These days, being a skeptic of the global warming story is tough. Expressing doubts about the standard climate change horror story (and, if it’s true, it really is a horror story) is akin to saying, say, that the President isn’t a natural born US Citizen. Nevertheless, there are people out there – I am one of them – who, while not themselves climatologists or otherwise scientifically credentialed, are more or less intelligent and, after some thought and reading on both sides of the question, are in fact skeptical of the idea that mankind’s production of greenhouse gasses is driving potentially catastrophic climate change; or that, if it is, near-term efforts to reduce greenhouse gas emissions are the best way to deal with it. What could we possibly be thinking? Well, here, at least, is what I am thinking.
Is the Climate Changing? The first question that has to be asked is: Is the climate in fact changing and if so will it continue to do so?
Perhaps surprisingly, I suspect the climate is in fact changing, and will continue to do so – though I am less certain what the future direction of change will be. The fact is that the climate has changed significantly many times in the last 100,000 years (to pick an arbitrary date). Well beyond the longer term trends of ice ages and interglacial periods, there is plenty of evidence that even during glacial and interglacial periods the climate has been quite variable, both globally and – at least as significant – regionally. Even during periods that appear to have been reasonably quiet in terms of global climate changes, there have been big swings in things like temperature and rainfall on regional scales. My conclusion: it would be strange indeed, given the historical evidence, if the climate was not changing.
Ok, so now the next question: has the climate, on a global scale, been getting warmer over the past couple of hundred years? My own view is that the evidence is pretty good, but not conclusive, that it has. Given how the technology has changed over the last couple of hundred years, and the quality and reliability of the data with it, coupled with the relatively small changes (not to say they are not significant in terms of potential impact; only that they are small relative to the mean), it is a bit over the top, I think, to take the data entirely at face value (even ignoring the recent scandals over data integrity).
But, ok, the bottom line is that I am willing to concede, for argument’s sake, that global temperatures have risen modestly over the last couple of hundred years. So what? That is far from a concession that they will continue that trend over the next few years (or few hundreds of years, a time scale that has seen significant variability over the last thousand years). And it is even farther from conceding that the reason for the rise is mankind’s production of greenhouse gasses.
Is Climate Change Driven by Man Made Greenhouse Gasses. Now we get to the real sticking point. Simply put, our climate models are incredibly ad hoc and unreliable. There are dozens of variables that impact the climate that we know of – and almost certainly dozens more that we don’t know of. And our understanding of how even the variables we know of interact (positively reinforcing, or negatively reinforcing, or neutral, and in each case over what ranges and what contingencies for the other variables) is sketchy and incomplete. In that kind of environment, it is very hard for me to accept that the current rise in global temperature is being driven entirely – or even in significant part – by the single variable of man-made CO2 emissions. (Further, the models that show climate change being driven by greenhouse gas emissions are not all that good at “predicting the past” so why should we assume they are good at predicting the future?)
What if the Global Warming Folks are Correct? Finally, what if I am wrong? What if the global warming folks are correct? Well, if the mainstream global warming folks are correct, from the models/predictions I’ve seen, the likelihood that we can do anything serious (in the sense of actually having a material impact on the scope of the coming disaster) about global warming by reducing man-made greenhouse gas emissions over the next 50 years is for all practical purposes zero. At best, the developed countries are talking about emission reductions to levels that were already causing significant warming decades and more ago. Even more, there are too many economic “have nots” in the world who are simply not going to remain in poverty out of fear of the consequences of global warming for their children and grand children. Finally, there is far more likelihood, I think, that investing even a fraction of the price tag associated with drastic reductions in greenhouse gas emissions in carbon sink technologies – i.e. in technologies to take greenhouse gases out of the atmosphere – will lead to technologies that can stave off the predicted catastrophe than there is that investing in greenhouse gas emission reductions with the technologies we have available today will be the answer.
Conclusion. So, my skepticism is grounded in several ideas. The climate change data is weak; the ties of the same to greenhouse gas emissions is even weaker; and even if we accept that there is a dangerous and continuing change occurring, and it is driven by mankind’s greenhouse gas emissions, any solution at this late date will most likely be found in a vastly cheaper (and politically more palatable) investment in carbon sink technologies than in prohibitively expensive (particularly in the developing world) reductions in greenhouse gas emissions with the technologies we have at hand today.