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Sun & climate: moving in opposite directions

What the science says...

Select a level... Basic Intermediate Advanced

The sun's energy has decreased since the 1980s but the Earth keeps warming faster than before.

Climate Myth...

It's the sun

"Over the past few hundred years, there has been a steady increase in the numbers of sunspots, at the time when the Earth has been getting warmer. The data suggests solar activity is influencing the global climate causing the world to get warmer." (BBC)

At a glance

Thankfully for us, our Sun is a very average kind of star. That means it behaves stably over billions of years, steadily consuming its hydrogen fuel in the nuclear reaction that produces sunshine.

Solar stability, along with the Greenhouse Effect, combine to give our planet a habitable range of surface temperatures. In contrast, less stable stars can vary a lot in their radiation output. That lack of stability can prevent life, as we know it, from evolving on any planets that might orbit such stars.

That the Sun is a stable type of star is clearly demonstrated by the amount of Solar energy reaching Earth's average orbital position: it varies very little at all. This quantity, called the Total Solar Irradiance, has been measured for around forty years with high accuracy by sensitive instruments aboard satellites. Its average value is 1,362 watts per square metre. Irradiance fluctuates by about a watt either way, depending on where we are within the 11-year long sunspot cycle. That's a variation of no more than 0.15%.

From the early 1970s until today, the Solar radiation reaching the top of Earth's atmosphere has in fact shown a very slight decline. Through that same period, global temperatures have continued to increase. The two data records, incoming Solar energy and global temperature, have diverged. That means they have gone in opposite directions. If incoming Solar energy has decreased while the Earth continues to warm up, the Sun cannot be the control-knob of that warming.

Attempts to blame the sun for the rise in global temperatures have had to involve taking the data but selecting only the time periods that support such an argument. The remaining parts of the information - showing that divergence - have had to be ditched. Proper science study requires that all the available data be considered, not just a part of it. This particular sin is known as “cherry-picking”.

Please use this form to provide feedback about this new "At a glance" section, which was updated on May 27, 2023 to improve its readability. Read a more technical version below or dig deeper via the tabs above!

Further details

Our Sun is an average-sized main sequence star that is steadily using its hydrogen fuel, situated some 150 million kilometres away from Earth. That distance was first determined (with a small error) by a time consuming and complex set of measurements in the late 1700s. It led to the first systemic considerations of Earth's climate by Joseph Fourier in the 1820s. Fourier's number-crunching led him to realise a planet of Earth's size situated that far from the Sun ought to be significantly colder than it was. He was thereby laying the foundation stone for the line of enquiry that led after a few decades to the discovery of what we now call the Greenhouse Effect – and the way that effect changes in intensity as a response to rising or falling levels of the various greenhouse gases.

TSI Solar cycles

Figure 1: Plot of the observational record (1979-2022) on the scale of the TSIS-1 instrument currently flying on the space station. In this plot, the different records are all cross calibrated to the TSIS-1 absolute scale (e.g., the TSIS1-absolute scale is 0.858 W/m^2 higher than the SORCE absolute scale) so the variability of TSI in this plot is considered to be its “true variability” (within cross calibration uncertainties). Image: Judith Lean.

The Sun has a strong magnetic field, but one that is constantly on the move, to the extent that around every 11 years or so, Solar polarity flips: north becomes south, until another 11 years has passed when it flips back again. These Solar Cycles affect what happens at the surface of the Sun, such as the sunspots caused by those magnetic fields. Each cycle starts at Solar Minimum with very few or no sunspots, then rises mid-cycle towards Solar Maximum, where sunspots are numerous, before falling back towards the end. The total radiation emitted by the Sun – total solar irradiance (TSI) is the technical term – essentially defined as the solar flux at the Earth's orbital radius, fluctuates through this 11-year cycle by up to 0.15% between maximum and minimum.

Such short term and small fluctuations in TSI do not have a strong long term influence on Earth's climate: they are not large enough and as it's a cycle, they essentially cancel one another out. Over the longer term, more sustained changes in TSI over centuries are more important. This is why such information is included, along with other natural and human-driven influences, when running climate models, to ask them, “what if?"

An examination of the past 1150 years found temperatures to have closely matched solar activity for much of that time (Usoskin et al. 2005). But also for much of that time, greenhouse gas concentrations hardly varied at all. This led the study to conclude, " that at least this most recent warming episode must have another source."

TSI vs. T
Figure 2: Annual global temperature change (thin light red) with 11 year moving average of temperature (thick dark red). Temperature from NASA GISS. Annual Total Solar Irradiance (thin light blue) with 11 year moving average of TSI (thick dark blue). TSI from 1880 to 1978 from Krivova et al. 2007. TSI from 1979 to 2015 from the World Radiation Center (see their PMOD index page for data updates). Plots of the most recent solar irradiance can be found at the Laboratory for Atmospheric and Space Physics LISIRD site.

The slight decline in Solar activity after 1975 was picked up through a number of independent measurements, so is definitely real. Over the last 45 years of global warming, Solar activity and global temperature have therefore been steadily diverging. In fact, an analysis of solar trends concluded that the sun has actually contributed a slight cooling influence into the mix that has driven global temperature through recent decades (Lockwood, 2008), but the massive increase in carbon-based greenhouse gases is the main forcing agent at present.

Other studies tend to agree. Foster & Rahmstorf (2011) used multiple linear regression to quantify and remove the effects of the El Niño Southern Oscillation (ENSO) and solar and volcanic activity from the surface and lower troposphere temperature data.  They found that from 1979 to 2010, solar activity had a very slight cooling effect of between -0.014 and -0.023°C per decade, depending on the data set. A more recent graphic, from the IPCC AR6, shows these trends to have continued.

AR6 WGI SPM Figure 1 Panel p

Figure 3: Figure SPM.1 (IPCC AR6 WGI SPM) - History of global temperature change and causes of recent warming panel (b). Changes in global surface temperature over the past 170 years (black line) relative to 1850–1900 and annually averaged, compared to Coupled Model Intercomparison Project Phase 6 (CMIP6) climate model simulations (see Box SPM.1) of the temperature response to both human and natural drivers (brown) and to only natural drivers (solar and volcanic activity, green). For the full image and caption please click here or on the image.

Like Foster & Rahmstorf, Lean & Rind (2008) performed a multiple linear regression on the temperature data, and found that while solar activity can account for about 11% of the global warming from 1889 to 2006, it can only account for 1.6% of the warming from 1955 to 2005, and had a slight cooling effect (-0.004°C per decade) from 1979 to 2005.

Finally, physics does not support the claim that changes in TSI drive current climate change. If that claim had any credence, we would not expect to see the current situation, in which Earth's lower atmosphere is warming strongly whereas the upper atmosphere is cooling. That is exactly the pattern predicted by physics, in our situation where we have overloaded Earth's atmosphere with greenhouse gases. If warming was solely down to the Sun, we would expect the opposite pattern. In fact, the only way to propagate this myth nowadays involves cherry-picking everything prior to 1975 and completely disregarding all the more recent data. That's simply not science.

Longer-term variations in TSI received by Earth

It's also important to mention variations in TSI driven not by Solar energy output but by variations in Earth's orbit, that are of course independent of Solar activity. Such variations, however, take place over very long periods, described by the Milankovitch orbital cycles operating over tens of thousands of years. Those cycles determine the distance between Earth and the Sun at perihelion and aphelion and in addition the tilt the planet's axis of rotation: both affect how much heat-radiation the planet receives at the top of its atmosphere through time. But such fluctuations are nothing like the rapid changes we see in the weather, such as the difference between a sunny day and a cloudy one. The long time-factor ensures that.

Another even more obscure approach used to claim, "it's the sun" was (and probably still is in some quarters) to talk about, "indirect effects". To wit, when studies can't find a sufficiently large direct effect, bring even lesser factors to the fore, such as cosmic rays. Fail.

In conclusion, the recent, post 1975 steep rise in global temperatures are not reflected in TSI changes that have in fact exerted a slight cooling influence. Milankovitch cycles that operate over vastly bigger time-scales simply don't work quickly enough to change climate drastically over a few decades. Instead, the enormous rise in greenhouse gas concentrations over the same period is the primary forcing-agent. The physics predicted what is now being observed.

Last updated on 27 May 2023 by John Mason. View Archives

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Further viewing

This video created by Andy Redwood in May 2020 is an interesting and creative interpretation of this rebuttal:

Myth Deconstruction

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Expert interview with Mike Lockwood


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Comments 1 to 25 out of 636:

  1. "From the actual data we conclude that the graphs from Lockwood and Frölish were flawed: 1. The methodology used by Lockwood and Frölish to smooth the lines was applied only to maxima of R (sunspot number), dismissing the TSI. This practice hides the minima, which for the issue are more important than the maxima. For example, if the minimum of TSI in 1975 was 1365.5 W/m^2, it would contrast dramatically with the minimum of TSI of 1998 that was 1366 W/m^2 (0.033% higher). That would make the Sun in 1975 “colder” than in 1998. However, if we compare minimum values with maximum values, then the Sun would be frankly “warmer” in 1998 -when the solar energy output was 1366 W/m^2- than in 1975 -when the energy output was 1366.1111 W/m^2. Today (21/07/07), the global TSI was 1367.6744 W/m^2); hence, we see that we must not smooth maxima values through movable trends because we would be hiding the minima values, which are more important because the baseline of the “cooler” or lower nuclear activity of the Sun are higher everyday. The coolest period of the Sun happened during the Maunder Minimum when the TSI was 1363.5 W/m^2. The coolest period of the Sun from 1985 to date occurred in 1996 when the TSI was 1365.6211 W/m^2. An interesting blotch is that in 1985 the TSI was 1365.6506 W/m^2 and in 2000 was 1366.6744."
  2. Just assuming for the sake of argument that your assertions based upon
    are proven by peer-reviewed studies to be correct and that: -
    Recent oppositely directed trends in solar climate forcings and the global mean surface air temperature BY MIKE LOCKWOOD AND CLAUS FROHLICH
    is shown by peer-reviewed studies to be wrong in some way, that still does not invalidate the fact that Solar output [once the 11-year cycle has been removed], has had no tend or virtually no trend.
    Claims that the recent anomalous warming are solely due to solar effects are unsustainable. It is clear that the current anomalos warming cannot be explained without including the effects of GHGs and CO2 in particular.
  3. I think I have the right to argue on my article based on peer reviewed papers. When we consider a short period, for example an 11 years period we can argue that the intensity of the solar irradiance is decreasing; however, if we consider a longer period, for example 400 years, we can see that the intensity of solar irradiance has not decreased. Some 400 years ago the solar irradiance intensity was 1365.5946 W/m^-2, while in 2000 the total solar irradiance intensity was 1366.6620 W/m^2. This year the Sun has been mostly spotless, but the solar irradiance intensity has been 1365 W/m^-2. This constitutes evidence on the existence of other solar "pulses" that we have not understood well: Regarding the particularity of CO2 on the global warming, I don't see why to blame the CO2 of GW when its particular thermal characteristics show that the CO2 is not capable of producing any warming. The Pp of the CO2 in the atmosphere is roughly 0.00034 atm*m, wich limits the absorptivity-emissivity of the CO2 to only 0.00092 (dimensionless value), not the 0.2 given by the IPCC. The absorptivity-emissivity of CO2 is 0.00092 conduces to its total emittancy of barely 0.414 W/m^2, not the 5.35 W/m^2 given by the IPCC. If I was to blame any atmospheric gas of a GH effect, I would blame the Water Vapor, not the the coolant CO2.
    Response: "its particular thermal characteristics show that the CO2 is not capable of producing any warming"

    On the contrary, the enhanced greenhouse effect from CO2 has been confirmed by multiple lines of empirical evidence (eg - satellite measurements of infrared spectra, surface measurements finding more downward infrared radiation warming the planet’s surface).

    "If I was to blame any atmospheric gas of a GH effect, I would blame the Water Vapor, not the the coolant CO2."

    You would be right in that water vapour is the most dominant greenhouse gas. It's also the dominant positive feedback in our climate system and amplifies any warming caused by changes in atmospheric CO2. This positive feedback is why climate is so sensitive to CO2 warming.
  4. Biocab: surely you can agree with the consensus that solar irradiance has not increased significantly in the last 50 years, while the global average temperature has? The only conclusion can be that changes in solar irradiance cannot have contributed to recent warming in the last half century. With regard to CO2: I think you are not completely aware of the exact concept of the natural greenhouse effect, the enhanced greenhouse effect and most important of all radiative forcing. I am not an expert on the exact chemistry of all the trace gases and how that works, so I cannot judge your comments on the exact emissivity (though my gut feeling hints at the missing of the immediate re-emittance of longwave IR-radiation while you seem to be talking only about the independent emittance of the absorbed heat). I do know the following though: the absolute value of carbon dioxide (whether expressed in ppm or Pp) is not relevant when it comes to the increase or decrease of the Earth's surface temperature. Changes in the exact amount of each gas are what is important. The reason for this is that such changes will cause changes in radiative fluxes and, as a part of the total atmospheric adjustment for these radiative inbalances, the earth's surface cools or warms. Now given that carbon dioxide concentrations have risen at least 35% since 1900, there surely must have been some warming due to carbon dioxide (though not due to the existance of the gas in the first place, but because of the increase in its concentration). I am more at home in meteorology, so some rough calculations about that: the upward surface flux of the earth is around 390 W/m² (sigma T^4 = 5,6704x10^-8 * 288^4 ~ 390) and the outward flux at the top of the atmosphere is (1-a)S/4 where a ~ 0.3 (the global, terrestial albedo of the atmosphere) so this flux comes down to about 240 W/m². Now you can easily see that a large amount of longwave radiation must have been absorbed by the atmosphere, roughly 150 W/m². We know that water vapour is by far the primary absorber and carbon dioxide relatively weak (that is what you have showed, I think). Then comes radiative forcing: this can be understood simply by looking at toy models, which show that if the solar input or emissivity of the earth or the atmosphere (e.g. the greenhouse gasses) changes, the Earth's surface temperature changes. To conclude, models have shown that a doubling in CO2 concentration will likely cause a radiative forcing of around 3,7 W/m². One can now find that the coefficient for determining the radiative forcing caused by an increase or decrease of CO2 concentration from any given value A to B, will be C = 3.7 / ln(2) = 5.34 (and reversing the equation results in DF = 5.34 ln(co2/co2_orig) ). I am just a layman but I am pretty sure the value you quoted, 5.35, is NOT the total emissivity of carbon dioxide but only a coefficient effectively indicating the climate sensitivity to CO2 doubling. The value is not even in W/m² but dimensionless. Note of caution: I consider myself a layman and excuse me for any dramatic failures in reasoning. Willing to learn though :). Ben
  5. 5.35 needs to have units: delta T = W/m^2 [Ln (ppmv/ppmv)] / 4 (W/m^2*K^4) (K^3) If don't, how could we eliminate W/m^2 from Stephan-Boltzmann constant?
  6. I don't agree with consensus, I agree with science. In the last 50 years the Intensity of Solar Irradiance increased in 1981 uo to 1366.6829 W/m^2. Higher than in 1957 (1365.7689 W/m^2); consequently, in 1981 was higher than 50 years ago. In 2000 the ISI was 1366.6620 W/m^2, and it was higher than 50 years ago (ISI in 1957 was 1365.7689 W/m^2). The last year (2006) the ISI was 1367.25 W/m^2, higher than in 1957, 1981 and 2000. Is ISI increasing or decreasing in the last 50 years? The inciding IR upon the surface is not 240 W/m^2, but ~469 W/m^2. From the last load of energy, the surface absorbs ~356.15 W/m^2 (median ~342 W/m^2) (1- Manrique, José Ángel V. Transferencia de Calor. 2002. Oxford University Press. England. 2- Maoz, Dan. Astrophysics. 2007. Princeton University Press. Princeton, New Jersey Some scientists from the IPCC think that the value 5.35 W/m^2 is wrong... I agree:
  7. An increase of 1365,7689 to 1366,6620 is not in any way statistical significant. Pick two others years and you get a decrease (e.g. what Lockwood did). You did not account for the 11-year periodic cycle which needs to be substracted before looking at trends, which underlines the uselessness of randomly picking TSI from any given year or years. Ergo: looking at the data with the 11-year cycle substracted, the trend in the last 50 years is more or less neutral (+0,08 W/m²) and in any case not statistical significant, given the amount of variance in that same period. Inciding IR upon the Earths surface is not ~240 W/m², sure I agree with that, but then again I am not claiming it is (I said it was the outgoing flux at the TOA). The ~469 W/m² is the [total] incoming IR at the surface, which is a combination of solar flux and radiation coming from the GHGs (water vapour, carbon dioxide, so on). IPCC puts it at 492 W/m² as a consensus though. Of that amount about 452 W/m² goes into the atmosphere by latent heat exchange, evapo(trans)piration and absorption by GHGs (the latter roughly 350 W/m²). The atmosphere itself radiates 195 W/m² upwards into space and 324 W/m² downwards towards the surface. About 40 W/m² makes it directly from the Earth's surface into space. The incoming solar flux is ~235 W/m² (and outgoing as well), of which 67 W/m² is absorbed by the atmosphere and 168 W/m² reaches the surface. So summarizing: the [surface] incoming flux is ~492 W/m² and outgoing as well, the TOA incoming and outgoing flux is ~235 W/m². The atmosphere absorbs 519 W/m², most of it from below from the Earth's surface, and emits this upwards and downwards (mostly the latter). As far as I can tell, nothing of this appears in real contradication with your article from Manrique (2007). The 5.34/5.35 is indeed in W/m², I stand corrected. The ln(co2/co2_orig) only scales the value and deltaF is in W/m². Ben
  8. Well, let's compare 1957 (50 years ago) with 2006 (one year ago). In 1957 the ISI was 1365.7689 W/m^2, while in 2006 the ISI was 1367.25 W/m^2. Where is the decrease? The radiative forcing from ISI is 0.85 K per each W/m^2 of solar IR. From 1957 the extent of ISI has been 1.4811 W/m^2, that is 1.26 K. It is more credible than the 0.02 K from the heat absorbed by the CO2. The point where I don't agree with you is the radiative forcing for CO2, which is not 5.35 W/m^2, but 0.414 W/m^2. That was considered in the NAS paper. It seems, from the article, that the value for deltaF wasarbitrarly fixed.
  9. What is your source of 1367,25 W/m² for 2006, honestly for me it would seem like an unrealistic jump from the late 1990's to now. According to the PMOD-WRC data (link above, 'direct satellite measurements'), which is consistent with Lean (2000), the average TSI last year was 1365,4 or 1365,5 W/m² which seems more appropriate than 1367 W/m². In any case you cannot directly compare 1957 with 2006 because 2006 was the 11-year cycle minimum and 1957 was a cycle maximum, so compare maxima or minima or averages per solar cycle instead. E.g. if I use the Lean (2000) data from your webpage and compare 1957 with 2000 (maximum of solar cycles 19 and 23), I get 1366,681 and 1366,724, which equates to deltaF = 0,043 W/m² or a deltaT of 0,06 according to your equation. The first half of the century however I see a deltaF of 1,6 W/m² in the maxima and deltaF of 1,0 W/m² in the minima, equating to deltaT = 1,6-2,4 degrees. This strikes me more as a debate on data than principals or methods, by the way. The detrended data shows no [significant] decrease or increase in TSI/ISI. From that perspective I neither agree with the Lockwood article that ISI has decreased in the last 25 years nor with the claim that it has increased in the last 50 years. I would have to make myself more familiar with the exact fundamentals of radiative forcing before investigating whether or not the trend found would induce any (significant) forcing, your equation looks nice but I want to check it for myself first :-). On CO2 forcing: climate sensitivity to doubling of its concentration has a probability range even in the IPCC reports, however further discussion on this is not meant for this page.
  10. Small addition: this is what you get when you compare random years, say 1966 and 1996 (thirty years): 1365,951 and 1365,621, a decrease of -0,330 W/m². This is all using the Lean (2000) data from your webpage. Now 1966 was three years away from the maximum of cycle 20 in 1969 and 1996 was the minimum at the end of cycle 22.
  11. I like your analysis Ben. If you haven't, check Tamino's post "PMOD vs ACRIM." He did an outstanding job of examining solar data. Hope John isn't going to get tired of me always referring to other sites!
    Response: Not at all - the point of Skeptical Science is to point people to relevant resources, primarily the peer reviewed papers but good blog posts too. Tamino has two great posts which I link to from my Is the sun getting hotter? page (and I even lifted one of his graphs to use on my page).
  12. Ben Lankamp, the source is It's not unrealistic given that the data is NH instrumental. Solar irradiance is going up, not down. You cannot take just one sunspots cycle out of context. The last would be pseusoscience.
    Response: The only information at the LASP page about long term trends in solar irradiance is the following graph:

    What it shows is a close correlation between Solar Irradiance (the orange line) and global temperature (dotted blue line). But they also show the correlation ends when the modern global warming trend begins in the mid-70's. The data is all there and it's unambiguous - there's a reason why so many studies (listed above under "Other Studies on solar influence on climate") conclude the sun's influence on recent global warming is minimal.
  13. No, what it shows is that the solar irradiance in 2006 was 1367.25 W/m^2.
  14. What it also shows for the 20th century is that the timing is not quite right. Temp increases sharply before the TSI and then, even before the TSI reaches its first 20th century spike, the temp actually starts to decrease, followed by a TSI decrease, and then the temp increases again, followed again (very modestly) by the TSI. If I was using a skeptical aproach to attempt a correlation between the 2 on this graph, it would appear that TSI was driven by temperature during the 20th century.
  15. I notice John, that you have done some renovating. Where did your last thirty years of satellite measurements of the TSI disappear to? To the unpracticed eye nothing out of the ordinary is apparent, but to people familiar with the site, it looks as though you are erasing key information that supports Biocab's contention that in regard to TSI it is the minimum measurement extended over time that is the most important. And the minimum is trending up - or rather was. If the current lack of sunspots extends a while longer, and the next solar cycle sees a drop in overall activity followed by a drop in global temperature, will you become a co2 denier? What about you Phil?
    Response: Not sure what you're refering to but I haven't removed anything (I am constantly tweaking the site but it's mostly adding links to new studies as I encounter them). Perhaps you were thinking of the discussion of satellite TSI data at The sun is getting hotter. As for the next solar cycle and the prospect of a drop in global temperature, it's funny you should mention that - I'm working up a page on that very subject which I'll post later this week.
  16. I'm checking out biocabs data and I cannot see where the mystery is here? There is no substantial hole where someone needs to plug CO2 into.
  17. So what is the data source for the dotted blue line? Is it USHCN? Or partially USHCN?
  18. I question the physics behind the response: a crucial finding was the correlation between solar activity and temperature ended around 1975....... The assumption is that there is always an energy balance between heat radiated from earth and input from the sun. Lets say that solar activity remained above this energy balance, one would have to assume that temperature would still increase, until some new energy balance is achieved. This means that temperature can still increase as long as the input is greater that the output. basic example: take a pot of water at room temperature, it is in an energy balance, and temperature is constant. then take that pot and turn the stove on high the temperature will increase then turn the elopement down, and the water still warms up. until it reaches an energy balance. It does not seem reasonable to assume that reduced solar activity always equals reduced temperatures on earth. Reduce solar activity, that is still more active then in 1900 should then still result in increasing temperature.
    Response: If solar activity increases then plateaus, the climate will then be in energy imbalance with more energy coming in than radiating back out to space. The earth will immediately start warming. As it warms, the energy radiated back to space gradually increases until the climate reaches radiative equilibrium. Then warming stops. This period it takes to reach equilibrium is refered to as climate time lag.

    However, this is not what is observed over the 20th century. Solar activity levels out in the 1950's. However, the modern global warming trend began in the mid 1970s. If the sun was the cause of global warming, the planet would've been at its highest energy imbalance in the 1950s. Then the planet would gradually have approached equilibrium over the next few decades.

    The opposite has occured. The energy imbalance has in fact increased over the past 3 decades and is still increasing. Of course, we now know why the planet is in radiative imbalance - due to an enhanced greenhouse effect caused by increasing greenhouse gases such as CO2 and methane.
  19. There is new evidence that TSI may have varied a lot less than previously thought, which would require an extremely high sensitivity to allow for such small variations to influence climate.
  20. I am seeing some papers that contradict the statement that the solar-climate connection somehow disappeared in 1975. To me it looks good at least through 2003, but, it seems the fit is good but the cause is too small for the effect. Neither the blue nor the red line in the second from top graph are right today, solar activity was most definitely not trending down in the 1998-2000 period for instance. Could you maybe update or correct them?
  21. I believe Leif Svalgaard paper (available as a pdf) might answer some of your questions. In any case, TSI and its reconstructions are thorny areas. See this post: and part2 of it as well. Would be nice to provide links or references when you mention peer-reviewed stuff, it helps. As an aside, Energy and Environment is not a peer-reviewed science publication.
  22. About the sun. Whether the solar irridiance has increased or not during the past 50 years, I think it's important to know that solar irridiance changes most in the shorter wavelengths such as UV during a sunspotcycle. Part of this extra radiation will be absorbed by stratopheric ozone and shouldn't reach the earth-atmosphere system at all. But... 1) Couldn't the climate became more sensitive to solar activity because of the 'ozone hole' the past few decades? Due to less ozone a higher intensity of UV-light reaches the earth surface. These are just the wavelenghts that an active sun submits. 2) Another point is that shortwave radiation penetrates deeper in the ocean as longwave radiation does (this effect gives the typical blue light in deep waters). So an active sun heats the deeper layers of the ocean where it can be stored for years or, probably, several decades, before it comes to the surface. This means that climate responds delayed on solar activity and perhaps explains the lag of about 10 years found by Solanki and the higher climate sensitivity for longterm sunspotcycles. The oceans absorb most solar energy in the tropics. The small zenit-angle results not only in a high net radiation but also in a deeper penetration of UV-light, and the ozone layer is thinner around the equator. Furthermore the ocean is stratified here so the heat can be well stored before it can be transported by ocean currents. The ocean releases its heat especially on higher latitudes to the atmosphere, possibly modulated by fluctuations in thermo-halien circulations. It also seems that climate responds more sensitive on high latitudes. This hypothesis means that we should't under-estimate the solar influence on global warming. Though there is no significant increase in solar irridiance in recent decades, the climate may still warming due to the major increase during the first half of twentieth century and loss of ozone. This is my first post on this site and I like to discuss about climate more. I'm a dutch meteorologist (semi-professional) and very interested in climate change and its mechanism. I'm not convinced by AGW because there are some questions left. Thanks to John Cook for this forum and the possibility to debate here with open mind. Regards, Victor de Vries
  23. Yes Victor, the change in output during high solar activity is not uniform for wavelength and I don't know how important that is. It does seem like a mighty large effect for such a small change so there must be something more to it.
  24. Odd I google it and get tons or references of course I typed in "Reginald Newell MIT" I felt it was safe to use him as an example as he has passed away. I would disagree that any of the 3 stated positions that were not supported by their research. Also if that was the criteria look how many people on the other side would be unemployed. Hey folks what is the other thread where people were discussing the solar spectra Victor asked about I cant remember.
  25. OK, I went back to do a little digging and found out that first, I appear to be incorrect since George Taylor appears to still be the State Climatologist. Was he one of the ones that you were thinking of? Anyway, keeping with Mr. Taylor, I tried to get a record of his publications and there was nothing listed on his site so I went the Web of Science and found the following 4 publications. Going back to your statement, “ people who have lost jobs because they did perfectly competent research that didn't support the AGW idea,” Which of these do you consider competent research that does not support AGW and how does it fit in with Mr. Taylor’s statements. Title: Regional precipitation-frequency analysis and spatial mapping for 24-hour and 2-hour durations for Washington State Title: Observer bias in daily precipitation measurements at United States cooperative network stations Title: A knowledge-based approach to the statistical mapping of climate Title: Spatial variability and interpolation of stochastic weather simulation model parameters In regards to Reginald Newell, thanks, the name change was a help. Unfortunately all I was able to find was a quote from an interview. Is there anything more substantive than that? Regards, John PS, For the thread with Victor, try It's the Sun

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