How much light is too much light? Satellite pictures show our planet as a brightly glowing orb, and in our era of constant illumination, light pollution has become a major issue. The world's flora and fauna have evolved to operate in the natural cycle of day and night. But in the last 150 years, we have extended our day—and in doing so have forced out the inhabitants of the night and disrupted the circadian rhythms necessary to sustain all living things, including ourselves.

The Darkness Manifesto depicts the domino effect of diminishing darkness: insects, dumbfounded by streetlamps, failing to reproduce; birds blinded and bewildered by artificial lights; and bats starving as they wait in vain for food insects that only come out in the dark of night. For humans, light-induced sleep disturbances impact our hormones and weight, and can contribute to mental health problems like chronic stress and depression. The streetlamps, floodlights, and neon signs of cities are altering entire ecosystems, and scientists are only just beginning to understand the long-term effects. The light bulb—long the symbol of progress and development—needs to be turned off.

Educational, eye-opening, and ultimately encouraging, The Darkness Manifesto outlines simple steps that we can take to benefit ourselves and the planet. In order to ensure a bright future, we must embrace the darkness.