Humanity has reached a critical point in its history. Our world, amidst instability and rapid changes, is facing dangers that will threaten its very existence by the end of the century. The possible outcomes - positive or negative - are numerous and diverse. However, our current approach to the future is characterized by shortsightedness, polarization, alarmism, and pessimism. In this small but hopeful book, distinguished astrophysicist Martin Rees argues that our prospects will depend on adopting a radically different conception of how we plan for tomorrow.

The future of humanity is closely linked to the future of science and the beneficial use of our technological achievements. If we want science to solve our problems and avoid the pitfalls of dystopia, we must think rationally, universally, collectively, and optimistically about our near and distant future.

The advancements in biotechnology, governance, robotics, and artificial intelligence, as well as their responsible utilization, could serve as weapons for the upliftment of both the developing and developed world, as well as for overcoming the many terrestrial threats, from climate change to nuclear annihilation. Simultaneously, further progress in space technology could allow us to explore our solar system and transcend its boundaries. However, there is no "Plan B" for our planet; no sustainable alternative exists if we do not first take care of our mother planet.