Re: 2009 April 21 - global warming
Posted: Wed Apr 22, 2009 5:12 pm
Chris Peterson wrote:For the most part, predictions of future solar cycles have always been poor. Nobody knows how to make such predictions yet.hydroresearch wrote:Chris, I would suggest checking the predicions from a few years ago about the new cycle. You will find they are all wrong.
It is easy to read too much into reports of solar activity. "A hundred year low" sounds so dramatic. But the current cycle isn't much lower than many others. It reminds me of the close approach of Mars a few years ago. Lots of people made a big deal about how it was closer than it had been for tens of thousands of years. That was true, but what usually went unmentioned was that it was only fractionally closer than it gets every couple of decades. Not really any big deal.
It's the same with the current minimum. True, we haven't seen such a deep one for a century. But we've seen other minimums during the last century that were nearly as deep. It is really premature to start seeing this as another Maunder minimum.
The bottom line is that actual measured solar irradiance over the last two solar cycles looks about the same. There's very little to suggest that the slightly deeper minimum we're coming out of has had much impact. There is a slight decline in average temperatures during every minimum. It's expected, it's part of the models, and it has nothing at all to do with the trend in global average temperature since we started pumping massive amounts of greenhouse gases into the atmosphere (a relationship for which good, solid, scientific evidence does exist).
The solar cycle is just one elemnt in the climate system. Large scale oscillations in ocean circulation are another example. If "future predictions of future solar cycles have always been poor", how do your models incorporate these poor predictions?
Solar irradiance is only one aspect of the solar cycle. With better instrumentation and satellite observations we are seeing other changes such as the solar wind which can have impacts on cloud generation. It seems the more we learn about the sun-climate relationship the more complicated we realize it is.
I have never claimed that we were entering a Maunder minimum, I just hate to see rash decisions made on models which are really not preforming at a level of accuracy to justify such decisions.
Thanks for all the good discussion.