This large format photo book features hundreds of stunning images highlighting the effects that our global population of 7 billion (and growing) has on the Earth.

There’s one very touchy subject in environmental circles that seems to be particularly polarizing, and which is often glossed over or avoided in favor of other, more comfortable topics, but this elephant in the room is at the root of most of our planetary ills. This somewhat taboo subject is the issue of human population, or to be more precise, human overpopulation (there are now more than 7 billion of us on the planet), and which is behind almost every other environmental issue.

Overpopulation takes a toll on human health and civil rights, on clean water and food supplies, on the climate and on our oceans and forests, and yet most of us never get to see those negative impacts because they seem so far away from our everyday lives. Perhaps if we got to see more of the devastating environmental and social effects we’re all ultimately responsible for, we’d be more inclined to talk about the issue, but even as environmental disasters such as major oil spills get quite a bit of attention from the media, those incidents are all too often seen as isolated events, with no connection made to the underlying cause: our population explosion.

In order to bring more awareness to the question of global overpopulation, a new book from the 2015 Global Population Speakout campaign starts by asking the question, “Isn’t it time to start talking about the equation that matters most to the future of people and the planet?” The book OVER: Overdevelopment, Overpopulation, Overshoot then proceeds to do just that with a series of hundreds of stunning photos accompanied by essays and insights from experts in the field.

“We wanted to go straight to the emotional center of a viewer, someone who has never thought about the population question, and say: Here is how the earth has been transformed.” – Tom Butler, Editor of OVER

This 300-page coffee table book features page after page of beautiful full-spread photos of the ugly side of overpopulation, evoking emotions ranging from stunning to heart-wrenching. Each one of these images are worthy of an essay on their own, but taken all together they make a very compelling case for taking action on population issues, and could help to spur both wider and more in-depth conversations about overpopulation initiatives worldwide.

To be honest, even though I know about the pressure that we are putting on our natural resources (and on each other), and even after years of covering individual aspects of environmental issues, when I cracked this mammoth book open and started flipping through it, I was immediately struck by how clueless most of us are (me included) about the effects of our rapidly increasing population.

“We sought to present a range of images reflecting how the human demographic explosion — 7.3 billion people and still growing by over 1.5 million every week — has diminished Earth’s richness and beauty, and contributed to so much misery among people.”

While some of the images aren’t explicitly negative when taken individually, the cumulative effect of viewing all of the photos is simply staggering. And I say that with all honesty, as the father of a family with more than the average number of children, and as someone who tries diligently to live more deliberately and with a smaller eco-footprint, because we’re all in this together. The only way we’re going to be able to effectively address our environmental challenges is for us all to start taking personal responsibility for not only the direct effects of our choices, but also the indirect and unintended consequences of our actions.

OVER is available to view online (or below), but for those who want to own the book and use it as a source of information and inspiration in their own work on global population issues, it is available for purchase ($50) but free copies are also available from Global Population Speakout on a request basis. The book is published by theFoundation for Deep Ecology, co-produced by the Population Institute, Population Media Center, and Foundation for Deep Ecology, and is edited by Tom Butler, conservation activist and author of Wildlands Philanthropy, Plundering Appalachia, andENERGY: Overdevelopment and the Delusion of Endless Growth.

In addition to OVER being available to read online, a number of campaign tools on the website allow readers to take action, including sending email postcards with images from the book, and sharing their insights via social media using the hashtags #Population and #SpeakOut (which are then compiled on the site).