The spark that starts a forest fire is only a proximate [2] cause. The ultimate cause is that these trees evolved to be highly flammable.
[1] https://en.wikipedia.org/wiki/Eucalyptus#Adaptation_to_fire
[2] https://en.wikipedia.org/wiki/Proximate_and_ultimate_causati...
The funniest thing about the fires to me is: can anyone research if they are out?
However, the issue has been that we suppress forest fires for years, leading to a buildup of fuel, leading to fires that are so big that they destroy the trees that normally survive them.
California has changed the way it deals with forest fires to try to prevent this... they don't try to stop ALL fires now.
The real rainforest would not really burn(for long), due to all the humidity stored up. But since it is already quite damaged and split up .. it dries up more easily and farmland does not hold much water. So it gets bad. And I do not think, it makes sense to compare current numbers to numbers from the last year - when you should compare it to numbers before the cuttung and burning down started to happen.
The Amazon Climate is wet and hot all year round. It rains more in Amazon Forest during the dry season of than in the wet season in most of the country. By the way, Brazil does have dry biomes, such Cerrado and Caatinga, where natural fires are common.
Most people are not aware the Amazon soil is very poor nutrition-wise. The trees depend on the decomposed organic material, the hot and wet climate is perfect to convert fallen leaves into hummus. Because of this, there's isn't much wild life in the forest at ground-level. It isn't a coincident that the pictures from the Amazon is usually from above.
Therefore, the biggest concern with the deforestation is actually the dim balance that keep the forest alive. If it goes beyond a certain point, it will be impossible to revert the end of the forest.
There is a lot of fantasy about the Amazon Forest, likely because it is a vast (almost the size of Continental USA) unexplored land. But from a biodiversity point of view, more efforts should be direct to other richer Brazilian biomes such the Atlantic Forest or Mato de Cocais.
As a curiosity. The country is named after a tree! The Pau Brasil is a tree that was used to make red dye during the Renaissance. It was explored by the portugues almost to extinction. It still endangered despite the efforts to reforest.