This headline is from an article from the Guardian, which claims evidence to be published in a Royal Society journal, shows that the current GW could not be caused by solar activity. It says that this is a direct response to debunk the idea of solar driven GW put forward by the programme - the Great Global Warming Swindle.
Does anyone agree with this study - or are the paper's findings not potentially biased if, as the Guardian article states, it was "carried out...to directly challenge the claims made in the Channel 4 programme"?
Originally posted by M Batchelor: This headline is from an article from the Guardian, which claims evidence to be published in a Royal Society journal, shows that the current GW could not be caused by solar activity. It says that this is a direct response to debunk the idea of solar driven GW put forward by the programme - the Great Global Warming Swindle.
Does anyone agree with this study - or are the paper's findings not potentially biased if, as the Guardian article states, it was "carried out...to directly challenge the claims made in the Channel 4 programme"?
1) It's hard to agree or disagree with a study that isn't out yet.
2) However, given that these hypotheses have been proposed many times, examined often, and were not convincing, it would be surprising if real scientists found anything else.
and the IPCC FAQ: http://ipcc-wg1.ucar.edu/wg1/Report/AR4WG1_Pub_FAQs.pdf is really pretty good: especially read at least through FAQ 2.1, Figure 2, which shows the relative sizes (and uncertainty limits) of various factors.
If you want to go deeper, you can look at hte main IPCC reports, and if deeper yet, off into the mass of primary research papers they reference.
If their report disagrees with all that, I'd be surprised. Maybe they've got a more persuasive way to explain it.
There is so much evidence now that rules out a solar role in the warming of the last 30 years. The evidence shows:
No trend in insolation (it levelled sometime before 1970).
No trend in cosmic-ray-flux - so changes in clouds lack a proven sun connected mechanism.
The trend in diurnal range.
The cooling of the stratosphere, increased insolation will warm it, increased CO2 cools it.
The fact that whilst ground insolation is not yet back at 1960 levels (it's increased because of a reduction of aerosols - global dimming), the temperature has gone up by 0.6degC since 1960.
We know what is the cause of the recent warming (and much of the 20th century warming before that). It's time to let this solar fantasy die, re-connect with reality, and move on with dealing with the main culprit - human CO2 emissions.
Sun comes up - temperature rises. Sun goes down - temperature drops.
If there has been a variation in solar activity that matches our trend in climate then that's your answer.
Simple.
Anybody that disagrees with that or ignores its effect in favour of some convoluted CO2 theory is just stupid, masochistic or one of the many people benefiting financially from our new "fad".
Ockams Razor: "All things being equal, the simplest solution tends to be the best one."
Originally posted by Mubbers: Sun comes up - temperature rises. Sun goes down - temperature drops.
If there has been a variation in solar activity that matches our trend in climate then that's your answer.
Simple.
Anybody that disagrees with that or ignores its effect in favour of some convoluted CO2 theory is just stupid, masochistic or one of the many people benefiting financially from our new "fad".
Ockams Razor: "All things being equal, the simplest solution tends to be the best one."
You'll need to explain that one to us. You seem to be saying that days are warmer than nights and summer is warmer than winter. I think we can agree with that, but what does it have to do with climate trends?
There has been no solar variation that matches recent warming. There has, however been a CO2 increase that explains it very well indeed, and it is based in quite simple physics.
Occam wouldn't use a razor as blunt and rusty as yours.
You'll need to explain that one to us. You seem to be saying that days are warmer than nights and summer is warmer than winter. I think we can agree with that, but what does it have to do with climate trends?
- LOL
quote:
There has been no solar variation that matches recent warming. There has, however been a CO2 increase that explains it very well indeed, and it is based in quite simple physics.
Mmmh I thought that there had been a correlation published that showed solar activity and GW were linked and that CO2 levels increased accrodingly due to the warming of the seas.
That must have been debunked. Sorry.
quote:
Occam wouldn't use a razor as blunt and rusty as yours.
Ockams Razor: "All things being equal, the simplest solution tends to be the best one."
Thank you so much!! this is the basis of all sciences!! the fact of the matter is that the CO2 story has to many random variables and unknowns while the sun story have very few, simples is the most likely if we where is the realms of normal science the AGW theory would be thrown out as "unlikely"
"he fact that whilst ground insolation is not yet back at 1960 levels (it's increased because of a reduction of aerosols - global dimming), the temperature has gone up by 0.6degC since 1960."
where did you get this 0.6degC since the 60's?? it's more like 0.5 in the last 200 years!!
Originally posted by Geowizard: "The fact that whilst ground insolation is not yet back at 1960 levels (it's increased because of a reduction of aerosols - global dimming), the temperature has gone up by 0.6degC since 1960."
where did you get this 0.6degC since the 60's?? it's more like 0.5 in the last 200 years!!
NASA GISS e.g. the 2005 Summary QUOTE "Global warming is now 0.6°C in the past three decades and 0.8°C in the past century. It is no longer correct to say that "most global warming occurred before 1940". More specifically, there was slow global warming, with large fluctuations, over the century up to 1975 and subsequent rapid warming of almost 0.2°C per decade."
Also CRU's Data (The apparent recent reduction of trend is an artefact of processing - if you use grid box averaging (as GISS use) on CRU's data then you get the same result as GISS (and vice versa).
Also CRU's Data (The apparent recent reduction of trend is an artefact of processing - if you use grid box averaging (as GISS use) on CRU's data then you get the same result as GISS (and vice versa).
And if you just look at the global actuals it's basically flat for the last 6 years and 0.1 deg C down on 1998. And only about 0.45 deg C up since 1877. Or 1 deg C up since 1860.
They must have been pumping a lot of CO2 into the atmosphere before they stopped in 1877 to create a 0.55 deg rise in the 17 years from 1860. And did they panic then? I'm sure it was everything under the sun and the sun itself causing changes back then but now it's just CO2 I gather.
Afraid I'm still sceptical that AGW is and will be significant into the future.
Originally posted by John_M: 1) It's hard to agree or disagree with a study that isn't out yet.
Indeed. And I'll defer further comment until then. But I'm curious if they have taken look at the geomagnetic storm statistics. The relationship with insolation is quite untrivial. See, for example:
Effects of electric heating have not been accounted for, as far as I can tell. And the article's statement only mentions heating by solar light.
Note that geomagnetic storm activity only relates to the solar plasma ejected in the Earth's direction, rather than to the overall level of solar activity. Within the Plasma Universe framework, it is quite possible for a planet to receive a preferential treatment, especially if the said planet's magnetic field is steadily going down in strength.
Geomagnetic storms and increased solar ultraviolet emission heat Earth's upper atmosphere, causing it to expand. The heated air rises, and the density at the orbit of satellites up to about 1000 km increases significantly. This results in increased drag on satellites in space, causing them to slow and change orbit slightly. Unless Low Earth Orbit satellites are routinely boosted to higher orbits, they slowly fall, and eventually burn up in Earth's atmosphere.
Skylab is an example of a spacecraft reentering Earth's atmosphere prematurely as a result of higher-than-expected solar activity. During the great geomagnetic storm of March 1989, four of the Navy's navigational satellites had to be taken out of service for up to a week, the U.S. Space Command had to post new orbital elements for over 1000 objects affected, and the Solar Maximum Mission satellite was sent towards meeting the Skylab fate in December the same year.
I thought that the drag on satellites was mainly due to expansion of the mesosphere, and below that the stratosphere is cooling - not warming.
Observation 1. The trend in diurnal range supports CO2, and the levelling of that trend after about 1985 as ground insolation increased due to a reduction of aerosols, supports a tropospherically situated radiative cause for the warming of the last 30 years.
Observation 2. The trend of cooling in the stratosphere is only partly due to reduced O3 levels, again strato-cooling supports the theory that CO2 is responsible for the recent warming.
Observation 3. Frohlich's (2006) work at the PMOD that asserts there is no increase in insolation in the satellite record solar cycle minima also agrees with Wentzler's Kitt Peak magnetograms to something like >85%. Whereas the ACRIM dataset, which shows a small increase in the last 30 years of insolation only agrees with Kitt Peak to a little over 60%.
I make these 3 points because I've come across this magnetic hypothesis before, and it doesn't seem to be able to explain very much in terms of observations. And it seems to lack a plausible mechanism to explain the 0.6degC warming ramp of the last 30 years.
CO2 forcing fits in with all of the above observations - 1 2 3 and it has a plausible mechanism.
There was a very thoughtful and helpful submission by John_M at 09:13 today 09-07-07 that has disappeared from this thread. Am I meant to take this site's editorial process seriously or was it an accident and will it be restored? Thanks.
Originally posted by Son of Mulder: There was a very thoughtful and helpful submission by John_M at 09:13 today 09-07-07 that has disappeared from this thread. Am I meant to take this site's editorial process seriously or was it an accident and will it be restored? Thanks.
This has happened before with some other posts. It appears that the mods don't like too many links, but it is hard to see just what the threshold is.
They could at least let us know when and why they do this.
The average global ground insolation level is not yet back to the value it was in the 1960s. So if the current 0.6degC increase is due to aerosol changes then why were the 1960s not warmer than now.
Furthermore, the reduction of atmospheric loading happened after about 1985, when the ground insolation started to climb. That's a decade into the current warming.
Finally the trend in diurnal range: Night time temperatures were increasing faster than daytime(expected result of GHG increases) - causing the diurnal range to reduce until about 1985. The theory is that reduced aerosols increased daytime insolation making the warming trend catch up with the night. So after about 1985 the difference between night and day trends reduced. This issue also suggests that whatever is causing the warming it's a radiative effect in the atmosphere.
The average global ground insolation level is not yet back to the value it was in the 1960s. So if the current 0.6degC increase is due to aerosol changes then why were the 1960s not warmer than now.
Furthermore, the reduction of atmospheric loading happened after about 1985, when the ground insolation started to climb. That's a decade into the current warming.
Finally the trend in diurnal range: Night time temperatures were increasing faster than daytime(expected result of GHG increases) - causing the diurnal range to reduce until about 1985. The theory is that reduced aerosols increased daytime insolation making the warming trend catch up with the night. So after about 1985 the difference between night and day trends reduced. This issue also suggests that whatever is causing the warming it's a radiative effect in the atmosphere
Figure 2.3 shows the relationship between cloudiness and the DTR for a number of regions where long-term cloud cover data are available (Dai et al., 1997a). For each region there was an increase in cloud cover over the 20th century and generally a decrease in DTR. In some instances the correlation between annual cloud cover and annual DTR is remarkably strong, suggesting a distinct relationship between cloud cover and DTR. This would be expected since cloud dampens the diurnal cycle of radiation balance at the surface. Anthropogenically-caused increases in tropospheric aerosol loadings have been implicated in some of these cloud cover changes, while the aerosols themselves can cause small changes in DTR without cloud changes (Hansen et al., 1998 and Chapter 6).
So nowhere am I arguing that all warming is Aerosol related but that the relationship between aerosols, anthropogenic GHG's and other with climate change / global warming is complex and any message that says that CO2 is the main causative agent is by no means clear as the above shows your implication that GHG is driving diurnal Temperature decrease is at odds with IPCC.
Originally posted by CobblyWorlds: I thought that the drag on satellites was mainly due to expansion of the mesosphere, and below that the stratosphere is cooling - not warming.
How energy input is redistributed in the atmosphere, and by what processes, is a separate matter. I have quoted the drag observations to underscore the fact that geomagnetic storms do provide additional heating. Coincidentally, it too may cause the stratosphere to cool.
But if you really want to go into details, then consider this. At the tropospheric density levels, carbon dioxide has been experimentally shown, way back in the 40s, to completely saturate absorption (that is, it already blocks all the heat that it can possibly block; adding more of it won't change a thing). It was only in the 50s when scientists realized that CO2 absorption may not be saturated in the upper atmosphere, so adding more of it *there* may make a difference. If CO2 is to cause any greenhouse effect, it's only in the upper atmosphere that you need to look. But then again, when it expands (and any heated gas expands, whether from a geomagnetic storm or not), whatever energy was absorbed by CO2 is radiatively lost back to space; just try to heat anything in a greenhouse that has no ceiling. Geomagnetic storms, however, heat not only the upper atmosphere, but the lower atmosphere as well, by means of induced currents.
Originally posted by Son of Mulder: There was a very thoughtful and helpful submission by John_M at 09:13 today 09-07-07 that has disappeared from this thread...
..It appears that the mods don't like too many links, but it is hard to see just what the threshold is. ...
Thanks. I didn't save a copy, but here's a shorter try, with less URLs ( I understand trying to avoid link-spam, but the URLs were generally government websites...)
See http://data.giss.nasa.gov/gistemp/2005/, especially Figure 2. This kind of chart shows: - major volcanic eruptions that blast sulfates into the stratosphere. After a while, they diffuse around the world, causing (in 1991's Pinatubo case), a .5C drop about a year later, and then the effect disappears ~4 years later. ENSO: - El Nino years, which can cause modest- to-major upward temperature spikes. 1998's was a big one. - La Nina years, which can cause dips. - Average years.
Human-created sulfates rose from 1850, with jiggles to around 1975, then fell due to clean air acts. Those created more localized cooling effects, as they don't get to the stratosphere. I cited a study of global sulfate production, but if there's some limit on links, Google: andres historical sulfur dioxide emissions
Summary: a) Some short term effects can generate .2-.5C temperature jiggles, but some combinations add up or cancel.
b) Given the noise, it is fairly useless to draw any strong conclusions about the temperature record by comparing specific years (as opposed to 5-year averages, for example), especially without understanding the ENSO/volcano context.
For instance, in comparing 2005 with 1998, one *has* to know that 1998 was one of the strongest El Ninos in modern records, whereas there was none in 2005, i.e., it got ~same temperature with no big El Nino boost.
c) BEFORE 1950: Earlier than modern records, we generally know about big eruptions, like 1883 Krakatoa, or the 1815 Tambora "Year without a summer", but of course we don't have good measurements of ENSO events, but they were certainly happening: See Brian Fagan's nice "Floods, Famines and Emperors: El Nino and the fate of civilizations."
Hence, without knowing exactly what was happening in the 1800s, I'd certainly guess that: Krakatoa + ENSOs explain most of the short-term spikes.
I'd expect that part of the long-term warming from 1850-1950 was increase in solar irradiance, and part was Industrial revolution. (Since then, solar irradiance has had the usual minor 11-year sunspot jiggles, but nothing major, which is why people attribute warming since then to other causes.)
I'd expect that there was some localized global dimming from sulfates, modest around WW I, major after WW II, which masked the AGW trend until Clean Air Acts took effect.
AS usual, it takes serious work to extract long-term signals from noisy data that has larger short-term fluctuations, but the Figure above really helps to make sense of them.
John_M, I constructed a reply to your deleted post which has also been deleted. I also quoted from the paper that can be found by googling PNNL-14537. I didn't keep a backup and don't have the time now to reconstruct it. I'll give it some thought tomorrow.
My post was innocuous but constructively built on what you were saying.
Originally posted by CobblyWorlds: I thought that the drag on satellites was mainly due to expansion of the mesosphere, and below that the stratosphere is cooling - not warming.
How energy input is redistributed in the atmosphere, and by what processes, is a separate matter. I have quoted the drag observations to underscore the fact that geomagnetic storms do provide additional heating. Coincidentally, it too may cause the stratosphere to cool.
But if you really want to go into details, then consider this. At the tropospheric density levels, carbon dioxide has been experimentally shown, way back in the 40s, to completely saturate absorption (that is, it already blocks all the heat that it can possibly block; adding more of it won't change a thing). It was only in the 50s when scientists realized that CO2 absorption may not be saturated in the upper atmosphere, so adding more of it *there* may make a difference. If CO2 is to cause any greenhouse effect, it's only in the upper atmosphere that you need to look. But then again, when it expands (and any heated gas expands, whether from a geomagnetic storm or not), whatever energy was absorbed by CO2 is radiatively lost back to space; just try to heat anything in a greenhouse that has no ceiling. Geomagnetic storms, however, heat not only the upper atmosphere, but the lower atmosphere as well, by means of induced currents.
Leo
Spectral Saturation is not total in the free troposphere, it's at sea level temp/pressure (SLTP) that there's total saturation. If more CO2 had no effect as far up as the effective radiating layer how would the greenhouse effect cause any additional warming at all?
Actually it was even earlier than the 1940s! It was Angstrom and others in the early 20th centruy (published 1905 I think) who found out about saturation at SLTP. It was in the 1950s that experimental proof vindicated Arrhenhuis.
I note that you have no comment on 3 observations that are explained by CO2 driven warming. That's key to me because I'm not qualified to consider the detals of your hypothesis. However if it is of use, should it not explain observations?
I'm saying the CO2 best explains those observations. What does your hypothesis imply about them, or are there other observations connected to the 0.2degC/decade trend of the last 30 years?
John M, Son of Mulder,
That document that's caused posts to be removed - In was unable to get it on my PC, but can get it from the formal page via Google. It seemed to be a 'bad link' to me. It may be the webmaster has set things up there end so you have to go viw that information bridge page.
