One on-line commenter recently responded to me with the following:
“It is one thing to deny climate change and a completely different thing to take credit for it.
It's a natural cycle, the earth has been doing it for millennium, and there isn't squat ‘man’ can do about that.”
In the past, this same individual has insisted that we are being “arrogant” to assume mere humans can impact the world’s climate.
Around 1960, a mathematician and meteorologist by the name of Edward Lorenz was working with a computerized weather model. He first noticed that with the same set of data, the model would present different results each time it was run. The raw data he was using was fractional to several decimal points of accuracy limited only by the computer. When data of this nature is used, it is the nature of computers to have an error in the most insignificant digit. For instance; 1.2341986 might actually be processed as 1.2341987 or – I suppose – 1.2341985 for that matter. These differences were caused by quantum noise effects and nobody really worried about it, since the final answer might be expressed only to the tenths.
But Lorenz’s model was different. He took thousands of points of data and processed them thousands of times. Each time a previous answer was used as the input data for a subsequent process. As a result, a difference in billionths of the original data had a significant – and unanticipated - impact on the final results.
When Lorenz truncated the actual data to well within the computer’s maximum degree of “accuracy” the model runs were identical with the same datasets (our example above could be truncated to 1.23419, for instance.) But were the results more accurate? Were these “identical” results the correct ones?
It turns out that they weren’t. Indeed, Lorenz had discovered a fundamental truth about chaotic systems which he coined “the butterfly effect,” which states that a very small change in the initial conditions of a chaotic system can result in a very large difference in the final conditions.
Weather and climate are chaotic systems and Lorenz’s modeling flaw discovered a very important fundamental truth about our weather and our climate. What he found to be true about the data accuracy is also true about the data completeness. If we miss even a very small piece of data, our predictions about climate change can be wrong.
Yes, climate modeling is a challenge. But by modeling the climate, scientists have been able to learn about it. And they are learning that mere humans are having an impact.
We can now account to some degree for the inaccuracies that the computers insert into the models. Our challenge is to find the complete dataset – and because of the Butterfly Effect, that dataset involves extremely small points. For instance, we know our barbeques create CO2 when they burn charcoal, but we don’t know how much our barbeques will contribute to atmospheric CO2 next Memorial Day, because we cannot possibly know how many barbeques are going to be fired up in the US next Memorial Day. But if we could, we cannot possibly know exactly when they will be fired up. But if we could, we cannot possibly know how much lighter fluid each “chef” will use. But if we could, we cannot possibly know how many steaks are to be “well done.” Each of these minute and interrelated actions impacts weather and ultimately – when all Memorial Days for the next twenty years are taken into account - climate change.
So I wonder; Is it arrogant to assume that we humans are bringing about changes in the climate that we might not find desirable or is it stubborn to insist that we are not?
Published on Friday, December 4, 2015 in the Winona Daily News under the title: Climate change is debate of arrogance vs. stubbornness