The sixth Democratic primary debate on Thursday was the first to raise climate change within the first half-hour, but the questions were framed largely around the sacrifices necessary to curb emissions and adapt to already-unavoidable warming.

Should we pay to relocate families from drowning coastal communities? And should we trade Americas oil and gas boom for climate policy, even if it displaces fossil fuel workers?

Sen. Amy Klobuchar (D-Minn.) called for rejoining the Paris agreement and restoring Obama-era regulations. South Bend, Indiana, Mayor Pete Buttigieg deflected and touted his carbon pricing proposal. Former Vice President Joe Biden said sacrifice was worth the opportunity of green jobs.

But Sen. Bernie Sanders (I-Vt.) pushed back against the very premise of the question.

Its not an issue of relocating people and towns, Sanders said. The issue now is whether we save the planet for our children and grandchildren.