From the University of Edinburgh , another one-paper syndrome in the making funded by an NGO research council with a political mission to grab a headline. And, another poorly written press release where they don’t even cite the name of paper. Sigh.
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Climate change has not been strongly influenced by variations in heat from the sun, a new scientific study shows
Climate change has not been strongly influenced by variations in heat from the sun, a new scientific study shows.
The findings overturn a widely held scientific view that lengthy periods of warm and cold weather in the past might have been caused by periodic fluctuations in solar activity.
Research examining the causes of climate change in the northern hemisphere over the past 1000 years has shown that until the year 1800, the key driver of periodic changes in climate was volcanic eruptions. These tend to prevent sunlight reaching the Earth, causing cool, drier weather. Since 1900, greenhouse gases have been the primary cause of climate change.
The findings show that periods of low sun activity should not be expected to have a large impact on temperatures on Earth, and are expected to improve scientists’ understanding and help climate forecasting.
Scientists at the University of Edinburgh carried out the study using records of past temperatures constructed with data from tree rings and other historical sources. They compared this data record with computer-based models of past climate, featuring both significant and minor changes in the sun.
They found that their model of weak changes in the sun gave the best correlation with temperature records, indicating that solar activity has had a minimal impact on temperature in the past millennium.
The study, published in Nature GeoScience, was supported by the Natural Environment Research Council.
Dr Andrew Schurer, of the University of Edinburgh’s School of GeoSciences, said: “Until now, the influence of the sun on past climate has been poorly understood. We hope that our new discoveries will help improve our understanding of how temperatures have changed over the past few centuries, and improve predictions for how they might develop in future. Links between the sun and anomalously cold winters in the UK are still being explored.”
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I’m not so sure this fellow is fully versed on climatology. His papers up to 2011 were all about cosmology, then all of the sudden he starts publishing on climatology issues. One wonders if his previous funding dried up to make such a dramatic shift in study. Then there is: “…climatic fingerprints of high and low solar forcing derived from model simulations…”. IPCC Models haven’t been able to reproduce the last ten years; what makes them think they are worth anything 100-200 years ago?
Here is the abstract: http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2040.html
Small influence of solar variability on climate over the past millennium
- Nature Geoscience (2013) doi:10.1038/ngeo2040
- Received 02 August 2013 Accepted 14 November 2013 Published online 22 December 2013
The climate of the past millennium was marked by substantial decadal and centennial scale variability in the Northern Hemisphere1. Low solar activity has been linked to cooling during the Little Ice Age (AD 1450–1850; ref. 1) and there may have been solar forcing of regional warmth during the Medieval Climate Anomaly2, 3, 4, 5 (AD 950–1250; ref. 1). The amplitude of the associated changes is, however, poorly constrained5, 6, with estimates of solar forcing spanning almost an order of magnitude7, 8, 9. Numerical simulations tentatively indicate that a small amplitude best agrees with available temperature reconstructions10, 11, 12, 13. Here we compare the climatic fingerprints of high and low solar forcing derived from model simulations with an ensemble of surface air temperature reconstructions14 for the past millennium. Our methodology15 also accounts for internal climate variability and other external drivers such as volcanic eruptions, as well as uncertainties in the proxy reconstructions and model output. We find that neither a high magnitude of solar forcing nor a strong climate effect of that forcing agree with the temperature reconstructions. We instead conclude that solar forcing probably had a minor effect on Northern Hemisphere climate over the past 1,000 years, while, volcanic eruptions and changes in greenhouse gas concentrations seem to be the most important influence over this period.
Figure 1: Simulations and temperature reconstructions.
a, Simulations with all forcings (red and green) compared with a reconstruction ensemble14 (blue), and instrumental HadCRUT4 (ref. 24) time series (centred on the average reconstruction over time of overlap, black).
The SI is here: http://www.nature.com/ngeo/journal/vaop/ncurrent/extref/ngeo2040-s1.pdf
h/t to Dr. Leif Svalgaard
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GlynnMhor says:
December 23, 2013 at 12:04 pm
Solar activity involves not merely how much heat is being produced by the Sun, but also magnetic field changes, solar wind changes in density and speed, spectral shifts of the solar output, cosmic ray flux changes,
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As any amateur radio operator (HAM) will confirm. There is much more to the sun than is measured by TSI. There are huge shifts in radio propagation within solar cycles and between solar cycles. Most people are unaware of this, because they mostly rely on “line of sight” radio transmissions. However, during strong sunspot cycles, truck drivers using CB can communicate over thousands of miles, and HAM operators can communicate around the world using radio’s no more powerful than 100 watt light bulbs.
These shifts in radio propagation are not a few percentage change as measured by TSI. They are many orders of magnitude change in signal strength.
Matt G says:
December 24, 2013 at 5:14 am
20 years ago global temperatures would have been warmer if it had not been for Pinatubo back in 1992.
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Are we therefore to conclude that the 300 years of warming since the little ice age are due to a decrease in volcanic activity? Are we to conclude that the minoan, roman, and medieval warnings were a time when there were not volcanoes erupting?
The problem is that volcanoes are a form of positive confirmation. If temperatures cool, researchers search for volcanoes and say the volcano caused the cooling. However, this is simply random chance. The same sort of confirmation that gives rise to superstitious beliefs. If you want to prove that volcanoes affect climate, you must looks at the warm periods and prove that there were no volcanoes.
ferdberple says:
December 24, 2013 at 5:36 am
My point being it only affected short periods of time (look at the graph linked above) and cant explain most of history including the recent pause and cooling between the 1940s to 1970s. Major volcanic eruptions like that of 1992 would have to occur for hundreds of years to keep the globe at that level. No evidence anywhere that this happened.
climateace says:
December 23, 2013 at 9:58 pm
My point stands. Until someone unpicks the model used, then no-one is in a position to diss it.
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On the contrary, the problem is chaos. It makes a mockery of our attempts to build reliable models of time series data. We can’t do it for atoms, planets, or stock markets. Yet climate science assumes it can be done for climate.
Where is the mathematical foundation that climate is well behaved, such that it is a suitable candidate for deterministic modelling?
The problem is that we have no finite mathematical solution for dealing with more than two independent objects in motion. With two objects the future is deterministic, we can calculate what will happen. However, when you add a third the nature of the future changes. The future becomes too complex to calculate exactly. For all practical purposes you cannot determine the future, you can only supply a probability.
Matt G says:
December 24, 2013 at 5:14 am
20 years ago global temperatures would have been warmer if it had not been for Pinatubo back in 1992.
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OK, I get your point. If temps 20+ years ago were warmer without Pinatubo, then the current “pause” in warming would today be 20+ years, not 17 years, which would be even more of a problem for the models to explain.
ferdberple says:
December 24, 2013 at 5:52 am
For all practical purposes you cannot determine the future, you can only supply a probability.
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the same problem applies to hincasting the past. You are hindcasting under the assumption that the past is deterministic, but it is not. The past is a probability, just like the future, so the uncertainty due to the probability function quickly overwhelms your statistical calculation of variance, making the hindcast meaningless.
What you see as correlation is nothing more than chance. Of the near infinte number of paths from the past to the future, you are assuming that that the path that we took to the present has special meaning. This is the Victorian era assumption of the clockwork universe, that there is only one path from the past to the present to the future. We now know that the universe at a fundamental level does not work that way.
There are a neat infinite number of ways to arrive at the present from the past, and none of them are more significant than the other. The path we arrived on is simply due to chance. So, when you hindcast the past you must include all possible ways we could have arrived at the present, and not give any special weight to the path that we happened to take by chance.
William Astley says:
December 24, 2013 at 2:38 am
It is an observational fact that there has be an abrupt reduction in total solar irradiation of roughly 1.5 Watts/meter^2
No, there is a solar cycle variation of TSI [no abrupt change] of 0.1% [or 1.3 W/m2]. This happens in every cycle. The PMOD data you show have a problem with sensor degradation and the purported lower TSI values for the last minimum are in error [too low] by about 0.25 W/m2.
The magnetic field strength of the flux tubes that rise up from the tachocline to form sunspots on the surface of the sun require a magnetic field strength of roughly 20,000 to 30,000 Gauss (Eugene Parker’s calculation) to avoid being torn apart by turbulent forces in the convection zone.
ALL flux tubes are ALWAYS torn apart in the convection zone, then reassembled at the surface. There is no ‘interruption’ of the cycle.
Based on what has happened in the solar Northern hemisphere there will be no visible sunspots in the solar Southern hemisphere by roughly quarter 4 of 2014.
It is quite normal for cycles to show such asymmetry. Figure 7 of http://www.leif.org/research/ApJ88587.pdf shows the asymmetry for Cycle 14. Cycle 24 is begiining to look like 14, so nothing out of the ordinary.
“Climate change has not been strongly influenced by variations in heat from the sun”
Are they talking of TSI?
What about UV variations? What about magnetic field variations?
They used treemometers data and compared with models.
“featuring both significant and minor changes in the sun.”
How did they do that? Made minor changes in TSI?
OK and found that their minor changes in TSI did not reflect major changes in their model?
They found some correlation between TSI and temperature and say that is all?
They eliminated a factor that they do not understand how it impacts the Earth based on the results of a model that did not had the means to model the complex interaction between Sun and Earth.
The conclusion is wrong, it does not prove missing Suns influence on the climate, but the modellers inability to model it.
Study shows: model not able to model past climate based on TSI.
Study suggests looking at volcanoes and greenhouse gases, however this has been already done, Genghis Khan has already been brought up to explain Little Ice Age as well as the Conquistadores and the farting megafauna to explain Younger Dryas.
Do they really want to bring up more such studies?
Not really? 🙂
As we have a very interesting live experiment with the Sun getting quiet we will have very soon more data to look at.
Hi Climateace,
I certainly haven’t had a close look at the model, that’s correct. You complain that I shouldn’t diss the model without first inspecting it closely? Diss is a fun but vague word. If memory serves it means ‘disrespect’? Well, I don’t think I’m doing that. I’m not disrespecting anything, I just don’t accept by default that a model is good because somebody says so. Further, I don’t think the burden is on me to validate the model.
If somebody comes and tells me they’ve got a model that accurately models something, if they want me to believe that their model accurately models something they are going to have to show me how they verified and validated the model. I have neither time or inclination to try to get through that mountain of work (because it is pretty darn difficult to validate some models) regarding every model and claim I bump into. For free. On my own time. No thanks! If somebody can’t show me up front evidence that they verified that the model is accurate and useful in some well defined context, then they can go fish.
Now, you can stick your fingers in your ears all day long and say ‘la la la, my point stands.’ Your argument is not persuasive, because it shifts the burden of work that should properly have been done by the scientist to anybody who cares to question the scientists claim. At least, I don’t find it persuasive. Besides, sticking your fingers in your ears and saying ‘la la la’ is annoying. It’s going to get you on Santa’s naughty list and you’ll end up with a bag of solid fossil fuel for Christmas if you’re not careful, so go on and be good for goodness sakes!
The oceans don’t appear to be losing energy at all.
Aside from that, I thought that temperatures were depressed throughout the Dalton Minimum. In fact, judging by the CET record a temperature decline occurred several years before the “Dalton cycles” began.
If the models produce useful predictions after the modeler is dead, I’m a believer.
ferdberple says:
December 24, 2013 at 5:57 am
Yes.
John Finn says:
December 24, 2013 at 8:24 am
The oceans are always losing energy and being topped up again by the sun on daily basis. It is fair to say the oceans have been increasing energy over recent decades, (at least at the surface) hence the warming in the 1980s and 1990s. There has been a change in the upper depths over recent years showing slight cooling.
“Aside from that, I thought that temperatures were depressed throughout the Dalton Minimum. In fact, judging by the CET record a temperature decline occurred several years before the “Dalton cycles” began.”
Before the Dalton Minimum began global temperatures were still recovering from Maunder Minimum and it wasn’t until after the Dalton ended that the planet went out of the Little Ice Age. (especially the NH)
I read the abstract of the paper, and also the abstracts of some of the papers he references in this paper.
This appears to be the upshot of the argument:
“Estimates of solar radiative ‘forcings’ are ‘poorly constrained’ (i.e., all over the place, by as much as an order of magnitude). We have created models of Greenhouse Gas ‘radiative forcings’ that are more consistent and also account for observed temperatures. Therefore the GHG forcings are what are causing the temperatures.”
Come on, really? Give me a break.
Otherwise known as ‘solar activity is complicated, but greenhouse gases are simple, so we are going to correlate temperatures with greenhouse gases.’
There is no ocean cooling.
http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/
This is the CET record from 1772.
http://www.metoffice.gov.uk/hadobs/hadcet/
Though there are cyclical fluctuations (probably related to the AMO) the trend between 1772 and 1900 is flat. There is no obvious “recovery” from the Dalton. Until the 1990s, the 1730s were the warmest decade in the CET record.
It must be true. Yesterday morning (Xmas eve) the sun rose here a little before 7:30am and by 9:00am the temperature had already dropped 3 degrees.
John Finn says:
December 25, 2013 at 3:36 am
The surface is cooling recently, the 0-700m depth is warming much lower rate than before.
http://www.woodfortrees.org/plot/hadsst2gl/from:2001/plot/hadsst2gl/from:2001/trend/plot/hadsst3gl/from:2001/plot/hadsst3gl/from:2001/trend
In the link the recovery occurs from 1900 after the Dalton and this is more obvious with a slow gradual warming and during that length of time cant be blamed on AMO or PDO. This gradual warming changes the pattern before, when there should have been a significant cooling again continuing the previous pattern. For example between the 1920s and 1930s should have a cooling near -1c before warming significantly after.
http://www.metoffice.gov.uk/hadobs/hadcet/
Gail Combs (December 23, 2013 at 4:10 pm) – you’re showing more reasons to believe and assert that the weather and climate changes are controlled largely by solar (& cosmic) photons, protons, and electrons, not downwelling LWR from carbon dioxide. Thank you for that.
Seems the writers of this article are really not very adept or even up to date on the different mechanisms found in the solar variation over the millennia..
Little or no solar forcing? huh
The new “AVERAGE” of GCR due to lower solar activity.. They graph is pretty telling..
Top graph of page 5 http://fallmeeting.agu.org/2013/files/2013/12/SEPs-Giacalone.pdf
Galactic Cosmic Rays (GCR) reached record intensities during the last solar minimum, and their intensity during the current maximum is higher than in previous cycles (surprisingly near the overall average!)
Cha cha cha changes..
NPR news was talking about Wisconsin yearly’s. April, May, June cooler and wetter. Cooler and wetter go hand in hand..
I have been waiting for the changes .. believing that mankind has had an effect .. but that the systems that affect natural variability are stronger .. there would be a longer delay .. before the recognizable change would be evident..
NPR news was talking about Wisconsin yearly’s. April, May, June cooler and wetter. Cooler and wetter go hand in hand..
Our summer was late. And now our January temps were here in the first part of December. And don’t ask about snowfalls..
Carla thanx for being part of the paradigm shift. Svensmark looks better every day. Get a clue you darned real climate deniers: its photons, protons, and electrons – not carbon dioxide – that have the controlling influence over weather and climate metrics.
John Finn says:
December 25, 2013 at 3:36 am
This is the CET record from 1772.
http://www.metoffice.gov.uk/hadobs/hadcet/
Though there are cyclical fluctuations (probably related to the AMO) the trend between 1772 and 1900 is flat.
Strongly, as it may appear to many, so it was the geological activity in the North Atlantic
http://www.vukcevic.talktalk.net/Contents.htm
Happy Xmas to all.
” JimS says: December 23, 2013 at 9:56 am
Everyone should try and read Paul Pierett’s paper above. ”
+1^
Thank you Paul. That is a great presentation to read through.
So any type of heating must then have a negative feedback. If this paper holds up, we have strong support for the thermostat hypothesis. The TH doesn’t need only CO2 heating to go into action. It would be interesting if the “small” effects have a measurable lag.
Carla said:
“Our summer was late. And now our January temps were here in the first part of December. And don’t ask about snowfalls.”
No don’t, especially in Siberia.
http://www.dailymail.co.uk/news/article-2525993/What-happened-Siberia-Russian-region-famous-cold-experiences-freak-warm-weather-December-time-living-memory.html
Err the US is not the World – though I note it’s inhabitants can tend to think that.
In a word – the climate is a complicated thing and if somewhere is colder – that also also means there is somewhere warmer. That’s how it works. In a regional sense it just does.
TB (December 25, 2013 at 2:20 pm) “In a word – the climate is a complicated thing and if somewhere is colder – that also also means there is somewhere warmer. That’s how it works. In a regional sense it just does.”
That’s not how “it” (weather) works. Colder weather in one region may or may not be offset by warmer weather elsewhere, especially in winter. Likewise, unusually warm weather may or may not be offset by colder weather elsewhere, especially in summer.
One reason is that the weather dictates regional albedo and albedo rising or dropping in one region has no affect on any other region. If there is a coincidental drop in albedo worldwide over the short, medium or long run, then there will be will global warming in that same time frame with a potential lag from thermal inertia.
Another reason is that weather controls the distribution of water vapor. If water vapor is concentrated then there will be cooling. If spread out, then warming. For example models that are run with more concentrated convection show global cooling. Just one of many ways that weather controls climate.
((Dr Andrew Schurer, of the University of Edinburgh’s School of GeoSciences, said: “Until now, the influence of the sun on past climate has been poorly understood))
and this clown calls himself a Doctor?? if the influence is so POORLY understood, why the high confidence in CO2?? Heellooooo!!!
regards