Oil and coal companies and their political allies warn us of fiscal catastrophe if we do that – as if heat waves, droughts, storms, and rising seas did not bring their own fiscal and social catastrophes. As Mayor of Seattle, I supported the creation of energy-efficient buildings, the development of solar, wind, and hydroelectric power, and a shift toward walking, biking, and public transit as alternatives to driving – strategies that can help to build a more resilient economy and provide viable alternatives to fossil fuels.