There is an existential threat related to climate, as Climate Strike activists claim, but it comes from the radical political agenda being promoted under cover of ‘saving the planet.’ The evidence refutes the claim that human emissions of carbon dioxide can catastrophically disrupt the Earth’s climate. Continuing to spend trillions of dollars to ‘fight climate change’ will have no effect on the climate and cannot meet human energy needs with ‘renewables. The existential threat is to our freedom, our prosperity, our capacity to provide medical care, and the integrity of our science and our profession. Physicians need to evaluate evidence independently and shun groupthink. They must not sacrifice their patients’ welfare to serve an agenda.