Don’t fall for simplistic claims about wildfires and global warming
Global warming is a problem. There are a lot of forest fires in California this year. And there is a plausible mechanism (dead or dried trees) that could connect the one idea with another. Therefore, it’s clear that global warming caused the current fires.
If you recognized the fallacy here, good for you. You are way ahead of the media and even some scientists who should know better than to confuse causation and correlation.
But in this case, the fallacy is even more obvious — because there isn’t even a valid correlation between the fires and the warming.
To be sure, this year’s tally of acres burned in California (1.4 million so far) is well above average for California’s last five years. In fact, by the time fire season ends, it will give the 2007 (1.5 million acres) and 2018 totals (1.67 million acres) a run for their money.
But what exactly does that mean? Is it valid to look at one or two years of fire data and jump to the conclusion that this must be global warming, wreaking its havoc? By that logic, we would be forced by the rules of deductive logic to conclude that global warming took a break during the recent nadir of California’s forest fires, when in 2010 only 134,000 acres burned and only 228,000 acres were burned in 2011. That seems rather silly.
The uninformed assertion of a causal effect between global warming and the current wildfires becomes even more ridiculous when one looks beyond the isolated situation of California. On a national scale, wildfire activity this year is not especially impressive compared to the recent past, let alone the far more fiery era prior to modern fire suppression tactics. At roughly 4.7 million acres, the extent of this year’s national burn lags the 10-year year-to-date average by more than 20%. Unless one is to contend that global warming is only affecting one or two states and not all the other fire-prone states as well, bald assertions of causality seem misplaced.
Every fire is different. The reasons each fire turns out to be milder or more dangerous than the others can include a wide variety of causes and effects. Random day-to-day wind patterns can turn a seemingly harmless blaze into a massive conflagration. The frequency and severity of fire can also be affected by long-term drought patterns that predate modern mass carbon emissions by centuries. Oceanic weather patterns such as “La Nina” can also change the pattern and course of Western U.S. wildfires, and man’s increasing encroachment on natural habitats tends to make them more damaging to human life and property.
Does that mean global warming doesn’t affect wildfires? Of course not. We assume it has some effect. But to make a simple cause-and-effect assertion in general, or about the specific fires raging now, is a mockery of science, not its practice.
The idea that anthropogenic global warming is occurring is not a controversial one. But the science about the effects of global warming is very unsettled. Anyone who tells you that global warming has set the nation ablaze right now, or that the election of one presidential candidate over the other will change that, is not someone you should be taking seriously.