Until the nineteenth century, the world was covered by the veil of darkness at night.

In the past two hundred years, humanity has dramatically altered the night sky. As a species adapted to daylight, we often overlook our desire to illuminate our world into the dark hours of the night. Urbanization patterns for the past century have pushed the boundaries of civilization ever further into the domain of the natural world. The need to light our sprawling cities has given rise to one of the least understood issues of our time, light pollution. The growth of human civilization is something that is not well taught in schools. Until the sixteenth century, the human population grew a snails pace. It was not until the New World crops such as corn and potatoes were introduced in Europe and Asia did humanity begin to grow to the vast numbers we're accustomed to today. From roughly the end of the sixteenth century to the end of the twentieth, the human population grew at an exponential rate. To put this in perspective, in 1800 there were less than one billion humans running around the Earth, by 2000 the population exceed six billion. Although the population growth rate has slowed in recent decades, the global population is projected to approach nine billion by middle of this century and plateau, or stabilize, sometime there after. Until the latter half of the twentieth century this growth was mostly limited to existing urban areas. However, mass transportation and seemingly abundant supplies of energy, fueled the expansion of cities outward. Nowhere is this more true than the United States. In the next 20 to 30 years, the United States will nearly double the total acreage of developed land across the country. This is an astonishing figure, especially given that it took over 300 years to develop the country to its current state. All of this amounts to encroachment on the rapidly shrinking and not-so-untouched natural world. Cities were once separated by vast wildernesses, now urban areas have grown so large, they essentially run together. The east coast of the United States is quickly becoming a single urban area. At present there is a continuous urban area that runs from metropolitan Boston to metro D.C. Taking into account the growth of the southeastern states, this urban area is likely to stretch to Jacksonville, Florida within 20 years. Aside from other commonly recognized forms of pollution these sprawling urban areas produce vast amounts of light at night. Light from urban areas radiates through the atmosphere 100 km from its origin. Rethinking the information from the paragraph above should paint a fairly interesting mental image of the sheer magnitude of light pollution in this country. Reducing light pollution is everyone's problem. This is because governments at any level with be restricted on how tightly they can regulate an individual's use of light. Individual homeowners and tenants throughout our sprawling urbanized world will have to take into account their lighting needs and limit their personal contribution to the greater issue of light pollution. Dark sky lighting will reduce excessive light, and is an international movement dedicated to reducing light pollution worldwide. California has actively been campaigning against light pollution and has created a standard known as Title 24. An former EPA program, Energy Star, is now an international collaboration which parallels the Dark Sky movement, while encompassing energy efficiency.