Updated below with comments and additional links September 17-19
Seeing a lot more of this lately, along with hearing the geese honking. And in the next month or so, we expect that trees around here will lose their leaves. It definitely is climate change of the seasonal variety.
Interestingly, the science on this is settled: It is all due to reduction of solar energy because of the shorter length of days (LOD). The trees drop their leaves and go dormant because of less sunlight, not because of lower temperatures. The latter is an effect, not the cause.
Of course, the farther north you go, the more remarkable the seasonal climate change. St. Petersburg, Russia has their balmy “White Nights” in June when twilight is as dark as it gets, followed by the cold, dark winter and a chance to see the Northern Lights.
And as we have been monitoring, the Arctic ice has been melting from sunlight in recent months, but will now begin to build again in the darkness to its maximum in March.
We can also expect in January and February for another migration of millions of Canadians (nicknamed “snowbirds”) to fly south in search of a summer-like climate to renew their memories and hopes. As was said to me by one man in Saskatchewan (part of the Canadian wheat breadbasket region): “Around here we have Triple-A farmers: April to August, and then Arizona.” Here’s what he was talking about: Quartzsite Arizona annually hosts 1.5M visitors, mostly between November and March.
Of course, this is just North America. Similar migrations occur in Europe, and in the Southern Hemisphere, the climates are changing in the opposite direction, Springtime currently. Since it is so obviously the sun causing this seasonal change, the question arises: Does the sunlight vary on longer than annual timescales?
The Solar-Climate Debate
And therein lies a great, enduring controversy between those (like the IPCC) who dismiss the sun as a driver of multi-Decadal climate change, and those who see a connection between solar cycles and Earth’s climate history. One side can be accused of ignoring the sun because of a prior commitment to CO2 as the climate “control knob”.
The other side is repeatedly denounced as “cyclomaniacs” in search of curve-fitting patterns to prove one or another thesis. It is also argued that a claim of 60-year cycles can not be validated with only 150 years or so of reliable data. That point has weight, but it is usually made by those on the CO2 bandwagon despite temperature and CO2 trends correlating for only 2 decades during the last century.
One scientist in this field is Nicola Scaffeta, who presents the basic concept this way:
“The theory is very simple in words. The solar system is characterized by a set of specific gravitational oscillations due to the fact that the planets are moving around the sun. Everything in the solar system tends to synchronize to these frequencies beginning with the sun itself. The oscillating sun then causes equivalent cycles in the climate system. Also the moon acts on the climate system with its own harmonics. In conclusion we have a climate system that is mostly made of a set of complex cycles that mirror astronomical cycles. Consequently it is possible to use these harmonics to both approximately hindcast and forecast the harmonic component of the climate, at least on a global scale. This theory is supported by strong empirical evidences using the available solar and climatic data.”
He goes on to say:
“The global surface temperature record appears to be made of natural specific oscillations with a likely solar/astronomical origin plus a noncyclical anthropogenic contribution during the last decades. Indeed, because the boundary condition of the climate system is regulated also by astronomical harmonic forcings, the astronomical frequencies need to be part of the climate signal in the same way the tidal oscillations are regulated by soli-lunar harmonics.”
He has concluded that “at least 60% of the warming of the Earth observed since 1970 appears to be induced by natural cycles which are present in the solar system.” For the near future he predicts a stabilization of global temperature until about 2016 and cooling until 2030-2040.
A Deeper, but Accessible Presentation of Solar-Climate Theory
I have found this presentation by Ian Wilson to be persuasive while honestly considering all of the complexities involved.
The author raises the question: What if there is a third factor that not only drives the variations in solar activity that we see on the Sun but also drives the changes that we see in climate here on the Earth?
The linked article is quite readable by a general audience, and comes to a similar conclusion as Scaffeta above: There is a connection, but it is not simple cause and effect. And yes, length of day (LOD) is a factor beyond the annual cycle.
It is fair to say that we are still at the theorizing stage of understanding a solar connection to earth’s climate. And at this stage, investigators look for correlations in the data and propose theories (explanations) for what mechanisms are at work. Interestingly, despite the lack of interest from the IPCC, solar and climate variability is a very active research field these days.
A summary of current studies is provided at NoTricksZone:
Ian Wilson has much more to say at his blog: http://astroclimateconnection.blogspot.com.au/
Once again, it appears that the world is more complicated than a simple cause and effect model suggests.
For everything there is a season, a time for every purpose under heaven.
What has been will be again, what has been done will be done again; there is nothing new under the sun.
(Ecclesiastes 3:1 and 1:9)
Update Sept. 17: Commentary with Dr. Arnd Bernaerts
Fine writing, Ron, well done!
No doubt the sun is the by far the most important factor for not living on a globe with temperatures down to minus 200°C. That makes me hesitating to comment on „solar and climate variability” or “the sun drives climate” (currently at NTZ – link above), but today merely requesting humbly that the claimed correlation should be based at least on some evidence showing that the sun has ever caused a significant climatic shift during the last one million years, which was not only a bit air temperature variability due to solar cycles that necessarily occur in correlation with the intake and release of solar-radiation by the oceans and seas.
Interestingly the UK MetOffice just released a report (Sept.2015, pages 21) titled:
“Big Changes Underway in the Climate System?”
by attributing the most possible and likely changes to the current status of El Niño, PDO, and AMO, and – of course – carbon dioxide -, and a bit speculation on less sun-energy (see following excerpt at link)
From p. 13: “It is well established that trace gases such as carbon dioxide warm our planet through the “greenhouse effect”. These gases are relatively transparent to incoming sunlight, but trap some of the longer-wavelength radiation emitted by the Earth. However, other factors, both natural and man-made, can also change global temperatures. For example, a cooling could be caused by a downturn of the amount of energy received from the sun, or an increase in the sunlight reflected back to space by aerosol particles in the atmosphere. Aerosols increase temporarily after volcanic eruptions, but are also generated by pollution such as sulphur dioxide from factories.
These “external” factors are imposed on the climate system and may also affect the ENSO, PDO and AMO variations……
Thanks Arnd for engaging in this topic.
My view is that the ocean makes the climate by means of its huge storage of solar energy, and the fluctuations, oscillations in the processes of distributing that energy globally and to the poles. In addition, the ocean is the most affected by any variation in the incoming solar energy, both by the sun outputting more or less, and also by clouds and aerosols blocking incoming radiation more or less (albedo or brightness variability).
The oscillations you mention, including the present El Nino (and Blob) phenomenon, show natural oceanic variability over years and decades. Other ocean cycles occur over multi-decadal and centennial scales, and are still being analyzed.
At the other end of the scale, I am persuaded that the earth switches between the “hot house” and the “ice house” mainly due to orbital cycles, which are an astronomical phenomenon. These are strong enough to overwhelm the moderating effect of the ocean thermal flywheel.
The debate centers on the extent to which solar activity has contributed to climate change over the last 3000 years of our current interglacial period, including current solar cycles.
Update September 19
Additional studies showing a solar-climate connection are here: https://translate.google.com/translate?hl=&sl=de&tl=en&u=http%3A%2F%2Fwww.kaltesonne.de%2Fsonne-macht-klima-neues-aus-europa%2F