This week’s record-breaking heat wave is bad enough, but global warming will cause more and hotter waves in the coming decades.

What can we do? For one, plant trees in your neighborhood. If you don’t have room, ask your neighbors. Shade makes a huge difference. The Seattle Trees for Neighborhoods program tells how and even offers a lottery for free trees for fall planting (seattle.gov/trees). Seattle Tree Consulting also offers free native trees (seattletreeconsulting.com/free-trees).

Tim Hesterberg, Seattle