Saturday, September 06, 2008

Public Lecture Review: Dr. Roy Spencer, Global Warming Skeptic

Dr. Roy Spencer, a professor of meteorology at the University of Alabama-Huntsville (UAH), was the guest speaker for HAL5's monthly meeting this week. He is a self-described global warming skeptic, which is a label that is bound to cause him trouble in certain sections of the news media. Spencer has probably earned himself an extra dose of opprobium by being the "official climatologist" of Rush Limbaugh's Excellence in Broadcasting network.

Regardless of his reputation in the media, Dr. Spencer is a serious climate scientist, and seems a rather low-key guy to be associated with Rush. Be that as it may, Spencer is a clear, fine speaker with a good sense of humor and patient, calm demeanor, which he no doubt needs when addressing critics in the media, the classroom, or in Congress.

What, exactly, does it mean to be a global warming skeptic? In the case of Spencer, it means a few things:
  • He does not deny that global warming has occurred in the last century. However, he notes that this is part of a general increase that has occurred since the "Little Ice Age," which lasted from around 1300 to 1850. The Little Ice Age, in turn, was preceded by the Medieval Warm Period, when average global temperatures were the same (or higher) than what they are now.
  • He does question exactly how much of that warming is the result of human-based activities, such as burning fossil fuels.
  • He does focus on the data related to climate change (actual numbers), not just rhetoric. (My big gripe with the global warming hysteria has been that I don't believe people repeating assertions proves that said assertions are true. Related to that gripe is a personal reaction to any mass movement: I don't like to be pushed around. People need to reason with me if they want to get their point across--I'll accept comprehensive data, not selective data, and not anecdote-based scare-mongering. But I digress.)
  • He does question some of the assumptions made by the physics-based computer climate models that have been used by James Hansen and others to declare that a global warming crisis is in the making (or already happening).
  • He does not believe that the Earth's climate system is hypersensitive to human activities.
  • He does believe that the natural processes of our planet have a larger impact on weather (short-term trends) and climate (long-term trends) than human activities.
  • He does believe that the climate model-makers have their causes and effects reversed.

I'll focus on the last point, since that was the focus of Spencer's talk. I'll have to use English-major terms here, since I'm not a scientist. He began by explaining that the Earth's atmosphere tends toward equilibrium, with the amount of heat absorbed from sunlight equalling the amount of infrared radiation (heat) radiated into space. The basic premise of global warming and the "greenhouse effect" is that excessive carbon dioxide created by human activities is disturbing this equilibrium. This is happening because carbon dioxide (CO2) is creating more clouds, preventing heat from escaping into space.

If I understand Spencer correctly, though, he believes that cloud changes affect temperatures more than temperatures affect cloud changes. At some point, he explained, scientists noticed that temperatures worldwide had increased, on average, and that carbon dioxide had increased as well. Scientists interpreted this coincidence of activity as a definite correlation--that is, A caused B. However, Spencer asserted (and this is the first time I'd heard this) that carbon dioxide increases occurred after the temperature increases. If true, this means that the temperature increases are due to something else.

Here's how Spencer explained the Earth's climate changes in response to increases in heat (wherever they come from):

  • More heat is pumped into the system.
  • More heat produces more water vapor.
  • More water vapor means more clouds are created.
  • More clouds in the Earth's atmosphere increases the planet's albedo (reflectivity), causing more sunlight to be reflected into space rather than reaching the surface. In this way, equilibrium is maintained.

So what's causing the temperature increases and ice ages? Here are some possibilities Spencer mentioned:

  • The tilt of the Earth.
  • The eccentricity of Earth's orbit.
  • Changes in solar radiation. On this point, Spencer indicated that the amount of light put out by the sun was not enough to account for climate change unless the climate was exceptionally sensitive to such changes--a position he opposes.
  • Natural fluctuations in heat circulation between the oceans and the atmosphere.

Spencer did show a lot of graphs and charts reflecting his models and the more traditional models being used by the global warming theorists. However, I must confess that I didn't "get" them. The numbers and the patterns of the lines on the charts (temperature on the X axis, changes in radiant energy lost on the Y axis) didn't tell a story I fully understood. I'd probably have to spend some more time with the equations and the data to understand the implications of what his model is showing.

However, Spencer's political comments were perfectly clear. He echoed the global warming believers' comments, mostly for laughs (this is, after all, Red State America):

  • "Everything's going to get worse."
  • "It's all George Bush's fault."
  • "How could they be wrong? They spent hundreds of millions of dollars!"

His own responses to some of the alarmist talk in the climate change community offer the patient listener food for thought:

  • "Most of the model makers were trained in physics, not meteorology. They're used to dealing with equations. The Earth's weather is biological in its complexity. It's really functioning according to chaos theory."
  • "Any time you replace vegetation with man-made structures, heating increases."
  • "Any time air is sinking in some places (the Sahara, parts of the Pacific), it's because air was forced to rise in other places."
  • "Why do we allow trees to change the environment, but not humanity?"
  • "It's not like I'm for pollution. Humans pollute just by existing. It's a matter of what you're willing to put up with."
  • "It's only the wealthy economies that can afford to develop the technologies to find the solutions [to global warming]."
  • "I"m probably being cynical, but I believe politicians and scientists who want to be politicians view this as an opportunity to control people by controlling their energy use."

It is this last statement that most likely wins over Limbaugh, though John Coleman (a former Chicago weather man--WLS-TV--and founder of The Weather Channel) has also taken issue with global warming alarmism. And Spencer's global average temperature chart, which I've seen in other places, does show a temperature drop for the last two years, coming down off a recent high in 2005. As Spencer put it in his low-key way, "It will be interesting to see if this trend continues over the next few years." The maximum temperature increase Spencer is predicting by 2100 is less than 1 degree Celsius, as compared to the 2.5 to 5 degrees predicted by the Intergovernmental Panel on Climate Change (IPCC). Which numbers do you think is more likely to get governmental attention and action?

I asked Spencer what he thought about solar power satellites, a favorite technology of mine and others in the pro-space community. I wanted to know, specifically, if he thought that the microwave power beams being transmitted to the Earth's surface would add considerably to the Earth's heat load. His response? "It sounds sexy, but it's just going to be excessively expensive compared to the amount of energy [production] you'll get."

Spencer is using cloud cover data gathered by NASA's Aqua satellite (and others). He is not making things up, nor is he exceptionally partisan. He is not shrill or screaming or pounding the table or denouncing global warming theorists as corrupt, evil, or part of some vast global conspiracy (governments are another matter entirely). What he is doing is asking these people to question their assumptions and their models, as good scientists should. He even admits, rather humbly, that "I could be wrong." It's unfortunate that the folks he's questioning do not have similar humility--that attitude used to be a cornerstone of the scientific method.

No comments: