From solar panels to electric vehicles, all sorts of exciting technologies are being used to address the climate crisis. But some solutions already exist in the natural world. Seaweed — yes, seaweed — could help us absorb carbon emissions, generate marine protein and replace petroleum-based products.

US President Joseph R. Biden recently announced ambitious new climate goals. What are the changes needed to reach these new targets? And how will they affect our lives? Climate policy expert Nathaniel Keohane explains.