March 22, 2011 UPDATE: A Q&A with Dr. Zweirs appears here, in which he says he combined his Washington testimony with another east coast trip.

Earlier this week a committee of the US House of Representatives held a one-day hearing on climate matters. As this background memo explains, the US Environmental Protection Agency (EPA) is taking initial steps to regulate greenhouse gases under the Clean Air Act.

There is nothing trivial about this. It represents a brand new area of EPA jurisdiction, a dramatic expansion of that agency’s remit. The memo points out that the initial regulations merely represent stage one. More are expected and the real world consequences will be profound.

Once businesses and institutions are obliged to spend time tracking – and reducing – their CO2 emissions they will have fewer resources to devote to their real purpose. Some companies will not survive this new regulatory regime. It will be the last straw for those already pushed to the breaking point by the struggle to stay alive in a harsh economy.

And let us not kid ourselves. Since virtually everything humans do requires the use of energy – agriculture, manufacturing, transportation – a world in which CO2 emissions are regulated is a world in which everything will be more expensive.

Before the EPA goes down this road it would therefore seem sensible to review what we know and don’t know about the connection between climate and CO2 emissions. This one-day hearing represented an attempt to do that. Seven people were invited to testify. Links to their written testimony are available here (video of the proceedings can also be accessed from that page).

Of particular interest are the two people who testified about extreme weather. Over at her blog, Judith Curry has devoted the last two days to discussing the testimony of these experts (see here and here). The first is John Christy, an award-winning US atmospheric scientist who happens to be a climate skeptic. The second is Francis Zwiers, a prominent climate modeler from Canada. Both of these men have helped write Intergovernmental Panel on Climate Change (IPCC) reports.

It’s interesting to note that Curry, a scientist who has done work on hurricanes – and who does not describe herself as a climate skeptic – has, in both blog posts, indicated that her personal views are nevertheless closer to those expressed by Christy.

Zwiers, now a senior IPCC official, expects to be viewed as an authoritative scientist, but his career has been all about the virtual world. Climate modelers spend their time writing and tweaking computer programs comprised of mathematical equations. They feed these programs into supercomputers that then attempt to simulate the climate system.

The people who’ve devoted their lives to climate models regard them as works of beauty and genius, but while models have their uses they’re hopeless at other things. No one really believes they’re capable of accurately predicting the future. Instead, we’re told the results are merely scenarios, possible futures that may or may not come to pass. (See this 2007 commentary in which Kevin Trenberth insists that the IPCC’s climate models don’t predict anything.)

If anyone really thinks computer models can be relied on for real-world decision-making what I want to know is this: why hasn’t anyone accurately simulated the stock market instead? Why haven’t they figured out how much gold will be trading for three, five, or ten years hence, made a killing, and already retired to a tropical island?

Take a look at Zwiers’ 15-page written testimony. He talks about (bold added by me):

• “the changes predicted by climate models” (p. 1)
• “temperature extremes predicted by climate models” (p. 8)
• “model averages” and “model simulations” (p. 10)

He also says, in his summary:

…the effects of increasing greenhouse gas concentrations provides a more plausible explanation for the observed changes in temperature and precipitation extremes than other possibilities, such as natural climate variations. While these studies do not provide the final word on the question of whether, and by how much, increasing greenhouse gas concentrations have affected the frequency and intensity of extreme climate and weather events, they suggests [sic] that human influence is now affecting the frequency and intensity of high impact events [bold added]

This is the murky state of climate science. Some ideas are more plausible than other ideas. In place of hard evidence there is research that suggests certain conclusions. In other words, it all comes down to interpretations and opinions.

Both Zwiers and Christy also discuss research results that are hot off the press. The problem with this is that just-published research hasn’t yet withstood the test of time. It hasn’t even been read by many people yet, never mind replicated successfully. Which means it isn’t smart for any decision-maker to place too much confidence in research findings that are brand new.

For those of you interested in (and equipped to understand) the scientific arguments, it seems to me that the competing testimony of these two men provide a useful snapshot of the larger debate.

But there are some side issues, as well. As a Canadian I’m interested in why Zwiers would fly 2,500 miles, across three time zones from his base in Victoria, British Columbia, to testify at this particular hearing in Washington, D.C. That’s a lot of CO2 emissions, especially when there are numerous American experts in his field.

Everyone who testified was required to fill out a Truth in Testimony form. According to the one Zwiers completed he did not testify on behalf of any government entity – or any non-government entity.

So who funded this trip? If it was Canadian taxpayers – how much did it cost? And why, exactly, have we been billed for it?

.

hearing main page

hearing background memo

John Christy – written testimony and Truth in Testimony form

Francis Zwiers – written testimony and Truth in Testimony form

Judith Curry’s blog posts: Extreme testimony and Extreme Testimony Part II: Floods

.

.