As science progresses, the great challenge is to believe the evidence and act accordingly. It’s not physics but ideologies that stand in the way. Energy harvesting near a bright star like ours can be done indefinitely if we don’t keep reproducing at unsustainable rates and always coveting more and fearing the loss of what we have.

Astrophysicists have already theorized how, as the sun heats up, our descendants can gradually enlarge Earth’s orbit to stay cool. A species that understands all this — as ours now does — can control the consequences of its energy harvesting for billions of years if it considers sacred the call to believe the evidence and protect its descendants.

NANCY ELLEN ABRAMS

Santa Cruz, Calif., Jan. 18, 2015