Just a couple of days ago it was announced that the sun seems to be cooling. The speculation was that this could be similar to the "Maunder Minimum" of the 17th and 18th centuries. This is usually given as the cause for a period of global cooling known as the Little Ice Age.
Sounds like we should forget about carbon taxes doesn't it?
Not so, says Michael Mann. Mann insists that it was a total coincidence that the Little Ice Age coincided with the Maunder Minimum. Volcanoes were to blame instead.
What goes unsaid is that Mann has a conflict of interest. His professional career has been built on the proposition that the main driver of climate change is CO2. Never mind that the only source of light and heat in the solar system is the sun, it is irrelevant to climate, according to Mann. He can prove it, too. He cites an article in Science magazine. Although, he wrote the article so he is citing himself.
Actually it is a major concession for him to admit that there was a Little Ice Age. He first came to prominence when he presented his reconstruction of historic climate to the International Panel on Climate Change (IPCC). It showed a fairly steady climate until the start of the Industrial Revolution. After that the global temperature rose rapidly. The chart is known as the Hockey Stick which it vaguely resembles. At that time the Little Ice age was dismissed as a phenomenon local to Europe.
Since then research has shown that the Little Ice Age was global. The idea of decades-long volcanic eruptions altering the climate is Mann's attempt to allow for a terrestrial explanation for the Little Ice Age.
So, Mann is hardly an unbiased source to evaluate the meaning of new solar activity.