I'm confused again: If CO2 causes wildfires, how can we explain all these massive, deadly forest fires that occurred in years like 1871, 1894, 1910, and 1918?

And if one of these fires were to occur today, how many cows would people like Bill McKibben, Joe Romm, and Chris Mooney give birth to in their rush to produce stories blaming CO2?

Weather Extremes : The Worst Wild Fires in World History | Weather Underground

All in all, well over 2,000 people died and close to 5 million acres (7,800 square miles) burned during the weeks of October 8-21, 1871 in Wisconsin, Michigan, and Illinois. An intriguing, but most likely apocryphal, theory is that the fires were actually caused by the impact of fragments from Comet Biela that was observed at this time.

It should be noted that all of the deadliest wild fires in American history have occurred in the Upper Midwest. Other notable fires were the Cloquet, Minnesota fire of October 13-15, 1918 that killed as many as 1,000, and the Hinkley, Minnesota fire of September 1, 1894 that killed 400-800.
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The worst wild fire in western history and the 2nd largest overall in the United States was the Great Fire of 1910. This massive forest fire burned some 3 million acres (4,700 square miles) in Idaho and Montana beginning on August 20-21, 1910.  It killed at least 87 people