I see this repeated a lot. Can you talk specifically about the effect of early/mid 20th century firefighting in the Big Basin fire as compared to the Australian bushfires last year, the Siberian fires in 2019, and the Amazon fires this year and last?
I am not sure any prior firefighting occurred in Siberia. And I feel like a lot of people repeat that "firefighting has left too much fuel and that's causing these fires" as though it's conventional wisdom... but it's not quantified so I don't know if it's 100% of the cause or just contributing 10%. In fact, I don't even know how to measure the buildup of flammable material (kg/sq meter?) or how it effects fire intensity. It feels like the discussion around this can veer into being hopeful and unscientific.
We already know that timber land in the Americas requires more active stewardship than colonial thinking suggests. These are not European forests. Microbial decay doesn't reduce the calories per acre the same way. Global warming makes the balance even more precarious. But there are ways we can address both of these problems which also serves as a carbon sink. As long as we do it before the dominant forest soil biome in North America flips to bacteria-dominant due to rising ambient temperatures.
Excess fuel means ladder fires - where fire gets high enough to engulf the crowns of the trees - are far more likely.
Many conifers rely on fire to open their cones. Artificially suppressing fire stops that process of renewal.
Those are just a few examples off the top of my head - this topic is well trod and a little poking around will provide even more context.
Old firefighting techniques have build up vast caches if flammable material that we cannot afford to remove by any other means than forest fires.
Changes in firefighting tactics should mean that once an area has burned, the next fire should be less severe, however the burns will take much longer to recover than they should.
Any time sequoias survive a fire is good news twice over. One, the danger for them in the next fire is diminished. Two, they now have space and the opportunity to reproduce, which is something we have been systemically denying them for generations.