President Obama’s forceful pledge to “respond to the threat of climate change” during his second inaugural address Monday was both specific and somewhat surprising. Also bold and welcome.

Coming in the wake of the federal government’s 1146-page National Climate Assessment ten days earlier, which makes for some pretty scary reading, his statements underscored in a major way why climate change has to be an urgent national priority. That’s because failing to act will “betray our children and future generations,” Obama said.