to consider correlations with any other variable.
i am asking for enlightenment it seems odd to identify a main cause while at the same time saying it is weakly correlated Which other variables. Greenhouse gasses
Other non-TSI hypothesis have been studied; some quite extensively like the galactic cosmic ray hypothesis. This is very much considered. It is the whole basis behind the difference between the transient climate response (TCR) and equilibrium climate response (ECR). The reason sunspot activity, by itself, has little correlation with tropospheric temperatures is because of the thermal inertia of the oceans. This is well known. The ocean takes up energy imbalances instantaneously, but the troposphere takes a few decades to equilibrate with the ocean. Yes. Climate scientists know what your argument is. You haven't figured something out that they don't already know. And your argument is wrong. We know this because of observations mainly via oceanic heat content (OHC). In your analogy if you put a pot of water of the stove at high heat it will warm. And it could still continue to warm even if you decreased the heat to medium. Duh. Everybody knows this. BUT... If you decrease heat input the rate at which the water warms decreases. In other words d'T > 0 but d''T < 0. It will take longer for that pot of water to reach the limiting temperature (boiling point) In other words, the warming decelerated. You can repeat this experiment at home. Now back in the real world you're hypothesis can be tested by measuring the rate at which the geosphere takes up heat. Sunspot activity peaked in 1958 and has been on a secular decline ever since. Ironically this is about the time when the OHC warming trend accelerated...by a lot.
And any that show better correlation with global temperature than TSI are ignored, and papers showing such correlations are rejected. No it isn't. But in fact, it is ignored. But ignored. Sunspot activity by itself obviously cannot affect temperature. To the extent that there is a correlation -- and there certainly is -- it must be because sunspots are a proxy for some other less readily observable effect. It takes centuries for ocean circulation to equilibrate water temperature. If they do, they ignore it. I don't know what they know. I only know what they claim. Garbage. OHC is largely guesswork, and has not been observable long enough to make the required inferences. But climate nonscientists pretend they don't. Duh. But still at a sustained multimillennial high. See Solanki et al, 2003, 2004 and 2007. Nonsense. Before it was erased by retroactive falsification of historical data, there was a strong warming trend from 1910-1940, well before solar activity peaked.
Who said TSI variation was the main cause of climate variation? Sunspots. Magnetic activity. Flares. There are lots of possibilities. The big problem is that a lot of solar data has only been available for a very short time relative to the typical duration of the variations. Sunspots, just by chance, have been recorded for centuries, and they appear to be a proxy for something relevant to climate variations.
What is tsi Yeah, But we are looking for something that has some correlation to data...l like gig. People have suggest that climate would warm because of ghosts... and it has So what alternate cause do you suggest that has a better correlation to actual warming data Like what are you referring to..l specifically Yes..l. But ghg has a much better correlation...l particularly in the context of recent history Sun spots are down, temperature is up
Ah yes...there it is...the good old conspiracy argument. That's a card you can always play no matter how convincing the evidence is right? Just curious...what would your response be if I pulled the conspiracy card on all of the contrarian talking points like you do?
Yeah...because you figured out something mind numblingly obvious that somehow escape the collective intelligence of the worlds leading experts right?
Total Solar Irradiance. It is the average solar flux (in W/m^2) over 1 orbital cycle measured at top-of-atmosphere (TOA) perpendicular to a tangent line on the Earthly sphere. The difference between the Maunder Minimum around 1700 and the Modern Maximum around 1960 is about +1.0 W/m^2. This represents a climate forcing of (1.0 / 4) * 0.7 = +0.18 W/m^2. As a point of comparison the climate forcing from CO2 is currently 5.35 * ln(410/280) = +2.0 W/m^2. Yep. And not only is the temperature going up, but it's going up at an accelerated rate.
Here is a chart of sunspot activity Whistle, as I understand it what the Mauder minimum refers to I do not see any correspondence To climate change.... either in the short or long term And certainly not the correspondence of ghg
internet discussions may ignore But science does not I searched for this topic and find this The majority of the G.W. we are concerned about came in last 50 years Which this graph covers And I just do not see how anyone can conclude this graph show tsi is the main cause of climate change
Just to be clear. Let’s suppose that the above chart was of co2 rather than tsi And let’s suppose I claimed the above chart proved AGW is mainly caused by the above factor (hypothetically co2 in this thought experiment). You climate skeptics would ravage me mercilessly And say there is clearly no correlation.... you know that is true And so I have the same incredulous skepticism that you would have if I presented the above chart as proof that this (hypothetically co2) factor was proof of AGW
Total solar irradiance. Solar activity + ocean circulation No it doesn't. There was strong warming 1910-1940, before ghgs could have been significant, and cooling 1940-1970 when ghgs were rising rapidly. Sunspots are only a proxy, and temperature is not up. Only fake data are up.
Manipulated "evidence" that contradicts both the evidence of my own senses and scientific logic is a lot less than convincing. You do.
No. I have never argued that contrarians have banded together in a grand conspiracy to hide the secret that they fraudulently manipulate data for the politically motivated gain of preventing action to combat global warming.
