@Parsable - Satellites. There is not one Earth and climate observation satellite that fails to show evidence of warming or the consequences of warming. The more they look, the better the instruments, the more evidence. In this case it is satellites observing wildfires.
I'll take the satellite data for the period there has been global satellite coverage over what a well known climate science denier says about (only) US data - an allegation of conspiracy to falsify data from a serial alleger of same, in this case alleged falsification by omission. Much more probable that any omission was actually for sound reason, eg because of poor data reliability; the assuming of bias is a well known climate science denier bias.
The further back weather and fire data goes the wider the error bars but if the weather conditions in one part of the world (the USA is NOT the world) really did exhibit exceptional extremes not seen since then that seems like real cause for
greater concern about global warming, not less. When those conditions come around again - and claiming them as natural implies they can and will come around again - in a world where temperatures
are significantly higher and, during dry times, rainfall is reduced and evaporation rates are higher, the consequences will be worse.
My personal experience is that for where I am (Eastern Australia) the warmer conditions during cool seasons make staying safe from hot weather bushfires harder again, by giving less windows of opportunity in the cooler times to safely do fuel reduction fires. Extreme fire risks is a recurrent and increasingly extreme hazard where I live and hazard reduction and preparation for it never, ever stops.
I've heard plenty of "but we've always had bushfires" kinds of denial that anything is different. Like "climate is always changing" those people have it backwards; it is
because bushfire risks were already so naturally high that making the conditions for them worse will have catastrophic consequences.