Laws and ordinances vary across each state, all the jurisdictions within them, little national legislation has been enacted however great the strides made with technology to eliminate light trespass NCSL National Conference of State Legislators Each local municipality will or will not, have ordinances on the books. Advocating for stringent codes is imperative to protect humans, creatures, insects, plants and our common view of the night sky.

The International Dark Sky Association 2022 report on the State of the Science of artificial light at night.

IDA 2022 State of the Science Report

This briefing summarizes the current state of knowledge about how the widespread and growing use of artificial light at night interacts with six key topics: the night sky (Section 1); wildlife and ecology (Section 2); human health (Section 3); public safety (Section 4); energy security and climate change (Section 5); and social justice (Section 6). It also includes a discussion of the emerging threat from light pollution caused by objects orbiting the Earth (Section7).

Without the term ‘light trespass’ spelled out in local codes and ordinances, lights shining into bedrooms or homes must be litigated as a private matter, using nuisance lighting. A high bar to clear to win a case, with uncertain outcome if the lights fall within current outdoor lighting ordinances, and a very expensive one. But outside lights are not the only cause of light trespass and light pollution, artificial light escaping from the inside of homes and buildings causes much light trespass and light pollution. Both must be addressed by the source of the light trespass, not the recipient.

DECLARATION

IN DEFENCE OF THE NIGHT SKY AND THE RIGHT TO STARLIGHT (La Palma Declaration)