Is a hotter climate making trees grow faster and have lighter wood?
Nothing to do with climate change . Faster growth produces somewhat lower density and strength. There are strength tables for wood written more than 50 years ago that have separate listings for &quot;new &quot; growth and &quot;old&quot; growth. &quot;New &quot; growth being trees growing faster in clear cut areas with less competition for water, light and nutrients. Old is trees in areas that not previously been harvested and grew slower in crowded conditions.  Power line failure is related to the increase in numbers of power lines in expanding populated areas, and to how much money utilities spend trimming trees near the power lines.  When I drove in western Europe  in the 80's , I was impressed by how many of the forests had been &quot;managed&quot;. Large old trees had been planted in regularly spaced straight lines ,maximizing growth speed = lower density . As silviculture is a minor hobby of mine I expect I noticed things others would not.