The concern about anthropogenic global warming (AGW) has been challenged by a Northumbrian mathematician. From the Washington Post [via Jack]:
This week, warnings of an impending “mini ice age,” set to hit in the 2030s, have been circulating in the media. ...
The ice age idea got rolling last week when researcher Valentina Zharkova, a professor of mathematics at Northumbria University in England, presented some of her recent research into solar variations at the Royal Astronomical Society’s National Astronomy Meeting in Wales. The presentation was based on a study ... which presented a technique for understanding variations in solar radiation and made some predictions about how this radiation will change in the near future. Most notably, the research predicts that between 2030 and 2040, solar activity should drop significantly, leading to a condition known as a “solar minimum.” ...
According to the research, solar activity at this time should resemble conditions last seen in the mid-1700s during a period known of low solar radiation known as the “Maunder Minimum.” The interesting thing about this period was that it coincided with a “little ice age” in Europe and North America — a time marked by unusually cold temperatures and bitter winters. Now that Zharkova and her colleagues are predicting another solar minimum coming up, media coverage has jumped on the idea that a modern “mini ice age” is in store.
Michael Mann, a leading proponent of concern about AGW (and whose work has been seriously criticized [see this] ), doesn't buy it, but his apparent only explanation is
As far as the solar variations go, “The effect is a drop in the bucket, a barely detectable blip, on the overall warming trajectory we can expect over the next several decades from greenhouse warming,” said Michael Mann, distinguished professor of meteorology at Pennsylvania State University, in an e-mail to The Washington Post.
The article points out that Zharkova refuses to go on the record scientifically as to whether her predicted mini-ice-age would have much of an impact on the earth's temperature. It does add, however, that
On the one hand, Zharkova maintains that her research was not intended to make assumptions about the effects of solar variation on climate — only to lay out predictions about the solar activity itself. “What will happen in the modern Maunder Minimum we do not know yet and can only speculate,” she says. On the other hand, she adds, her gut assumption is that temperatures will drop as they did 370 years ago.