28th June 2010
The role of the sun in climate
In this blog post I continue my summary of findings from various readings in relation to climate change. This post deals with the role of the sun. (My other blog posts on the subject are here)
Where the sun fits into the scheme of things
To set the context we must look more broadly at the universe, from the more distant things to the more proximal things. The order in which we must look is:
a) Big Bang: The Big Bang energy currently pervades the Universe as microwaves. This ensures a background temperature of 2.73 degrees Kelvin (i.e. -270.42 degrees centigrade). Does this radiation vary? No. So clearly this can't be responsible for climate change. [NOT IMPORTANT]
b) Galaxies: The Milky way and other galaxies spew out energy at higher wavelengths such as cosmic rays which hit the Earth and heat it up. This perhaps adds some degrees C to the Earth. Does this radiation vary? Yes, depending on the Sun's and Earth's magnetic fields. It also varies depending on the relative position of the sun in the spiral arms of the Milky Way. This effect is very slow, however, and unlikely to influence climate within the lifetime of an average human being. [NOT IMPORTANT] (http://www.sciencebits.com/ice-ages)
c) Sun: The biggest variable source of energy that hits the Earth is the Sun. It is a pulsing star, and its energy outputs goes through various cycles. It really PULSES! It started life as a rather dim star and has significantly increased in intensity over billions of years. The sun is the ELEPHANT IN THE ROOM that must be studied carefully if we are to find the causes of climate change. [IMPORTANT].
d) Earth's rotation around the sun: This significant shifts the amount of energy flowing into the Earth (seasons). Its tilt matters as well, although these are pretty much long term effects and can be mostly discounted. [NOT IMPORTANT]
e) Moon: Some energy is perhaps reflected back to the Earth by the moon. If tides are a result of the moon's gravitational force, then definitely some of solar energy reflected back to the earth should matter – but it is a regular phenomenon and can be excluded. [NOT IMPORTANT]
f) Earth's core: The Earth is molten inside. But that doesn't explain its inner heat, which is largely attributable to radioactivity. That is why as you go deeper into the earth (e.g. as in a deep mine) it heats up dramatically. (I've been inside the Kolar Gold fields, and sure, it gets really hot below these deepest gold mines in the world) . Does the radioactivity at the centre of the earth vary a lot? Possibly only minimally. But it is still a crucially important unknown. [IMPORTANT].
g) Crust of the earth: The crust of the Earth is brittle and mobile. Tectonics releases a lot of energy into the Earth's surface, and includes volcanic activity. This is highly variable, hence likely to be quite important. [IMPORTANT].
g) Water: 2/3rd of the surface of the earth is water, and quite deep. Water absorbs heat slowly and releases it slowly. It leads a convection currents across the earth and has a dramatic influence on the Earth's climate. Snow and ice have properties that affect the Earth's climate significantly, as well.While the total amount of water doesn't change, its distribution and influence is constantly in flux. This must be important. [IMPORTANT].
h) Gases: Water vapour and methane are critical here, being powerful greenhouse gases, but CO2 also matters. [IMPORTANT].
g) Plant and animal life. This is absolutely crucial. [IMPORTANT].
h) Humans: This is another important variable given our significant re-design of the surface of the earth. [IMPORTANT].
I've noted some findings on other causal factors elsewhere so won't go into these things here. Just the sun.
The effect of the sun
Sunspots and other measures of solar activity
Have the changes in solar activity (sunspots) made an impact?
The key issue here is whether the above figure shows a relationship with the Little Ice Age that ended in about 1850. If solar activity has delayed impacts on the earth's climate (possibly through absorption of heat by sea water and slow changes on ocean currents), then a broad relationship exists between the little Ice Age that lasted till 1850, and the subsequent increase in temperature that we have seen in the last four decades.
If the sun's impact is immediate, then of course the relationship is much weaker. However, there is no reason why the entire heat from the sun should instantly impact climate. If that were the case then we would see sea levels rise everyday in the afternoon and subside at night. Sea temperatures change very slowly, because of their depth. It seems plausible therefore that at least some portion of the effect is relatively longer term. In which case, the increased solar activity over mid-20th century could be leading to warming today, as the energy is released from within the deep oceans.
Further, there seems to be clear evidence that there has been extra solar activity during the 20th century, particularly in the 1950s and 1990s (http://en.wikipedia.org/wiki/Modern_Maximum). This comes out clearly in the figure below:
Claims that there are inaccuracies in the IPCC report on solar activity: http://climatechange.thinkaboutit.eu/think2/post/judithgate_ipcc_consensus_was_only_one_solar_physicist
This article seems to be particularly important and argues that "the original satellite data showed, that TSI (measured in Watts) increased from 1986 to 1996 by cca one third… But then Judith and Clause "laundered" the graphs and voila… solar output increase was gone. The people, who were in charge of the satellites and who created the original graphs (the best world astro-physicists: Doug Hoyt, Richard C.Willson) protested against this manipulation. In vain." (see here).
My view on this is that this is all too much for me to examine in detail given limitations of time. However, I've been compiling a few articles on the subject which might help me find the accurate position on this subject in the coming year/s. I'll keep adding information here.
My tentative conclusion
I've already come to the view that CO2 is a boon and that sea levels (and climate) always change. So regardless of whether the sun is a significant explanatory variable in the current increasing temperatures of the earth (which are relatively minor, though), climate change is not a threat. That much is clear.
I am unable to figure, though, out why so much self-contradictory evidence is published regarding the influence of the sun, and look forward to the day when I'll be able to form a much clearer understanding on its role on the climate. It is highly implausible that the sun has a negligible influence on the earth's climate, as the IPCC has claimed. So if there was genuine fraud (see the article here, again), that's a serious matter for scientists to resolve. But even without the claims of fraud, there doesn't seem to me to have been sufficient evidence provided that the sun is not the MAJOR factor driving climate change. It is highly implausible that CO2 is the key factor in such change (that doesn't fit historical records).
I haven't had the time to fully read this particular academic paper here (this paper is rather significant!), but over the next year I hope to read a lot more in my spare time and publish my findings as I arrive at various conclusions.
Articles of interest (too little time to summarise)
I hope to find time to summarise and classify these better in the coming weeks/months/years.
Things that aren't conclusive
General opposition to arguments of man-made climate change