How we know that the sun changes the Climate. Part I: The past
Posted on April 18, 2024 by curryja
by Javier Vinós
Part I of a three part series.
The Sun is a variable star and the amount of energy it emits varies from month to month, year to year, and century to century. One of the manifestations of these variations are sunspots, which are more common when the Sun is more active and disappear when it is less active. These spots follow a solar cycle of about 11 years, but sometimes there is a longer period, decades or centuries, when the Sun’s activity is so low that there are no spots. These periods are called grand solar minima. There are also periods of decades or centuries when the activity is higher. These are called grand solar maxima.
The Sun provides 99.9% of the energy that the climate system receives. So, there have always been scientists who thought that variations in the Sun were the cause of climate change. The problem is that they never had enough evidence to prove it. Until now.
The IPCC and NASA say…
The IPCC and NASA are convinced that changes in the Sun have very little effect on climate. They rely on two arguments. The first is that changes in solar activity are very small. We measure them with satellites because they cannot be measured from the surface, and we know that the radiant energy coming from the Sun varies by only 0.1%. The magnitude of the changes is better appreciated when we use the full scale. Many scientists believe that such a small change can only produce small changes in climate.
https://judithcurry.com/2024/04/18/how-we-know-that-the-sun-changes-the-climate-part-i-the-past/#_edn5
