The Trend toward Global Cooling?

On November 18, the first snow and the first frost were observed among many parts of Japan. The first snow was observed earlier than usual in a broad range of areas in Japan although it was observed later than usual in some high latitudes such as Sapporo in Hokkaido and and in some mountainous areas. In recent years, the snow has been rarely observed in most of the flat areas of Japan in November. This trend is not confined to Japan. In London, it snowed in October for the first time in 74 years since 1934. Why is it so early to get cold in a broad range of areas in the world? It seemed to be because there were many cloudy or rainy days from spring to summer this year. So, what made so much cloud arise this year? The cause can be seen in the solar activity.

From last year to this year, the number of the sunspots has been in minimum. The number of the sunspots indicates the solar activity. When the solar activity diminishes, the solar wind, which is the rapid flow of plasma shot from the solar surface, gets weaker. The solar wind pushes back the cosmic ray from outside the solar system. That is that the more the solar activity diminishes, to the more cosmic ray Earth gets explosed.

The cosmic ray is also the rapid flow of plasma. Once the cosmic ray comes in the atmosphere of Earth, it inonizes the atoms in the atmosphere. Then, the ionized atoms act as the condensation nuclei, and more cloud gets formed.
This mechanism is called the Svensmark effect named after a Danish physicist Henrik Svensmark, which is still no more than a hypothesis. In a short words, when the solar activity diminishes, the more cosmic ray come into the atmosphere, and more cloud gets formed.

Therefore, it is natural that it is cool all over the world this year. The last year was notable for the heat waves, but it might have been a temporary phenomenon caused by La Niña. If so, it is not entirely inconceivable that Earth is heading for global cooling. Of course it is possible that the cold waves of this year is also just a temporary phenomenon.

Thus, there are many factors on global climate. We need to take all these factors into consideration on discussing climate change.