You may not want to drink the rainwater in Tibet. Or Greenland. Or New York. That’s because rain everywhere on our planet has been contaminated with man-made chemicals. Just think about that for a minute. Chemical industries are churning out substances that, according to research recently published, have contaminated all of the rainwater on the planet.

The research was looking at data about PFAS (per-and polyfluoroalkyl substances), those ubiquitous and toxic “forever” chemicals used in everything from carpeting and snowsuits to plastics and fire-fighting foam. We may be looking at a planetary crisis of yet unknown proportions when you start thinking about how much humans and other living things rely on rainwater for drinking and irrigating crops, among other life-sustaining needs.

But chemical contamination of the planet is just one of nine “planetary boundaries” that scientists have developed. These are thresholds within which humanity can survive and thrive. When a single boundary is crossed, it can compromise other boundaries as well as they are all inextricably linked.

The world actually successfully mitigated one of these potentially catastrophic breaches. In the 1980s, scientists became alarmed by the depletion of the earth’s ozone layer, which absorbs most of the sun’s ultraviolet radiation. Without this layer, they warned, exposure to the sun’s rays would cause massive increases in skin cancers and irreversible damage to agricultural crops, plants and micro-organisms, ultimately affecting the world’s ecosystems and food chains.

So countries came together and in 1987 the Montreal Protocol was signed, a global agreement to protect the ozone layer by phasing out the production and consumption of ozone-depleting substances, such as CFCs. or chlorofluorocarbons. The agreement has been remarkably successful in stopping the depletion of the ozone layer, and scientists are now seeing signs that it is actually repairing itself. A bit of good news!

I don’t spend every day thinking about our planet and whether we are, as a species, engaging in activities that are moving the Earth closer to the edge. During my waking hours, I am mostly focused on the minutiae of everyday life. But there is a growing number of people across the world, mostly scientists, who are spending their days studying our planetary boundaries and trying to raise both awareness and a warning flag across the global community. Some think the human footprint now rivals nature, becoming a geological force in its own right.

Consumer products that we buy and use everyday are also contributing to the pollution of our air and water, although it’s certainly not as dramatic as a radioactive release from a nuclear power plant or the derailment and burning of train cars carrying hazardous and cancer-causing chemicals that will contaminate communities for hundreds of miles. But our appetite for red meat, our desire for non-stick pans and mascara that won’t run, our use of plastic everything, our insistence on getting on airplanes and traveling far and wide anytime we choose is a way of life that is having an impact and is not sustainable.

While not front page news, others too are paying attention. The United Nation’s Millennium Ecosystem Assessment concludes, among other things, that changes to ecosystems caused by human activities have been more rapid in the past 50 years than at any time in human history, increasing the risks of abrupt and irreversible changes. The UN Convention of Biological Diversity Researchers is also looking at the alarming rate of extinction of species, which is 100 to 1,000 times more than would be considered “normal” or natural. The group has concluded that the extinction can only be addressed through transformative changes across economic, social, political, and technological factors and not at current trajectories. Like climate change, human activities are the main cause of this acceleration.

Natural ecosystems have declined by 47% on average: half of the coral reefs have been lost since the late 1800s, 429 million acres of forest have been destroyed and over 85% of wetlands.

The science couldn’t be clearer and it implores our community (i.e. all the people in the world), to understand that we are inexorably bound together. Wealthy countries overall are the drivers of this crisis and poor countries bear the burden. But we are seeing that burden shift to every country with the ravages of climate change.

The nine planetary boundaries are Stratospheric ozone depletion, Biodiversity loss and extinctions, Chemical pollution and novel entities (radioactive materials, microplastics, nanomaterials), Climate change, Ocean acidification, Freshwater consumption and the global hydrological cycle, Land system changes, and finally, Nitrogen and phosphorus flows to the biosphere and oceans. More can be learned at https://greenly.earth/en-us/blog/ecology-news/all-you-need-to-know-about-the-9-planetary-boundaries.