Environmental Talk

Is DaVinci painting a self-portrait? Or a picture of a man on a mule?

Jim O’Brien is the smartest guy I ever met. He has a Ph.D. in chemical engineering from Yale and is an amazing software designer. It was from Jim that I first heard the phrase: “If you torture the data long enough, it will confess.”

I suppose this means we should have a Geneva Convention for data, but failing that, it’s a good saying to remember when both sides of the climate change debate look at the same data and come up with different conclusions.

The following chart is from a study by Robert-Muir Wood, Stuart Miller and Auguste Boissonade attempting to discover whether evidence supports the conclusion that damage from extreme weather events has increased over the past 50 years. The graph shows normalized damages in U.S. dollars for “tropical cyclone, flood (storm surge and inland) and across all weather related perils.”

What do you see?

If you look at the chart since the 1980s, there would appear to be a slight uptrend in extreme weather events with a spike in the last few years.

If you look at the chart since the 1950s, there is no discernible trend, with the exception of the recent spike to new highs.

So, what conclusion do you draw? If you believe that man-made global warming is responsible for more extreme weather events, you focus on the more recent data and ignore the fact that, while economic losses have risen in the U.S., they’ve actually decreased in many other parts of the world. You’d also want to ignore what the study authors note is a tendency to include more items in what is defined as “economic loss.” Specifically, losses associated with the 2004 tsunami in Indonesia include “an estimated $1.53 billion USD for initial reduction in economic activity” - a factor not included in previous events.

If you believe that anthropogenic global warming has not contributed to an uptick in extreme weather events, you might take a longer view of the data stretching back to 1950. Plus, you’d want to note that the data would appear to be biased upward by the aforementioned “broader definition” bias as well as a U.S.-centric bias that was exacerbated by losses associated with Hurricane Katrina.

The study’s authors are well-aware of how the Katrina numbers bias their conclusions and are careful not to read too much into the data.

Unfortunately, mainstream media outlets have little time for such subtleties and will tend to publish what they see are the “conclusions” reached by the study’s authors but which more accurately reflect the biases of the reporter or publisher.

In the end, it’s not just the data that suffers - it’s all of us.

global warming, climate change, Katrina, extreme weather, Robert-Muir Wood, Stuart Miller, Auguste Boissonade