Below the fold are my remarks to the Valley Forward lunch today — I only had five minutes, so I was fairly limited.
It’s popular among those who want to cut off debate to call skeptic’s “deniers,” in large part because it evokes the term “holocaust denier” and therefore marginalizes criticism of catastrophic man-made global warming theory.
But I will accept the denier label, as long as we are clear what proposition it is I am denying. I do not deny the world is warming. The couple of hundred years ending around 1800 were among the coldest in the last 5000 years, so it is natural we should see a warming recovery since this period. Glaciers are retreating and sea levels are rising in part because they have been doing so every since this little ice age, long before man put CO2 in the atmosphere in earnest.
Further, I don’t deny greenhouse gas theory, that man’s CO2 can cause some incremental warming. The Greenhouse gas theory has to be real, or the world would be much colder right now.
No, what I deny is the catastrophe, that temperatures a hundred years hence will be five or ten degrees Celsius higher due to man’s co2
Interestingly, I think most everyone on the scientific end of the debate agrees that the direct warming from man’s Co2 acting alone will be relatively modest – on the order of a degree Celsius by the year 2100 according to the IPCC. Yeah, I know this seems oddly low — you never hear of global warming numbers as low as 1 degree — but it is actually a second theory, independent of greenhouse gas theory, that drives most of the warming. This second theory is that the climate is dominated by strong positive feedbacks that multiply the warming from CO2 many fold, and increase a modest 1 degree C of warming from man’s CO2 to catastrophic levels of 5 or even 10 degrees.
The example I use is to think of climate as a car. Co2 from man provides only a nudge to the car. The catastrophe comes from a second theory that the car (representing the climate) is perched precariously on the top of a hill with its brakes off, and a nudge from CO2 will start it rolling downhill until it crashes at the bottom.
When people say the science is settled, they generally mean greenhouse gas theory. But that means only the nudge is settled. What is far from settled is the second theory of strong net positive feedback in the climate, ie the theory the climate is perched on top of a hill. It is unusual for long-term stable but chaotic systems to be dominated by such strong positive feedbacks. In fact, only the most severe contortions allow scientists to claim their high-sensitivity models of catastrophic warming are consistent with the relatively modest warming of the past century.
Historically, the effects of a degree or so of warming have been small and generally positive. Times of warmth have been times of prosperity. Unfortunately, we seem to be suffering under a massive case of observer bias in assessing any current effects of climate change. Extreme events, which have always existed, are used by both sides of the debate as supposed proof of long term global trends. But there is little useful we can learn about trends at the tails of the distribution, and it turns out that the means of key weather events in the US, from droughts to wet weather to tornadoes to hurricanes, show no meaningful trends.
Climate observation is hard enough without this confusion. Imagine we wanted to look at customer visitation of the old Pink Pony Steakhouse in Scottsdale. If we watched for only a few hours, we might miss the huge variability of the crowds from early morning through each mealtime rush. Watch only for a day, and we might miss the seasonal variation, as snowbirds pack the restaurant in March. Watch for just a year, and we might have missed the long, slow decline in visitation that eventually led to the restaurant closing. In climate, we are trying to decide if there is a long term decline at the Pink Pony after watching for the equivalent of only a few hours.
My fear over the last several years is that the obsession with trace levels of CO2 has sucked the oxygen, so to speak, out of the rest of the environmental movement. Things that used to matter – water quality, wilderness preservation, hygene and public health in poorer nations — seem to get short shrift. In fact, in the name of CO2 reduction, we have subsidized, even mandated goals like corn ethanol that are destructive to the environment, and diverted money and attention from other causes.
Our obsessive focus on CO2 has real costs, and the current Administration’s position that CO2 abatement can be a net positive for the economy via green jobs creation is simply a fantasy. It is Bastiat’s broken windows fallacy writ large, this contention that obsoleting our perfectly good energy infrastructure and replacing it with something more expensive will be cost-free. I have to laugh every time I see the logic that Arizona wants to be a leader in solar manufacturing because, uh, we have a lot of sun. This makes as much sense as saying radio manufacturers should all relocate to New York City because it has the most radio stations. But the real problem is that every city and state in the country is chasing the same alternate energy manufacturers, competing with each other to subsidize this small industry the most.
My sense is that all of this public and private money chasing the same small industry, combined with an emerging reality that global warming forecasts are likely greatly exaggerated, may be leading us into yet another disastrous bubble.