How much light is too much light? The Darkness Manifesto urges us to cherish natural darkness for the sake of the environment, our own wellbeing, and all life on earth.

The world's flora and fauna have evolved to operate in the natural cycle of day and night. But constant illumination has made light pollution a major issue. From space, our planet glows brightly, 24/7. By extending our day, we have forced out the inhabitants of the night and disrupted the circadian rhythms necessary to sustain all living things. Our cities' streetlamps and neon signs are altering entire ecosystems.

As a devoted friend of the night, Johan Eklof encourages us to appreciate natural darkness, its creatures, and its unique benefits.

He ponders the beauties of the night sky, traces the paths of light-drunk moths and the dives of keen-eyed owls, and shows us the bioluminescent creatures of the deep oceans. He writes passionately about the domino effect of damage we inflict by keeping the lights on: insects failing to reproduce; birds blinded and bewildered; bats starving as they wait in vain for insects that only come out in the dark. For humans, light-induced sleep disturbances impact our hormones and weight, and can contribute to mental health problems.