The near future will be extremely interesting. I think it is important to accept that Nature pays no heed to what we humans think about it. Will the greenhouse theory survive a significant cooling of the Earth? Not in its current dominant form. Unfortunately, tomorrow’s climate challenges will be quite different from the greenhouse theory’s predictions. Perhaps it will become fashionable again to investigate the Sun’s impact on our climate. __ Henrik Svensmark
Does The Sun Influence Earth’s Climate? If So, How?
According to spokespersons for the Climate Apocalypse movement, variable energy from the sun has no appreciable influence on the global climate. But as we shall see below, a number of intelligent and well-trained scientists hold different views on that topic. First, we will look at the “cosmic ray hypothesis,” which states that a less active sun (fewer sunspots) allows more galactic cosmic rays to reach Earth’s atmosphere, where they help form “cooling clouds” which partially deflect a greater amount solar heating from the Earth.
A few years ago Henrik Svensmark described a mechanism how solar activity could change cloud cover. Was this the long-sought solar amplifier? The proposed process involves a series of steps where the sun’s magnetic field shields the earth’s atmosphere, at times more and at times less, from cosmic rays – thus acting as a modulator. The tiny galactic particles then act as seeds for condensation and cloud formation, which in turn regulate the Earth’s temperature. This mechanism allowed Svensmark to establish a correlation between solar activity and clouds… ___
When the Sun is active, its magnetic field is better at shielding us against the cosmic rays coming from outer space, before they reach our planet. By regulating the Earth’s cloud cover, the Sun can turn the temperature up and down. High solar activity means fewer clouds and and a warmer world. Low solar activity and poorer shielding against cosmic rays result in increased cloud cover and hence a cooling. As the Sun’s magnetism doubled in strength during the 20th century, this natural mechanism may be responsible for a large part of global warming seen then.
… The outcome may be that the Sun itself will demonstrate its importance for climate and so challenge the theories of global warming. No climate model has predicted a cooling of the Earth – quite the contrary. And this means that the projections of future climate are unreliable. A forecast saying it may be either warmer or colder for 50 years is not very useful, and science is not yet able to predict solar activity.
The Solar Effect on Ozone Hypothesis
Another hypothesis for how the sun might affect global climate is put forward by Stephen Wilde:
In essence: The Sun affects the ozone layer through changes in UV or charged particles. When the Sun is more active there is more ozone above the equator and less over the poles, and vice versa. An increase in ozone warms the stratosphere or mesosphere, which pushes the tropopause lower. There is thus a solar induced see-saw effect on the height of the tropopause, which causes the climate zones to shift towards then away from the equator, moving the jet streams and changing them from “zonal” jet streams to “meridonal” ones. When meridonal, the jet streams wander in loops further north and south, resulting in longer lines of air mass mixing at climate zone boundaries, which creates more clouds. Clouds reflect sunlight back out to space, determining how much the climate system is heated by the near-constant incoming solar radiation. Thus the Sun’s UV and charged particles modulate the solar heating of the Earth.
… The jet streams are high-level rivers of fast moving air threading between the climate zones, and are driven by temperature, humidity and density differentials between the different types of air mass:
An equatorward shift of the climate zones gives the jets more room to loop north and south, and that gives more meridonal jets (the north-south components of the jets).
A poleward shift of the zones pushes the jets poleward, forcing them to more closely following the lines of latitude, that is, more zonal jets (the east-west components).
Such shifts are also associated with the Arctic Oscillation, wherein a positive phase results in the climate zones being pulled poleward and the jets adopting a more zonal (straighter) pattern. A negative phase results in the opposite. A more frequent positive phase is associated with a more active Sun due to cooling of the polar stratosphere (less mesospheric ozone descending through the polar vortex) and consequent lifting of the polar tropopause. A more frequent or more pronounced negative phase (as observed to a record extent during the very low solar minimum between cycles 23 and 24) is associated with a less active Sun due to warming of the polar stratosphere (more mesospheric ozone descending through the polar vortex).
Matching Solar Variability w/ Northern Hemisphere Temperature Trends
It is clear from all satellite data that the Sun’s output varies with sunspot activity. The sunspot cycle averages 11 years, but varies from 8 to 14 years. As the number of sunspots goes up, total solar output goes up and the reverse is also true. Satellite measurements agree that peak to trough the variation is about 2 Watts/m2. The satellites disagree on the amount of total solar irradiance at 1 AU (the average distance from the Earth to the Sun) by 14 Watts/m2, and the reason for this disagreement is unclear, but each satellite shows the same trend over a sunspot cycle (see SCC15 Figure 2 below).
… This is Figure 31 from SCC15. The top plot (a) shows the northern hemisphere temperature reconstruction (in blue) from SCC15 compared to the atmospheric CO2 concentration (in red). This fit is very poor. The second (b) fits the CO2concentration to the temperature record and then the residuals to TSI, the fit here is also poor. The third plot (c) fits the temperatures to TSI only and the fit is much better. Finally the fourth plot (d) fits the TSI to the temperature record and the residuals to CO2 and the fit is the best.
… While the correlation between SCC15’s new temperature reconstruction and the Hoyt and Schatten TSI reconstruction is very good, the exact mechanism of how TSI variations affect the Earth’s climate is not known. SCC15 discusses two options, one is ocean circulation of heat and the other is the transport of heat between the Troposphere and the Stratosphere. Probably both of these mechanisms play some role in our changing climate.
The article above with its corresponding graphics reveal a remarkable fit between solar variability and actual temperatures. The authors do not suggest a mechanism for the solar effect on climate, but their data strongly suggests that the effect is real.
The Maunder Minimum was a time of very low sunspot numbers and very cold global climate. Coincidence? I think not.
An update of David Archibald’s observations of Solar Cycle 24. Archibald and others keep watch on the sun, so you won’t have to.
There is a lot more happening that affects the global climate than a mere trace gas (0.04% of the atmosphere) which also happens to be necessary for plants to grow.
Start with the sun and potential variability. Then go to the oceans, and the massive amounts of heat that are stored and released from that reservoir in oscillatory cycles — and how many atmospheric chemicals, including CO2, that the ocean absorbs and transforms. Then look comprehensively at atmospheric phenomenon of a chemical, physical, and biological nature — including massive storms and other energy transfers. Look at aerosols, volcanic activity, and black soot. Then look at temperatures, if you must, but on a much larger scale (and over a much longer time scale) than is currently being done over land, ocean, and ice masses. If you still have a significant unexplained temperature residual at this point, look at human activity — such as land use changes, the urban heat island effect, and industrial pollution. If significant residuals still remain, look at CO2 if you must — but the total CO2 cycle including the meniscule part of the CO2 cycle that human activities contribute to.
Even then, continue looking for further significant factors potentially affecting climate, in an open-minded way.
The climate apocalypse movement is a feeble-minded pseudo-scientific attempt by politicians and political cronies to cash in on the public’s gullibility and unwise trust in politicised science.
We are going to need a lot more guillotines!
Update: Another near-term ice age scare