Irreversible sea-level rise is among the permanent consequences of human-caused climate change. That’s one of the findings of the new report out this week from the United Nation’s panel of scientists, the IPCC. On the front lines of the new challenges that poses are Washington’s coastal tribes. They’re experiencing the effects of climate change firsthand, as the warming ocean swells into waterfront villages and alters the chemistry of ecosystems in the Salish Sea.