Hailed as ‘the last piece of the puzzle’ in codifying our understanding of the mechanism(s) that cause climate changes, scientists are increasingly turning to Sun-modulated cosmic ray flux and cloud cover variations as the explanation for decadal- and centennial-scale global warming and cooling. In other words, climate changes are increasingly being attributed to natural variability, not anthropogenic activity.
Image Source: Sciencedaily.com and Climate4you.com
Fewer sunspots leads to low solar activity and more low-level cloud cover that reflects rather than absorbs the incoming solar heat. The result is colder climates. Higher solar activity leads to fewer low clouds and warmer climates, consistent with what has occurred in recent decades. The Modern Grand Maximum of very high solar activity (1940-2015) recently ended.
Periods with few sunspots are associated with low solar activity and cold climate periods. Periods with many sunspots are associated with high solar activity and warm climate periods. … Deterministic models based on the stationary periods confirm the results through a close relation to known long solar minima since 1000 A.D. and suggest a modern maximum period from 1940 to 2015. The conclusion is that the activity level of the Modern Maximum (1940–2000) is a relatively rare event, with the previous similarly high levels of solar activity observed 4 and 8 millennia ago (Usoskin et al., 2003).
With fewer clouds, more solar radiation can be absorbed by the oceans rather than reflected back to space; this, in turn, leads to warming.
Therefore, cloud cover changes and the concomitant alteration of surface solar heat absorption can explain the 1980s to 2000s warming via the increase in absorbed solar radiation (Pinker et al., 2005; Pallé et al., 2004; Herman et al., 2013; Wang et al., 2012; Calbó et al., 2016; Kauppinen et al, 2014; McLean, 2014).
There has recently been a scientific “breakthrough” in understanding the “missing link” between the Sun’s modulation of cosmic rays and thus cloud cover, supported by real-world observational evidence (3,100 hours of data sampling and controlled experimentation). More and more papers detailing the Sun-Climate connection are being published in scientific journals.
The following is an abbreviated list of scientific papers supporting the Sunspot Activity→Cosmic Ray Flux→Cloud Cover Changes→Climate Changes conceptualization published within the last year.
The missing link between exploding stars, clouds, and climate on Earth
Breakthrough in understanding of how cosmic rays from supernovae can influence Earth’s cloud cover and thereby climate
The new results reveal, both theoretically and experimentally, how interactions between ions and aerosols can accelerate the growth by adding material to the small aerosols and thereby help them survive to become cloud condensation nuclei. It gives a physical foundation to the large body of empirical evidence showing that Solar activity plays a role in variations in Earth’s climate. For example, the Medieval Warm Period around year 1000 AD and the cold period in the Little Ice Age 1300-1900 AD both fits with changes in Solar activity.
“‘Finally we have the last piece of the puzzle explaining how particles from space affect climate on Earth. It gives an understanding of how changes caused by Solar activity or by super nova activity can change climate.’ says Henrik Svensmark, from DTU Space at the Technical University of Denmark, lead author of the study.
Data was taken over a period of 2 years with total 3100 hours of data sampling. The results of the experiments agreed with the theoretical predictions.
• Low clouds made with liquid water droplets cool the Earth’s surface.
•Variations in the Sun’s magnetic activity alter the influx of cosmic rays to the Earth.
•When the Sun is lazy, magnetically speaking, there are more cosmic rays and more low clouds, and the world is cooler.
•When the Sun is active fewer cosmic rays reach the Earth and, with fewer low clouds, the world warms up.
The implications of the study suggests that the mechanism can have affected:
• The climate changes observed during the 20th century
• The coolings and warmings of around 2°C that have occurred repeatedly over the past 10,000 years, as the Sun’s activity and the cosmic ray influx have varied.
• The much larger variations of up to 10°C occuring as the Sun and Earth travel through the Galaxy visiting regions with varying numbers of exploding stars.
The spectral analysis of the sedimentological parameters reveals the significant periodicities (>95% significance) centering at ∼1067, ∼907, and ∼824 years. The long-term trends in the data suggest the possible fluctuation of Antarctic ice-sheet superimposed on global climatic fluctuations due to solar activity. … The curiosity of climate scientists arises on the mechanism of reaction of the climate system in response to the changes in solar forcing. There are two possible mechanisms proposed which work through the atmospheric processes. The first mechanism includes the action of the ozone layer by increasing more UV radiations with increased solar activity. It must have raised the temperature in the stratosphere which produces stronger winds in lower stratosphere and troposphere. These strong winds in the troposphere result in the relocation of pressure cells and storm tracks which ultimately disturbs the climate system (Schindell et al., 1999; Crosta et al., 2007). The second proposed mechanism considers the cosmic rays and cloud cover responsible for amplifying the climate forcing (Svensmark, 2000). High solar activity is believed to be responsible for less cooling of the lower atmosphere due to reduced cloud cover (Marsh and Svensmar, 2000). Conversely, low solar activity is believed to provide additional cooling of the lower atmosphere. These two feedback mechanisms responsible for the climatic forcing due to solar activity may work alone or in conjugation and are also superposed to other climate forcing as well as variability of internal cycling (Rind, 2002). Further, the periodic increase in solar activity results in increased temperature in the lower atmosphere which causes melting of ice-sheets in the Antarctic region. It may further provide the periodicity in freshwater discharge in the Schirmacher lakes and hence regulates the depositional environment of the studies lake.
The results of this review point to the extreme value of CO2 to all life forms, but no role of CO2 in any significant change of the Earth’s climate. … There is no correlation of CO2 with temperature in any historical data set that was reviewed. The climate-change cooling over the 1940–1975 time period of the Modern Warming period was shown to be influenced by a combination of solar factors. The cause of the Medieval Warm Period and the Little Ice Age climate changes was the solar magnetic field and cosmic ray connection. When the solar magnetic field is strong, it acts as a barrier to cosmic rays entering the Earth’s atmosphere, clouds decrease and the Earth warms. Conversely when the solar magnetic field is weak, there is no barrier to cosmic rays—they greatly increase large areas of low-level clouds, increasing the Earth’s albedo and the planet cools.
Nevertheless, these results over this long period strongly suggest that the solar magnetic feld/cosmic ray interaction is the primary cause of major climate-change events over the past 9400 years of the interglacial period. The 35-year cool period within the current Modern Warming was an example where the Gleissberg cycle imposed only a modest impact on the existing strength of the magnetic feld that was in place. The current Modern Warming will continue until the strength of the Sun’s magnetic field declines.
A similar result was also found for the relationship between solar activity and cosmic ray flux with a negative correlation, i.e. 0.69/year. When solar activities decrease, the clouds cover rate increase due-0.61/month and – to secondary ions produced by cosmic rays. The increase in the cloud cover rate causes the decrease in solar constant value and solar radiation on the earth’s surface. … The increase in the formation rate of cloud would affect the decrease in the intensity of solar radiation reaching the Earth’s surface. The relationship between cosmic rays and solar constant is an “opposite” relationship because of the negative correlation type (r < 0). The phenomenon of “opposite” is in a good agreement with the result by Svensmark (1997) who found a correlation between temperature and global cloud coverage with the cosmic rays… [T]he climate also depends on variations in the flux of solar energy received by the earth’s surface. Variation in the solar energy flux is caused by variations in solar activity cycle. Thus the climate is a manifestation of how solar radiation is absorbed, redistributed by the atmosphere, land and oceans, and ultimately radiated back into space. Every variation of solar energy received at the earth’s surface and reradiated by the earth into space will have a direct impact on climate change on Earth.