Monday, March 9, 2015

My Global Warming Skepticism, for Dummies


by Roy W. Spencer, Ph.D. in meteorology

I receive many e-mails, and a recurring complaint is that many of my posts are too technical to understand. This morning’s installment arrived with the subject line, “Please Talk to Us”, and suggested I provide short, concise, easily understood summaries and explanations “for dummies”.
So, here’s a list of basic climate change questions, and brief answers based upon what I know today. I might update them as I receive suggestions and comments. I will also be adding links to other sources, and some visual aids, as appropriate.

Deja vu tells me I might have done this once before, but I’m too lazy to go back and see. So, I’ll start over from scratch. (Insert smiley)

It is important to understand at the outset that those of us who are skeptical of mankind’s influence on climate have a wide variety of views on the subject, and we can’t all be right. In fact, in this business, it is really easy to be wrong. It seems like everyone has a theory of what causes climate change. But it only takes one of us to be right for the IPCC’s anthropogenic global warming (AGW) house of cards to collapse.

As I like to say, taking measurements of the climate system is much easier than figuring out what those measurements mean in terms of cause and effect. Generally speaking, it’s not the warming that is in dispute…it’s the cause of the warming.

If you disagree with my views on something, please don’t flame me. Chances are, I’ve already heard your point of view; very seldom am I provided with new evidence I haven’t already taken into account.

1) Are Global Temperatures Rising Now? There is no way to know, because natural year-to-year variability in global temperature is so large, with warming and cooling occurring all the time. What we can say is that surface and lower atmospheric temperature have risen in the last 30 to 50 years, with most of that warming in the Northern Hemisphere. Also, the magnitude of recent warming is somewhat uncertain, due to problems in making long-term temperature measurements with thermometers without those measurements being corrupted by a variety of non-climate effects. But there is no way to know if temperatures are continuing to rise now…we only see warming (or cooling) in the rearview mirror, when we look back in time.

2) Why Do Some Scientists Say It’s Cooling, while Others Say the Warming is Even Accelerating?