OH, my! Things are getting interesting concerning climate change and solar activity. First a little primer. There have been 26 ice ages in the last 3 million years that we can observe in deep ice core samples from Greenland. The first 24 exactly match the earth’s nutations, every 100,000 years. A nutation is when the earth’s axis wobbles between 22 and 24 degrees. Like a spinning top which is not perfect, a little wobble has to occur every once in awhile for conservation of angular momentum. It is thus thought that these wobbles cause climate disruption at the poles. Since the poles are landlocked (Arctic) and sea-locked (Antarctic) we have ice caps on both ‘these days’ (speaking geologically). And a climate disruption may dump large amounts of snow on these caps causing them to grow and the increased albedo (reflectance) of all that white causes further cooling, further snow, further buildup until a new ice age occurs.
The last two ice ages don’t correspond to nutation and were weaker. Maybe earth is getting out of the ice ages as more exchange of waters is occurring in the Arctic as Eurasia and N. America grow wider apart via plate tectonics. (Just conjecture. Antarctica’s poles keep piling up more ice) But what of the other climate factors—ocean currents, albedo of atmosphere (cloud cover), solar radiation and the much discussed chemical make-up of the atmosphere? Of these 4, solar activity seems most important. A one percent decrease of solar radiation energy would cause a near ice age all by itself. In 1309, lasting until about 1850, the sun went mysteriously depleted of sun spots. Earth mean temp decreased 5-10 degrees F and the era is known as “the little ice age”. It likely caused many phenoms like the decline of grain production in Europe, the uninhabitability of Greenland by Scandinavians, decline of fish production in Chinese rivers, and emergence of scavengers including rats that multiplied and carried bubonic plague across Eurasia.
Increasing CO2 no doubt changes the atmosphere, but our experience is increase of .8 degrees C (1 degree F) since 1880. But the last 25 years of observation of solar activity is getting to be a bigger story. The solar cycle of sun spot activity maxes every eleven years—1969, 1980, 1991, 2002, 2013. The ’69 radiation measurements were lower than those of 1980, 1991, and 2002. But the 2013 energy flux is lower than even 1969. We don’t know if solar energy fluctuates every few cycles or few hundred years, as climate eras seem to indicate. But whatever the case, sun activity swamps CO2. The last 18 years have been cool. Secondly, there is research that indicates that when solar activity minimizes, more neutrons are shed. These enter our atmosphere and cause more cloud cover. Other research indicates that increased CO2 makes the tropical atmosphere cloudier and thus more reflective. Both are occurring now. Sunspots declined from 1500 to 1000 from the max cycles of 1991 to the one in 2013. Measure of solar magnetic field shows a similar decline. But realize, we have sun spot recordings going back to about the year 1000 (Chinese monks) but solar magnetic fields for only a quarter century.
What does this mean? Cooler era or new ice age? Best guess is just cooler temps. But realize that the 100,000 year ice ages had roughly 12000 years of warm-up between, and that is about what we have used up now. What it probably means is that Al Gore is going to eat crow. He points out that Greenland is shedding ice rapidly. True, but once a warming begins, Greenland is a huge ice cube—10,000 feet thick and 500,000 sq. miles. If you put an ice cube under a heat lamp, how long does it last? If you cool down or heat up a bit, it won’t have much effect on the melting. So the Greenland ice and about half the declining glaciers may well have been on this course long before modern manmade CO2. A cool spell would also be either a respite from the warming (allowing the private sector to come up with solutions to increased CO2 emissions like it has done by reducing USA’s output by 18% since 2000.)or it could be a long term trend like the Little Ice Age or Younger-Dryas of 10,000 years ago. We will just have to find out.