Gardeners are being warned not to use lights on their houses or in gardens any more because of an 'apocalyptic' impact that artificial lighting is thought to be having on wildlife and nature at night.
While low-level, dim solar lights are generally okay, more powerful lighting, such as security lights and bright battery or plug-in lighting, is potentially accelerating the decline of life in your garden, according to research shared by the Royal Horticultural Society.
They want gardeners to follow the advice because the loss of insects, in particular, could have huge ramifications right up the food chain - if insects die, we all die due to lack of food if nothing gets pollinated. In a research paper published in the journal Biological Conservation, a group of researchers posed that artificial lighting at night could be bringing on what they call "the insect apocalypse".
They said: "Insects around the world are rapidly declining. Concerns over what this loss means for food security and ecological communities have compelled a growing number of researchers to search for the key drivers behind the declines. Habitat loss, pesticide use, invasive species, and climate change all have likely played a role, but we posit here that artificial light at night (ALAN) is another important - but often overlooked - bringer of the insect apocalypse."
The authors added: "A growing body of research demonstrates that ALAN can impact the fitness of plants and animals and more recent reviews have catalogued its broadscale effects on insects in particular. Some estimates suggest that one third of insects attracted to stationary artificial light sources die before morning, either through exhaustion or predation."
The research paper concluded: "Some estimates predict that one million species, including up to 40% of insects, will go extinct within the next several decades. It is urgent therefore that we seek to identify the range of threats that insects face, and understand how to best address them. In light of the evidence presented above, we strongly believe that ALAN - in combination with habitat loss, chemical pollution, invasive species, and climate change - is driving insect declines."
Based on the research, the Royal Horticultural Society is asking gardeners to consider whether they really need artificial lighting in their gardens.
It said: "Since artificial light in gardens disrupts natural behaviour for a range of wildlife it's important to retain some dark areas and also question whether you really need lighting.
"The trend for lighting up gardens as an extension of our living space may seem an inviting one but needs to be done with great care. A garden can be just as magical a place enjoyed in moonlight or simply with the aid of a torch."
It added: "Turn garden lights off when not in use or use PIR motion sensors or timers for essential or security lighting so they only come on when absolutely necessary.
"Position lights as low as possible and aim them downwards or to where they're needed. When angling lights make sure you think about how it impacts on your neighbours too (such as not glaring right into their windows) and always position them considerately.
"Choose low-intensity lighting and warmer hues (warm white, yellow or amber): solar lighting is cheap, safe and emits a dull glow suitable for garden use.
"Encourage local councils to adopt switch-off schemes for street lighting: even part-night lighting instead of full-night lighting has been found to reduce negative impact on the behaviour of moths."