(From the December 8, 2011 issue of the Grand Haven Tribune)
I’ve been thinking about “global warming” recently, as the weather gets colder.
Currently the mantra of climate change is that the earth is warming significantly, and that man is the cause. Others have doubts about the particulars behind this claim and the projections that come from it. But attempts to discuss the topic rationally seem to generate more warming instead of illumination.
In spite of Al Gore and others trying to settle the issue rhetorically by asserting oversimplified mantras, there is much about the science of climate change that is still open to rational and scientific consideration.
Attempts to persuade people to the global warming cause by demonizing those with doubts can only be counter-productive because that’s more propaganda than science. No one likes to be told to accept something “because I said so.” This may be why a Pew Research Center poll last week showed that those who think global warming is “very serious” or “somewhat serious” is down from 79% in 2006 to 65% this year, and those who think there is solid evidence that the earth is warming due to man-made activity is down from 47% in 2006 to 38% currently.
The discussion needs to continue and should do so productively, which is best done by employing the scientific method. Since the early 1900s, thanks to philosopher of science Karl Popper, scientific theories were considered more legitimate if they could not be “falsified.” In other words, attempting to disprove science is part of science, not a denial of it.
In that spirit, we can consider a list of reasonable questions about the claims in the climate change mantra.
Is the current observable temperature warming trend significant? Some high temperature records have been set in the past decade, but records have only been kept for 150 years. Temperatures were much higher in earlier eras, and consequences were not catastrophic. Read on.
A related question has to do with man being the cause of global warming. The Keeling Curve is a measure of the parts per million of CO2 in the earth’s atmosphere measured since the late 1950s. The scale does go up since the first measurements, but one can wonder if the span of 60 years is long enough to assert that this spike will continue to go up or whether it will level and reduce again in the future. Such a question is reasonable given that, as pointed out in an article in the October 2011 issue of National Geographic, there was a massive surge of carbon in the atmosphere 56 million years ago in what is called the Paleocene-Eocene era. The magazine rightly notes that this carbon increase is unexplained, and certainly was not the result of man-made causes. We have to consider that the increasing temperatures in merely the past 60 years have multiple causes with some of them being natural. While humans burning fossil fuels may be part of the cause, the natural scientific question would be what percentage of the variance in global temperature increase is explained by man-made causes?
That leads to a long-standing scientific caution about correlation and causality. Just because the increase in the number of factories and automobiles correlates with increased C02 in the atmosphere, it does not necessarily mean than one is the cause of the other. And again, if it is causal, what portion is caused by humans and what are the other variables?
Measurement error is another scientific reason for skepticism. There have been more than 1 billion temperature readings, but the whole earth’s surface has not been measured. Measurements have been taken in different ways in different countries, potentially leading to inconsistent data. The “urban effect,” in which a concentration of tall buildings increases surface temperature, could skew data. And the satellite data and computer models used versus actual thermometer readings in many cases could be inaccurate.
The question of whether all scientists agree, a common assertion, is also cause for skepticism. Leaked emails from climate scientists—one in 2009 and another just last month, as reported in the Guardian in the U.K.—shows efforts by some scientists attempting to publicly “smear” their skeptical colleagues, control who is part of the Intergovernmental Panel on Climate Change (IPCC), and expressing doubts about the conclusions and predictions of some climate change studies. Those expressing science-based skepticism include professors of atmospheric science, directors of centers on climate science, and state climatologists for several U.S. states. They stress that water vapor accounts for five-sixths of warming attributed to greenhouse gases and that extreme weather is not increasing to any significant degree.
If you want to win climate change arguments by saying you believe the scientists, you’ll have to specify which scientists you believe, and on which aspects of climate research.
The bottom line is that the subject of climate change should be based on science, not assertion, over-simplified rhetoric, or blind belief or denial. Daniel Botkin, president of the Center for the Study of the Environment and professor emeritus at the University of California, Santa Barbara, made this point especially well in his recent guest editorial in the Wall Street Journal: “Global warming alarmists betray their cause when they declare that it is irresponsible to question them.”
Indeed, most academic journal articles include a section called “limitations,” in which authors recognize potential flaws in the research method or conclusions. If more climate change scientists would acknowledge limitations, it’s more likely that citizens would acknowledge the parts of their work about which we can be certain.