Will reduced solar activity counteract global warming in the coming decades? That is what outgoing German electric utility executive Fritz Vahrenholt claims in a new book. In an interview with SPIEGEL, he argues that the official United Nations forecasts on the severity of climate change are overstated and supported by weak science.
Vahrenholt: In the second half of the 20th century, the sun was more active than it had been in more than 2,000 years. This "large solar maximum," as astronomers call it, has contributed at least as much to global warming as the greenhouse gas CO2. But the sun has been getting weaker since 2005, and it will continue to do so in the next few decades. Consequently, we can only expect cooling from the sun for now.
SPIEGEL: It is undisputed that fluctuations in solar activity can influence the climate. Most experts assume that an unusually long solar minimum, evidenced by the very small number of sunspots at the time, led to the "Little Ice Age" that began in 1645. There were many severe winters at the time, with rivers freezing over. However, astrophysicists still don't know the extent to which solar fluctuations actually affect temperatures.
Via Alice Ruxton Abler